>From 1bacfabf8369764126758bbbea1d3963ac778cce Mon Sep 17 00:00:00 2001
From: Lu Zhigang <z...@tilera.com>
Date: Thu, 8 Nov 2012 04:31:05 -0500
Subject: [PATCH 1/1] perf symbol: Don't assume .text section is the first
section of vmlinux
The start address derived from /proc/kallsyms in is the start address of
kernel, but not the start address of .text section of kernel. If the .text
section is not at the beginning of vmlinux, perf will mess up the sections'
address range, thus failing to resolve the kernel symbols.
Verified on TILE architecture whose kernel sections are as following.
Sections:
Idx Name Size VMA LMA File off Algn
0 .intrpt1 00003fe8 fffffff700000000 0000000000000000 00010000 2**3
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .text 008485a0 fffffff700020000 0000000000020000 00020000 2**6
CONTENTS, ALLOC, LOAD, READONLY, CODE
2 .init.text 00047e88 fffffff700870000 0000000000870000 00870000 2**3
...
Signed-off-by: Lu Zhigang <z...@tilera.com>
---
tools/perf/util/symbol-elf.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index db0cc92..7fc219b 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -645,6 +645,7 @@ int dso__load_sym(struct dso *dso, struct map *map,
Elf_Scn *sec, *sec_strndx;
Elf *elf;
int nr = 0;
+ u64 kernel_start = map->start;
dso->symtab_type = syms_ss->type;
@@ -746,6 +747,7 @@ int dso__load_sym(struct dso *dso, struct map *map,
goto new_symbol;
if (strcmp(section_name, ".text") == 0) {
+ map->start = kernel_start + shdr.sh_offset;
curr_map = map;
curr_dso = dso;
goto new_symbol;
@@ -759,7 +761,7 @@ int dso__load_sym(struct dso *dso, struct map *map,
u64 start = sym.st_value;
if (kmodule)
- start += map->start + shdr.sh_offset;
+ start += kernel_start + shdr.sh_offset;
curr_dso = dso__new(dso_name);
if (curr_dso == NULL)
--
1.7.10.3
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