1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450145114521453145414551456145714581459146014611462146314641465146614671468146914701471147214731474147514761477147814791480148114821483148414851486148714881489149014911492149314941495149614971498149915001501150215031504150515061507150815091510151115121513151415151516151715181519152015211522152315241525152615271528152915301531153215331534153515361537153815391540154115421543154415451546154715481549155015511552155315541555155615571558155915601561156215631564156515661567156815691570157115721573157415751576157715781579158015811582158315841585158615871588158915901591159215931594159515961597159815991600160116021603160416051606160716081609161016111612161316141615161616171618161916201621162216231624162516261627162816291630163116321633163416351636163716381639164016411642164316441645164616471648164916501651165216531654165516561657165816591660166116621663166416651666166716681669167016711672167316741675167616771678167916801681168216831684168516861687168816891690169116921693169416951696169716981699170017011702170317041705170617071708170917101711171217131714171517161717171817191720172117221723172417251726172717281729173017311732173317341735173617371738173917401741174217431744174517461747174817491750175117521753175417551756175717581759176017611762176317641765176617671768176917701771177217731774177517761777177817791780178117821783178417851786178717881789179017911792179317941795 |
- #include <fcntl.h>
- #include <stdio.h>
- #include <errno.h>
- #include <string.h>
- #include <unistd.h>
- #include <inttypes.h>
- #include "symbol.h"
- #include "machine.h"
- #include "vdso.h"
- #include <symbol/kallsyms.h>
- #include "debug.h"
- #ifndef EM_AARCH64
- #define EM_AARCH64 183 /* ARM 64 bit */
- #endif
- #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
- extern char *cplus_demangle(const char *, int);
- static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
- {
- return cplus_demangle(c, i);
- }
- #else
- #ifdef NO_DEMANGLE
- static inline char *bfd_demangle(void __maybe_unused *v,
- const char __maybe_unused *c,
- int __maybe_unused i)
- {
- return NULL;
- }
- #else
- #define PACKAGE 'perf'
- #include <bfd.h>
- #endif
- #endif
- #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
- static int elf_getphdrnum(Elf *elf, size_t *dst)
- {
- GElf_Ehdr gehdr;
- GElf_Ehdr *ehdr;
- ehdr = gelf_getehdr(elf, &gehdr);
- if (!ehdr)
- return -1;
- *dst = ehdr->e_phnum;
- return 0;
- }
- #endif
- #ifndef NT_GNU_BUILD_ID
- #define NT_GNU_BUILD_ID 3
- #endif
- /**
- * elf_symtab__for_each_symbol - iterate thru all the symbols
- *
- * @syms: struct elf_symtab instance to iterate
- * @idx: uint32_t idx
- * @sym: GElf_Sym iterator
- */
- #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
- for (idx = 0, gelf_getsym(syms, idx, &sym);\
- idx < nr_syms; \
- idx++, gelf_getsym(syms, idx, &sym))
- static inline uint8_t elf_sym__type(const GElf_Sym *sym)
- {
- return GELF_ST_TYPE(sym->st_info);
- }
- static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
- {
- return GELF_ST_VISIBILITY(sym->st_other);
- }
- #ifndef STT_GNU_IFUNC
- #define STT_GNU_IFUNC 10
- #endif
- static inline int elf_sym__is_function(const GElf_Sym *sym)
- {
- return (elf_sym__type(sym) == STT_FUNC ||
- elf_sym__type(sym) == STT_GNU_IFUNC) &&
- sym->st_name != 0 &&
- sym->st_shndx != SHN_UNDEF;
- }
- static inline bool elf_sym__is_object(const GElf_Sym *sym)
- {
- return elf_sym__type(sym) == STT_OBJECT &&
- sym->st_name != 0 &&
- sym->st_shndx != SHN_UNDEF;
- }
- static inline int elf_sym__is_label(const GElf_Sym *sym)
- {
- return elf_sym__type(sym) == STT_NOTYPE &&
- sym->st_name != 0 &&
- sym->st_shndx != SHN_UNDEF &&
- sym->st_shndx != SHN_ABS &&
- elf_sym__visibility(sym) != STV_HIDDEN &&
- elf_sym__visibility(sym) != STV_INTERNAL;
- }
- static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
- {
- switch (type) {
- case MAP__FUNCTION:
- return elf_sym__is_function(sym);
- case MAP__VARIABLE:
- return elf_sym__is_object(sym);
- default:
- return false;
- }
- }
- static inline const char *elf_sym__name(const GElf_Sym *sym,
- const Elf_Data *symstrs)
- {
- return symstrs->d_buf + sym->st_name;
- }
- static inline const char *elf_sec__name(const GElf_Shdr *shdr,
- const Elf_Data *secstrs)
- {
- return secstrs->d_buf + shdr->sh_name;
- }
- static inline int elf_sec__is_text(const GElf_Shdr *shdr,
- const Elf_Data *secstrs)
- {
- return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
- }
- static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
- const Elf_Data *secstrs)
- {
- return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
- }
- static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
- enum map_type type)
- {
- switch (type) {
- case MAP__FUNCTION:
- return elf_sec__is_text(shdr, secstrs);
- case MAP__VARIABLE:
- return elf_sec__is_data(shdr, secstrs);
- default:
- return false;
- }
- }
- static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
- {
- Elf_Scn *sec = NULL;
- GElf_Shdr shdr;
- size_t cnt = 1;
- while ((sec = elf_nextscn(elf, sec)) != NULL) {
- gelf_getshdr(sec, &shdr);
- if ((addr >= shdr.sh_addr) &&
- (addr < (shdr.sh_addr + shdr.sh_size)))
- return cnt;
- ++cnt;
- }
- return -1;
- }
- Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
- GElf_Shdr *shp, const char *name, size_t *idx)
- {
- Elf_Scn *sec = NULL;
- size_t cnt = 1;
- /* Elf is corrupted/truncated, avoid calling elf_strptr. */
- if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
- return NULL;
- while ((sec = elf_nextscn(elf, sec)) != NULL) {
- char *str;
- gelf_getshdr(sec, shp);
- str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
- if (str && !strcmp(name, str)) {
- if (idx)
- *idx = cnt;
- return sec;
- }
- ++cnt;
- }
- return NULL;
- }
- #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
- for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
- idx < nr_entries; \
- ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
- #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
- for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
- idx < nr_entries; \
- ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
- /*
- * We need to check if we have a .dynsym, so that we can handle the
- * .plt, synthesizing its symbols, that aren't on the symtabs (be it
- * .dynsym or .symtab).
