Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752824AbZGKR0e (ORCPT ); Sat, 11 Jul 2009 13:26:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754056AbZGKR0C (ORCPT ); Sat, 11 Jul 2009 13:26:02 -0400 Received: from hera.kernel.org ([140.211.167.34]:39243 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753884AbZGKRZ7 (ORCPT ); Sat, 11 Jul 2009 13:25:59 -0400 Date: Sat, 11 Jul 2009 17:25:31 GMT From: tip-bot for Arnaldo Carvalho de Melo To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1247325517-12272-4-git-send-email-acme@redhat.com> References: <1247325517-12272-4-git-send-email-acme@redhat.com> Subject: [tip:perfcounters/core] perf_counter tools: PLT info is stripped in -debuginfo packages Message-ID: Git-Commit-ID: a25e46c46311316cd1b3f27f8bb036df1693c032 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sat, 11 Jul 2009 17:25:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7765 Lines: 252 Commit-ID: a25e46c46311316cd1b3f27f8bb036df1693c032 Gitweb: http://git.kernel.org/tip/a25e46c46311316cd1b3f27f8bb036df1693c032 Author: Arnaldo Carvalho de Melo AuthorDate: Sat, 11 Jul 2009 12:18:36 -0300 Committer: Ingo Molnar CommitDate: Sat, 11 Jul 2009 19:20:26 +0200 perf_counter tools: PLT info is stripped in -debuginfo packages So we need to get the richer .symtab from the debuginfo packages but the PLT info from the original DSO where we have just the leaner .dynsym symtab. Example: | [acme@doppio pahole]$ perf report --sort comm,dso,symbol > before | [acme@doppio pahole]$ perf report --sort comm,dso,symbol > after | [acme@doppio pahole]$ diff -U1 before after | --- before 2009-07-11 11:04:22.688595741 -0300 | +++ after 2009-07-11 11:04:33.380595676 -0300 | @@ -80,3 +80,2 @@ | 0.07% pahole ./build/pahole [.] pahole_stealer | - 0.06% pahole /usr/lib64/libdw-0.141.so [.] 0x00000000007140 | 0.06% pahole /usr/lib64/libdw-0.141.so [.] __libdw_getabbrev | @@ -91,2 +90,3 @@ | 0.06% pahole [kernel] [k] free_hot_cold_page | + 0.06% pahole /usr/lib64/libdw-0.141.so [.] tfind@plt | 0.05% pahole ./build/libdwarves.so.1.0.0 [.] ftype__add_parameter | @@ -242,2 +242,3 @@ | 0.01% pahole [kernel] [k] account_group_user_time | + 0.01% pahole /usr/lib64/libdw-0.141.so [.] strlen@plt | 0.01% pahole ./build/pahole [.] strcmp@plt | [acme@doppio pahole]$ Signed-off-by: Arnaldo Carvalho de Melo LKML-Reference: <1247325517-12272-4-git-send-email-acme@redhat.com> Signed-off-by: Ingo Molnar --- tools/perf/util/symbol.c | 116 ++++++++++++++++++++++++++-------------------- 1 files changed, 65 insertions(+), 51 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 8efe7e4..f40266b 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -374,36 +374,61 @@ static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, idx < nr_entries; \ ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) -static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf, - GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym, - GElf_Shdr *shdr_dynsym, - size_t dynsym_idx, int verbose) +/* + * 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). + */ +static int dso__synthesize_plt_symbols(struct dso *self, int verbose) { uint32_t nr_rel_entries, idx; GElf_Sym sym; u64 plt_offset; GElf_Shdr shdr_plt; struct symbol *f; - GElf_Shdr shdr_rel_plt; + GElf_Shdr shdr_rel_plt, shdr_dynsym; Elf_Data *reldata, *syms, *symstrs; - Elf_Scn *scn_plt_rel, *scn_symstrs; + Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; + size_t dynsym_idx; + GElf_Ehdr ehdr; char sympltname[1024]; - int nr = 0, symidx; + Elf *elf; + int nr = 0, symidx, fd, err = 0; + + fd = open(self->name, O_RDONLY); + if (fd < 0) + goto out; + + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (elf == NULL) + goto