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- /*
- * Infrastructure for profiling code inserted by 'gcc -pg'.
- *
- * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
- * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
- *
- * Originally ported from the -rt patch by:
- * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
- *
- * Based on code in the latency_tracer, that is:
- *
- * Copyright (C) 2004-2006 Ingo Molnar
- * Copyright (C) 2004 Nadia Yvette Chambers
- */
- #include <linux/stop_machine.h>
- #include <linux/clocksource.h>
- #include <linux/kallsyms.h>
- #include <linux/seq_file.h>
- #include <linux/suspend.h>
- #include <linux/tracefs.h>
- #include <linux/hardirq.h>
- #include <linux/kthread.h>
- #include <linux/uaccess.h>
- #include <linux/bsearch.h>
- #include <linux/module.h>
- #include <linux/ftrace.h>
- #include <linux/sysctl.h>
- #include <linux/slab.h>
- #include <linux/ctype.h>
- #include <linux/sort.h>
- #include <linux/list.h>
- #include <linux/hash.h>
- #include <linux/rcupdate.h>
- #include <linux/kprobes.h>
- #include <trace/events/sched.h>
- #include <asm/setup.h>
- #include "trace_output.h"
- #include "trace_stat.h"
- #define FTRACE_WARN_ON(cond) \
- ({ \
- int ___r = cond; \
- if (WARN_ON(___r)) \
- ftrace_kill(); \
- ___r; \
- })
- #define FTRACE_WARN_ON_ONCE(cond) \
- ({ \
- int ___r = cond; \
- if (WARN_ON_ONCE(___r)) \
- ftrace_kill(); \
- ___r; \
- })
- /* hash bits for specific function selection */
- #define FTRACE_HASH_BITS 7
- #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
- #define FTRACE_HASH_DEFAULT_BITS 10
- #define FTRACE_HASH_MAX_BITS 12
- #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
- #ifdef CONFIG_DYNAMIC_FTRACE
- #define INIT_OPS_HASH(opsname) \
- .func_hash = &opsname.local_hash, \
- .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
- #define ASSIGN_OPS_HASH(opsname, val) \
- .func_hash = val, \
- .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
- #else
- #define INIT_OPS_HASH(opsname)
- #define ASSIGN_OPS_HASH(opsname, val)
- #endif
- static struct ftrace_ops ftrace_list_end __read_mostly = {
- .func = ftrace_stub,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
- INIT_OPS_HASH(ftrace_list_end)
- };
- /* ftrace_enabled is a method to turn ftrace on or off */
- int ftrace_enabled __read_mostly;
- static int last_ftrace_enabled;
- /* Current function tracing op */
- struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
- /* What to set function_trace_op to */
- static struct ftrace_ops *set_function_trace_op;
- /* List for set_ftrace_pid's pids. */
- LIST_HEAD(ftrace_pids);
- struct ftrace_pid {
- struct list_head list;
- struct pid *pid;
- };
- static bool ftrace_pids_enabled(void)
- {
- return !list_empty(&ftrace_pids);
- }
- static void ftrace_update_trampoline(struct ftrace_ops *ops);
- /*
- * ftrace_disabled is set when an anomaly is discovered.
- * ftrace_disabled is much stronger than ftrace_enabled.
- */
- static int ftrace_disabled __read_mostly;
- static DEFINE_MUTEX(ftrace_lock);
- static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
- static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
- ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
- static struct ftrace_ops global_ops;
- static struct ftrace_ops control_ops;
- static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs);
- #if ARCH_SUPPORTS_FTRACE_OPS
- static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs);
- #else
- /* See comment below, where ftrace_ops_list_func is defined */
- static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
- #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
- #endif
- /*
- * Traverse the ftrace_global_list, invoking all entries. The reason that we
- * can use rcu_dereference_raw_notrace() is that elements removed from this list
- * are simply leaked, so there is no need to interact with a grace-period
- * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
- * concurrent insertions into the ftrace_global_list.
- *
- * Silly Alpha and silly pointer-speculation compiler optimizations!
- */
- #define do_for_each_ftrace_op(op, list) \
- op = rcu_dereference_raw_notrace(list); \
- do
- /*
- * Optimized for just a single item in the list (as that is the normal case).
- */
- #define while_for_each_ftrace_op(op) \
- while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
- unlikely((op) != &ftrace_list_end))
- static inline void ftrace_ops_init(struct ftrace_ops *ops)
- {
- #ifdef CONFIG_DYNAMIC_FTRACE
- if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
- mutex_init(&ops->local_hash.regex_lock);
- ops->func_hash = &ops->local_hash;
- ops->flags |= FTRACE_OPS_FL_INITIALIZED;
- }
- #endif
- }
- /**
- * ftrace_nr_registered_ops - return number of ops registered
- *
- * Returns the number of ftrace_ops registered and tracing functions
- */
- int ftrace_nr_registered_ops(void)
- {
- struct ftrace_ops *ops;
- int cnt = 0;
- mutex_lock(&ftrace_lock);
- for (ops = ftrace_ops_list;
- ops != &ftrace_list_end; ops = ops->next)
- cnt++;
- mutex_unlock(&ftrace_lock);
- return cnt;
- }
- static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
- {
- if (!test_tsk_trace_trace(current))
- return;
- op->saved_func(ip, parent_ip, op, regs);
- }
- /**
- * clear_ftrace_function - reset the ftrace function
- *
- * This NULLs the ftrace function and in essence stops
- * tracing. There may be lag
- */
- void clear_ftrace_function(void)
- {
- ftrace_trace_function = ftrace_stub;
- }
- static void control_ops_disable_all(struct ftrace_ops *ops)
- {
- int cpu;
- for_each_possible_cpu(cpu)
- *per_cpu_ptr(ops->disabled, cpu) = 1;
- }
- static int control_ops_alloc(struct ftrace_ops *ops)
- {
- int __percpu *disabled;
- disabled = alloc_percpu(int);
- if (!disabled)
- return -ENOMEM;
- ops->disabled = disabled;
- control_ops_disable_all(ops);
- return 0;
- }
- static void ftrace_sync(struct work_struct *work)
- {
- /*
- * This function is just a stub to implement a hard force
- * of synchronize_sched(). This requires synchronizing
- * tasks even in userspace and idle.
- *
- * Yes, function tracing is rude.
- */
- }
- static void ftrace_sync_ipi(void *data)
- {
- /* Probably not needed, but do it anyway */
- smp_rmb();
- }
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static void update_function_graph_func(void);
- /* Both enabled by default (can be cleared by function_graph tracer flags */
- static bool fgraph_sleep_time = true;
- static bool fgraph_graph_time = true;
- #else
- static inline void update_function_graph_func(void) { }
- #endif
- static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
- {
- /*
- * If this is a dynamic ops or we force list func,
- * then it needs to call the list anyway.
- */
- if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
- return ftrace_ops_list_func;
- return ftrace_ops_get_func(ops);
- }
- static void update_ftrace_function(void)
- {
- ftrace_func_t func;
- /*
- * Prepare the ftrace_ops that the arch callback will use.
- * If there's only one ftrace_ops registered, the ftrace_ops_list
- * will point to the ops we want.
- */
- set_function_trace_op = ftrace_ops_list;
- /* If there's no ftrace_ops registered, just call the stub function */
- if (ftrace_ops_list == &ftrace_list_end) {
- func = ftrace_stub;
- /*
- * If we are at the end of the list and this ops is
- * recursion safe and not dynamic and the arch supports passing ops,
- * then have the mcount trampoline call the function directly.
- */
- } else if (ftrace_ops_list->next == &ftrace_list_end) {
- func = ftrace_ops_get_list_func(ftrace_ops_list);
- } else {
- /* Just use the default ftrace_ops */
- set_function_trace_op = &ftrace_list_end;
- func = ftrace_ops_list_func;
- }
- update_function_graph_func();
- /* If there's no change, then do nothing more here */
- if (ftrace_trace_function == func)
- return;
- /*
- * If we are using the list function, it doesn't care
- * about the function_trace_ops.
- */
- if (func == ftrace_ops_list_func) {
- ftrace_trace_function = func;
- /*
- * Don't even bother setting function_trace_ops,
- * it would be racy to do so anyway.
- */
- return;
- }
- #ifndef CONFIG_DYNAMIC_FTRACE
- /*
- * For static tracing, we need to be a bit more careful.
- * The function change takes affect immediately. Thus,
- * we need to coorditate the setting of the function_trace_ops
- * with the setting of the ftrace_trace_function.
- *
- * Set the function to the list ops, which will call the
- * function we want, albeit indirectly, but it handles the
- * ftrace_ops and doesn't depend on function_trace_op.
- */
- ftrace_trace_function = ftrace_ops_list_func;
- /*
- * Make sure all CPUs see this. Yes this is slow, but static
- * tracing is slow and nasty to have enabled.
- */
- schedule_on_each_cpu(ftrace_sync);
- /* Now all cpus are using the list ops. */
- function_trace_op = set_function_trace_op;
- /* Make sure the function_trace_op is visible on all CPUs */
- smp_wmb();
- /* Nasty way to force a rmb on all cpus */
- smp_call_function(ftrace_sync_ipi, NULL, 1);
- /* OK, we are all set to update the ftrace_trace_function now! */
- #endif /* !CONFIG_DYNAMIC_FTRACE */
- ftrace_trace_function = func;
- }
- int using_ftrace_ops_list_func(void)
- {
- return ftrace_trace_function == ftrace_ops_list_func;
- }
- static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
- {
- ops->next = *list;
- /*
- * We are entering ops into the list but another
- * CPU might be walking that list. We need to make sure
- * the ops->next pointer is valid before another CPU sees
- * the ops pointer included into the list.
- */
- rcu_assign_pointer(*list, ops);
- }
- static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
- {
- struct ftrace_ops **p;
- /*
- * If we are removing the last function, then simply point
- * to the ftrace_stub.
- */
- if (*list == ops && ops->next == &ftrace_list_end) {
- *list = &ftrace_list_end;
- return 0;
- }
- for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
- if (*p == ops)
- break;
- if (*p != ops)
- return -1;
- *p = (*p)->next;
- return 0;
- }
- static void add_ftrace_list_ops(struct ftrace_ops **list,
- struct ftrace_ops *main_ops,
- struct ftrace_ops *ops)
- {
- int first = *list == &ftrace_list_end;
- add_ftrace_ops(list, ops);
- if (first)
- add_ftrace_ops(&ftrace_ops_list, main_ops);
- }
- static int remove_ftrace_list_ops(struct ftrace_ops **list,
- struct ftrace_ops *main_ops,
- struct ftrace_ops *ops)
- {
- int ret = remove_ftrace_ops(list, ops);
- if (!ret && *list == &ftrace_list_end)
- ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
- return ret;
- }
- static void ftrace_update_trampoline(struct ftrace_ops *ops);
- static int __register_ftrace_function(struct ftrace_ops *ops)
- {
- if (ops->flags & FTRACE_OPS_FL_DELETED)
- return -EINVAL;
- if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
- return -EBUSY;
- #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- /*
- * If the ftrace_ops specifies SAVE_REGS, then it only can be used
- * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
- * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
- */
- if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
- !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
- return -EINVAL;
- if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
- ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
- #endif
- if (!core_kernel_data((unsigned long)ops))
- ops->flags |= FTRACE_OPS_FL_DYNAMIC;
- if (ops->flags & FTRACE_OPS_FL_CONTROL) {
- if (control_ops_alloc(ops))
- return -ENOMEM;
- add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
- /* The control_ops needs the trampoline update */
- ops = &control_ops;
- } else
- add_ftrace_ops(&ftrace_ops_list, ops);
- /* Always save the function, and reset at unregistering */
- ops->saved_func = ops->func;
- if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled())
- ops->func = ftrace_pid_func;
- ftrace_update_trampoline(ops);
- if (ftrace_enabled)
- update_ftrace_function();
- return 0;
- }
- static int __unregister_ftrace_function(struct ftrace_ops *ops)
- {
- int ret;
- if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
- return -EBUSY;
- if (ops->flags & FTRACE_OPS_FL_CONTROL) {
- ret = remove_ftrace_list_ops(&ftrace_control_list,
- &control_ops, ops);
- } else
- ret = remove_ftrace_ops(&ftrace_ops_list, ops);
- if (ret < 0)
- return ret;
- if (ftrace_enabled)
- update_ftrace_function();
- ops->func = ops->saved_func;
- return 0;
- }
- static void ftrace_update_pid_func(void)
- {
- bool enabled = ftrace_pids_enabled();
- struct ftrace_ops *op;
- /* Only do something if we are tracing something */
- if (ftrace_trace_function == ftrace_stub)
- return;
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (op->flags & FTRACE_OPS_FL_PID) {
- op->func = enabled ? ftrace_pid_func :
- op->saved_func;
- ftrace_update_trampoline(op);
- }
- } while_for_each_ftrace_op(op);
- update_ftrace_function();
- }
- #ifdef CONFIG_FUNCTION_PROFILER
- struct ftrace_profile {
- struct hlist_node node;
- unsigned long ip;
- unsigned long counter;
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- unsigned long long time;
- unsigned long long time_squared;
- #endif
- };
- struct ftrace_profile_page {
- struct ftrace_profile_page *next;
- unsigned long index;
- struct ftrace_profile records[];
- };
- struct ftrace_profile_stat {
- atomic_t disabled;
- struct hlist_head *hash;
- struct ftrace_profile_page *pages;
- struct ftrace_profile_page *start;
- struct tracer_stat stat;
- };
- #define PROFILE_RECORDS_SIZE \
- (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
- #define PROFILES_PER_PAGE \
- (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
- static int ftrace_profile_enabled __read_mostly;
- /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
- static DEFINE_MUTEX(ftrace_profile_lock);
- static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
- #define FTRACE_PROFILE_HASH_BITS 10
- #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
- static void *
- function_stat_next(void *v, int idx)
- {
- struct ftrace_profile *rec = v;
- struct ftrace_profile_page *pg;
- pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
- again:
- if (idx != 0)
- rec++;
- if ((void *)rec >= (void *)&pg->records[pg->index]) {
- pg = pg->next;
- if (!pg)
- return NULL;
- rec = &pg->records[0];
- if (!rec->counter)
- goto again;
- }
- return rec;
- }
- static void *function_stat_start(struct tracer_stat *trace)
- {
- struct ftrace_profile_stat *stat =
- container_of(trace, struct ftrace_profile_stat, stat);
- if (!stat || !stat->start)
- return NULL;
- return function_stat_next(&stat->start->records[0], 0);
- }
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- /* function graph compares on total time */
- static int function_stat_cmp(void *p1, void *p2)
- {
- struct ftrace_profile *a = p1;
- struct ftrace_profile *b = p2;
- if (a->time < b->time)
- return -1;
- if (a->time > b->time)
- return 1;
- else
- return 0;
- }
- #else
- /* not function graph compares against hits */
- static int function_stat_cmp(void *p1, void *p2)
- {
- struct ftrace_profile *a = p1;
- struct ftrace_profile *b = p2;
- if (a->counter < b->counter)
- return -1;
- if (a->counter > b->counter)
- return 1;
- else
- return 0;
- }
- #endif
- static int function_stat_headers(struct seq_file *m)
- {
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- seq_puts(m, " Function "
- "Hit Time Avg s^2\n"
- " -------- "
- "--- ---- --- ---\n");
- #else
- seq_puts(m, " Function Hit\n"
- " -------- ---\n");
- #endif
- return 0;
- }
- static int function_stat_show(struct seq_file *m, void *v)
- {
- struct ftrace_profile *rec = v;
- char str[KSYM_SYMBOL_LEN];
- int ret = 0;
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static struct trace_seq s;
- unsigned long long avg;
- unsigned long long stddev;
- #endif
- mutex_lock(&ftrace_profile_lock);
- /* we raced with function_profile_reset() */
- if (unlikely(rec->counter == 0)) {
- ret = -EBUSY;
- goto out;
- }
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- avg = rec->time;
- do_div(avg, rec->counter);
- if (tracing_thresh && (avg < tracing_thresh))
- goto out;
- #endif
- kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
- seq_printf(m, " %-30.30s %10lu", str, rec->counter);
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- seq_puts(m, " ");
- /* Sample standard deviation (s^2) */
- if (rec->counter <= 1)
- stddev = 0;
- else {
- /*
- * Apply Welford's method:
- * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
- */
- stddev = rec->counter * rec->time_squared -
- rec->time * rec->time;
- /*
- * Divide only 1000 for ns^2 -> us^2 conversion.
- * trace_print_graph_duration will divide 1000 again.
- */
- do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
- }
- trace_seq_init(&s);
- trace_print_graph_duration(rec->time, &s);
- trace_seq_puts(&s, " ");
- trace_print_graph_duration(avg, &s);
- trace_seq_puts(&s, " ");
- trace_print_graph_duration(stddev, &s);
- trace_print_seq(m, &s);
- #endif
- seq_putc(m, '\n');
- out:
- mutex_unlock(&ftrace_profile_lock);
- return ret;
- }
- static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
- {
- struct ftrace_profile_page *pg;
- pg = stat->pages = stat->start;
- while (pg) {
- memset(pg->records, 0, PROFILE_RECORDS_SIZE);
- pg->index = 0;
- pg = pg->next;
- }
- memset(stat->hash, 0,
- FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
- }
- int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
- {
- struct ftrace_profile_page *pg;
- int functions;
- int pages;
- int i;
- /* If we already allocated, do nothing */
- if (stat->pages)
- return 0;
- stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
- if (!stat->pages)
- return -ENOMEM;
- #ifdef CONFIG_DYNAMIC_FTRACE
- functions = ftrace_update_tot_cnt;
- #else
- /*
- * We do not know the number of functions that exist because
- * dynamic tracing is what counts them. With past experience
- * we have around 20K functions. That should be more than enough.
- * It is highly unlikely we will execute every function in
- * the kernel.