- * And always look at the original dso, not at debuginfo packages, that
- * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
- */
- int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
- symbol_filter_t filter)
- {
- uint32_t nr_rel_entries, idx;
- GElf_Sym sym;
- u64 plt_offset;
- GElf_Shdr shdr_plt;
- struct symbol *f;
- GElf_Shdr shdr_rel_plt, shdr_dynsym;
- Elf_Data *reldata, *syms, *symstrs;
- Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
- size_t dynsym_idx;
- GElf_Ehdr ehdr;
- char sympltname[1024];
- Elf *elf;
- int nr = 0, symidx, err = 0;
- if (!ss->dynsym)
- return 0;
- elf = ss->elf;
- ehdr = ss->ehdr;
- scn_dynsym = ss->dynsym;
- shdr_dynsym = ss->dynshdr;
- dynsym_idx = ss->dynsym_idx;
- if (scn_dynsym == NULL)
- goto out_elf_end;
- scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
- ".rela.plt", NULL);
- if (scn_plt_rel == NULL) {
- scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
- ".rel.plt", NULL);
- if (scn_plt_rel == NULL)
- goto out_elf_end;
- }
- err = -1;
- if (shdr_rel_plt.sh_link != dynsym_idx)
- goto out_elf_end;
- if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
- goto out_elf_end;
- /*
- * Fetch the relocation section to find the idxes to the GOT
- * and the symbols in the .dynsym they refer to.
- */
- reldata = elf_getdata(scn_plt_rel, NULL);
- if (reldata == NULL)
- goto out_elf_end;
- syms = elf_getdata(scn_dynsym, NULL);
- if (syms == NULL)
- goto out_elf_end;
- scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
- if (scn_symstrs == NULL)
- goto out_elf_end;
- symstrs = elf_getdata(scn_symstrs, NULL);
- if (symstrs == NULL)
- goto out_elf_end;
- if (symstrs->d_size == 0)
- goto out_elf_end;
- nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
- plt_offset = shdr_plt.sh_offset;
- if (shdr_rel_plt.sh_type == SHT_RELA) {
- GElf_Rela pos_mem, *pos;
- elf_section__for_each_rela(reldata, pos, pos_mem, idx,
- nr_rel_entries) {
- symidx = GELF_R_SYM(pos->r_info);
- plt_offset += shdr_plt.sh_entsize;
- gelf_getsym(syms, symidx, &sym);
- snprintf(sympltname, sizeof(sympltname),
- "%s@plt", elf_sym__name(&sym, symstrs));
- f = symbol__new(plt_offset, shdr_plt.sh_entsize,
- STB_GLOBAL, sympltname);
- if (!f)
- goto out_elf_end;
- if (filter && filter(map, f))
- symbol__delete(f);
- else {
- symbols__insert(&dso->symbols[map->type], f);
- ++nr;
- }
- }
- } else if (shdr_rel_plt.sh_type == SHT_REL) {
- GElf_Rel pos_mem, *pos;
- elf_section__for_each_rel(reldata, pos, pos_mem, idx,
- nr_rel_entries) {
- symidx = GELF_R_SYM(pos->r_info);
- plt_offset += shdr_plt.sh_entsize;
- gelf_getsym(syms, symidx, &sym);
- snprintf(sympltname, sizeof(sympltname),
- "%s@plt", elf_sym__name(&sym, symstrs));
- f = symbol__new(plt_offset, shdr_plt.sh_entsize,
- STB_GLOBAL, sympltname);
- if (!f)
- goto out_elf_end;
- if (filter && filter(map, f))
- symbol__delete(f);
- else {
- symbols__insert(&dso->symbols[map->type], f);
- ++nr;
- }
- }
- }
- err = 0;
- out_elf_end:
- if (err == 0)
- return nr;
- pr_debug("%s: problems reading %s PLT info.\n",
- __func__, dso->long_name);
- return 0;
- }
- /*
- * Align offset to 4 bytes as needed for note name and descriptor data.
