[PATCH 13/16] perf symbol: switch dso__synthesize_plt_symbols() to use symsrc

[Cody P Schafer <cody@linux.vnet.ibm.com>]

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 symbol: use both runtime and debug images"

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
---
 tools/perf/util/symbol.c | 33 ++++++++++++---------------------
 1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 61b9cdb..f8fbde2 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1149,7 +1149,7 @@ out_close:
  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
  */
 static int
-dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
+dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
 			    symbol_filter_t filter)
 {
 	uint32_t nr_rel_entries, idx;
@@ -1164,21 +1164,15 @@ 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;
 
@@ -1274,13 +1268,8 @@ 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;
@@ -1960,21 +1949,23 @@ restart:
 
 		ret = dso__load_sym(dso, map, &ss, filter, 0,
 				    want_symtab);
-		symsrc__destroy(&ss);
 
 		/*
 		 * Some people seem to have debuginfo files _WITHOUT_ debug
 		 * info!?!?
 		 */
-		if (!ret)
+		if (!ret) {
+			symsrc__destroy(&ss);
 			continue;
+		}
 
 		if (ret > 0) {
 			int nr_plt;
 
-			nr_plt = dso__synthesize_plt_symbols(dso, name, map, filter);
+			nr_plt = dso__synthesize_plt_symbols(dso, &ss, map, filter);
 			if (nr_plt > 0)
 				ret += nr_plt;
+			symsrc__destroy(&ss);
 			break;
 		}
 	}
-- 
1.7.11.3