- */
- functions = 20000;
- #endif
- pg = stat->start = stat->pages;
- pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
- for (i = 1; i < pages; i++) {
- pg->next = (void *)get_zeroed_page(GFP_KERNEL);
- if (!pg->next)
- goto out_free;
- pg = pg->next;
- }
- return 0;
- out_free:
- pg = stat->start;
- while (pg) {
- unsigned long tmp = (unsigned long)pg;
- pg = pg->next;
- free_page(tmp);
- }
- stat->pages = NULL;
- stat->start = NULL;
- return -ENOMEM;
- }
- static int ftrace_profile_init_cpu(int cpu)
- {
- struct ftrace_profile_stat *stat;
- int size;
- stat = &per_cpu(ftrace_profile_stats, cpu);
- if (stat->hash) {
- /* If the profile is already created, simply reset it */
- ftrace_profile_reset(stat);
- return 0;
- }
- /*
- * We are profiling all functions, but usually only a few thousand
- * functions are hit. We'll make a hash of 1024 items.
- */
- size = FTRACE_PROFILE_HASH_SIZE;
- stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
- if (!stat->hash)
- return -ENOMEM;
- /* Preallocate the function profiling pages */
- if (ftrace_profile_pages_init(stat) < 0) {
- kfree(stat->hash);
- stat->hash = NULL;
- return -ENOMEM;
- }
- return 0;
- }
- static int ftrace_profile_init(void)
- {
- int cpu;
- int ret = 0;
- for_each_possible_cpu(cpu) {
- ret = ftrace_profile_init_cpu(cpu);
- if (ret)
- break;
- }
- return ret;
- }
- /* interrupts must be disabled */
- static struct ftrace_profile *
- ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
- {
- struct ftrace_profile *rec;
- struct hlist_head *hhd;
- unsigned long key;
- key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
- hhd = &stat->hash[key];
- if (hlist_empty(hhd))
- return NULL;
- hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
- if (rec->ip == ip)
- return rec;
- }
- return NULL;
- }
- static void ftrace_add_profile(struct ftrace_profile_stat *stat,
- struct ftrace_profile *rec)
- {
- unsigned long key;
- key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
- hlist_add_head_rcu(&rec->node, &stat->hash[key]);
- }
- /*
- * The memory is already allocated, this simply finds a new record to use.
- */
- static struct ftrace_profile *
- ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
- {
- struct ftrace_profile *rec = NULL;
- /* prevent recursion (from NMIs) */
- if (atomic_inc_return(&stat->disabled) != 1)
- goto out;
- /*
- * Try to find the function again since an NMI
- * could have added it
- */
- rec = ftrace_find_profiled_func(stat, ip);
- if (rec)
- goto out;
- if (stat->pages->index == PROFILES_PER_PAGE) {
- if (!stat->pages->next)
- goto out;
- stat->pages = stat->pages->next;
- }
- rec = &stat->pages->records[stat->pages->index++];
- rec->ip = ip;
- ftrace_add_profile(stat, rec);
- out:
- atomic_dec(&stat->disabled);
- return rec;
- }
- static void
- function_profile_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *regs)
- {
- struct ftrace_profile_stat *stat;
- struct ftrace_profile *rec;
- unsigned long flags;
- if (!ftrace_profile_enabled)
- return;
- local_irq_save(flags);
- stat = this_cpu_ptr(&ftrace_profile_stats);
- if (!stat->hash || !ftrace_profile_enabled)
- goto out;
- rec = ftrace_find_profiled_func(stat, ip);
- if (!rec) {
- rec = ftrace_profile_alloc(stat, ip);
- if (!rec)
- goto out;
- }
- rec->counter++;
- out:
- local_irq_restore(flags);
- }
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static int profile_graph_entry(struct ftrace_graph_ent *trace)
- {
- function_profile_call(trace->func, 0, NULL, NULL);
- return 1;
- }
- static void profile_graph_return(struct ftrace_graph_ret *trace)
- {
- struct ftrace_profile_stat *stat;
- unsigned long long calltime;
- struct ftrace_profile *rec;
- unsigned long flags;
- local_irq_save(flags);
- stat = this_cpu_ptr(&ftrace_profile_stats);
- if (!stat->hash || !ftrace_profile_enabled)
- goto out;
- /* If the calltime was zero'd ignore it */
- if (!trace->calltime)
- goto out;
- calltime = trace->rettime - trace->calltime;
- if (!fgraph_graph_time) {
- int index;
- index = trace->depth;
- /* Append this call time to the parent time to subtract */
- if (index)
- current->ret_stack[index - 1].subtime += calltime;
- if (current->ret_stack[index].subtime < calltime)
- calltime -= current->ret_stack[index].subtime;
- else
- calltime = 0;
- }
- rec = ftrace_find_profiled_func(stat, trace->func);
- if (rec) {
- rec->time += calltime;
- rec->time_squared += calltime * calltime;
- }
- out:
- local_irq_restore(flags);
- }
- static int register_ftrace_profiler(void)
- {
- return register_ftrace_graph(&profile_graph_return,
- &profile_graph_entry);
- }
- static void unregister_ftrace_profiler(void)
- {
- unregister_ftrace_graph();
- }
- #else
- static struct ftrace_ops ftrace_profile_ops __read_mostly = {
- .func = function_profile_call,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
- INIT_OPS_HASH(ftrace_profile_ops)
- };
- static int register_ftrace_profiler(void)
- {
- return register_ftrace_function(&ftrace_profile_ops);
- }
- static void unregister_ftrace_profiler(void)
- {
- unregister_ftrace_function(&ftrace_profile_ops);
- }
- #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
- static ssize_t
- ftrace_profile_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- unsigned long val;
- int ret;
- ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
- if (ret)
- return ret;
- val = !!val;
- mutex_lock(&ftrace_profile_lock);
- if (ftrace_profile_enabled ^ val) {
- if (val) {
- ret = ftrace_profile_init();
- if (ret < 0) {
- cnt = ret;
- goto out;
- }
- ret = register_ftrace_profiler();
- if (ret < 0) {
- cnt = ret;
- goto out;
- }
- ftrace_profile_enabled = 1;
- } else {
- ftrace_profile_enabled = 0;
- /*
- * unregister_ftrace_profiler calls stop_machine
- * so this acts like an synchronize_sched.
- */
- unregister_ftrace_profiler();
- }
- }
- out:
- mutex_unlock(&ftrace_profile_lock);
- *ppos += cnt;
- return cnt;
- }
- static ssize_t
- ftrace_profile_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- char buf[64]; /* big enough to hold a number */
- int r;
- r = sprintf(buf, "%u\n", ftrace_profile_enabled);
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
- }
- static const struct file_operations ftrace_profile_fops = {
- .open = tracing_open_generic,
- .read = ftrace_profile_read,
- .write = ftrace_profile_write,
- .llseek = default_llseek,
- };
- /* used to initialize the real stat files */
- static struct tracer_stat function_stats __initdata = {
- .name = "functions",
- .stat_start = function_stat_start,
- .stat_next = function_stat_next,
- .stat_cmp = function_stat_cmp,
- .stat_headers = function_stat_headers,
- .stat_show = function_stat_show
- };
- static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
- {
- struct ftrace_profile_stat *stat;
- struct dentry *entry;
- char *name;
- int ret;
- int cpu;
- for_each_possible_cpu(cpu) {
- stat = &per_cpu(ftrace_profile_stats, cpu);
- /* allocate enough for function name + cpu number */
- name = kmalloc(32, GFP_KERNEL);
- if (!name) {
- /*
- * The files created are permanent, if something happens
- * we still do not free memory.
- */
- WARN(1,
- "Could not allocate stat file for cpu %d\n",
- cpu);
- return;
- }
- stat->stat = function_stats;
- snprintf(name, 32, "function%d", cpu);
- stat->stat.name = name;
- ret = register_stat_tracer(&stat->stat);
- if (ret) {
- WARN(1,
- "Could not register function stat for cpu %d\n",
- cpu);
- kfree(name);
- return;
- }
- }
- entry = tracefs_create_file("function_profile_enabled", 0644,
- d_tracer, NULL, &ftrace_profile_fops);
- if (!entry)
- pr_warning("Could not create tracefs "
- "'function_profile_enabled' entry\n");
- }
- #else /* CONFIG_FUNCTION_PROFILER */
- static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
- {
- }
- #endif /* CONFIG_FUNCTION_PROFILER */
- static struct pid * const ftrace_swapper_pid = &init_struct_pid;
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static int ftrace_graph_active;
- #else
- # define ftrace_graph_active 0
- #endif
- #ifdef CONFIG_DYNAMIC_FTRACE
- static struct ftrace_ops *removed_ops;
- /*
- * Set when doing a global update, like enabling all recs or disabling them.
- * It is not set when just updating a single ftrace_ops.
- */
- static bool update_all_ops;
- #ifndef CONFIG_FTRACE_MCOUNT_RECORD
- # error Dynamic ftrace depends on MCOUNT_RECORD
- #endif
- static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
- struct ftrace_func_probe {
- struct hlist_node node;
- struct ftrace_probe_ops *ops;
- unsigned long flags;
- unsigned long ip;
- void *data;
- struct list_head free_list;
- };
- struct ftrace_func_entry {
- struct hlist_node hlist;
- unsigned long ip;
- };
- struct ftrace_hash {
- unsigned long size_bits;
- struct hlist_head *buckets;
- unsigned long count;
- struct rcu_head rcu;
- };
- /*
- * We make these constant because no one should touch them,
- * but they are used as the default "empty hash", to avoid allocating
- * it all the time. These are in a read only section such that if
- * anyone does try to modify it, it will cause an exception.
- */
- static const struct hlist_head empty_buckets[1];
- static const struct ftrace_hash empty_hash = {
- .buckets = (struct hlist_head *)empty_buckets,
- };
- #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
- static struct ftrace_ops global_ops = {
- .func = ftrace_stub,
- .local_hash.notrace_hash = EMPTY_HASH,
- .local_hash.filter_hash = EMPTY_HASH,
- INIT_OPS_HASH(global_ops)
- .flags = FTRACE_OPS_FL_RECURSION_SAFE |
- FTRACE_OPS_FL_INITIALIZED |
- FTRACE_OPS_FL_PID,
- };
- /*
- * This is used by __kernel_text_address() to return true if the
- * address is on a dynamically allocated trampoline that would
- * not return true for either core_kernel_text() or
- * is_module_text_address().
- */
- bool is_ftrace_trampoline(unsigned long addr)
- {
- struct ftrace_ops *op;
- bool ret = false;
- /*
- * Some of the ops may be dynamically allocated,
- * they are freed after a synchronize_sched().
- */
- preempt_disable_notrace();
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- /*
- * This is to check for dynamically allocated trampolines.
- * Trampolines that are in kernel text will have
- * core_kernel_text() return true.
- */
- if (op->trampoline && op->trampoline_size)
- if (addr >= op->trampoline &&
- addr < op->trampoline + op->trampoline_size) {
- ret = true;
- goto out;
- }
- } while_for_each_ftrace_op(op);
- out:
- preempt_enable_notrace();
- return ret;
- }
- struct ftrace_page {
- struct ftrace_page *next;
- struct dyn_ftrace *records;
- int index;
- int size;
- };
- #define ENTRY_SIZE sizeof(struct dyn_ftrace)
- #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
- /* estimate from running different kernels */
- #define NR_TO_INIT 10000
- static struct ftrace_page *ftrace_pages_start;
- static struct ftrace_page *ftrace_pages;
- static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
- {
- return !hash || !hash->count;
- }
- static struct ftrace_func_entry *
- ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
- {
- unsigned long key;
- struct ftrace_func_entry *entry;
- struct hlist_head *hhd;
- if (ftrace_hash_empty(hash))
- return NULL;
- if (hash->size_bits > 0)
- key = hash_long(ip, hash->size_bits);
- else
- key = 0;
- hhd = &hash->buckets[key];
- hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
- if (entry->ip == ip)
- return entry;
- }
- return NULL;
- }
- static void __add_hash_entry(struct ftrace_hash *hash,
- struct ftrace_func_entry *entry)
- {
- struct hlist_head *hhd;
- unsigned long key;
- if (hash->size_bits)
- key = hash_long(entry->ip, hash->size_bits);
- else
- key = 0;
- hhd = &hash->buckets[key];
- hlist_add_head(&entry->hlist, hhd);
- hash->count++;
- }
- static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
- {
- struct ftrace_func_entry *entry;
- entry = kmalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry)
- return -ENOMEM;
- entry->ip = ip;
- __add_hash_entry(hash, entry);
- return 0;
- }
- static void
- free_hash_entry(struct ftrace_hash *hash,
- struct ftrace_func_entry *entry)
- {
- hlist_del(&entry->hlist);
- kfree(entry);
- hash->count--;
- }
- static void
- remove_hash_entry(struct ftrace_hash *hash,
- struct ftrace_func_entry *entry)
- {
- hlist_del(&entry->hlist);
- hash->count--;
- }
- static void ftrace_hash_clear(struct ftrace_hash *hash)
- {
- struct hlist_head *hhd;
- struct hlist_node *tn;
- struct ftrace_func_entry *entry;
- int size = 1 << hash->size_bits;
- int i;
- if (!hash->count)
- return;
- for (i = 0; i < size; i++) {
- hhd = &hash->buckets[i];
- hlist_for_each_entry_safe(entry, tn, hhd, hlist)
- free_hash_entry(hash, entry);
- }
- FTRACE_WARN_ON(hash->count);
- }
- static void free_ftrace_hash(struct ftrace_hash *hash)
- {
- if (!hash || hash == EMPTY_HASH)
- return;
- ftrace_hash_clear(hash);
- kfree(hash->buckets);
- kfree(hash);
- }
- static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
- {
- struct ftrace_hash *hash;
- hash = container_of(rcu, struct ftrace_hash, rcu);
- free_ftrace_hash(hash);
- }
- static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
- {
- if (!hash || hash == EMPTY_HASH)
- return;
- call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
- }
- void ftrace_free_filter(struct ftrace_ops *ops)
- {
- ftrace_ops_init(ops);
- free_ftrace_hash(ops->func_hash->filter_hash);
- free_ftrace_hash(ops->func_hash->notrace_hash);
- }
- static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
- {
- struct ftrace_hash *hash;
- int size;
- hash = kzalloc(sizeof(*hash), GFP_KERNEL);
- if (!hash)
- return NULL;
- size = 1 << size_bits;
- hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
- if (!hash->buckets) {
- kfree(hash);
- return NULL;
- }
- hash->size_bits = size_bits;
- return hash;
- }
- static struct ftrace_hash *
- alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
- {
- struct ftrace_func_entry *entry;
- struct ftrace_hash *new_hash;
- int size;
- int ret;
- int i;
- new_hash = alloc_ftrace_hash(size_bits);
- if (!new_hash)
- return NULL;
- /* Empty hash? */
- if (ftrace_hash_empty(hash))
- return new_hash;
- size = 1 << hash->size_bits;
- for (i = 0; i < size; i++) {
- hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
- ret = add_hash_entry(new_hash, entry->ip);
- if (ret < 0)
- goto free_hash;
- }
- }
- FTRACE_WARN_ON(new_hash->count != hash->count);
- return new_hash;
- free_hash:
- free_ftrace_hash(new_hash);
- return NULL;
- }
- static void
- ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
- static void
- ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
- static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
- struct ftrace_hash *new_hash);
- static int
- ftrace_hash_move(struct ftrace_ops *ops, int enable,
- struct ftrace_hash **dst, struct ftrace_hash *src)
- {
- struct ftrace_func_entry *entry;
- struct hlist_node *tn;
- struct hlist_head *hhd;
- struct ftrace_hash *new_hash;
- int size = src->count;
- int bits = 0;
- int ret;
- int i;
- /* Reject setting notrace hash on IPMODIFY ftrace_ops */
- if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
- return -EINVAL;
- /*
- * If the new source is empty, just free dst and assign it
- * the empty_hash.
- */
- if (!src->count) {
- new_hash = EMPTY_HASH;
- goto update;
- }
- /*
- * Make the hash size about 1/2 the # found
- */
- for (size /= 2; size; size >>= 1)
- bits++;
- /* Don't allocate too much */
- if (bits > FTRACE_HASH_MAX_BITS)
- bits = FTRACE_HASH_MAX_BITS;
- new_hash = alloc_ftrace_hash(bits);
- if (!new_hash)
- return -ENOMEM;
- size = 1 << src->size_bits;
- for (i = 0; i < size; i++) {
- hhd = &src->buckets[i];
- hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
- remove_hash_entry(src, entry);
- __add_hash_entry(new_hash, entry);
- }
- }
- update:
- /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
- if (enable) {
- /* IPMODIFY should be updated only when filter_hash updating */
- ret = ftrace_hash_ipmodify_update(ops, new_hash);
- if (ret < 0) {
- free_ftrace_hash(new_hash);
- return ret;
- }
- }
- /*
- * Remove the current set, update the hash and add
- * them back.
- */
- ftrace_hash_rec_disable_modify(ops, enable);
- rcu_assign_pointer(*dst, new_hash);
- ftrace_hash_rec_enable_modify(ops, enable);
- return 0;
- }
- static bool hash_contains_ip(unsigned long ip,
- struct ftrace_ops_hash *hash)
- {
- /*
- * The function record is a match if it exists in the filter
- * hash and not in the notrace hash. Note, an emty hash is
- * considered a match for the filter hash, but an empty
- * notrace hash is considered not in the notrace hash.
- */
- return (ftrace_hash_empty(hash->filter_hash) ||
- ftrace_lookup_ip(hash->filter_hash, ip)) &&
- (ftrace_hash_empty(hash->notrace_hash) ||
- !ftrace_lookup_ip(hash->notrace_hash, ip));
- }
- /*
- * Test the hashes for this ops to see if we want to call
- * the ops->func or not.
- *
- * It's a match if the ip is in the ops->filter_hash or
- * the filter_hash does not exist or is empty,
- * AND
- * the ip is not in the ops->notrace_hash.