- */
- #define NOTE_ALIGN(n) (((n) + 3) & -4U)
- static int elf_read_build_id(Elf *elf, void *bf, size_t size)
- {
- int err = -1;
- GElf_Ehdr ehdr;
- GElf_Shdr shdr;
- Elf_Data *data;
- Elf_Scn *sec;
- Elf_Kind ek;
- void *ptr;
- if (size < BUILD_ID_SIZE)
- goto out;
- ek = elf_kind(elf);
- if (ek != ELF_K_ELF)
- goto out;
- if (gelf_getehdr(elf, &ehdr) == NULL) {
- pr_err("%s: cannot get elf header.\n", __func__);
- goto out;
- }
- /*
- * Check following sections for notes:
- * '.note.gnu.build-id'
- * '.notes'
- * '.note' (VDSO specific)
- */
- do {
- sec = elf_section_by_name(elf, &ehdr, &shdr,
- ".note.gnu.build-id", NULL);
- if (sec)
- break;
- sec = elf_section_by_name(elf, &ehdr, &shdr,
- ".notes", NULL);
- if (sec)
- break;
- sec = elf_section_by_name(elf, &ehdr, &shdr,
- ".note", NULL);
- if (sec)
- break;
- return err;
- } while (0);
- data = elf_getdata(sec, NULL);
- if (data == NULL)
- goto out;
- ptr = data->d_buf;
- while (ptr < (data->d_buf + data->d_size)) {
- GElf_Nhdr *nhdr = ptr;
- size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
- descsz = NOTE_ALIGN(nhdr->n_descsz);
- const char *name;
- ptr += sizeof(*nhdr);
- name = ptr;
- ptr += namesz;
- if (nhdr->n_type == NT_GNU_BUILD_ID &&
- nhdr->n_namesz == sizeof("GNU")) {
- if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
- size_t sz = min(size, descsz);
- memcpy(bf, ptr, sz);
- memset(bf + sz, 0, size - sz);
- err = descsz;
- break;
- }
- }
- ptr += descsz;
- }
- out:
- return err;
- }
- int filename__read_build_id(const char *filename, void *bf, size_t size)
- {
- int fd, err = -1;
- Elf *elf;
- if (size < BUILD_ID_SIZE)
- goto out;
- fd = open(filename, O_RDONLY);
- if (fd < 0)
- goto out;
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL) {
- pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
- goto out_close;
- }
- err = elf_read_build_id(elf, bf, size);
- elf_end(elf);
- out_close:
- close(fd);
- out:
- return err;
- }
- int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
- {
- int fd, err = -1;
- if (size < BUILD_ID_SIZE)
- goto out;
- fd = open(filename, O_RDONLY);
- if (fd < 0)
- goto out;
- while (1) {
- char bf[BUFSIZ];
- GElf_Nhdr nhdr;
- size_t namesz, descsz;
- if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
- break;
- namesz = NOTE_ALIGN(nhdr.n_namesz);
- descsz = NOTE_ALIGN(nhdr.n_descsz);
- if (nhdr.n_type == NT_GNU_BUILD_ID &&
- nhdr.n_namesz == sizeof("GNU")) {
- if (read(fd, bf, namesz) != (ssize_t)namesz)
- break;
- if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
- size_t sz = min(descsz, size);
- if (read(fd, build_id, sz) == (ssize_t)sz) {
- memset(build_id + sz, 0, size - sz);
- err = 0;
- break;
- }
- } else if (read(fd, bf, descsz) != (ssize_t)descsz)
- break;
- } else {
- int n = namesz + descsz;
- if (n > (int)sizeof(bf)) {
- n = sizeof(bf);
- pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
- __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
- }
- if (read(fd, bf, n) != n)
- break;
- }
- }
- close(fd);
- out:
- return err;
- }
- int filename__read_debuglink(const char *filename, char *debuglink,
- size_t size)
- {
- int fd, err = -1;
- Elf *elf;
- GElf_Ehdr ehdr;
- GElf_Shdr shdr;
- Elf_Data *data;
- Elf_Scn *sec;
- Elf_Kind ek;
- fd = open(filename, O_RDONLY);
- if (fd < 0)
- goto out;
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL) {
- pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
- goto out_close;
- }
- ek = elf_kind(elf);
- if (ek != ELF_K_ELF)
- goto out_elf_end;
- if (gelf_getehdr(elf, &ehdr) == NULL) {
- pr_err("%s: cannot get elf header.\n", __func__);
- goto out_elf_end;
- }
- sec = elf_section_by_name(elf, &ehdr, &shdr,
- ".gnu_debuglink", NULL);
- if (sec == NULL)
- goto out_elf_end;
- data = elf_getdata(sec, NULL);
- if (data == NULL)
- goto out_elf_end;
- /* the start of this section is a zero-terminated string */
- strncpy(debuglink, data->d_buf, size);
- err = 0;
- out_elf_end:
- elf_end(elf);
- out_close:
- close(fd);
- out:
- return err;
- }
- static int dso__swap_init(struct dso *dso, unsigned char eidata)
- {
- static unsigned int const endian = 1;
- dso->needs_swap = DSO_SWAP__NO;
- switch (eidata) {
- case ELFDATA2LSB:
- /* We are big endian, DSO is little endian. */
- if (*(unsigned char const *)&endian != 1)
- dso->needs_swap = DSO_SWAP__YES;
- break;
- case ELFDATA2MSB:
- /* We are little endian, DSO is big endian. */
- if (*(unsigned char const *)&endian != 0)
- dso->needs_swap = DSO_SWAP__YES;
- break;
- default:
- pr_err("unrecognized DSO data encoding %d\n", eidata);
- return -EINVAL;
- }
- return 0;
- }
- static int decompress_kmodule(struct dso *dso, const char *name,
- enum dso_binary_type type)
- {
- int fd = -1;
- char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
- struct kmod_path m;
- if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
- type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
- type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
- return -1;
- if (type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
- name = dso->long_name;
- if (kmod_path__parse_ext(&m, name) || !m.comp)
- return -1;
- fd = mkstemp(tmpbuf);
- if (fd < 0) {
- dso->load_errno = errno;
- goto out;
- }
- if (!decompress_to_file(m.ext, name, fd)) {
- dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
- close(fd);
- fd = -1;
- }
- unlink(tmpbuf);
- out:
- free(m.ext);
- return fd;
- }
- bool symsrc__possibly_runtime(struct symsrc *ss)
- {
- return ss->dynsym || ss->opdsec;
- }
- bool symsrc__has_symtab(struct symsrc *ss)
- {
- return ss->symtab != NULL;
- }
- void symsrc__destroy(struct symsrc *ss)
- {
- zfree(&ss->name);
- elf_end(ss->elf);
- close(ss->fd);
- }
- bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
