diff options
Diffstat (limited to 'tools/perf/util')
-rw-r--r-- | tools/perf/util/symbol-elf.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 07cfcf8f40e3..a002fc0bea03 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -381,6 +381,42 @@ static int sort_rel(struct rel_info *ri) return 0; } +/* + * For x86_64, the GNU linker is putting IFUNC information in the relocation + * addend. + */ +static bool addend_may_be_ifunc(GElf_Ehdr *ehdr, struct rel_info *ri) +{ + return ehdr->e_machine == EM_X86_64 && ri->is_rela && + GELF_R_TYPE(ri->rela.r_info) == R_X86_64_IRELATIVE; +} + +static bool get_ifunc_name(Elf *elf, struct dso *dso, GElf_Ehdr *ehdr, + struct rel_info *ri, char *buf, size_t buf_sz) +{ + u64 addr = ri->rela.r_addend; + struct symbol *sym; + GElf_Phdr phdr; + + if (!addend_may_be_ifunc(ehdr, ri)) + return false; + + if (elf_read_program_header(elf, addr, &phdr)) + return false; + + addr -= phdr.p_vaddr - phdr.p_offset; + + sym = dso__find_symbol_nocache(dso, addr); + + /* Expecting the address to be an IFUNC or IFUNC alias */ + if (!sym || sym->start != addr || (sym->type != STT_GNU_IFUNC && !sym->ifunc_alias)) + return false; + + snprintf(buf, buf_sz, "%s@plt", sym->name); + + return true; +} + static void exit_rel(struct rel_info *ri) { free(ri->sorted); @@ -560,7 +596,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) elf_name = demangled; if (*elf_name) snprintf(sympltname, sizeof(sympltname), "%s@plt", elf_name); - else + else if (!get_ifunc_name(elf, dso, &ehdr, &ri, sympltname, sizeof(sympltname))) snprintf(sympltname, sizeof(sympltname), "offset_%#" PRIx64 "@plt", plt_offset); free(demangled); |