perf symbols: Switch dso__synthesize_plt_symbols() to use symsrc

Previously dso__synthesize_plt_symbols() was reopening the elf file to
obtain dynsyms from it. Rather than reopen the file, use the already
opened reference within the symsrc to access it.

Setup for the later patch

"perf symbols: Use both runtime and debug images"

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matt Hellsley <matthltc@us.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1344637382-22789-14-git-send-email-cody@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 7 insertions, 18 deletions

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 3a9c38a39bc9..591594775904 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -166,7 +166,7 @@ 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).
  */
-int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
+int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
 				symbol_filter_t filter)
 {
 	uint32_t nr_rel_entries, idx;
@@ -181,21 +181,15 @@ int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
 	GElf_Ehdr ehdr;
 	char sympltname[1024];
 	Elf *elf;
-	int nr = 0, symidx, fd, err = 0;
+	int nr = 0, symidx, err = 0;
 
-	fd = open(name, O_RDONLY);
-	if (fd < 0)
-		goto out;
-
-	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
-	if (elf == NULL)
-		goto out_close;
+	elf = ss->elf;
+	ehdr = ss->ehdr;
 
-	if (gelf_getehdr(elf, &ehdr) == NULL)
-		goto out_elf_end;
+	scn_dynsym = ss->dynsym;
+	shdr_dynsym = ss->dynshdr;
+	dynsym_idx = ss->dynsym_idx;
 
-	scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
-					 ".dynsym", &dynsym_idx);
 	if (scn_dynsym == NULL)
 		goto out_elf_end;
 
@@ -291,13 +285,8 @@ int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
 
 	err = 0;
 out_elf_end:
-	elf_end(elf);
-out_close:
-	close(fd);
-
 	if (err == 0)
 		return nr;
-out:
 	pr_debug("%s: problems reading %s PLT info.\n",
 		 __func__, dso->long_name);
 	return 0;