- {
- return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
- }
- int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
- enum dso_binary_type type)
- {
- int err = -1;
- GElf_Ehdr ehdr;
- Elf *elf;
- int fd;
- if (dso__needs_decompress(dso)) {
- fd = decompress_kmodule(dso, name, type);
- if (fd < 0)
- return -1;
- } else {
- fd = open(name, O_RDONLY);
- if (fd < 0) {
- dso->load_errno = errno;
- return -1;
- }
- }
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL) {
- pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
- dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
- goto out_close;
- }
- if (gelf_getehdr(elf, &ehdr) == NULL) {
- dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
- pr_debug("%s: cannot get elf header.\n", __func__);
- goto out_elf_end;
- }
- if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
- dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
- goto out_elf_end;
- }
- /* Always reject images with a mismatched build-id: */
- if (dso->has_build_id) {
- u8 build_id[BUILD_ID_SIZE];
- if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
- dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
- goto out_elf_end;
- }
- if (!dso__build_id_equal(dso, build_id)) {
- pr_debug("%s: build id mismatch for %s.\n", __func__, name);
- dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
- goto out_elf_end;
- }
- }
- ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
- ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
- NULL);
- if (ss->symshdr.sh_type != SHT_SYMTAB)
- ss->symtab = NULL;
- ss->dynsym_idx = 0;
- ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
- &ss->dynsym_idx);
- if (ss->dynshdr.sh_type != SHT_DYNSYM)
- ss->dynsym = NULL;
- ss->opdidx = 0;
- ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
- &ss->opdidx);
- if (ss->opdshdr.sh_type != SHT_PROGBITS)
- ss->opdsec = NULL;
- if (dso->kernel == DSO_TYPE_USER) {
- GElf_Shdr shdr;
- ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
- ehdr.e_type == ET_REL ||
- dso__is_vdso(dso) ||
- elf_section_by_name(elf, &ehdr, &shdr,
- ".gnu.prelink_undo",
- NULL) != NULL);
- } else {
- ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
- }
- ss->name = strdup(name);
- if (!ss->name) {
- dso->load_errno = errno;
- goto out_elf_end;
- }
- ss->elf = elf;
- ss->fd = fd;
- ss->ehdr = ehdr;
- ss->type = type;
- return 0;
- out_elf_end:
- elf_end(elf);
- out_close:
- close(fd);
- return err;
- }
- /**
- * ref_reloc_sym_not_found - has kernel relocation symbol been found.
- * @kmap: kernel maps and relocation reference symbol
- *
- * This function returns %true if we are dealing with the kernel maps and the
- * relocation reference symbol has not yet been found. Otherwise %false is
- * returned.
- */
- static bool ref_reloc_sym_not_found(struct kmap *kmap)
- {
- return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
- !kmap->ref_reloc_sym->unrelocated_addr;
- }
- /**
- * ref_reloc - kernel relocation offset.
- * @kmap: kernel maps and relocation reference symbol
- *
- * This function returns the offset of kernel addresses as determined by using
- * the relocation reference symbol i.e. if the kernel has not been relocated
- * then the return value is zero.
- */
- static u64 ref_reloc(struct kmap *kmap)
- {
- if (kmap && kmap->ref_reloc_sym &&
- kmap->ref_reloc_sym->unrelocated_addr)
- return kmap->ref_reloc_sym->addr -
- kmap->ref_reloc_sym->unrelocated_addr;
- return 0;
- }
- static bool want_demangle(bool is_kernel_sym)
- {
- return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
- }
- void __weak arch__elf_sym_adjust(GElf_Sym *sym __maybe_unused) { }
- int dso__load_sym(struct dso *dso, struct map *map,
- struct symsrc *syms_ss, struct symsrc *runtime_ss,
- symbol_filter_t filter, int kmodule)
- {
- struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
- struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
- struct map *curr_map = map;
- struct dso *curr_dso = dso;
- Elf_Data *symstrs, *secstrs;
- uint32_t nr_syms;
- int err = -1;
- uint32_t idx;
- GElf_Ehdr ehdr;
- GElf_Shdr shdr;
- Elf_Data *syms, *opddata = NULL;
- GElf_Sym sym;
- Elf_Scn *sec, *sec_strndx;
- Elf *elf;
- int nr = 0;
- bool remap_kernel = false, adjust_kernel_syms = false;
- if (kmap && !kmaps)
- return -1;
- dso->symtab_type = syms_ss->type;
- dso->is_64_bit = syms_ss->is_64_bit;
- dso->rel = syms_ss->ehdr.e_type == ET_REL;
- /*
- * Modules may already have symbols from kallsyms, but those symbols
- * have the wrong values for the dso maps, so remove them.
- */
- if (kmodule && syms_ss->symtab)
- symbols__delete(&dso->symbols[map->type]);
- if (!syms_ss->symtab) {
- /*
- * If the vmlinux is stripped, fail so we will fall back
- * to using kallsyms. The vmlinux runtime symbols aren't
- * of much use.
- */
- if (dso->kernel)
- goto out_elf_end;
- syms_ss->symtab = syms_ss->dynsym;
- syms_ss->symshdr = syms_ss->dynshdr;
- }
- elf = syms_ss->elf;
- ehdr = syms_ss->ehdr;
- sec = syms_ss->symtab;
- shdr = syms_ss->symshdr;
- if (runtime_ss->opdsec)
- opddata = elf_rawdata(runtime_ss->opdsec, NULL);
- syms = elf_getdata(sec, NULL);
- if (syms == NULL)
- goto out_elf_end;
- sec = elf_getscn(elf, shdr.sh_link);
- if (sec == NULL)
- goto out_elf_end;
- symstrs = elf_getdata(sec, NULL);
- if (symstrs == NULL)
- goto out_elf_end;
- sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
- if (sec_strndx == NULL)
- goto out_elf_end;
- secstrs = elf_getdata(sec_strndx, NULL);
- if (secstrs == NULL)
- goto out_elf_end;
- nr_syms = shdr.sh_size / shdr.sh_entsize;
- memset(&sym, 0, sizeof(sym));
- /*
- * The kernel relocation symbol is needed in advance in order to adjust
- * kernel maps correctly.