- *
- * This needs to be called with preemption disabled as
- * the hashes are freed with call_rcu_sched().
- */
- static int
- ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
- {
- struct ftrace_ops_hash hash;
- int ret;
- #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- /*
- * There's a small race when adding ops that the ftrace handler
- * that wants regs, may be called without them. We can not
- * allow that handler to be called if regs is NULL.
- */
- if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
- return 0;
- #endif
- hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
- hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
- if (hash_contains_ip(ip, &hash))
- ret = 1;
- else
- ret = 0;
- return ret;
- }
- /*
- * This is a double for. Do not use 'break' to break out of the loop,
- * you must use a goto.
- */
- #define do_for_each_ftrace_rec(pg, rec) \
- for (pg = ftrace_pages_start; pg; pg = pg->next) { \
- int _____i; \
- for (_____i = 0; _____i < pg->index; _____i++) { \
- rec = &pg->records[_____i];
- #define while_for_each_ftrace_rec() \
- } \
- }
- static int ftrace_cmp_recs(const void *a, const void *b)
- {
- const struct dyn_ftrace *key = a;
- const struct dyn_ftrace *rec = b;
- if (key->flags < rec->ip)
- return -1;
- if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
- return 1;
- return 0;
- }
- static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
- {
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- struct dyn_ftrace key;
- key.ip = start;
- key.flags = end; /* overload flags, as it is unsigned long */
- for (pg = ftrace_pages_start; pg; pg = pg->next) {
- if (end < pg->records[0].ip ||
- start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
- continue;
- rec = bsearch(&key, pg->records, pg->index,
- sizeof(struct dyn_ftrace),
- ftrace_cmp_recs);
- if (rec)
- return rec->ip;
- }
- return 0;
- }
- /**
- * ftrace_location - return true if the ip giving is a traced location
- * @ip: the instruction pointer to check
- *
- * Returns rec->ip if @ip given is a pointer to a ftrace location.
- * That is, the instruction that is either a NOP or call to
- * the function tracer. It checks the ftrace internal tables to
- * determine if the address belongs or not.
- */
- unsigned long ftrace_location(unsigned long ip)
- {
- return ftrace_location_range(ip, ip);
- }
- /**
- * ftrace_text_reserved - return true if range contains an ftrace location
- * @start: start of range to search
- * @end: end of range to search (inclusive). @end points to the last byte to check.
- *
- * Returns 1 if @start and @end contains a ftrace location.
- * That is, the instruction that is either a NOP or call to
- * the function tracer. It checks the ftrace internal tables to
- * determine if the address belongs or not.
- */
- int ftrace_text_reserved(const void *start, const void *end)
- {
- unsigned long ret;
- ret = ftrace_location_range((unsigned long)start,
- (unsigned long)end);
- return (int)!!ret;
- }
- /* Test if ops registered to this rec needs regs */
- static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *ops;
- bool keep_regs = false;
- for (ops = ftrace_ops_list;
- ops != &ftrace_list_end; ops = ops->next) {
- /* pass rec in as regs to have non-NULL val */
- if (ftrace_ops_test(ops, rec->ip, rec)) {
- if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
- keep_regs = true;
- break;
- }
- }
- }
- return keep_regs;
- }
- static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
- int filter_hash,
- bool inc)
- {
- struct ftrace_hash *hash;
- struct ftrace_hash *other_hash;
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- int count = 0;
- int all = 0;
- /* Only update if the ops has been registered */
- if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
- return;
- /*
- * In the filter_hash case:
- * If the count is zero, we update all records.
- * Otherwise we just update the items in the hash.
- *
- * In the notrace_hash case:
- * We enable the update in the hash.
- * As disabling notrace means enabling the tracing,
- * and enabling notrace means disabling, the inc variable
- * gets inversed.
- */
- if (filter_hash) {
- hash = ops->func_hash->filter_hash;
- other_hash = ops->func_hash->notrace_hash;
- if (ftrace_hash_empty(hash))
- all = 1;
- } else {
- inc = !inc;
- hash = ops->func_hash->notrace_hash;
- other_hash = ops->func_hash->filter_hash;
- /*
- * If the notrace hash has no items,
- * then there's nothing to do.
- */
- if (ftrace_hash_empty(hash))
- return;
- }
- do_for_each_ftrace_rec(pg, rec) {
- int in_other_hash = 0;
- int in_hash = 0;
- int match = 0;
- if (all) {
- /*
- * Only the filter_hash affects all records.
- * Update if the record is not in the notrace hash.
- */
- if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
- match = 1;
- } else {
- in_hash = !!ftrace_lookup_ip(hash, rec->ip);
- in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
- /*
- * If filter_hash is set, we want to match all functions
- * that are in the hash but not in the other hash.
- *
- * If filter_hash is not set, then we are decrementing.
- * That means we match anything that is in the hash
- * and also in the other_hash. That is, we need to turn
- * off functions in the other hash because they are disabled
- * by this hash.
- */
- if (filter_hash && in_hash && !in_other_hash)
- match = 1;
- else if (!filter_hash && in_hash &&
- (in_other_hash || ftrace_hash_empty(other_hash)))
- match = 1;
- }
- if (!match)
- continue;
- if (inc) {
- rec->flags++;
- if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
- return;
- /*
- * If there's only a single callback registered to a
- * function, and the ops has a trampoline registered
- * for it, then we can call it directly.
- */
- if (ftrace_rec_count(rec) == 1 && ops->trampoline)
- rec->flags |= FTRACE_FL_TRAMP;
- else
- /*
- * If we are adding another function callback
- * to this function, and the previous had a
- * custom trampoline in use, then we need to go
- * back to the default trampoline.
- */
- rec->flags &= ~FTRACE_FL_TRAMP;
- /*
- * If any ops wants regs saved for this function
- * then all ops will get saved regs.
- */
- if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
- rec->flags |= FTRACE_FL_REGS;
- } else {
- if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
- return;
- rec->flags--;
- /*
- * If the rec had REGS enabled and the ops that is
- * being removed had REGS set, then see if there is
- * still any ops for this record that wants regs.
- * If not, we can stop recording them.
- */
- if (ftrace_rec_count(rec) > 0 &&
- rec->flags & FTRACE_FL_REGS &&
- ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
- if (!test_rec_ops_needs_regs(rec))
- rec->flags &= ~FTRACE_FL_REGS;
- }
- /*
- * If the rec had TRAMP enabled, then it needs to
- * be cleared. As TRAMP can only be enabled iff
- * there is only a single ops attached to it.
- * In otherwords, always disable it on decrementing.
- * In the future, we may set it if rec count is
- * decremented to one, and the ops that is left
- * has a trampoline.
- */
- rec->flags &= ~FTRACE_FL_TRAMP;
- /*
- * flags will be cleared in ftrace_check_record()
- * if rec count is zero.
- */
- }
- count++;
- /* Shortcut, if we handled all records, we are done. */
- if (!all && count == hash->count)
- return;
- } while_for_each_ftrace_rec();
- }
- static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
- int filter_hash)
- {
- __ftrace_hash_rec_update(ops, filter_hash, 0);
- }
- static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
- int filter_hash)
- {
- __ftrace_hash_rec_update(ops, filter_hash, 1);
- }
- static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
- int filter_hash, int inc)
- {
- struct ftrace_ops *op;
- __ftrace_hash_rec_update(ops, filter_hash, inc);
- if (ops->func_hash != &global_ops.local_hash)
- return;
- /*
- * If the ops shares the global_ops hash, then we need to update
- * all ops that are enabled and use this hash.
- */
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- /* Already done */
- if (op == ops)
- continue;
- if (op->func_hash == &global_ops.local_hash)
- __ftrace_hash_rec_update(op, filter_hash, inc);
- } while_for_each_ftrace_op(op);
- }
- static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
- int filter_hash)
- {
- ftrace_hash_rec_update_modify(ops, filter_hash, 0);
- }
- static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
- int filter_hash)
- {
- ftrace_hash_rec_update_modify(ops, filter_hash, 1);
- }
- /*
- * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
- * or no-needed to update, -EBUSY if it detects a conflict of the flag
- * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
- * Note that old_hash and new_hash has below meanings
- * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
- * - If the hash is EMPTY_HASH, it hits nothing
- * - Anything else hits the recs which match the hash entries.
- */
- static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
- struct ftrace_hash *old_hash,
- struct ftrace_hash *new_hash)
- {
- struct ftrace_page *pg;
- struct dyn_ftrace *rec, *end = NULL;
- int in_old, in_new;
- /* Only update if the ops has been registered */
- if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
- return 0;
- if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
- return 0;
- /*
- * Since the IPMODIFY is a very address sensitive action, we do not
- * allow ftrace_ops to set all functions to new hash.
- */
- if (!new_hash || !old_hash)
- return -EINVAL;
- /* Update rec->flags */
- do_for_each_ftrace_rec(pg, rec) {
- /* We need to update only differences of filter_hash */
- in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
- in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
- if (in_old == in_new)
- continue;
- if (in_new) {
- /* New entries must ensure no others are using it */
- if (rec->flags & FTRACE_FL_IPMODIFY)
- goto rollback;
- rec->flags |= FTRACE_FL_IPMODIFY;
- } else /* Removed entry */
- rec->flags &= ~FTRACE_FL_IPMODIFY;
- } while_for_each_ftrace_rec();
- return 0;
- rollback:
- end = rec;
- /* Roll back what we did above */
- do_for_each_ftrace_rec(pg, rec) {
- if (rec == end)
- goto err_out;
- in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
- in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
- if (in_old == in_new)
- continue;
- if (in_new)
- rec->flags &= ~FTRACE_FL_IPMODIFY;
- else
- rec->flags |= FTRACE_FL_IPMODIFY;
- } while_for_each_ftrace_rec();
- err_out:
- return -EBUSY;
- }
- static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
- {
- struct ftrace_hash *hash = ops->func_hash->filter_hash;
- if (ftrace_hash_empty(hash))
- hash = NULL;
- return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
- }
- /* Disabling always succeeds */
- static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
- {
- struct ftrace_hash *hash = ops->func_hash->filter_hash;
- if (ftrace_hash_empty(hash))
- hash = NULL;
- __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
- }
- static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
- struct ftrace_hash *new_hash)
- {
- struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
- if (ftrace_hash_empty(old_hash))
- old_hash = NULL;
- if (ftrace_hash_empty(new_hash))
- new_hash = NULL;
- return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
- }
- static void print_ip_ins(const char *fmt, unsigned char *p)
- {
- int i;
- printk(KERN_CONT "%s", fmt);
- for (i = 0; i < MCOUNT_INSN_SIZE; i++)
- printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
- }
- static struct ftrace_ops *
- ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
- /**
- * ftrace_bug - report and shutdown function tracer
- * @failed: The failed type (EFAULT, EINVAL, EPERM)
- * @rec: The record that failed
- *
- * The arch code that enables or disables the function tracing
- * can call ftrace_bug() when it has detected a problem in
- * modifying the code. @failed should be one of either:
- * EFAULT - if the problem happens on reading the @ip address
- * EINVAL - if what is read at @ip is not what was expected
- * EPERM - if the problem happens on writting to the @ip address
- */
- void ftrace_bug(int failed, struct dyn_ftrace *rec)
- {
- unsigned long ip = rec ? rec->ip : 0;
- switch (failed) {
- case -EFAULT:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on modifying ");
- print_ip_sym(ip);
- break;
- case -EINVAL:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace failed to modify ");
- print_ip_sym(ip);
- print_ip_ins(" actual: ", (unsigned char *)ip);
- pr_cont("\n");
- break;
- case -EPERM:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on writing ");
- print_ip_sym(ip);
- break;
- default:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on unknown error ");
- print_ip_sym(ip);
- }
- if (rec) {
- struct ftrace_ops *ops = NULL;
- pr_info("ftrace record flags: %lx\n", rec->flags);
- pr_cont(" (%ld)%s", ftrace_rec_count(rec),
- rec->flags & FTRACE_FL_REGS ? " R" : " ");
- if (rec->flags & FTRACE_FL_TRAMP_EN) {
- ops = ftrace_find_tramp_ops_any(rec);
- if (ops)
- pr_cont("\ttramp: %pS",
- (void *)ops->trampoline);
- else
- pr_cont("\ttramp: ERROR!");
- }
- ip = ftrace_get_addr_curr(rec);
- pr_cont(" expected tramp: %lx\n", ip);
- }
- }
- static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
- {
- unsigned long flag = 0UL;
- /*
- * If we are updating calls:
- *
- * If the record has a ref count, then we need to enable it
- * because someone is using it.
- *
- * Otherwise we make sure its disabled.
- *
- * If we are disabling calls, then disable all records that
- * are enabled.
- */
- if (enable && ftrace_rec_count(rec))
- flag = FTRACE_FL_ENABLED;
- /*
- * If enabling and the REGS flag does not match the REGS_EN, or
- * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
- * this record. Set flags to fail the compare against ENABLED.
- */
- if (flag) {
- if (!(rec->flags & FTRACE_FL_REGS) !=
- !(rec->flags & FTRACE_FL_REGS_EN))
- flag |= FTRACE_FL_REGS;
- if (!(rec->flags & FTRACE_FL_TRAMP) !=
- !(rec->flags & FTRACE_FL_TRAMP_EN))
- flag |= FTRACE_FL_TRAMP;
- }
- /* If the state of this record hasn't changed, then do nothing */
- if ((rec->flags & FTRACE_FL_ENABLED) == flag)
- return FTRACE_UPDATE_IGNORE;
- if (flag) {
- /* Save off if rec is being enabled (for return value) */
- flag ^= rec->flags & FTRACE_FL_ENABLED;
- if (update) {
- rec->flags |= FTRACE_FL_ENABLED;
- if (flag & FTRACE_FL_REGS) {
- if (rec->flags & FTRACE_FL_REGS)
- rec->flags |= FTRACE_FL_REGS_EN;
- else
- rec->flags &= ~FTRACE_FL_REGS_EN;
- }
- if (flag & FTRACE_FL_TRAMP) {
- if (rec->flags & FTRACE_FL_TRAMP)
- rec->flags |= FTRACE_FL_TRAMP_EN;
- else
- rec->flags &= ~FTRACE_FL_TRAMP_EN;
- }
- }
- /*
- * If this record is being updated from a nop, then
- * return UPDATE_MAKE_CALL.
- * Otherwise,
- * return UPDATE_MODIFY_CALL to tell the caller to convert
- * from the save regs, to a non-save regs function or
- * vice versa, or from a trampoline call.
- */
- if (flag & FTRACE_FL_ENABLED)
- return FTRACE_UPDATE_MAKE_CALL;
- return FTRACE_UPDATE_MODIFY_CALL;
- }
- if (update) {
- /* If there's no more users, clear all flags */
- if (!ftrace_rec_count(rec))
- rec->flags = 0;
- else
- /*
- * Just disable the record, but keep the ops TRAMP
- * and REGS states. The _EN flags must be disabled though.
- */
- rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
- FTRACE_FL_REGS_EN);
- }
- return FTRACE_UPDATE_MAKE_NOP;
- }
- /**
- * ftrace_update_record, set a record that now is tracing or not
- * @rec: the record to update
- * @enable: set to 1 if the record is tracing, zero to force disable
- *
- * The records that represent all functions that can be traced need
- * to be updated when tracing has been enabled.
- */
- int ftrace_update_record(struct dyn_ftrace *rec, int enable)
- {
- return ftrace_check_record(rec, enable, 1);
- }
- /**
- * ftrace_test_record, check if the record has been enabled or not
- * @rec: the record to test
- * @enable: set to 1 to check if enabled, 0 if it is disabled
- *
- * The arch code may need to test if a record is already set to
- * tracing to determine how to modify the function code that it
- * represents.
- */
- int ftrace_test_record(struct dyn_ftrace *rec, int enable)
- {
- return ftrace_check_record(rec, enable, 0);
- }
- static struct ftrace_ops *
- ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *op;
- unsigned long ip = rec->ip;
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (!op->trampoline)
- continue;
- if (hash_contains_ip(ip, op->func_hash))
- return op;
- } while_for_each_ftrace_op(op);
- return NULL;
- }
- static struct ftrace_ops *
- ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *op;
- unsigned long ip = rec->ip;
- /*
- * Need to check removed ops first.
- * If they are being removed, and this rec has a tramp,
- * and this rec is in the ops list, then it would be the
- * one with the tramp.
- */
- if (removed_ops) {
- if (hash_contains_ip(ip, &removed_ops->old_hash))
- return removed_ops;
- }
- /*
- * Need to find the current trampoline for a rec.
- * Now, a trampoline is only attached to a rec if there
- * was a single 'ops' attached to it. But this can be called
- * when we are adding another op to the rec or removing the
- * current one. Thus, if the op is being added, we can
- * ignore it because it hasn't attached itself to the rec
- * yet.
- *
- * If an ops is being modified (hooking to different functions)
- * then we don't care about the new functions that are being
- * added, just the old ones (that are probably being removed).
- *
- * If we are adding an ops to a function that already is using
- * a trampoline, it needs to be removed (trampolines are only
- * for single ops connected), then an ops that is not being
- * modified also needs to be checked.
- */
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (!op->trampoline)
- continue;
- /*
- * If the ops is being added, it hasn't gotten to
- * the point to be removed from this tree yet.
- */
- if (op->flags & FTRACE_OPS_FL_ADDING)
- continue;
- /*
- * If the ops is being modified and is in the old
- * hash, then it is probably being removed from this
- * function.
- */
- if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
- hash_contains_ip(ip, &op->old_hash))
- return op;
- /*
- * If the ops is not being added or modified, and it's
- * in its normal filter hash, then this must be the one
- * we want!