out_close; + + if (gelf_getehdr(elf, &ehdr) == NULL) + goto out_elf_end; + + scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym, + ".dynsym", &dynsym_idx); + if (scn_dynsym == NULL) + goto out_elf_end; - scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt, + 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, + scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, ".rel.plt", NULL); if (scn_plt_rel == NULL) - return 0; + goto out_elf_end; } + err = -1; + if (shdr_rel_plt.sh_link != dynsym_idx) - return 0; + goto out_elf_end; - if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL) - return 0; + if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) + goto out_elf_end; /* * Fetch the relocation section to find the indexes to the GOT @@ -411,19 +436,19 @@ static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf, */ reldata = elf_getdata(scn_plt_rel, NULL); if (reldata == NULL) - return -1; + goto out_elf_end; syms = elf_getdata(scn_dynsym, NULL); if (syms == NULL) - return -1; + goto out_elf_end; - scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link); + scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); if (scn_symstrs == NULL) - return -1; + goto out_elf_end; symstrs = elf_getdata(scn_symstrs, NULL); if (symstrs == NULL) - return -1; + goto out_elf_end; nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; plt_offset = shdr_plt.sh_offset; @@ -442,7 +467,7 @@ static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf, f = symbol__new(plt_offset, shdr_plt.sh_entsize, sympltname, self->sym_priv_size, 0, verbose); if (!f) - return -1; + goto out_elf_end; dso__insert_symbol(self, f); ++nr; @@ -460,19 +485,25 @@ static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf, f = symbol__new(plt_offset, shdr_plt.sh_entsize, sympltname, self->sym_priv_size, 0, verbose); if (!f) - return -1; + goto out_elf_end; dso__insert_symbol(self, f); ++nr; } - } else { - /* - * TODO: There are still one more shdr_rel_plt.sh_type - * I have to investigate, but probably should be ignored. - */ } - return nr; + err = 0; +out_elf_end: + elf_end(elf); +out_close: + close(fd); + + if (err == 0) + return nr; +out: + fprintf(stderr, "%s: problems reading %s PLT info.\n", + __func__, self->name); + return 0; } static int dso__load_sym(struct dso *self, int fd, const char *name, @@ -486,9 +517,8 @@ static int dso__load_sym(struct dso *self, int fd, const char *name, GElf_Shdr shdr; Elf_Data *syms; GElf_Sym sym; - Elf_Scn *sec, *sec_dynsym, *sec_strndx; + Elf_Scn *sec, *sec_strndx; Elf *elf; - size_t dynsym_idx; int nr = 0; elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); @@ -505,32 +535,11 @@ static int dso__load_sym(struct dso *self, int fd, const char *name, goto out_elf_end; } - /* - * 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) - */ - sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr, - ".dynsym", &dynsym_idx); - if (sec_dynsym != NULL) { - nr = dso__synthesize_plt_symbols(self, elf, &ehdr, - sec_dynsym, &shdr, - dynsym_idx, verbose); - if (nr < 0) - goto out_elf_end; - } - - /* - * But if we have a full .symtab (that is a superset of .dynsym) we - * should add the symbols not in the .dynsyn - */ sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL); if (sec == NULL) { - if (sec_dynsym == NULL) + sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL); + if (sec == NULL) goto out_elf_end; - - sec = sec_dynsym; - gelf_getshdr(sec, &shdr); } syms = elf_getdata(sec, NULL); @@ -669,6 +678,11 @@ more: if (!ret) goto more; + if (ret > 0) { + int nr_plt = dso__synthesize_plt_symbols(self, verbose); + if (nr_plt > 0) + ret += nr_plt; + } out: free(name); return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/