- */
- if (ref_reloc_sym_not_found(kmap)) {
- elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
- const char *elf_name = elf_sym__name(&sym, symstrs);
- if (strcmp(elf_name, kmap->ref_reloc_sym->name))
- continue;
- kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
- map->reloc = kmap->ref_reloc_sym->addr -
- kmap->ref_reloc_sym->unrelocated_addr;
- break;
- }
- }
- /*
- * Handle any relocation of vdso necessary because older kernels
- * attempted to prelink vdso to its virtual address.
- */
- if (dso__is_vdso(dso)) {
- GElf_Shdr tshdr;
- if (elf_section_by_name(elf, &ehdr, &tshdr, ".text", NULL))
- map->reloc = map->start - tshdr.sh_addr + tshdr.sh_offset;
- }
- dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
- /*
- * Initial kernel and module mappings do not map to the dso. For
- * function mappings, flag the fixups.
- */
- if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
- remap_kernel = true;
- adjust_kernel_syms = dso->adjust_symbols;
- }
- elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
- struct symbol *f;
- const char *elf_name = elf_sym__name(&sym, symstrs);
- char *demangled = NULL;
- int is_label = elf_sym__is_label(&sym);
- const char *section_name;
- bool used_opd = false;
- if (!is_label && !elf_sym__is_a(&sym, map->type))
- continue;
- /* Reject ARM ELF "mapping symbols": these aren't unique and
- * don't identify functions, so will confuse the profile
- * output: */
- if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
- if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
- && (elf_name[2] == '\0' || elf_name[2] == '.'))
- continue;
- }
- if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
- u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
- u64 *opd = opddata->d_buf + offset;
- sym.st_value = DSO__SWAP(dso, u64, *opd);
- sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
- sym.st_value);
- used_opd = true;
- }
- /*
- * When loading symbols in a data mapping, ABS symbols (which
- * has a value of SHN_ABS in its st_shndx) failed at
- * elf_getscn(). And it marks the loading as a failure so
- * already loaded symbols cannot be fixed up.
- *
- * I'm not sure what should be done. Just ignore them for now.
- * - Namhyung Kim
- */
- if (sym.st_shndx == SHN_ABS)
- continue;
- sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
- if (!sec)
- goto out_elf_end;
- gelf_getshdr(sec, &shdr);
- if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
- continue;
- section_name = elf_sec__name(&shdr, secstrs);
- /* On ARM, symbols for thumb functions have 1 added to
- * the symbol address as a flag - remove it */
- if ((ehdr.e_machine == EM_ARM) &&
- (map->type == MAP__FUNCTION) &&
- (sym.st_value & 1))
- --sym.st_value;
- arch__elf_sym_adjust(&sym);
- if (dso->kernel || kmodule) {
- char dso_name[PATH_MAX];
- /* Adjust symbol to map to file offset */
- if (adjust_kernel_syms)
- sym.st_value -= shdr.sh_addr - shdr.sh_offset;
- if (strcmp(section_name,
- (curr_dso->short_name +
- dso->short_name_len)) == 0)
- goto new_symbol;
- if (strcmp(section_name, ".text") == 0) {
- /*
- * The initial kernel mapping is based on
- * kallsyms and identity maps. Overwrite it to
- * map to the kernel dso.
- */
- if (remap_kernel && dso->kernel) {
- remap_kernel = false;
- map->start = shdr.sh_addr +
- ref_reloc(kmap);
- map->end = map->start + shdr.sh_size;
- map->pgoff = shdr.sh_offset;
- map->map_ip = map__map_ip;
- map->unmap_ip = map__unmap_ip;
- /* Ensure maps are correctly ordered */
- if (kmaps) {
- map__get(map);
- map_groups__remove(kmaps, map);
- map_groups__insert(kmaps, map);
- map__put(map);
- }
- }
- /*
- * The initial module mapping is based on
- * /proc/modules mapped to offset zero.
- * Overwrite it to map to the module dso.
- */
- if (remap_kernel && kmodule) {
- remap_kernel = false;
- map->pgoff = shdr.sh_offset;
- }
- curr_map = map;
- curr_dso = dso;
- goto new_symbol;
- }
- if (!kmap)
- goto new_symbol;
- snprintf(dso_name, sizeof(dso_name),
- "%s%s", dso->short_name, section_name);
- curr_map = map_groups__find_by_name(kmaps, map->type, dso_name);
- if (curr_map == NULL) {
- u64 start = sym.st_value;
- if (kmodule)
- start += map->start + shdr.sh_offset;
- curr_dso = dso__new(dso_name);
- if (curr_dso == NULL)
- goto out_elf_end;
- curr_dso->kernel = dso->kernel;
- curr_dso->long_name = dso->long_name;
- curr_dso->long_name_len = dso->long_name_len;
- curr_map = map__new2(start, curr_dso,
- map->type);
- if (curr_map == NULL) {
- dso__put(curr_dso);
- goto out_elf_end;
- }
- if (adjust_kernel_syms) {
- curr_map->start = shdr.sh_addr +
- ref_reloc(kmap);
- curr_map->end = curr_map->start +
- shdr.sh_size;
- curr_map->pgoff = shdr.sh_offset;
- } else {
- curr_map->map_ip = identity__map_ip;
- curr_map->unmap_ip = identity__map_ip;
- }
- curr_dso->symtab_type = dso->symtab_type;
- map_groups__insert(kmaps, curr_map);
- dsos__add(&map->groups->machine->dsos, curr_dso);
- dso__set_loaded(curr_dso, map->type);
- } else
- curr_dso = curr_map->dso;
- goto new_symbol;
- }
- if ((used_opd && runtime_ss->adjust_symbols)
- || (!used_opd && syms_ss->adjust_symbols)) {
- pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
- "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
- (u64)sym.st_value, (u64)shdr.sh_addr,
- (u64)shdr.sh_offset);
- sym.st_value -= shdr.sh_addr - shdr.sh_offset;
- }
- new_symbol:
- /*
- * We need to figure out if the object was created from C++ sources
- * DWARF DW_compile_unit has this, but we don't always have access
- * to it...