- */
- if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
- hash_contains_ip(ip, op->func_hash))
- return op;
- } while_for_each_ftrace_op(op);
- return NULL;
- }
- static struct ftrace_ops *
- ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *op;
- unsigned long ip = rec->ip;
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- /* pass rec in as regs to have non-NULL val */
- if (hash_contains_ip(ip, op->func_hash))
- return op;
- } while_for_each_ftrace_op(op);
- return NULL;
- }
- /**
- * ftrace_get_addr_new - Get the call address to set to
- * @rec: The ftrace record descriptor
- *
- * If the record has the FTRACE_FL_REGS set, that means that it
- * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
- * is not not set, then it wants to convert to the normal callback.
- *
- * Returns the address of the trampoline to set to
- */
- unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *ops;
- /* Trampolines take precedence over regs */
- if (rec->flags & FTRACE_FL_TRAMP) {
- ops = ftrace_find_tramp_ops_new(rec);
- if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
- pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
- (void *)rec->ip, (void *)rec->ip, rec->flags);
- /* Ftrace is shutting down, return anything */
- return (unsigned long)FTRACE_ADDR;
- }
- return ops->trampoline;
- }
- if (rec->flags & FTRACE_FL_REGS)
- return (unsigned long)FTRACE_REGS_ADDR;
- else
- return (unsigned long)FTRACE_ADDR;
- }
- /**
- * ftrace_get_addr_curr - Get the call address that is already there
- * @rec: The ftrace record descriptor
- *
- * The FTRACE_FL_REGS_EN is set when the record already points to
- * a function that saves all the regs. Basically the '_EN' version
- * represents the current state of the function.
- *
- * Returns the address of the trampoline that is currently being called
- */
- unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *ops;
- /* Trampolines take precedence over regs */
- if (rec->flags & FTRACE_FL_TRAMP_EN) {
- ops = ftrace_find_tramp_ops_curr(rec);
- if (FTRACE_WARN_ON(!ops)) {
- pr_warning("Bad trampoline accounting at: %p (%pS)\n",
- (void *)rec->ip, (void *)rec->ip);
- /* Ftrace is shutting down, return anything */
- return (unsigned long)FTRACE_ADDR;
- }
- return ops->trampoline;
- }
- if (rec->flags & FTRACE_FL_REGS_EN)
- return (unsigned long)FTRACE_REGS_ADDR;
- else
- return (unsigned long)FTRACE_ADDR;
- }
- static int
- __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
- {
- unsigned long ftrace_old_addr;
- unsigned long ftrace_addr;
- int ret;
- ftrace_addr = ftrace_get_addr_new(rec);
- /* This needs to be done before we call ftrace_update_record */
- ftrace_old_addr = ftrace_get_addr_curr(rec);
- ret = ftrace_update_record(rec, enable);
- switch (ret) {
- case FTRACE_UPDATE_IGNORE:
- return 0;
- case FTRACE_UPDATE_MAKE_CALL:
- return ftrace_make_call(rec, ftrace_addr);
- case FTRACE_UPDATE_MAKE_NOP:
- return ftrace_make_nop(NULL, rec, ftrace_old_addr);
- case FTRACE_UPDATE_MODIFY_CALL:
- return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
- }
- return -1; /* unknow ftrace bug */
- }
- void __weak ftrace_replace_code(int enable)
- {
- struct dyn_ftrace *rec;
- struct ftrace_page *pg;
- int failed;
- if (unlikely(ftrace_disabled))
- return;
- do_for_each_ftrace_rec(pg, rec) {
- failed = __ftrace_replace_code(rec, enable);
- if (failed) {
- ftrace_bug(failed, rec);
- /* Stop processing */
- return;
- }
- } while_for_each_ftrace_rec();
- }
- struct ftrace_rec_iter {
- struct ftrace_page *pg;
- int index;
- };
- /**
- * ftrace_rec_iter_start, start up iterating over traced functions
- *
- * Returns an iterator handle that is used to iterate over all
- * the records that represent address locations where functions
- * are traced.
- *
- * May return NULL if no records are available.
- */
- struct ftrace_rec_iter *ftrace_rec_iter_start(void)
- {
- /*
- * We only use a single iterator.
- * Protected by the ftrace_lock mutex.
- */
- static struct ftrace_rec_iter ftrace_rec_iter;
- struct ftrace_rec_iter *iter = &ftrace_rec_iter;
- iter->pg = ftrace_pages_start;
- iter->index = 0;
- /* Could have empty pages */
- while (iter->pg && !iter->pg->index)
- iter->pg = iter->pg->next;
- if (!iter->pg)
- return NULL;
- return iter;
- }
- /**
- * ftrace_rec_iter_next, get the next record to process.
- * @iter: The handle to the iterator.
- *
- * Returns the next iterator after the given iterator @iter.
- */
- struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
- {
- iter->index++;
- if (iter->index >= iter->pg->index) {
- iter->pg = iter->pg->next;
- iter->index = 0;
- /* Could have empty pages */
- while (iter->pg && !iter->pg->index)
- iter->pg = iter->pg->next;
- }
- if (!iter->pg)
- return NULL;
- return iter;
- }
- /**
- * ftrace_rec_iter_record, get the record at the iterator location
- * @iter: The current iterator location
- *
- * Returns the record that the current @iter is at.
- */
- struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
- {
- return &iter->pg->records[iter->index];
- }
- static int
- ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
- {
- int ret;
- if (unlikely(ftrace_disabled))
- return 0;
- ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
- if (ret) {
- ftrace_bug(ret, rec);
- return 0;
- }
- return 1;
- }
- /*
- * archs can override this function if they must do something
- * before the modifying code is performed.
- */
- int __weak ftrace_arch_code_modify_prepare(void)
- {
- return 0;
- }
- /*
- * archs can override this function if they must do something
- * after the modifying code is performed.
- */
- int __weak ftrace_arch_code_modify_post_process(void)
- {
- return 0;
- }
- void ftrace_modify_all_code(int command)
- {
- int update = command & FTRACE_UPDATE_TRACE_FUNC;
- int err = 0;
- /*
- * If the ftrace_caller calls a ftrace_ops func directly,
- * we need to make sure that it only traces functions it
- * expects to trace. When doing the switch of functions,
- * we need to update to the ftrace_ops_list_func first
- * before the transition between old and new calls are set,
- * as the ftrace_ops_list_func will check the ops hashes
- * to make sure the ops are having the right functions
- * traced.
- */
- if (update) {
- err = ftrace_update_ftrace_func(ftrace_ops_list_func);
- if (FTRACE_WARN_ON(err))
- return;
- }
- if (command & FTRACE_UPDATE_CALLS)
- ftrace_replace_code(1);
- else if (command & FTRACE_DISABLE_CALLS)
- ftrace_replace_code(0);
- if (update && ftrace_trace_function != ftrace_ops_list_func) {
- function_trace_op = set_function_trace_op;
- smp_wmb();
- /* If irqs are disabled, we are in stop machine */
- if (!irqs_disabled())
- smp_call_function(ftrace_sync_ipi, NULL, 1);
- err = ftrace_update_ftrace_func(ftrace_trace_function);
- if (FTRACE_WARN_ON(err))
- return;
- }
- if (command & FTRACE_START_FUNC_RET)
- err = ftrace_enable_ftrace_graph_caller();
- else if (command & FTRACE_STOP_FUNC_RET)
- err = ftrace_disable_ftrace_graph_caller();
- FTRACE_WARN_ON(err);
- }
- static int __ftrace_modify_code(void *data)
- {
- int *command = data;
- ftrace_modify_all_code(*command);
- return 0;
- }
- /**
- * ftrace_run_stop_machine, go back to the stop machine method
- * @command: The command to tell ftrace what to do
- *
- * If an arch needs to fall back to the stop machine method, the
- * it can call this function.
- */
- void ftrace_run_stop_machine(int command)
- {
- stop_machine(__ftrace_modify_code, &command, NULL);
- }
- /**
- * arch_ftrace_update_code, modify the code to trace or not trace
- * @command: The command that needs to be done
- *
- * Archs can override this function if it does not need to
- * run stop_machine() to modify code.
- */
- void __weak arch_ftrace_update_code(int command)
- {
- ftrace_run_stop_machine(command);
- }
- static void ftrace_run_update_code(int command)
- {
- int ret;
- ret = ftrace_arch_code_modify_prepare();
- FTRACE_WARN_ON(ret);
- if (ret)
- return;
- /*
- * By default we use stop_machine() to modify the code.
- * But archs can do what ever they want as long as it
- * is safe. The stop_machine() is the safest, but also
- * produces the most overhead.
- */
- arch_ftrace_update_code(command);
- ret = ftrace_arch_code_modify_post_process();
- FTRACE_WARN_ON(ret);
- }
- static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
- struct ftrace_ops_hash *old_hash)
- {
- ops->flags |= FTRACE_OPS_FL_MODIFYING;
- ops->old_hash.filter_hash = old_hash->filter_hash;
- ops->old_hash.notrace_hash = old_hash->notrace_hash;
- ftrace_run_update_code(command);
- ops->old_hash.filter_hash = NULL;
- ops->old_hash.notrace_hash = NULL;
- ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
- }
- static ftrace_func_t saved_ftrace_func;
- static int ftrace_start_up;
- void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
- {
- }
- static void control_ops_free(struct ftrace_ops *ops)
- {
- free_percpu(ops->disabled);
- }
- static void ftrace_startup_enable(int command)
- {
- if (saved_ftrace_func != ftrace_trace_function) {
- saved_ftrace_func = ftrace_trace_function;
- command |= FTRACE_UPDATE_TRACE_FUNC;
- }
- if (!command || !ftrace_enabled)
- return;
- ftrace_run_update_code(command);
- }
- static void ftrace_startup_all(int command)
- {
- update_all_ops = true;
- ftrace_startup_enable(command);
- update_all_ops = false;
- }
- static int ftrace_startup(struct ftrace_ops *ops, int command)
- {
- int ret;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- ret = __register_ftrace_function(ops);
- if (ret)
- return ret;
- ftrace_start_up++;
- command |= FTRACE_UPDATE_CALLS;
- /*
- * Note that ftrace probes uses this to start up
- * and modify functions it will probe. But we still
- * set the ADDING flag for modification, as probes
- * do not have trampolines. If they add them in the
- * future, then the probes will need to distinguish
- * between adding and updating probes.
- */
- ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
- ret = ftrace_hash_ipmodify_enable(ops);
- if (ret < 0) {
- /* Rollback registration process */
- __unregister_ftrace_function(ops);
- ftrace_start_up--;
- ops->flags &= ~FTRACE_OPS_FL_ENABLED;
- return ret;
- }
- ftrace_hash_rec_enable(ops, 1);
- ftrace_startup_enable(command);
- ops->flags &= ~FTRACE_OPS_FL_ADDING;
- return 0;
- }
- static int ftrace_shutdown(struct ftrace_ops *ops, int command)
- {
- int ret;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- ret = __unregister_ftrace_function(ops);
- if (ret)
- return ret;
- ftrace_start_up--;
- /*
- * Just warn in case of unbalance, no need to kill ftrace, it's not
- * critical but the ftrace_call callers may be never nopped again after
- * further ftrace uses.
- */
- WARN_ON_ONCE(ftrace_start_up < 0);
- /* Disabling ipmodify never fails */
- ftrace_hash_ipmodify_disable(ops);
- ftrace_hash_rec_disable(ops, 1);
- ops->flags &= ~FTRACE_OPS_FL_ENABLED;
- command |= FTRACE_UPDATE_CALLS;
- if (saved_ftrace_func != ftrace_trace_function) {
- saved_ftrace_func = ftrace_trace_function;
- command |= FTRACE_UPDATE_TRACE_FUNC;
- }
- if (!command || !ftrace_enabled) {
- /*
- * If these are dynamic or control ops, they still
- * need their data freed. Since, function tracing is
- * not currently active, we can just free them
- * without synchronizing all CPUs.
- */
- if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL))
- goto free_ops;
- return 0;
- }
- /*
- * If the ops uses a trampoline, then it needs to be
- * tested first on update.
- */
- ops->flags |= FTRACE_OPS_FL_REMOVING;
- removed_ops = ops;
- /* The trampoline logic checks the old hashes */
- ops->old_hash.filter_hash = ops->func_hash->filter_hash;
- ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
- ftrace_run_update_code(command);
- /*
- * If there's no more ops registered with ftrace, run a
- * sanity check to make sure all rec flags are cleared.
- */
- if (ftrace_ops_list == &ftrace_list_end) {
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- do_for_each_ftrace_rec(pg, rec) {
- if (FTRACE_WARN_ON_ONCE(rec->flags))
- pr_warn(" %pS flags:%lx\n",
- (void *)rec->ip, rec->flags);
- } while_for_each_ftrace_rec();
- }
- ops->old_hash.filter_hash = NULL;
- ops->old_hash.notrace_hash = NULL;
- removed_ops = NULL;
- ops->flags &= ~FTRACE_OPS_FL_REMOVING;
- /*
- * Dynamic ops may be freed, we must make sure that all
- * callers are done before leaving this function.
- * The same goes for freeing the per_cpu data of the control
- * ops.
- *
- * Again, normal synchronize_sched() is not good enough.
- * We need to do a hard force of sched synchronization.
- * This is because we use preempt_disable() to do RCU, but
- * the function tracers can be called where RCU is not watching
- * (like before user_exit()). We can not rely on the RCU
- * infrastructure to do the synchronization, thus we must do it
- * ourselves.
- */
- if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
- schedule_on_each_cpu(ftrace_sync);
- free_ops:
- arch_ftrace_trampoline_free(ops);
- if (ops->flags & FTRACE_OPS_FL_CONTROL)
- control_ops_free(ops);
- }
- return 0;
- }
- static void ftrace_startup_sysctl(void)
- {
- int command;
- if (unlikely(ftrace_disabled))
- return;
- /* Force update next time */
- saved_ftrace_func = NULL;
- /* ftrace_start_up is true if we want ftrace running */
- if (ftrace_start_up) {
- command = FTRACE_UPDATE_CALLS;
- if (ftrace_graph_active)
- command |= FTRACE_START_FUNC_RET;
- ftrace_startup_enable(command);
- }
- }
- static void ftrace_shutdown_sysctl(void)
- {
- int command;
- if (unlikely(ftrace_disabled))
- return;
- /* ftrace_start_up is true if ftrace is running */
- if (ftrace_start_up) {
- command = FTRACE_DISABLE_CALLS;
- if (ftrace_graph_active)
- command |= FTRACE_STOP_FUNC_RET;
- ftrace_run_update_code(command);
- }
- }
- static cycle_t ftrace_update_time;
- unsigned long ftrace_update_tot_cnt;
- static inline int ops_traces_mod(struct ftrace_ops *ops)
- {
- /*
- * Filter_hash being empty will default to trace module.
- * But notrace hash requires a test of individual module functions.
- */
- return ftrace_hash_empty(ops->func_hash->filter_hash) &&
- ftrace_hash_empty(ops->func_hash->notrace_hash);
- }
- /*
- * Check if the current ops references the record.
- *
- * If the ops traces all functions, then it was already accounted for.
- * If the ops does not trace the current record function, skip it.
- * If the ops ignores the function via notrace filter, skip it.
- */
- static inline bool
- ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
- {
- /* If ops isn't enabled, ignore it */
- if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
- return 0;
- /* If ops traces all mods, we already accounted for it */
- if (ops_traces_mod(ops))
- return 0;
- /* The function must be in the filter */
- if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
- !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
- return 0;
- /* If in notrace hash, we ignore it too */
- if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
- return 0;
- return 1;
- }
- static int referenced_filters(struct dyn_ftrace *rec)
- {
- struct ftrace_ops *ops;
- int cnt = 0;
- for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
- if (ops_references_rec(ops, rec))
- cnt++;
- }
- return cnt;
- }
- static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
- {
- struct ftrace_page *pg;
- struct dyn_ftrace *p;
- cycle_t start, stop;
- unsigned long update_cnt = 0;
- unsigned long ref = 0;
- bool test = false;
- int i;
- /*
- * When adding a module, we need to check if tracers are
- * currently enabled and if they are set to trace all functions.
- * If they are, we need to enable the module functions as well
- * as update the reference counts for those function records.
- */
- if (mod) {
- struct ftrace_ops *ops;
- for (ops = ftrace_ops_list;
- ops != &ftrace_list_end; ops = ops->next) {
- if (ops->flags & FTRACE_OPS_FL_ENABLED) {
- if (ops_traces_mod(ops))
- ref++;
- else
- test = true;
- }
- }
- }
- start = ftrace_now(raw_smp_processor_id());
- for (pg = new_pgs; pg; pg = pg->next) {
- for (i = 0; i < pg->index; i++) {
- int cnt = ref;
- /* If something went wrong, bail without enabling anything */
- if (unlikely(ftrace_disabled))
- return -1;
- p = &pg->records[i];
- if (test)
- cnt += referenced_filters(p);
- p->flags = cnt;
- /*
- * Do the initial record conversion from mcount jump
- * to the NOP instructions.
- */
- if (!ftrace_code_disable(mod, p))
- break;
- update_cnt++;
- /*
- * If the tracing is enabled, go ahead and enable the record.
- *
- * The reason not to enable the record immediatelly is the
- * inherent check of ftrace_make_nop/ftrace_make_call for
- * correct previous instructions. Making first the NOP
- * conversion puts the module to the correct state, thus
- * passing the ftrace_make_call check.
- */
- if (ftrace_start_up && cnt) {
- int failed = __ftrace_replace_code(p, 1);
- if (failed)
- ftrace_bug(failed, p);
- }
- }
- }
- stop = ftrace_now(raw_smp_processor_id());
- ftrace_update_time = stop - start;
- ftrace_update_tot_cnt += update_cnt;
- return 0;
- }
- static int ftrace_allocate_records(struct ftrace_page *pg, int count)
- {
- int order;
- int cnt;
- if (WARN_ON(!count))
- return -EINVAL;
- order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
- /*
- * We want to fill as much as possible. No more than a page
- * may be empty.
