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Commit 82164161 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by Ingo Molnar
Browse files

perf symbols: Call the symbol filter in dso__synthesize_plt_symbols() 



We need to pass the symbol to the filter so that, for instance,
'perf top' can do filtering and also set the private area it
manages, setting the ->map pointer, etc.

I found this while running 'perf top' on a machine where hits
happened on PLT symbols, where ->map wasn't being set up and
segfaults thus happened.

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1258386491-20278-1-git-send-email-acme@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 559fdc3c

tools/perf/util/symbol.c

+20 −6
Original line number Diff line number Diff line
@@ -281,6 +281,11 @@ static int kernel_maps__load_all_kallsyms(void) 
		if (sym == NULL)

			goto out_delete_line;



		/*

		 * We will pass the symbols to the filter later, in

		 * kernel_maps__split_kallsyms, when we have split the

		 * maps per module

		 */

		dso__insert_symbol(kernel_map->dso, sym);

	}
@@ -555,7 +560,8 @@ static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, 
 * 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)

static int dso__synthesize_plt_symbols(struct  dso *self, struct map *map,

				       symbol_filter_t filter)

{

	uint32_t nr_rel_entries, idx;

	GElf_Sym sym;
@@ -643,9 +649,13 @@ static int dso__synthesize_plt_symbols(struct dso *self) 
			if (!f)

				goto out_elf_end;



			if (filter && filter(map, f))

				symbol__delete(f);

			else {

				dso__insert_symbol(self, 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,
@@ -661,10 +671,14 @@ static int dso__synthesize_plt_symbols(struct dso *self) 
			if (!f)

				goto out_elf_end;



			if (filter && filter(map, f))

				symbol__delete(f);

			else {

				dso__insert_symbol(self, f);

				++nr;

			}

		}

	}



	err = 0;

out_elf_end:
@@ -1050,7 +1064,7 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter) 
		goto more;



	if (ret > 0) {

		int nr_plt = dso__synthesize_plt_symbols(self);

		int nr_plt = dso__synthesize_plt_symbols(self, map, filter);

		if (nr_plt > 0)

			ret += nr_plt;

	}