- */
- if (want_demangle(dso->kernel || kmodule)) {
- int demangle_flags = DMGL_NO_OPTS;
- if (verbose)
- demangle_flags = DMGL_PARAMS | DMGL_ANSI;
- demangled = bfd_demangle(NULL, elf_name, demangle_flags);
- if (demangled != NULL)
- elf_name = demangled;
- }
- f = symbol__new(sym.st_value, sym.st_size,
- GELF_ST_BIND(sym.st_info), elf_name);
- free(demangled);
- if (!f)
- goto out_elf_end;
- if (filter && filter(curr_map, f))
- symbol__delete(f);
- else {
- symbols__insert(&curr_dso->symbols[curr_map->type], f);
- nr++;
- }
- }
- /*
- * For misannotated, zeroed, ASM function sizes.
- */
- if (nr > 0) {
- symbols__fixup_end(&dso->symbols[map->type]);
- symbols__fixup_duplicate(&dso->symbols[map->type]);
- if (kmap) {
- /*
- * We need to fixup this here too because we create new
- * maps here, for things like vsyscall sections.
- */
- __map_groups__fixup_end(kmaps, map->type);
- }
- }
- err = nr;
- out_elf_end:
- return err;
- }
- static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
- {
- GElf_Phdr phdr;
- size_t i, phdrnum;
- int err;
- u64 sz;
- if (elf_getphdrnum(elf, &phdrnum))
- return -1;
- for (i = 0; i < phdrnum; i++) {
- if (gelf_getphdr(elf, i, &phdr) == NULL)
- return -1;
- if (phdr.p_type != PT_LOAD)
- continue;
- if (exe) {
- if (!(phdr.p_flags & PF_X))
- continue;
- } else {
- if (!(phdr.p_flags & PF_R))
- continue;
- }
- sz = min(phdr.p_memsz, phdr.p_filesz);
- if (!sz)
- continue;
- err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
- if (err)
- return err;
- }
- return 0;
- }
- int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
- bool *is_64_bit)
- {
- int err;
- Elf *elf;
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL)
- return -1;
- if (is_64_bit)
- *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
- err = elf_read_maps(elf, exe, mapfn, data);
- elf_end(elf);
- return err;
- }
- enum dso_type dso__type_fd(int fd)
- {
- enum dso_type dso_type = DSO__TYPE_UNKNOWN;
- GElf_Ehdr ehdr;
- Elf_Kind ek;
- Elf *elf;
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL)
- goto out;
- ek = elf_kind(elf);
- if (ek != ELF_K_ELF)
- goto out_end;
- if (gelf_getclass(elf) == ELFCLASS64) {
- dso_type = DSO__TYPE_64BIT;
- goto out_end;
- }
- if (gelf_getehdr(elf, &ehdr) == NULL)
- goto out_end;
- if (ehdr.e_machine == EM_X86_64)
- dso_type = DSO__TYPE_X32BIT;
- else
- dso_type = DSO__TYPE_32BIT;
- out_end:
- elf_end(elf);
- out:
- return dso_type;
- }
- static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
- {
- ssize_t r;
- size_t n;
- int err = -1;
- char *buf = malloc(page_size);
- if (buf == NULL)
- return -1;
- if (lseek(to, to_offs, SEEK_SET) != to_offs)
- goto out;
- if (lseek(from, from_offs, SEEK_SET) != from_offs)
- goto out;
- while (len) {
- n = page_size;
- if (len < n)
- n = len;
- /* Use read because mmap won't work on proc files */
- r = read(from, buf, n);
- if (r < 0)
- goto out;
- if (!r)
- break;
- n = r;
- r = write(to, buf, n);
- if (r < 0)
- goto out;
- if ((size_t)r != n)
- goto out;
- len -= n;
- }
- err = 0;
- out:
- free(buf);
- return err;
- }
- struct kcore {
- int fd;
- int elfclass;
- Elf *elf;
- GElf_Ehdr ehdr;
- };
- static int kcore__open(struct kcore *kcore, const char *filename)
- {
- GElf_Ehdr *ehdr;
- kcore->fd = open(filename, O_RDONLY);
- if (kcore->fd == -1)
- return -1;
- kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
- if (!kcore->elf)
- goto out_close;
- kcore->elfclass = gelf_getclass(kcore->elf);
- if (kcore->elfclass == ELFCLASSNONE)
- goto out_end;
- ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
- if (!ehdr)
- goto out_end;
- return 0;
- out_end:
- elf_end(kcore->elf);
- out_close:
- close(kcore->fd);
- return -1;
- }
- static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
- bool temp)
- {
- kcore->elfclass = elfclass;
- if (temp)
- kcore->fd = mkstemp(filename);
- else
- kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
- if (kcore->fd == -1)
- return -1;
- kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
- if (!kcore->elf)
- goto out_close;
- if (!gelf_newehdr(kcore->elf, elfclass))
- goto out_end;
- memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
- return 0;
- out_end:
- elf_end(kcore->elf);
- out_close:
- close(kcore->fd);
- unlink(filename);
- return -1;
- }
- static void kcore__close(struct kcore *kcore)
- {
- elf_end(kcore->elf);
- close(kcore->fd);
- }
- static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
- {
- GElf_Ehdr *ehdr = &to->ehdr;
- GElf_Ehdr *kehdr = &from->ehdr;
- memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
- ehdr->e_type = kehdr->e_type;
- ehdr->e_machine = kehdr->e_machine;
- ehdr->e_version = kehdr->e_version;
- ehdr->e_entry = 0;
- ehdr->e_shoff = 0;
- ehdr->e_flags = kehdr->e_flags;
- ehdr->e_phnum = count;
- ehdr->e_shentsize = 0;
- ehdr->e_shnum = 0;
- ehdr->e_shstrndx = 0;
- if (from->elfclass == ELFCLASS32) {
- ehdr->e_phoff = sizeof(Elf32_Ehdr);
- ehdr->e_ehsize = sizeof(Elf32_Ehdr);
- ehdr->e_phentsize = sizeof(Elf32_Phdr);
- } else {
- ehdr->e_phoff = sizeof(Elf64_Ehdr);
- ehdr->e_ehsize = sizeof(Elf64_Ehdr);
- ehdr->e_phentsize = sizeof(Elf64_Phdr);
- }
- if (!gelf_update_ehdr(to->elf, ehdr))