- */
- while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
- order--;
- again:
- pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
- if (!pg->records) {
- /* if we can't allocate this size, try something smaller */
- if (!order)
- return -ENOMEM;
- order >>= 1;
- goto again;
- }
- cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
- pg->size = cnt;
- if (cnt > count)
- cnt = count;
- return cnt;
- }
- static struct ftrace_page *
- ftrace_allocate_pages(unsigned long num_to_init)
- {
- struct ftrace_page *start_pg;
- struct ftrace_page *pg;
- int order;
- int cnt;
- if (!num_to_init)
- return 0;
- start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
- if (!pg)
- return NULL;
- /*
- * Try to allocate as much as possible in one continues
- * location that fills in all of the space. We want to
- * waste as little space as possible.
- */
- for (;;) {
- cnt = ftrace_allocate_records(pg, num_to_init);
- if (cnt < 0)
- goto free_pages;
- num_to_init -= cnt;
- if (!num_to_init)
- break;
- pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
- if (!pg->next)
- goto free_pages;
- pg = pg->next;
- }
- return start_pg;
- free_pages:
- pg = start_pg;
- while (pg) {
- order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
- start_pg = pg->next;
- kfree(pg);
- pg = start_pg;
- }
- pr_info("ftrace: FAILED to allocate memory for functions\n");
- return NULL;
- }
- #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
- struct ftrace_iterator {
- loff_t pos;
- loff_t func_pos;
- struct ftrace_page *pg;
- struct dyn_ftrace *func;
- struct ftrace_func_probe *probe;
- struct trace_parser parser;
- struct ftrace_hash *hash;
- struct ftrace_ops *ops;
- int hidx;
- int idx;
- unsigned flags;
- };
- static void *
- t_hash_next(struct seq_file *m, loff_t *pos)
- {
- struct ftrace_iterator *iter = m->private;
- struct hlist_node *hnd = NULL;
- struct hlist_head *hhd;
- (*pos)++;
- iter->pos = *pos;
- if (iter->probe)
- hnd = &iter->probe->node;
- retry:
- if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
- return NULL;
- hhd = &ftrace_func_hash[iter->hidx];
- if (hlist_empty(hhd)) {
- iter->hidx++;
- hnd = NULL;
- goto retry;
- }
- if (!hnd)
- hnd = hhd->first;
- else {
- hnd = hnd->next;
- if (!hnd) {
- iter->hidx++;
- goto retry;
- }
- }
- if (WARN_ON_ONCE(!hnd))
- return NULL;
- iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
- return iter;
- }
- static void *t_hash_start(struct seq_file *m, loff_t *pos)
- {
- struct ftrace_iterator *iter = m->private;
- void *p = NULL;
- loff_t l;
- if (!(iter->flags & FTRACE_ITER_DO_HASH))
- return NULL;
- if (iter->func_pos > *pos)
- return NULL;
- iter->hidx = 0;
- for (l = 0; l <= (*pos - iter->func_pos); ) {
- p = t_hash_next(m, &l);
- if (!p)
- break;
- }
- if (!p)
- return NULL;
- /* Only set this if we have an item */
- iter->flags |= FTRACE_ITER_HASH;
- return iter;
- }
- static int
- t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
- {
- struct ftrace_func_probe *rec;
- rec = iter->probe;
- if (WARN_ON_ONCE(!rec))
- return -EIO;
- if (rec->ops->print)
- return rec->ops->print(m, rec->ip, rec->ops, rec->data);
- seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
- if (rec->data)
- seq_printf(m, ":%p", rec->data);
- seq_putc(m, '\n');
- return 0;
- }
- static void *
- t_next(struct seq_file *m, void *v, loff_t *pos)
- {
- struct ftrace_iterator *iter = m->private;
- struct ftrace_ops *ops = iter->ops;
- struct dyn_ftrace *rec = NULL;
- if (unlikely(ftrace_disabled))
- return NULL;
- if (iter->flags & FTRACE_ITER_HASH)
- return t_hash_next(m, pos);
- (*pos)++;
- iter->pos = iter->func_pos = *pos;
- if (iter->flags & FTRACE_ITER_PRINTALL)
- return t_hash_start(m, pos);
- retry:
- if (iter->idx >= iter->pg->index) {
- if (iter->pg->next) {
- iter->pg = iter->pg->next;
- iter->idx = 0;
- goto retry;
- }
- } else {
- rec = &iter->pg->records[iter->idx++];
- if (((iter->flags & FTRACE_ITER_FILTER) &&
- !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
- ((iter->flags & FTRACE_ITER_NOTRACE) &&
- !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
- ((iter->flags & FTRACE_ITER_ENABLED) &&
- !(rec->flags & FTRACE_FL_ENABLED))) {
- rec = NULL;
- goto retry;
- }
- }
- if (!rec)
- return t_hash_start(m, pos);
- iter->func = rec;
- return iter;
- }
- static void reset_iter_read(struct ftrace_iterator *iter)
- {
- iter->pos = 0;
- iter->func_pos = 0;
- iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
- }
- static void *t_start(struct seq_file *m, loff_t *pos)
- {
- struct ftrace_iterator *iter = m->private;
- struct ftrace_ops *ops = iter->ops;
- void *p = NULL;
- loff_t l;
- mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
- return NULL;
- /*
- * If an lseek was done, then reset and start from beginning.
- */
- if (*pos < iter->pos)
- reset_iter_read(iter);
- /*
- * For set_ftrace_filter reading, if we have the filter
- * off, we can short cut and just print out that all
- * functions are enabled.
- */
- if ((iter->flags & FTRACE_ITER_FILTER &&
- ftrace_hash_empty(ops->func_hash->filter_hash)) ||
- (iter->flags & FTRACE_ITER_NOTRACE &&
- ftrace_hash_empty(ops->func_hash->notrace_hash))) {
- if (*pos > 0)
- return t_hash_start(m, pos);
- iter->flags |= FTRACE_ITER_PRINTALL;
- /* reset in case of seek/pread */
- iter->flags &= ~FTRACE_ITER_HASH;
- return iter;
- }
- if (iter->flags & FTRACE_ITER_HASH)
- return t_hash_start(m, pos);
- /*
- * Unfortunately, we need to restart at ftrace_pages_start
- * every time we let go of the ftrace_mutex. This is because
- * those pointers can change without the lock.
- */
- iter->pg = ftrace_pages_start;
- iter->idx = 0;
- for (l = 0; l <= *pos; ) {
- p = t_next(m, p, &l);
- if (!p)
- break;
- }
- if (!p)
- return t_hash_start(m, pos);
- return iter;
- }
- static void t_stop(struct seq_file *m, void *p)
- {
- mutex_unlock(&ftrace_lock);
- }
- void * __weak
- arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
- {
- return NULL;
- }
- static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
- struct dyn_ftrace *rec)
- {
- void *ptr;
- ptr = arch_ftrace_trampoline_func(ops, rec);
- if (ptr)
- seq_printf(m, " ->%pS", ptr);
- }
- static int t_show(struct seq_file *m, void *v)
- {
- struct ftrace_iterator *iter = m->private;
- struct dyn_ftrace *rec;
- if (iter->flags & FTRACE_ITER_HASH)
- return t_hash_show(m, iter);
- if (iter->flags & FTRACE_ITER_PRINTALL) {
- if (iter->flags & FTRACE_ITER_NOTRACE)
- seq_puts(m, "#### no functions disabled ####\n");
- else
- seq_puts(m, "#### all functions enabled ####\n");
- return 0;
- }
- rec = iter->func;
- if (!rec)
- return 0;
- seq_printf(m, "%ps", (void *)rec->ip);
- if (iter->flags & FTRACE_ITER_ENABLED) {
- struct ftrace_ops *ops = NULL;
- seq_printf(m, " (%ld)%s%s",
- ftrace_rec_count(rec),
- rec->flags & FTRACE_FL_REGS ? " R" : " ",
- rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
- if (rec->flags & FTRACE_FL_TRAMP_EN) {
- ops = ftrace_find_tramp_ops_any(rec);
- if (ops)
- seq_printf(m, "\ttramp: %pS",
- (void *)ops->trampoline);
- else
- seq_puts(m, "\ttramp: ERROR!");
- }
- add_trampoline_func(m, ops, rec);
- }
- seq_putc(m, '\n');
- return 0;
- }
- static const struct seq_operations show_ftrace_seq_ops = {
- .start = t_start,
- .next = t_next,
- .stop = t_stop,
- .show = t_show,
- };
- static int
- ftrace_avail_open(struct inode *inode, struct file *file)
- {
- struct ftrace_iterator *iter;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
- if (iter) {
- iter->pg = ftrace_pages_start;
- iter->ops = &global_ops;
- }
- return iter ? 0 : -ENOMEM;
- }
- static int
- ftrace_enabled_open(struct inode *inode, struct file *file)
- {
- struct ftrace_iterator *iter;
- iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
- if (iter) {
- iter->pg = ftrace_pages_start;
- iter->flags = FTRACE_ITER_ENABLED;
- iter->ops = &global_ops;
- }
- return iter ? 0 : -ENOMEM;
- }
- /**
- * ftrace_regex_open - initialize function tracer filter files
- * @ops: The ftrace_ops that hold the hash filters
- * @flag: The type of filter to process
- * @inode: The inode, usually passed in to your open routine
- * @file: The file, usually passed in to your open routine
- *
- * ftrace_regex_open() initializes the filter files for the
- * @ops. Depending on @flag it may process the filter hash or
- * the notrace hash of @ops. With this called from the open
- * routine, you can use ftrace_filter_write() for the write
- * routine if @flag has FTRACE_ITER_FILTER set, or
- * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
- * tracing_lseek() should be used as the lseek routine, and
- * release must call ftrace_regex_release().
- */
- int
- ftrace_regex_open(struct ftrace_ops *ops, int flag,
- struct inode *inode, struct file *file)
- {
- struct ftrace_iterator *iter;
- struct ftrace_hash *hash;
- int ret = 0;
- ftrace_ops_init(ops);
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- iter = kzalloc(sizeof(*iter), GFP_KERNEL);
- if (!iter)
- return -ENOMEM;
- if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
- kfree(iter);
- return -ENOMEM;
- }
- iter->ops = ops;
- iter->flags = flag;
- mutex_lock(&ops->func_hash->regex_lock);
- if (flag & FTRACE_ITER_NOTRACE)
- hash = ops->func_hash->notrace_hash;
- else
- hash = ops->func_hash->filter_hash;
- if (file->f_mode & FMODE_WRITE) {
- const int size_bits = FTRACE_HASH_DEFAULT_BITS;
- if (file->f_flags & O_TRUNC)
- iter->hash = alloc_ftrace_hash(size_bits);
- else
- iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
- if (!iter->hash) {
- trace_parser_put(&iter->parser);
- kfree(iter);
- ret = -ENOMEM;
- goto out_unlock;
- }
- }
- if (file->f_mode & FMODE_READ) {
- iter->pg = ftrace_pages_start;
- ret = seq_open(file, &show_ftrace_seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = iter;
- } else {
- /* Failed */
- free_ftrace_hash(iter->hash);
- trace_parser_put(&iter->parser);
- kfree(iter);
- }
- } else
- file->private_data = iter;
- out_unlock:
- mutex_unlock(&ops->func_hash->regex_lock);
- return ret;
- }
- static int
- ftrace_filter_open(struct inode *inode, struct file *file)
- {
- struct ftrace_ops *ops = inode->i_private;
- return ftrace_regex_open(ops,
- FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
- inode, file);
- }
- static int
- ftrace_notrace_open(struct inode *inode, struct file *file)
- {
- struct ftrace_ops *ops = inode->i_private;
- return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
- inode, file);
- }
- /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
- struct ftrace_glob {
- char *search;
- unsigned len;
- int type;
- };
- static int ftrace_match(char *str, struct ftrace_glob *g)
- {
- int matched = 0;
- int slen;
- switch (g->type) {
- case MATCH_FULL:
- if (strcmp(str, g->search) == 0)
- matched = 1;
- break;
- case MATCH_FRONT_ONLY:
- if (strncmp(str, g->search, g->len) == 0)
- matched = 1;
- break;
- case MATCH_MIDDLE_ONLY:
- if (strstr(str, g->search))
- matched = 1;
- break;
- case MATCH_END_ONLY:
- slen = strlen(str);
- if (slen >= g->len &&
- memcmp(str + slen - g->len, g->search, g->len) == 0)
- matched = 1;
- break;
- }
- return matched;
- }
- static int
- enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
- {
- struct ftrace_func_entry *entry;
- int ret = 0;
- entry = ftrace_lookup_ip(hash, rec->ip);
- if (clear_filter) {
- /* Do nothing if it doesn't exist */
- if (!entry)
- return 0;
- free_hash_entry(hash, entry);
- } else {
- /* Do nothing if it exists */
- if (entry)
- return 0;
- ret = add_hash_entry(hash, rec->ip);
- }
- return ret;
- }
- static int
- ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
- struct ftrace_glob *mod_g, int exclude_mod)
- {
- char str[KSYM_SYMBOL_LEN];
- char *modname;
- kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
- if (mod_g) {
- int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
- /* blank module name to match all modules */
- if (!mod_g->len) {
- /* blank module globbing: modname xor exclude_mod */
- if ((!exclude_mod) != (!modname))
- goto func_match;
- return 0;
- }
- /* not matching the module */
- if (!modname || !mod_matches) {
- if (exclude_mod)
- goto func_match;
- else
- return 0;
- }
- if (mod_matches && exclude_mod)
- return 0;
- func_match:
- /* blank search means to match all funcs in the mod */
- if (!func_g->len)
- return 1;
- }
- return ftrace_match(str, func_g);
- }
- static int
- match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
- {
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- struct ftrace_glob func_g = { .type = MATCH_FULL };
- struct ftrace_glob mod_g = { .type = MATCH_FULL };
- struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
- int exclude_mod = 0;
- int found = 0;
- int ret;
- int clear_filter = 0;
- if (func) {
- func_g.type = filter_parse_regex(func, len, &func_g.search,
- &clear_filter);
- func_g.len = strlen(func_g.search);
- }
- if (mod) {
- mod_g.type = filter_parse_regex(mod, strlen(mod),
- &mod_g.search, &exclude_mod);
- mod_g.len = strlen(mod_g.search);
- }
- mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
- goto out_unlock;
- do_for_each_ftrace_rec(pg, rec) {
- if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
- ret = enter_record(hash, rec, clear_filter);
- if (ret < 0) {
- found = ret;
- goto out_unlock;
- }
- found = 1;
- }
- } while_for_each_ftrace_rec();
- out_unlock:
- mutex_unlock(&ftrace_lock);
- return found;
- }
- static int
- ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
- {
- return match_records(hash, buff, len, NULL);
- }
- /*
- * We register the module command as a template to show others how
- * to register the a command as well.
- */
- static int
- ftrace_mod_callback(struct ftrace_hash *hash,
- char *func, char *cmd, char *module, int enable)
- {
- int ret;
- /*
- * cmd == 'mod' because we only registered this func
- * for the 'mod' ftrace_func_command.
- * But if you register one func with multiple commands,
- * you can tell which command was used by the cmd
- * parameter.
- */
- ret = match_records(hash, func, strlen(func), module);
- if (!ret)
- return -EINVAL;
- if (ret < 0)
- return ret;
- return 0;
- }
- static struct ftrace_func_command ftrace_mod_cmd = {
- .name = "mod",
- .func = ftrace_mod_callback,
- };
- static int __init ftrace_mod_cmd_init(void)
- {
- return register_ftrace_command(&ftrace_mod_cmd);
- }
- core_initcall(ftrace_mod_cmd_init);
- static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
- {
- struct ftrace_func_probe *entry;
- struct hlist_head *hhd;
- unsigned long key;
- key = hash_long(ip, FTRACE_HASH_BITS);
- hhd = &ftrace_func_hash[key];
- if (hlist_empty(hhd))
- return;
- /*
- * Disable preemption for these calls to prevent a RCU grace
- * period. This syncs the hash iteration and freeing of items
- * on the hash. rcu_read_lock is too dangerous here.
- */
- preempt_disable_notrace();
- hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
- if (entry->ip == ip)
- entry->ops->func(ip, parent_ip, &entry->data);
- }
- preempt_enable_notrace();
- }
- static struct ftrace_ops trace_probe_ops __read_mostly =
- {
- .func = function_trace_probe_call,
- .flags = FTRACE_OPS_FL_INITIALIZED,
- INIT_OPS_HASH(trace_probe_ops)
- };
- static int ftrace_probe_registered;
- static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)
- {
- int ret;
- int i;
- if (ftrace_probe_registered) {
- /* still need to update the function call sites */
- if (ftrace_enabled)
- ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
- old_hash);
- return;
- }
- for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
- struct hlist_head *hhd = &ftrace_func_hash[i];
- if (hhd->first)
- break;
- }
- /* Nothing registered? */
- if (i == FTRACE_FUNC_HASHSIZE)
- return;
- ret = ftrace_startup(&trace_probe_ops, 0);
- ftrace_probe_registered = 1;
- }
- static bool __disable_ftrace_function_probe(void)
- {
- int i;
- if (!ftrace_probe_registered)
- return false;
- for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
- struct hlist_head *hhd = &ftrace_func_hash[i];
- if (hhd->first)
- return false;
- }
- /* no more funcs left */
- ftrace_shutdown(&trace_probe_ops, 0);
- ftrace_probe_registered = 0;
- return true;
- }
- static void ftrace_free_entry(struct ftrace_func_probe *entry)
- {
- if (entry->ops->free)
- entry->ops->free(entry->ops, entry->ip, &entry->data);
- kfree(entry);
- }
- int
- register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
- void *data)
- {
- struct ftrace_ops_hash old_hash_ops;
- struct ftrace_func_probe *entry;
- struct ftrace_glob func_g;
- struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
- struct ftrace_hash *old_hash = *orig_hash;
- struct ftrace_hash *hash;
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- int not;
- unsigned long key;
- int count = 0;
- int ret;
- func_g.type = filter_parse_regex(glob, strlen(glob),
- &func_g.search, ¬);
- func_g.len = strlen(func_g.search);
- /* we do not support '!' for function probes */
- if (WARN_ON(not))
- return -EINVAL;
- mutex_lock(&trace_probe_ops.func_hash->regex_lock);
- old_hash_ops.filter_hash = old_hash;
- /* Probes only have filters */
- old_hash_ops.notrace_hash = NULL;
- hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
- if (!hash) {
- count = -ENOMEM;
- goto out;
- }
- if (unlikely(ftrace_disabled)) {
- count = -ENODEV;
- goto out;
- }
- mutex_lock(&ftrace_lock);
- do_for_each_ftrace_rec(pg, rec) {
- if (!ftrace_match_record(rec, &func_g, NULL, 0))
- continue;
- entry = kmalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry) {
- /* If we did not process any, then return error */
- if (!count)
- count = -ENOMEM;
- goto out_unlock;
- }
- count++;
- entry->data = data;
- /*
- * The caller might want to do something special
- * for each function we find. We call the callback
- * to give the caller an opportunity to do so.
