diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 18e656712f5a..143720d1ecb1 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1236,17 +1236,28 @@ uint16_t dso__e_machine(struct dso *dso, struct machine *machine) try_to_open_dso(dso, machine); fd = dso__data(dso)->fd; if (fd >= 0) { - _Static_assert(offsetof(Elf32_Ehdr, e_machine) == 18, "Unexpected offset"); - _Static_assert(offsetof(Elf64_Ehdr, e_machine) == 18, "Unexpected offset"); - if (dso__needs_swap(dso) == DSO_SWAP__UNSET) { - unsigned char eidata; + unsigned char e_ident[EI_NIDENT]; - if (pread(fd, &eidata, sizeof(eidata), EI_DATA) == sizeof(eidata)) - dso__swap_init(dso, eidata); + _Static_assert(offsetof(Elf32_Ehdr, e_ident) == 0, "Unexpected offset"); + _Static_assert(offsetof(Elf64_Ehdr, e_ident) == 0, "Unexpected offset"); + if (pread(fd, &e_ident, sizeof(e_ident), 0) == sizeof(e_ident) && + memcmp(e_ident, ELFMAG, SELFMAG) == 0 && + e_ident[EI_CLASS] > ELFCLASSNONE && e_ident[EI_CLASS] < ELFCLASSNUM && + e_ident[EI_DATA] > ELFDATANONE && e_ident[EI_DATA] < ELFDATANUM && + e_ident[EI_VERSION] == EV_CURRENT) { + _Static_assert(offsetof(Elf32_Ehdr, e_machine) == 18, "Unexpected offset"); + _Static_assert(offsetof(Elf64_Ehdr, e_machine) == 18, "Unexpected offset"); + + if (dso__needs_swap(dso) == DSO_SWAP__UNSET) + dso__swap_init(dso, e_ident[EI_DATA]); + + if (dso__needs_swap(dso) != DSO_SWAP__UNSET && + pread(fd, &e_machine, sizeof(e_machine), 18) == sizeof(e_machine) && + e_machine < EM_NUM) + e_machine = DSO__SWAP(dso, uint16_t, e_machine); + else + e_machine = EM_NONE; } - if (dso__needs_swap(dso) != DSO_SWAP__UNSET && - pread(fd, &e_machine, sizeof(e_machine), 18) == sizeof(e_machine)) - e_machine = DSO__SWAP(dso, uint16_t, e_machine); } mutex_unlock(dso__data_open_lock()); return e_machine;