- return -1;
- if (!gelf_newphdr(to->elf, count))
- return -1;
- return 0;
- }
- static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
- u64 addr, u64 len)
- {
- GElf_Phdr phdr = {
- .p_type = PT_LOAD,
- .p_flags = PF_R | PF_W | PF_X,
- .p_offset = offset,
- .p_vaddr = addr,
- .p_paddr = 0,
- .p_filesz = len,
- .p_memsz = len,
- .p_align = page_size,
- };
- if (!gelf_update_phdr(kcore->elf, idx, &phdr))
- return -1;
- return 0;
- }
- static off_t kcore__write(struct kcore *kcore)
- {
- return elf_update(kcore->elf, ELF_C_WRITE);
- }
- struct phdr_data {
- off_t offset;
- u64 addr;
- u64 len;
- };
- struct kcore_copy_info {
- u64 stext;
- u64 etext;
- u64 first_symbol;
- u64 last_symbol;
- u64 first_module;
- u64 last_module_symbol;
- struct phdr_data kernel_map;
- struct phdr_data modules_map;
- };
- static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
- u64 start)
- {
- struct kcore_copy_info *kci = arg;
- if (!symbol_type__is_a(type, MAP__FUNCTION))
- return 0;
- if (strchr(name, '[')) {
- if (start > kci->last_module_symbol)
- kci->last_module_symbol = start;
- return 0;
- }
- if (!kci->first_symbol || start < kci->first_symbol)
- kci->first_symbol = start;
- if (!kci->last_symbol || start > kci->last_symbol)
- kci->last_symbol = start;
- if (!strcmp(name, "_stext")) {
- kci->stext = start;
- return 0;
- }
- if (!strcmp(name, "_etext")) {
- kci->etext = start;
- return 0;
- }
- return 0;
- }
- static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
- const char *dir)
- {
- char kallsyms_filename[PATH_MAX];
- scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
- if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
- return -1;
- if (kallsyms__parse(kallsyms_filename, kci,
- kcore_copy__process_kallsyms) < 0)
- return -1;
- return 0;
- }
- static int kcore_copy__process_modules(void *arg,
- const char *name __maybe_unused,
- u64 start)
- {
- struct kcore_copy_info *kci = arg;
- if (!kci->first_module || start < kci->first_module)
- kci->first_module = start;
- return 0;
- }
- static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
- const char *dir)
- {
- char modules_filename[PATH_MAX];
- scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
- if (symbol__restricted_filename(modules_filename, "/proc/modules"))
- return -1;
- if (modules__parse(modules_filename, kci,
- kcore_copy__process_modules) < 0)
- return -1;
- return 0;
- }
- static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
- u64 s, u64 e)
- {
- if (p->addr || s < start || s >= end)
- return;
- p->addr = s;
- p->offset = (s - start) + pgoff;
- p->len = e < end ? e - s : end - s;
- }
- static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
- {
- struct kcore_copy_info *kci = data;
- u64 end = start + len;
- kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
- kci->etext);
- kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
- kci->last_module_symbol);
- return 0;
- }
- static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
- {
- if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
- return -1;
- return 0;
- }
- static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
- Elf *elf)
- {
- if (kcore_copy__parse_kallsyms(kci, dir))
- return -1;
- if (kcore_copy__parse_modules(kci, dir))
- return -1;
- if (kci->stext)
- kci->stext = round_down(kci->stext, page_size);
- else
- kci->stext = round_down(kci->first_symbol, page_size);
- if (kci->etext) {
- kci->etext = round_up(kci->etext, page_size);
- } else if (kci->last_symbol) {
- kci->etext = round_up(kci->last_symbol, page_size);
- kci->etext += page_size;
- }
- kci->first_module = round_down(kci->first_module, page_size);
- if (kci->last_module_symbol) {
- kci->last_module_symbol = round_up(kci->last_module_symbol,
- page_size);
- kci->last_module_symbol += page_size;
- }
- if (!kci->stext || !kci->etext)
- return -1;
- if (kci->first_module && !kci->last_module_symbol)
- return -1;
- return kcore_copy__read_maps(kci, elf);
- }
- static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
- const char *name)
- {
- char from_filename[PATH_MAX];
- char to_filename[PATH_MAX];
- scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
- scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
- return copyfile_mode(from_filename, to_filename, 0400);
- }
- static int kcore_copy__unlink(const char *dir, const char *name)
- {
- char filename[PATH_MAX];
- scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
- return unlink(filename);
- }
- static int kcore_copy__compare_fds(int from, int to)
- {
- char *buf_from;
- char *buf_to;
- ssize_t ret;
- size_t len;
- int err = -1;
- buf_from = malloc(page_size);
- buf_to = malloc(page_size);
- if (!buf_from || !buf_to)
- goto out;
- while (1) {
- /* Use read because mmap won't work on proc files */
- ret = read(from, buf_from, page_size);
- if (ret < 0)
- goto out;
- if (!ret)
- break;
- len = ret;
- if (readn(to, buf_to, len) != (int)len)
- goto out;
- if (memcmp(buf_from, buf_to, len))
- goto out;
- }
- err = 0;
- out:
- free(buf_to);
- free(buf_from);
- return err;
- }
- static int kcore_copy__compare_files(const char *from_filename,
- const char *to_filename)