- */
- if (ops->init) {
- if (ops->init(ops, rec->ip, &entry->data) < 0) {
- /* caller does not like this func */
- kfree(entry);
- continue;
- }
- }
- ret = enter_record(hash, rec, 0);
- if (ret < 0) {
- kfree(entry);
- count = ret;
- goto out_unlock;
- }
- entry->ops = ops;
- entry->ip = rec->ip;
- key = hash_long(entry->ip, FTRACE_HASH_BITS);
- hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
- } while_for_each_ftrace_rec();
- ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
- __enable_ftrace_function_probe(&old_hash_ops);
- if (!ret)
- free_ftrace_hash_rcu(old_hash);
- else
- count = ret;
- out_unlock:
- mutex_unlock(&ftrace_lock);
- out:
- mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
- free_ftrace_hash(hash);
- return count;
- }
- enum {
- PROBE_TEST_FUNC = 1,
- PROBE_TEST_DATA = 2
- };
- static void
- __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
- void *data, int flags)
- {
- struct ftrace_ops_hash old_hash_ops;
- struct ftrace_func_entry *rec_entry;
- struct ftrace_func_probe *entry;
- struct ftrace_func_probe *p;
- struct ftrace_glob func_g;
- struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
- struct ftrace_hash *old_hash = *orig_hash;
- struct list_head free_list;
- struct ftrace_hash *hash;
- struct hlist_node *tmp;
- char str[KSYM_SYMBOL_LEN];
- int i, ret;
- bool disabled;
- if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
- func_g.search = NULL;
- else if (glob) {
- int not;
- func_g.type = filter_parse_regex(glob, strlen(glob),
- &func_g.search, ¬);
- func_g.len = strlen(func_g.search);
- /* we do not support '!' for function probes */
- if (WARN_ON(not))
- return;
- }
- mutex_lock(&trace_probe_ops.func_hash->regex_lock);
- old_hash_ops.filter_hash = old_hash;
- /* Probes only have filters */
- old_hash_ops.notrace_hash = NULL;
- hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
- if (!hash)
- /* Hmm, should report this somehow */
- goto out_unlock;
- INIT_LIST_HEAD(&free_list);
- for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
- struct hlist_head *hhd = &ftrace_func_hash[i];
- hlist_for_each_entry_safe(entry, tmp, hhd, node) {
- /* break up if statements for readability */
- if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
- continue;
- if ((flags & PROBE_TEST_DATA) && entry->data != data)
- continue;
- /* do this last, since it is the most expensive */
- if (func_g.search) {
- kallsyms_lookup(entry->ip, NULL, NULL,
- NULL, str);
- if (!ftrace_match(str, &func_g))
- continue;
- }
- rec_entry = ftrace_lookup_ip(hash, entry->ip);
- /* It is possible more than one entry had this ip */
- if (rec_entry)
- free_hash_entry(hash, rec_entry);
- hlist_del_rcu(&entry->node);
- list_add(&entry->free_list, &free_list);
- }
- }
- mutex_lock(&ftrace_lock);
- disabled = __disable_ftrace_function_probe();
- /*
- * Remove after the disable is called. Otherwise, if the last
- * probe is removed, a null hash means *all enabled*.
- */
- ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
- /* still need to update the function call sites */
- if (ftrace_enabled && !disabled)
- ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
- &old_hash_ops);
- synchronize_sched();
- if (!ret)
- free_ftrace_hash_rcu(old_hash);
- list_for_each_entry_safe(entry, p, &free_list, free_list) {
- list_del(&entry->free_list);
- ftrace_free_entry(entry);
- }
- mutex_unlock(&ftrace_lock);
- out_unlock:
- mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
- free_ftrace_hash(hash);
- }
- void
- unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
- void *data)
- {
- __unregister_ftrace_function_probe(glob, ops, data,
- PROBE_TEST_FUNC | PROBE_TEST_DATA);
- }
- void
- unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
- {
- __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
- }
- void unregister_ftrace_function_probe_all(char *glob)
- {
- __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
- }
- static LIST_HEAD(ftrace_commands);
- static DEFINE_MUTEX(ftrace_cmd_mutex);
- /*
- * Currently we only register ftrace commands from __init, so mark this
- * __init too.
- */
- __init int register_ftrace_command(struct ftrace_func_command *cmd)
- {
- struct ftrace_func_command *p;
- int ret = 0;
- mutex_lock(&ftrace_cmd_mutex);
- list_for_each_entry(p, &ftrace_commands, list) {
- if (strcmp(cmd->name, p->name) == 0) {
- ret = -EBUSY;
- goto out_unlock;
- }
- }
- list_add(&cmd->list, &ftrace_commands);
- out_unlock:
- mutex_unlock(&ftrace_cmd_mutex);
- return ret;
- }
- /*
- * Currently we only unregister ftrace commands from __init, so mark
- * this __init too.
- */
- __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
- {
- struct ftrace_func_command *p, *n;
- int ret = -ENODEV;
- mutex_lock(&ftrace_cmd_mutex);
- list_for_each_entry_safe(p, n, &ftrace_commands, list) {
- if (strcmp(cmd->name, p->name) == 0) {
- ret = 0;
- list_del_init(&p->list);
- goto out_unlock;
- }
- }
- out_unlock:
- mutex_unlock(&ftrace_cmd_mutex);
- return ret;
- }
- static int ftrace_process_regex(struct ftrace_hash *hash,
- char *buff, int len, int enable)
- {
- char *func, *command, *next = buff;
- struct ftrace_func_command *p;
- int ret = -EINVAL;
- func = strsep(&next, ":");
- if (!next) {
- ret = ftrace_match_records(hash, func, len);
- if (!ret)
- ret = -EINVAL;
- if (ret < 0)
- return ret;
- return 0;
- }
- /* command found */
- command = strsep(&next, ":");
- mutex_lock(&ftrace_cmd_mutex);
- list_for_each_entry(p, &ftrace_commands, list) {
- if (strcmp(p->name, command) == 0) {
- ret = p->func(hash, func, command, next, enable);
- goto out_unlock;
- }
- }
- out_unlock:
- mutex_unlock(&ftrace_cmd_mutex);
- return ret;
- }
- static ssize_t
- ftrace_regex_write(struct file *file, const char __user *ubuf,
- size_t cnt, loff_t *ppos, int enable)
- {
- struct ftrace_iterator *iter;
- struct trace_parser *parser;
- ssize_t ret, read;
- if (!cnt)
- return 0;
- if (file->f_mode & FMODE_READ) {
- struct seq_file *m = file->private_data;
- iter = m->private;
- } else
- iter = file->private_data;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- /* iter->hash is a local copy, so we don't need regex_lock */
- parser = &iter->parser;
- read = trace_get_user(parser, ubuf, cnt, ppos);
- if (read >= 0 && trace_parser_loaded(parser) &&
- !trace_parser_cont(parser)) {
- ret = ftrace_process_regex(iter->hash, parser->buffer,
- parser->idx, enable);
- trace_parser_clear(parser);
- if (ret < 0)
- goto out;
- }
- ret = read;
- out:
- return ret;
- }
- ssize_t
- ftrace_filter_write(struct file *file, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
- }
- ssize_t
- ftrace_notrace_write(struct file *file, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
- }
- static int
- ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
- {
- struct ftrace_func_entry *entry;
- if (!ftrace_location(ip))
- return -EINVAL;
- if (remove) {
- entry = ftrace_lookup_ip(hash, ip);
- if (!entry)
- return -ENOENT;
- free_hash_entry(hash, entry);
- return 0;
- }
- return add_hash_entry(hash, ip);
- }
- static void ftrace_ops_update_code(struct ftrace_ops *ops,
- struct ftrace_ops_hash *old_hash)
- {
- struct ftrace_ops *op;
- if (!ftrace_enabled)
- return;
- if (ops->flags & FTRACE_OPS_FL_ENABLED) {
- ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
- return;
- }
- /*
- * If this is the shared global_ops filter, then we need to
- * check if there is another ops that shares it, is enabled.
- * If so, we still need to run the modify code.
- */
- if (ops->func_hash != &global_ops.local_hash)
- return;
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (op->func_hash == &global_ops.local_hash &&
- op->flags & FTRACE_OPS_FL_ENABLED) {
- ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
- /* Only need to do this once */
- return;
- }
- } while_for_each_ftrace_op(op);
- }
- static int
- ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
- unsigned long ip, int remove, int reset, int enable)
- {
- struct ftrace_hash **orig_hash;
- struct ftrace_ops_hash old_hash_ops;
- struct ftrace_hash *old_hash;
- struct ftrace_hash *hash;
- int ret;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- mutex_lock(&ops->func_hash->regex_lock);
- if (enable)
- orig_hash = &ops->func_hash->filter_hash;
- else
- orig_hash = &ops->func_hash->notrace_hash;
- if (reset)
- hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
- else
- hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
- if (!hash) {
- ret = -ENOMEM;
- goto out_regex_unlock;
- }
- if (buf && !ftrace_match_records(hash, buf, len)) {
- ret = -EINVAL;
- goto out_regex_unlock;
- }
- if (ip) {
- ret = ftrace_match_addr(hash, ip, remove);
- if (ret < 0)
- goto out_regex_unlock;
- }
- mutex_lock(&ftrace_lock);
- old_hash = *orig_hash;
- old_hash_ops.filter_hash = ops->func_hash->filter_hash;
- old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
- ret = ftrace_hash_move(ops, enable, orig_hash, hash);
- if (!ret) {
- ftrace_ops_update_code(ops, &old_hash_ops);
- free_ftrace_hash_rcu(old_hash);
- }
- mutex_unlock(&ftrace_lock);
- out_regex_unlock:
- mutex_unlock(&ops->func_hash->regex_lock);
- free_ftrace_hash(hash);
- return ret;
- }
- static int
- ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
- int reset, int enable)
- {
- return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
- }
- /**
- * ftrace_set_filter_ip - set a function to filter on in ftrace by address
- * @ops - the ops to set the filter with
- * @ip - the address to add to or remove from the filter.
- * @remove - non zero to remove the ip from the filter
- * @reset - non zero to reset all filters before applying this filter.
- *
- * Filters denote which functions should be enabled when tracing is enabled
- * If @ip is NULL, it failes to update filter.
- */
- int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
- int remove, int reset)
- {
- ftrace_ops_init(ops);
- return ftrace_set_addr(ops, ip, remove, reset, 1);
- }
- EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
- static int
- ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
- int reset, int enable)
- {
- return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
- }
- /**
- * ftrace_set_filter - set a function to filter on in ftrace
- * @ops - the ops to set the filter with
- * @buf - the string that holds the function filter text.
- * @len - the length of the string.
- * @reset - non zero to reset all filters before applying this filter.
- *
- * Filters denote which functions should be enabled when tracing is enabled.
- * If @buf is NULL and reset is set, all functions will be enabled for tracing.
- */
- int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
- int len, int reset)
- {
- ftrace_ops_init(ops);
- return ftrace_set_regex(ops, buf, len, reset, 1);
- }
- EXPORT_SYMBOL_GPL(ftrace_set_filter);
- /**
- * ftrace_set_notrace - set a function to not trace in ftrace
- * @ops - the ops to set the notrace filter with
- * @buf - the string that holds the function notrace text.
- * @len - the length of the string.
- * @reset - non zero to reset all filters before applying this filter.
- *
- * Notrace Filters denote which functions should not be enabled when tracing
- * is enabled. If @buf is NULL and reset is set, all functions will be enabled
- * for tracing.
- */
- int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
- int len, int reset)
- {
- ftrace_ops_init(ops);
- return ftrace_set_regex(ops, buf, len, reset, 0);
- }
- EXPORT_SYMBOL_GPL(ftrace_set_notrace);
- /**
- * ftrace_set_global_filter - set a function to filter on with global tracers
- * @buf - the string that holds the function filter text.
- * @len - the length of the string.
- * @reset - non zero to reset all filters before applying this filter.
- *
- * Filters denote which functions should be enabled when tracing is enabled.
- * If @buf is NULL and reset is set, all functions will be enabled for tracing.
- */
- void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
- {
- ftrace_set_regex(&global_ops, buf, len, reset, 1);
- }
- EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
- /**
- * ftrace_set_global_notrace - set a function to not trace with global tracers
- * @buf - the string that holds the function notrace text.
- * @len - the length of the string.
- * @reset - non zero to reset all filters before applying this filter.
- *
- * Notrace Filters denote which functions should not be enabled when tracing
- * is enabled. If @buf is NULL and reset is set, all functions will be enabled
- * for tracing.
- */
- void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
- {
- ftrace_set_regex(&global_ops, buf, len, reset, 0);
- }
- EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
- /*
- * command line interface to allow users to set filters on boot up.
- */
- #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
- static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
- static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
- /* Used by function selftest to not test if filter is set */
- bool ftrace_filter_param __initdata;
- static int __init set_ftrace_notrace(char *str)
- {
- ftrace_filter_param = true;
- strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
- return 1;
- }
- __setup("ftrace_notrace=", set_ftrace_notrace);
- static int __init set_ftrace_filter(char *str)
- {
- ftrace_filter_param = true;
- strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
- return 1;
- }
- __setup("ftrace_filter=", set_ftrace_filter);
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
- static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
- static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
- static int __init set_graph_function(char *str)
- {
- strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
- return 1;
- }
- __setup("ftrace_graph_filter=", set_graph_function);
- static int __init set_graph_notrace_function(char *str)
- {
- strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
- return 1;
- }
- __setup("ftrace_graph_notrace=", set_graph_notrace_function);
- static void __init set_ftrace_early_graph(char *buf, int enable)
- {
- int ret;
- char *func;
- unsigned long *table = ftrace_graph_funcs;
- int *count = &ftrace_graph_count;
- if (!enable) {
- table = ftrace_graph_notrace_funcs;
- count = &ftrace_graph_notrace_count;
- }
- while (buf) {
- func = strsep(&buf, ",");
- /* we allow only one expression at a time */
- ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
- if (ret)
- printk(KERN_DEBUG "ftrace: function %s not "
- "traceable\n", func);
- }
- }
- #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
- void __init
- ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
- {
- char *func;
- ftrace_ops_init(ops);
- while (buf) {
- func = strsep(&buf, ",");
- ftrace_set_regex(ops, func, strlen(func), 0, enable);
- }
- }
- static void __init set_ftrace_early_filters(void)
- {
- if (ftrace_filter_buf[0])
- ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
- if (ftrace_notrace_buf[0])
- ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- if (ftrace_graph_buf[0])
- set_ftrace_early_graph(ftrace_graph_buf, 1);
- if (ftrace_graph_notrace_buf[0])
- set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
- #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
- }
- int ftrace_regex_release(struct inode *inode, struct file *file)
- {
- struct seq_file *m = (struct seq_file *)file->private_data;
- struct ftrace_ops_hash old_hash_ops;
- struct ftrace_iterator *iter;
- struct ftrace_hash **orig_hash;
- struct ftrace_hash *old_hash;
- struct trace_parser *parser;
- int filter_hash;
- int ret;
- if (file->f_mode & FMODE_READ) {
- iter = m->private;
- seq_release(inode, file);
- } else
- iter = file->private_data;
- parser = &iter->parser;
- if (trace_parser_loaded(parser)) {
- parser->buffer[parser->idx] = 0;
- ftrace_match_records(iter->hash, parser->buffer, parser->idx);
- }
- trace_parser_put(parser);
- mutex_lock(&iter->ops->func_hash->regex_lock);
- if (file->f_mode & FMODE_WRITE) {
- filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
- if (filter_hash)
- orig_hash = &iter->ops->func_hash->filter_hash;
- else
- orig_hash = &iter->ops->func_hash->notrace_hash;
- mutex_lock(&ftrace_lock);
- old_hash = *orig_hash;
- old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash;
- old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash;
- ret = ftrace_hash_move(iter->ops, filter_hash,
- orig_hash, iter->hash);
- if (!ret) {
- ftrace_ops_update_code(iter->ops, &old_hash_ops);
- free_ftrace_hash_rcu(old_hash);
- }
- mutex_unlock(&ftrace_lock);
- }
- mutex_unlock(&iter->ops->func_hash->regex_lock);
- free_ftrace_hash(iter->hash);
- kfree(iter);
- return 0;
- }
- static const struct file_operations ftrace_avail_fops = {
- .open = ftrace_avail_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release_private,
- };
- static const struct file_operations ftrace_enabled_fops = {
- .open = ftrace_enabled_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release_private,
- };
- static const struct file_operations ftrace_filter_fops = {
- .open = ftrace_filter_open,
- .read = seq_read,
- .write = ftrace_filter_write,
- .llseek = tracing_lseek,
- .release = ftrace_regex_release,
- };
- static const struct file_operations ftrace_notrace_fops = {
- .open = ftrace_notrace_open,
- .read = seq_read,
- .write = ftrace_notrace_write,
- .llseek = tracing_lseek,
- .release = ftrace_regex_release,
- };
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static DEFINE_MUTEX(graph_lock);
- int ftrace_graph_count;
- int ftrace_graph_notrace_count;
- unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
- unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
- struct ftrace_graph_data {
- unsigned long *table;
- size_t size;
- int *count;
- const struct seq_operations *seq_ops;
- };
- static void *
- __g_next(struct seq_file *m, loff_t *pos)
- {
- struct ftrace_graph_data *fgd = m->private;
- if (*pos >= *fgd->count)
- return NULL;
- return &fgd->table[*pos];
- }
- static void *
- g_next(struct seq_file *m, void *v, loff_t *pos)
- {
- (*pos)++;
- return __g_next(m, pos);
- }
- static void *g_start(struct seq_file *m, loff_t *pos)
- {
- struct ftrace_graph_data *fgd = m->private;
- mutex_lock(&graph_lock);
- /* Nothing, tell g_show to print all functions are enabled */
- if (!*fgd->count && !*pos)
- return (void *)1;
- return __g_next(m, pos);
- }
- static void g_stop(struct seq_file *m, void *p)
- {
- mutex_unlock(&graph_lock);
- }
- static int g_show(struct seq_file *m, void *v)
- {
- unsigned long *ptr = v;
- if (!ptr)
- return 0;
- if (ptr == (unsigned long *)1) {
- struct ftrace_graph_data *fgd = m->private;
- if (fgd->table == ftrace_graph_funcs)
- seq_puts(m, "#### all functions enabled ####\n");
- else
- seq_puts(m, "#### no functions disabled ####\n");
- return 0;
- }
- seq_printf(m, "%ps\n", (void *)*ptr);
- return 0;
- }
- static const struct seq_operations ftrace_graph_seq_ops = {
- .start = g_start,
- .next = g_next,
- .stop = g_stop,
- .show = g_show,
- };
- static int
- __ftrace_graph_open(struct inode *inode, struct file *file,
- struct ftrace_graph_data *fgd)
- {
- int ret = 0;
- mutex_lock(&graph_lock);
- if ((file->f_mode & FMODE_WRITE) &&
- (file->f_flags & O_TRUNC)) {
- *fgd->count = 0;
- memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
- }
- mutex_unlock(&graph_lock);
- if (file->f_mode & FMODE_READ) {
- ret = seq_open(file, fgd->seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = fgd;
- }
- } else
- file->private_data = fgd;
- return ret;
- }
- static int
- ftrace_graph_open(struct inode *inode, struct file *file)
- {
- struct ftrace_graph_data *fgd;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
- if (fgd == NULL)
- return -ENOMEM;
- fgd->table = ftrace_graph_funcs;
- fgd->size = FTRACE_GRAPH_MAX_FUNCS;
- fgd->count = &ftrace_graph_count;
- fgd->seq_ops = &ftrace_graph_seq_ops;
- return __ftrace_graph_open(inode, file, fgd);
- }
- static int
- ftrace_graph_notrace_open(struct inode *inode, struct file *file)
- {
- struct ftrace_graph_data *fgd;
- if (unlikely(ftrace_disabled))
- return -ENODEV;
- fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
- if (fgd == NULL)
- return -ENOMEM;
- fgd->table = ftrace_graph_notrace_funcs;
- fgd->size = FTRACE_GRAPH_MAX_FUNCS;
- fgd->count = &ftrace_graph_notrace_count;
- fgd->seq_ops = &ftrace_graph_seq_ops;
- return __ftrace_graph_open(inode, file, fgd);
- }
- static int
- ftrace_graph_release(struct inode *inode, struct file *file)
- {
- if (file->f_mode & FMODE_READ) {
- struct seq_file *m = file->private_data;
- kfree(m->private);
- seq_release(inode, file);
- } else {
- kfree(file->private_data);
- }
- return 0;
- }
- static int
- ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
- {
- struct ftrace_glob func_g;
- struct dyn_ftrace *rec;
- struct ftrace_page *pg;
- int fail = 1;
- int not;
- bool exists;
- int i;
- /* decode regex */
- func_g.type = filter_parse_regex(buffer, strlen(buffer),
- &func_g.search, ¬);
- if (!not && *idx >= size)
- return -EBUSY;
- func_g.len = strlen(func_g.search);
- mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled)) {
- mutex_unlock(&ftrace_lock);
- return -ENODEV;
- }
- do_for_each_ftrace_rec(pg, rec) {
- if (ftrace_match_record(rec, &func_g, NULL, 0)) {
- /* if it is in the array */
- exists = false;
- for (i = 0; i < *idx; i++) {
- if (array[i] == rec->ip) {
- exists = true;
- break;
- }
- }
- if (!not) {
- fail = 0;
- if (!exists) {
- array[(*idx)++] = rec->ip;
- if (*idx >= size)
- goto out;
- }
- } else {
- if (exists) {
- array[i] = array[--(*idx)];
- array[*idx] = 0;
- fail = 0;
- }
- }
- }
- } while_for_each_ftrace_rec();
- out:
- mutex_unlock(&ftrace_lock);
- if (fail)
- return -EINVAL;
- return 0;
- }
- static ssize_t
- ftrace_graph_write(struct file *file, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- struct trace_parser parser;
- ssize_t read, ret = 0;
- struct ftrace_graph_data *fgd = file->private_data;
- if (!cnt)
- return 0;
- if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
- return -ENOMEM;
- read = trace_get_user(&parser, ubuf, cnt, ppos);
- if (read >= 0 && trace_parser_loaded((&parser))) {
- parser.buffer[parser.idx] = 0;
- mutex_lock(&graph_lock);
- /* we allow only one expression at a time */
- ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
- parser.buffer);
- mutex_unlock(&graph_lock);
- }
- if (!ret)
- ret = read;
- trace_parser_put(&parser);
- return ret;
- }
- static const struct file_operations ftrace_graph_fops = {
- .open = ftrace_graph_open,
- .read = seq_read,
- .write = ftrace_graph_write,
- .llseek = tracing_lseek,
- .release = ftrace_graph_release,
- };
- static const struct file_operations ftrace_graph_notrace_fops = {
- .open = ftrace_graph_notrace_open,
- .read = seq_read,
- .write = ftrace_graph_write,
- .llseek = tracing_lseek,
- .release = ftrace_graph_release,
- };
- #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
- void ftrace_create_filter_files(struct ftrace_ops *ops,
- struct dentry *parent)
- {
- trace_create_file("set_ftrace_filter", 0644, parent,
- ops, &ftrace_filter_fops);
- trace_create_file("set_ftrace_notrace", 0644, parent,
- ops, &ftrace_notrace_fops);
- }
- /*
- * The name "destroy_filter_files" is really a misnomer. Although
- * in the future, it may actualy delete the files, but this is
- * really intended to make sure the ops passed in are disabled
- * and that when this function returns, the caller is free to
- * free the ops.
- *
- * The "destroy" name is only to match the "create" name that this
- * should be paired with.
- */
- void ftrace_destroy_filter_files(struct ftrace_ops *ops)
- {
- mutex_lock(&ftrace_lock);
- if (ops->flags & FTRACE_OPS_FL_ENABLED)
- ftrace_shutdown(ops, 0);
- ops->flags |= FTRACE_OPS_FL_DELETED;
- ftrace_free_filter(ops);
- mutex_unlock(&ftrace_lock);
- }
- static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
- {
- trace_create_file("available_filter_functions", 0444,
- d_tracer, NULL, &ftrace_avail_fops);
- trace_create_file("enabled_functions", 0444,
- d_tracer, NULL, &ftrace_enabled_fops);
- ftrace_create_filter_files(&global_ops, d_tracer);
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- trace_create_file("set_graph_function", 0444, d_tracer,
- NULL,
- &ftrace_graph_fops);
- trace_create_file("set_graph_notrace", 0444, d_tracer,
- NULL,
- &ftrace_graph_notrace_fops);
- #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
- return 0;
- }
- static int ftrace_cmp_ips(const void *a, const void *b)
- {
- const unsigned long *ipa = a;
- const unsigned long *ipb = b;
- if (*ipa > *ipb)
- return 1;
- if (*ipa < *ipb)
- return -1;
- return 0;
- }
- static int ftrace_process_locs(struct module *mod,
- unsigned long *start,
- unsigned long *end)
- {
- struct ftrace_page *start_pg;
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- unsigned long count;
- unsigned long *p;
- unsigned long addr;
- unsigned long flags = 0; /* Shut up gcc */
- int ret = -ENOMEM;
- count = end - start;
- if (!count)
- return 0;
- sort(start, count, sizeof(*start),
- ftrace_cmp_ips, NULL);
- start_pg = ftrace_allocate_pages(count);
- if (!start_pg)
- return -ENOMEM;
- mutex_lock(&ftrace_lock);
- /*
- * Core and each module needs their own pages, as
- * modules will free them when they are removed.
- * Force a new page to be allocated for modules.
- */
- if (!mod) {
- WARN_ON(ftrace_pages || ftrace_pages_start);
- /* First initialization */
- ftrace_pages = ftrace_pages_start = start_pg;
- } else {
- if (!ftrace_pages)
- goto out;
- if (WARN_ON(ftrace_pages->next)) {
- /* Hmm, we have free pages? */
- while (ftrace_pages->next)
- ftrace_pages = ftrace_pages->next;
- }
- ftrace_pages->next = start_pg;
- }
- p = start;
- pg = start_pg;
- while (p < end) {
- addr = ftrace_call_adjust(*p++);
- /*
- * Some architecture linkers will pad between
- * the different mcount_loc sections of different
- * object files to satisfy alignments.
- * Skip any NULL pointers.
- */
- if (!addr)
- continue;
- if (pg->index == pg->size) {
- /* We should have allocated enough */
- if (WARN_ON(!pg->next))
- break;
- pg = pg->next;
- }
- rec = &pg->records[pg->index++];
- rec->ip = addr;
- }
- /* We should have used all pages */
- WARN_ON(pg->next);
- /* Assign the last page to ftrace_pages */
- ftrace_pages = pg;
- /*
- * We only need to disable interrupts on start up
- * because we are modifying code that an interrupt
- * may execute, and the modification is not atomic.
- * But for modules, nothing runs the code we modify
- * until we are finished with it, and there's no
- * reason to cause large interrupt latencies while we do it.
- */
- if (!mod)
- local_irq_save(flags);
- ftrace_update_code(mod, start_pg);
- if (!mod)
- local_irq_restore(flags);
- ret = 0;
- out:
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- #ifdef CONFIG_MODULES
- #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
- void ftrace_release_mod(struct module *mod)
- {
- struct dyn_ftrace *rec;
- struct ftrace_page **last_pg;
- struct ftrace_page *pg;
- int order;
- mutex_lock(&ftrace_lock);
- if (ftrace_disabled)
- goto out_unlock;
- /*
- * Each module has its own ftrace_pages, remove
- * them from the list.
- */
- last_pg = &ftrace_pages_start;
- for (pg = ftrace_pages_start; pg; pg = *last_pg) {
- rec = &pg->records[0];
- if (within_module_core(rec->ip, mod)) {
- /*
- * As core pages are first, the first
- * page should never be a module page.
- */
- if (WARN_ON(pg == ftrace_pages_start))
- goto out_unlock;
- /* Check if we are deleting the last page */
- if (pg == ftrace_pages)
- ftrace_pages = next_to_ftrace_page(last_pg);
- *last_pg = pg->next;
- order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
- kfree(pg);
- } else
- last_pg = &pg->next;
- }
- out_unlock:
- mutex_unlock(&ftrace_lock);
- }
- static void ftrace_init_module(struct module *mod,
- unsigned long *start, unsigned long *end)
- {
- if (ftrace_disabled || start == end)
- return;
- ftrace_process_locs(mod, start, end);
- }
- void ftrace_module_init(struct module *mod)
- {
- ftrace_init_module(mod, mod->ftrace_callsites,
- mod->ftrace_callsites +
- mod->num_ftrace_callsites);
- }
- static int ftrace_module_notify_exit(struct notifier_block *self,
- unsigned long val, void *data)
- {
- struct module *mod = data;
- if (val == MODULE_STATE_GOING)
- ftrace_release_mod(mod);
- return 0;
- }
- #else
- static int ftrace_module_notify_exit(struct notifier_block *self,
- unsigned long val, void *data)
- {
- return 0;
- }
- #endif /* CONFIG_MODULES */
- struct notifier_block ftrace_module_exit_nb = {
- .notifier_call = ftrace_module_notify_exit,
- .priority = INT_MIN, /* Run after anything that can remove kprobes */
- };
- void __init ftrace_init(void)
- {
- extern unsigned long __start_mcount_loc[];
- extern unsigned long __stop_mcount_loc[];
- unsigned long count, flags;
- int ret;
- local_irq_save(flags);
- ret = ftrace_dyn_arch_init();
- local_irq_restore(flags);
- if (ret)
- goto failed;
- count = __stop_mcount_loc - __start_mcount_loc;
- if (!count) {
- pr_info("ftrace: No functions to be traced?\n");
- goto failed;
- }
- pr_info("ftrace: allocating %ld entries in %ld pages\n",
- count, count / ENTRIES_PER_PAGE + 1);
- last_ftrace_enabled = ftrace_enabled = 1;
- ret = ftrace_process_locs(NULL,
- __start_mcount_loc,
- __stop_mcount_loc);
- ret = register_module_notifier(&ftrace_module_exit_nb);
- if (ret)
- pr_warning("Failed to register trace ftrace module exit notifier\n");
- set_ftrace_early_filters();
- return;
- failed:
- ftrace_disabled = 1;
- }
- /* Do nothing if arch does not support this */
- void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
- {
- }
- static void ftrace_update_trampoline(struct ftrace_ops *ops)
- {
- /*
- * Currently there's no safe way to free a trampoline when the kernel
- * is configured with PREEMPT. That is because a task could be preempted
- * when it jumped to the trampoline, it may be preempted for a long time
- * depending on the system load, and currently there's no way to know
- * when it will be off the trampoline. If the trampoline is freed
- * too early, when the task runs again, it will be executing on freed
- * memory and crash.
- */
- #ifdef CONFIG_PREEMPT
- /* Currently, only non dynamic ops can have a trampoline */
- if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
- return;
- #endif
- arch_ftrace_update_trampoline(ops);
- }
- #else
- static struct ftrace_ops global_ops = {
- .func = ftrace_stub,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE |
- FTRACE_OPS_FL_INITIALIZED |
- FTRACE_OPS_FL_PID,
- };
- static int __init ftrace_nodyn_init(void)
- {
- ftrace_enabled = 1;
- return 0;
- }
- core_initcall(ftrace_nodyn_init);
- static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
- static inline void ftrace_startup_enable(int command) { }
- static inline void ftrace_startup_all(int command) { }
- /* Keep as macros so we do not need to define the commands */
- # define ftrace_startup(ops, command) \
- ({ \
- int ___ret = __register_ftrace_function(ops); \
- if (!___ret) \
- (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
- ___ret; \
- })
- # define ftrace_shutdown(ops, command) \
- ({ \
- int ___ret = __unregister_ftrace_function(ops); \
- if (!___ret) \
- (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
- ___ret; \
- })
- # define ftrace_startup_sysctl() do { } while (0)
- # define ftrace_shutdown_sysctl() do { } while (0)
- static inline int
- ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
- {
- return 1;
- }
- static void ftrace_update_trampoline(struct ftrace_ops *ops)
- {
- }
- #endif /* CONFIG_DYNAMIC_FTRACE */
- __init void ftrace_init_global_array_ops(struct trace_array *tr)
- {
- tr->ops = &global_ops;
- tr->ops->private = tr;
- }
- void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
- {
- /* If we filter on pids, update to use the pid function */
- if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
- if (WARN_ON(tr->ops->func != ftrace_stub))
- printk("ftrace ops had %pS for function\n",
- tr->ops->func);
- }
- tr->ops->func = func;
- tr->ops->private = tr;
- }
- void ftrace_reset_array_ops(struct trace_array *tr)
- {
- tr->ops->func = ftrace_stub;
- }
- static void
- ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
- {
- if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
- return;
- /*
- * Some of the ops may be dynamically allocated,
- * they must be freed after a synchronize_sched().
- */
- preempt_disable_notrace();
- trace_recursion_set(TRACE_CONTROL_BIT);
- /*
- * Control funcs (perf) uses RCU. Only trace if
- * RCU is currently active.
- */
- if (!rcu_is_watching())
- goto out;
- do_for_each_ftrace_op(op, ftrace_control_list) {
- if (!(op->flags & FTRACE_OPS_FL_STUB) &&
- !ftrace_function_local_disabled(op) &&
- ftrace_ops_test(op, ip, regs))
- op->func(ip, parent_ip, op, regs);
- } while_for_each_ftrace_op(op);
- out:
- trace_recursion_clear(TRACE_CONTROL_BIT);
- preempt_enable_notrace();
- }
- static struct ftrace_ops control_ops = {
- .func = ftrace_ops_control_func,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
- INIT_OPS_HASH(control_ops)
- };
- static nokprobe_inline void
- __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ignored, struct pt_regs *regs)
- {
- struct ftrace_ops *op;
- int bit;
- bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
- if (bit < 0)
- return;
- /*
- * Some of the ops may be dynamically allocated,
- * they must be freed after a synchronize_sched().
- */
- preempt_disable_notrace();
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (ftrace_ops_test(op, ip, regs)) {
- if (FTRACE_WARN_ON(!op->func)) {
- pr_warn("op=%p %pS\n", op, op);
- goto out;
- }
- op->func(ip, parent_ip, op, regs);
- }
- } while_for_each_ftrace_op(op);
- out:
- preempt_enable_notrace();
- trace_clear_recursion(bit);
- }
- /*
- * Some archs only support passing ip and parent_ip. Even though
- * the list function ignores the op parameter, we do not want any
- * C side effects, where a function is called without the caller
- * sending a third parameter.
- * Archs are to support both the regs and ftrace_ops at the same time.
- * If they support ftrace_ops, it is assumed they support regs.