- {
- int from, to, err = -1;
- from = open(from_filename, O_RDONLY);
- if (from < 0)
- return -1;
- to = open(to_filename, O_RDONLY);
- if (to < 0)
- goto out_close_from;
- err = kcore_copy__compare_fds(from, to);
- close(to);
- out_close_from:
- close(from);
- return err;
- }
- static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
- const char *name)
- {
- char from_filename[PATH_MAX];
- char to_filename[PATH_MAX];
- scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
- scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
- return kcore_copy__compare_files(from_filename, to_filename);
- }
- /**
- * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
- * @from_dir: from directory
- * @to_dir: to directory
- *
- * This function copies kallsyms, modules and kcore files from one directory to
- * another. kallsyms and modules are copied entirely. Only code segments are
- * copied from kcore. It is assumed that two segments suffice: one for the
- * kernel proper and one for all the modules. The code segments are determined
- * from kallsyms and modules files. The kernel map starts at _stext or the
- * lowest function symbol, and ends at _etext or the highest function symbol.
- * The module map starts at the lowest module address and ends at the highest
- * module symbol. Start addresses are rounded down to the nearest page. End
- * addresses are rounded up to the nearest page. An extra page is added to the
- * highest kernel symbol and highest module symbol to, hopefully, encompass that
- * symbol too. Because it contains only code sections, the resulting kcore is
- * unusual. One significant peculiarity is that the mapping (start -> pgoff)
- * is not the same for the kernel map and the modules map. That happens because
- * the data is copied adjacently whereas the original kcore has gaps. Finally,
- * kallsyms and modules files are compared with their copies to check that
- * modules have not been loaded or unloaded while the copies were taking place.
- *
- * Return: %0 on success, %-1 on failure.
- */
- int kcore_copy(const char *from_dir, const char *to_dir)
- {
- struct kcore kcore;
- struct kcore extract;
- size_t count = 2;
- int idx = 0, err = -1;
- off_t offset = page_size, sz, modules_offset = 0;
- struct kcore_copy_info kci = { .stext = 0, };
- char kcore_filename[PATH_MAX];
- char extract_filename[PATH_MAX];
- if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
- return -1;
- if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
- goto out_unlink_kallsyms;
- scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
- scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
- if (kcore__open(&kcore, kcore_filename))
- goto out_unlink_modules;
- if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
- goto out_kcore_close;
- if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
- goto out_kcore_close;
- if (!kci.modules_map.addr)
- count -= 1;
- if (kcore__copy_hdr(&kcore, &extract, count))
- goto out_extract_close;
- if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
- kci.kernel_map.len))
- goto out_extract_close;
- if (kci.modules_map.addr) {
- modules_offset = offset + kci.kernel_map.len;
- if (kcore__add_phdr(&extract, idx, modules_offset,
- kci.modules_map.addr, kci.modules_map.len))
- goto out_extract_close;
- }
- sz = kcore__write(&extract);
- if (sz < 0 || sz > offset)
- goto out_extract_close;
- if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
- kci.kernel_map.len))
- goto out_extract_close;
- if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
- extract.fd, modules_offset,
- kci.modules_map.len))
- goto out_extract_close;
- if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
- goto out_extract_close;
- if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
- goto out_extract_close;
- err = 0;
- out_extract_close:
- kcore__close(&extract);
- if (err)
- unlink(extract_filename);
- out_kcore_close:
- kcore__close(&kcore);
- out_unlink_modules:
- if (err)
- kcore_copy__unlink(to_dir, "modules");
- out_unlink_kallsyms:
- if (err)
- kcore_copy__unlink(to_dir, "kallsyms");
- return err;
- }
- int kcore_extract__create(struct kcore_extract *kce)
- {
- struct kcore kcore;
- struct kcore extract;
- size_t count = 1;
- int idx = 0, err = -1;
- off_t offset = page_size, sz;
- if (kcore__open(&kcore, kce->kcore_filename))
- return -1;
- strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
- if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
- goto out_kcore_close;
- if (kcore__copy_hdr(&kcore, &extract, count))
- goto out_extract_close;
- if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
- goto out_extract_close;
- sz = kcore__write(&extract);
- if (sz < 0 || sz > offset)
- goto out_extract_close;
- if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
- goto out_extract_close;
- err = 0;
- out_extract_close:
- kcore__close(&extract);
- if (err)
- unlink(kce->extract_filename);
- out_kcore_close:
- kcore__close(&kcore);
- return err;
- }
- void kcore_extract__delete(struct kcore_extract *kce)
- {
- unlink(kce->extract_filename);
- }
- void symbol__elf_init(void)
- {
- elf_version(EV_CURRENT);
- }
|