- * If call backs want to use regs, they must either check for regs
- * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
- * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
- * An architecture can pass partial regs with ftrace_ops and still
- * set the ARCH_SUPPORT_FTARCE_OPS.
- */
- #if ARCH_SUPPORTS_FTRACE_OPS
- static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
- {
- __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
- }
- NOKPROBE_SYMBOL(ftrace_ops_list_func);
- #else
- static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
- {
- __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
- }
- NOKPROBE_SYMBOL(ftrace_ops_no_ops);
- #endif
- /*
- * If there's only one function registered but it does not support
- * recursion, this function will be called by the mcount trampoline.
- * This function will handle recursion protection.
- */
- static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
- {
- int bit;
- bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
- if (bit < 0)
- return;
- op->func(ip, parent_ip, op, regs);
- trace_clear_recursion(bit);
- }
- NOKPROBE_SYMBOL(ftrace_ops_recurs_func);
- /**
- * ftrace_ops_get_func - get the function a trampoline should call
- * @ops: the ops to get the function for
- *
- * Normally the mcount trampoline will call the ops->func, but there
- * are times that it should not. For example, if the ops does not
- * have its own recursion protection, then it should call the
- * ftrace_ops_recurs_func() instead.
- *
- * Returns the function that the trampoline should call for @ops.
- */
- ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
- {
- /*
- * If the func handles its own recursion, call it directly.
- * Otherwise call the recursion protected function that
- * will call the ftrace ops function.
- */
- if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE))
- return ftrace_ops_recurs_func;
- return ops->func;
- }
- static void clear_ftrace_swapper(void)
- {
- struct task_struct *p;
- int cpu;
- get_online_cpus();
- for_each_online_cpu(cpu) {
- p = idle_task(cpu);
- clear_tsk_trace_trace(p);
- }
- put_online_cpus();
- }
- static void set_ftrace_swapper(void)
- {
- struct task_struct *p;
- int cpu;
- get_online_cpus();
- for_each_online_cpu(cpu) {
- p = idle_task(cpu);
- set_tsk_trace_trace(p);
- }
- put_online_cpus();
- }
- static void clear_ftrace_pid(struct pid *pid)
- {
- struct task_struct *p;
- rcu_read_lock();
- do_each_pid_task(pid, PIDTYPE_PID, p) {
- clear_tsk_trace_trace(p);
- } while_each_pid_task(pid, PIDTYPE_PID, p);
- rcu_read_unlock();
- put_pid(pid);
- }
- static void set_ftrace_pid(struct pid *pid)
- {
- struct task_struct *p;
- rcu_read_lock();
- do_each_pid_task(pid, PIDTYPE_PID, p) {
- set_tsk_trace_trace(p);
- } while_each_pid_task(pid, PIDTYPE_PID, p);
- rcu_read_unlock();
- }
- static void clear_ftrace_pid_task(struct pid *pid)
- {
- if (pid == ftrace_swapper_pid)
- clear_ftrace_swapper();
- else
- clear_ftrace_pid(pid);
- }
- static void set_ftrace_pid_task(struct pid *pid)
- {
- if (pid == ftrace_swapper_pid)
- set_ftrace_swapper();
- else
- set_ftrace_pid(pid);
- }
- static int ftrace_pid_add(int p)
- {
- struct pid *pid;
- struct ftrace_pid *fpid;
- int ret = -EINVAL;
- mutex_lock(&ftrace_lock);
- if (!p)
- pid = ftrace_swapper_pid;
- else
- pid = find_get_pid(p);
- if (!pid)
- goto out;
- ret = 0;
- list_for_each_entry(fpid, &ftrace_pids, list)
- if (fpid->pid == pid)
- goto out_put;
- ret = -ENOMEM;
- fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
- if (!fpid)
- goto out_put;
- list_add(&fpid->list, &ftrace_pids);
- fpid->pid = pid;
- set_ftrace_pid_task(pid);
- ftrace_update_pid_func();
- ftrace_startup_all(0);
- mutex_unlock(&ftrace_lock);
- return 0;
- out_put:
- if (pid != ftrace_swapper_pid)
- put_pid(pid);
- out:
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- static void ftrace_pid_reset(void)
- {
- struct ftrace_pid *fpid, *safe;
- mutex_lock(&ftrace_lock);
- list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
- struct pid *pid = fpid->pid;
- clear_ftrace_pid_task(pid);
- list_del(&fpid->list);
- kfree(fpid);
- }
- ftrace_update_pid_func();
- ftrace_startup_all(0);
- mutex_unlock(&ftrace_lock);
- }
- static void *fpid_start(struct seq_file *m, loff_t *pos)
- {
- mutex_lock(&ftrace_lock);
- if (!ftrace_pids_enabled() && (!*pos))
- return (void *) 1;
- return seq_list_start(&ftrace_pids, *pos);
- }
- static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
- {
- if (v == (void *)1)
- return NULL;
- return seq_list_next(v, &ftrace_pids, pos);
- }
- static void fpid_stop(struct seq_file *m, void *p)
- {
- mutex_unlock(&ftrace_lock);
- }
- static int fpid_show(struct seq_file *m, void *v)
- {
- const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
- if (v == (void *)1) {
- seq_puts(m, "no pid\n");
- return 0;
- }
- if (fpid->pid == ftrace_swapper_pid)
- seq_puts(m, "swapper tasks\n");
- else
- seq_printf(m, "%u\n", pid_vnr(fpid->pid));
- return 0;
- }
- static const struct seq_operations ftrace_pid_sops = {
- .start = fpid_start,
- .next = fpid_next,
- .stop = fpid_stop,
- .show = fpid_show,
- };
- static int
- ftrace_pid_open(struct inode *inode, struct file *file)
- {
- int ret = 0;
- if ((file->f_mode & FMODE_WRITE) &&
- (file->f_flags & O_TRUNC))
- ftrace_pid_reset();
- if (file->f_mode & FMODE_READ)
- ret = seq_open(file, &ftrace_pid_sops);
- return ret;
- }
- static ssize_t
- ftrace_pid_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
- {
- char buf[64], *tmp;
- long val;
- int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
- buf[cnt] = 0;
- /*
- * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
- * to clean the filter quietly.
- */
- tmp = strstrip(buf);
- if (strlen(tmp) == 0)
- return 1;
- ret = kstrtol(tmp, 10, &val);
- if (ret < 0)
- return ret;
- ret = ftrace_pid_add(val);
- return ret ? ret : cnt;
- }
- static int
- ftrace_pid_release(struct inode *inode, struct file *file)
- {
- if (file->f_mode & FMODE_READ)
- seq_release(inode, file);
- return 0;
- }
- static const struct file_operations ftrace_pid_fops = {
- .open = ftrace_pid_open,
- .write = ftrace_pid_write,
- .read = seq_read,
- .llseek = tracing_lseek,
- .release = ftrace_pid_release,
- };
- static __init int ftrace_init_tracefs(void)
- {
- struct dentry *d_tracer;
- d_tracer = tracing_init_dentry();
- if (IS_ERR(d_tracer))
- return 0;
- ftrace_init_dyn_tracefs(d_tracer);
- trace_create_file("set_ftrace_pid", 0644, d_tracer,
- NULL, &ftrace_pid_fops);
- ftrace_profile_tracefs(d_tracer);
- return 0;
- }
- fs_initcall(ftrace_init_tracefs);
- /**
- * ftrace_kill - kill ftrace
- *
- * This function should be used by panic code. It stops ftrace
- * but in a not so nice way. If you need to simply kill ftrace
- * from a non-atomic section, use ftrace_kill.
- */
- void ftrace_kill(void)
- {
- ftrace_disabled = 1;
- ftrace_enabled = 0;
- clear_ftrace_function();
- }
- /**
- * Test if ftrace is dead or not.
- */
- int ftrace_is_dead(void)
- {
- return ftrace_disabled;
- }
- /**
- * register_ftrace_function - register a function for profiling
- * @ops - ops structure that holds the function for profiling.
- *
- * Register a function to be called by all functions in the
- * kernel.
- *
- * Note: @ops->func and all the functions it calls must be labeled
- * with "notrace", otherwise it will go into a
- * recursive loop.
- */
- int register_ftrace_function(struct ftrace_ops *ops)
- {
- int ret = -1;
- ftrace_ops_init(ops);
- mutex_lock(&ftrace_lock);
- ret = ftrace_startup(ops, 0);
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- EXPORT_SYMBOL_GPL(register_ftrace_function);
- /**
- * unregister_ftrace_function - unregister a function for profiling.
- * @ops - ops structure that holds the function to unregister
- *
- * Unregister a function that was added to be called by ftrace profiling.
- */
- int unregister_ftrace_function(struct ftrace_ops *ops)
- {
- int ret;
- mutex_lock(&ftrace_lock);
- ret = ftrace_shutdown(ops, 0);
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- EXPORT_SYMBOL_GPL(unregister_ftrace_function);
- int
- ftrace_enable_sysctl(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
- {
- int ret = -ENODEV;
- mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
- goto out;
- ret = proc_dointvec(table, write, buffer, lenp, ppos);
- if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
- goto out;
- last_ftrace_enabled = !!ftrace_enabled;
- if (ftrace_enabled) {
- /* we are starting ftrace again */
- if (ftrace_ops_list != &ftrace_list_end)
- update_ftrace_function();
- ftrace_startup_sysctl();
- } else {
- /* stopping ftrace calls (just send to ftrace_stub) */
- ftrace_trace_function = ftrace_stub;
- ftrace_shutdown_sysctl();
- }
- out:
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- #ifdef CONFIG_FUNCTION_GRAPH_TRACER
- static struct ftrace_ops graph_ops = {
- .func = ftrace_stub,
- .flags = FTRACE_OPS_FL_RECURSION_SAFE |
- FTRACE_OPS_FL_INITIALIZED |
- FTRACE_OPS_FL_PID |
- FTRACE_OPS_FL_STUB,
- #ifdef FTRACE_GRAPH_TRAMP_ADDR
- .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
- /* trampoline_size is only needed for dynamically allocated tramps */
- #endif
- ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
- };
- void ftrace_graph_sleep_time_control(bool enable)
- {
- fgraph_sleep_time = enable;
- }
- void ftrace_graph_graph_time_control(bool enable)
- {
- fgraph_graph_time = enable;
- }
- int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
- {
- return 0;
- }
- /* The callbacks that hook a function */
- trace_func_graph_ret_t ftrace_graph_return =
- (trace_func_graph_ret_t)ftrace_stub;
- trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
- static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
- /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
- static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
- {
- int i;
- int ret = 0;
- unsigned long flags;
- int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
- struct task_struct *g, *t;
- for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
- ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
- * sizeof(struct ftrace_ret_stack),
- GFP_KERNEL);
- if (!ret_stack_list[i]) {
- start = 0;
- end = i;
- ret = -ENOMEM;
- goto free;
- }
- }
- read_lock_irqsave(&tasklist_lock, flags);
- do_each_thread(g, t) {
- if (start == end) {
- ret = -EAGAIN;
- goto unlock;
- }
- if (t->ret_stack == NULL) {
- atomic_set(&t->tracing_graph_pause, 0);
- atomic_set(&t->trace_overrun, 0);
- t->curr_ret_stack = -1;
- /* Make sure the tasks see the -1 first: */
- smp_wmb();
- t->ret_stack = ret_stack_list[start++];
- }
- } while_each_thread(g, t);
- unlock:
- read_unlock_irqrestore(&tasklist_lock, flags);
- free:
- for (i = start; i < end; i++)
- kfree(ret_stack_list[i]);
- return ret;
- }
- static void
- ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
- struct task_struct *prev, struct task_struct *next)
- {
- unsigned long long timestamp;
- int index;
- /*
- * Does the user want to count the time a function was asleep.
- * If so, do not update the time stamps.
- */
- if (fgraph_sleep_time)
- return;
- timestamp = trace_clock_local();
- prev->ftrace_timestamp = timestamp;
- /* only process tasks that we timestamped */
- if (!next->ftrace_timestamp)
- return;
- /*
- * Update all the counters in next to make up for the
- * time next was sleeping.
- */
- timestamp -= next->ftrace_timestamp;
- for (index = next->curr_ret_stack; index >= 0; index--)
- next->ret_stack[index].calltime += timestamp;
- }
- /* Allocate a return stack for each task */
- static int start_graph_tracing(void)
- {
- struct ftrace_ret_stack **ret_stack_list;
- int ret, cpu;
- ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
- sizeof(struct ftrace_ret_stack *),
- GFP_KERNEL);
- if (!ret_stack_list)
- return -ENOMEM;
- /* The cpu_boot init_task->ret_stack will never be freed */
- for_each_online_cpu(cpu) {
- if (!idle_task(cpu)->ret_stack)
- ftrace_graph_init_idle_task(idle_task(cpu), cpu);
- }
- do {
- ret = alloc_retstack_tasklist(ret_stack_list);
- } while (ret == -EAGAIN);
- if (!ret) {
- ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
- if (ret)
- pr_info("ftrace_graph: Couldn't activate tracepoint"
- " probe to kernel_sched_switch\n");
- }
- kfree(ret_stack_list);
- return ret;
- }
- /*
- * Hibernation protection.
- * The state of the current task is too much unstable during
- * suspend/restore to disk. We want to protect against that.
- */
- static int
- ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
- void *unused)
- {
- switch (state) {
- case PM_HIBERNATION_PREPARE:
- pause_graph_tracing();
- break;
- case PM_POST_HIBERNATION:
- unpause_graph_tracing();
- break;
- }
- return NOTIFY_DONE;
- }
- static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
- {
- if (!ftrace_ops_test(&global_ops, trace->func, NULL))
- return 0;
- return __ftrace_graph_entry(trace);
- }
- /*
- * The function graph tracer should only trace the functions defined
- * by set_ftrace_filter and set_ftrace_notrace. If another function
- * tracer ops is registered, the graph tracer requires testing the
- * function against the global ops, and not just trace any function
- * that any ftrace_ops registered.
- */
- static void update_function_graph_func(void)
- {
- struct ftrace_ops *op;
- bool do_test = false;
- /*
- * The graph and global ops share the same set of functions
- * to test. If any other ops is on the list, then
- * the graph tracing needs to test if its the function
- * it should call.
- */
- do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (op != &global_ops && op != &graph_ops &&
- op != &ftrace_list_end) {
- do_test = true;
- /* in double loop, break out with goto */
- goto out;
- }
- } while_for_each_ftrace_op(op);
- out:
- if (do_test)
- ftrace_graph_entry = ftrace_graph_entry_test;
- else
- ftrace_graph_entry = __ftrace_graph_entry;
- }
- static struct notifier_block ftrace_suspend_notifier = {
- .notifier_call = ftrace_suspend_notifier_call,
- };
- int register_ftrace_graph(trace_func_graph_ret_t retfunc,
- trace_func_graph_ent_t entryfunc)
- {
- int ret = 0;
- mutex_lock(&ftrace_lock);
- /* we currently allow only one tracer registered at a time */
- if (ftrace_graph_active) {
- ret = -EBUSY;
- goto out;
- }
- register_pm_notifier(&ftrace_suspend_notifier);
- ftrace_graph_active++;
- ret = start_graph_tracing();
- if (ret) {
- ftrace_graph_active--;
- goto out;
- }
- ftrace_graph_return = retfunc;
- /*
- * Update the indirect function to the entryfunc, and the
- * function that gets called to the entry_test first. Then
- * call the update fgraph entry function to determine if
- * the entryfunc should be called directly or not.
- */
- __ftrace_graph_entry = entryfunc;
- ftrace_graph_entry = ftrace_graph_entry_test;
- update_function_graph_func();
- ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
- out:
- mutex_unlock(&ftrace_lock);
- return ret;
- }
- void unregister_ftrace_graph(void)
- {
- mutex_lock(&ftrace_lock);
- if (unlikely(!ftrace_graph_active))
- goto out;
- ftrace_graph_active--;
- ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
- ftrace_graph_entry = ftrace_graph_entry_stub;
- __ftrace_graph_entry = ftrace_graph_entry_stub;
- ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
- unregister_pm_notifier(&ftrace_suspend_notifier);
- unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
- out:
- mutex_unlock(&ftrace_lock);
- }
- static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
- static void
- graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
- {
- atomic_set(&t->tracing_graph_pause, 0);
- atomic_set(&t->trace_overrun, 0);
- t->ftrace_timestamp = 0;
- /* make curr_ret_stack visible before we add the ret_stack */
- smp_wmb();
- t->ret_stack = ret_stack;
- }
- /*
- * Allocate a return stack for the idle task. May be the first
- * time through, or it may be done by CPU hotplug online.
- */
- void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
- {
- t->curr_ret_stack = -1;
- /*
- * The idle task has no parent, it either has its own
- * stack or no stack at all.
- */
- if (t->ret_stack)
- WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
- if (ftrace_graph_active) {
- struct ftrace_ret_stack *ret_stack;
- ret_stack = per_cpu(idle_ret_stack, cpu);
- if (!ret_stack) {
- ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
- * sizeof(struct ftrace_ret_stack),
- GFP_KERNEL);
- if (!ret_stack)
- return;
- per_cpu(idle_ret_stack, cpu) = ret_stack;
- }
- graph_init_task(t, ret_stack);
- }
- }
- /* Allocate a return stack for newly created task */
- void ftrace_graph_init_task(struct task_struct *t)
- {
- /* Make sure we do not use the parent ret_stack */
- t->ret_stack = NULL;
- t->curr_ret_stack = -1;
- if (ftrace_graph_active) {
- struct ftrace_ret_stack *ret_stack;
- ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
- * sizeof(struct ftrace_ret_stack),
- GFP_KERNEL);
- if (!ret_stack)
- return;
- graph_init_task(t, ret_stack);
- }
- }
- void ftrace_graph_exit_task(struct task_struct *t)
- {
- struct ftrace_ret_stack *ret_stack = t->ret_stack;
- t->ret_stack = NULL;
- /* NULL must become visible to IRQs before we free it: */
- barrier();
- kfree(ret_stack);
- }
- #endif
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