[tip:perf/core] perf symbols: Export elf_section_by_name and reuse
From: tip-bot for Masami Hiramatsu
Date: Sun Jan 19 2014 - 07:26:46 EST
Commit-ID: 99ca423387a3e718f9887a99475cb5271bc610f2
Gitweb: http://git.kernel.org/tip/99ca423387a3e718f9887a99475cb5271bc610f2
Author: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
AuthorDate: Thu, 16 Jan 2014 09:39:49 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 16 Jan 2014 16:29:44 -0300
perf symbols: Export elf_section_by_name and reuse
Remove duplicated elf_section_by_name() functions from unwind.c and
probe-event.c and use one exported elf_section_by_name() instance
defined in symbol-elf.c.
Note that this also moves get_text_start_address() to merge
HAVE_DWARF_SUPPORT defined area.
Reported-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: "David A. Long" <dave.long@xxxxxxxxxx>
Cc: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: yrl.pp-manager.tt@xxxxxxxxxxx
Link: http://lkml.kernel.org/r/20140116093949.24403.38093.stgit@xxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/probe-event.c | 76 ++++++++++++++++---------------------------
tools/perf/util/symbol-elf.c | 5 ++-
tools/perf/util/symbol.h | 5 +++
tools/perf/util/unwind.c | 20 ++----------
4 files changed, 37 insertions(+), 69 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index c68711c..a8a9b6c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -173,54 +173,6 @@ const char *kernel_get_module_path(const char *module)
return (dso) ? dso->long_name : NULL;
}
-#ifdef HAVE_DWARF_SUPPORT
-/* Copied from unwind.c */
-static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
- GElf_Shdr *shp, const char *name)
-{
- Elf_Scn *sec = NULL;
-
- while ((sec = elf_nextscn(elf, sec)) != NULL) {
- char *str;
-
- gelf_getshdr(sec, shp);
- str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
- if (!strcmp(name, str))
- break;
- }
-
- return sec;
-}
-
-static int get_text_start_address(const char *exec, unsigned long *address)
-{
- Elf *elf;
- GElf_Ehdr ehdr;
- GElf_Shdr shdr;
- int fd, ret = -ENOENT;
-
- fd = open(exec, O_RDONLY);
- if (fd < 0)
- return -errno;
-
- elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
- if (elf == NULL)
- return -EINVAL;
-
- if (gelf_getehdr(elf, &ehdr) == NULL)
- goto out;
-
- if (!elf_section_by_name(elf, &ehdr, &shdr, ".text"))
- goto out;
-
- *address = shdr.sh_addr - shdr.sh_offset;
- ret = 0;
-out:
- elf_end(elf);
- return ret;
-}
-#endif
-
static int init_user_exec(void)
{
int ret = 0;
@@ -341,6 +293,34 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
return 0;
}
+static int get_text_start_address(const char *exec, unsigned long *address)
+{
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ int fd, ret = -ENOENT;
+
+ fd = open(exec, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ return -EINVAL;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL)
+ goto out;
+
+ if (!elf_section_by_name(elf, &ehdr, &shdr, ".text", NULL))
+ goto out;
+
+ *address = shdr.sh_addr - shdr.sh_offset;
+ ret = 0;
+out:
+ elf_end(elf);
+ return ret;
+}
+
static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *exec)
{
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 4b0a127..7594567 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -136,9 +136,8 @@ static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
return -1;
}
-static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
- GElf_Shdr *shp, const char *name,
- size_t *idx)
+Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+ GElf_Shdr *shp, const char *name, size_t *idx)
{
Elf_Scn *sec = NULL;
size_t cnt = 1;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index cbd6803..fffe288 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -52,6 +52,11 @@ static inline char *bfd_demangle(void __maybe_unused *v,
# define PERF_ELF_C_READ_MMAP ELF_C_READ
#endif
+#ifdef HAVE_LIBELF_SUPPORT
+extern Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+ GElf_Shdr *shp, const char *name, size_t *idx);
+#endif
+
#ifndef DMGL_PARAMS
#define DMGL_PARAMS (1 << 0) /* Include function args */
#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c
index 416f22b..742f23b 100644
--- a/tools/perf/util/unwind.c
+++ b/tools/perf/util/unwind.c
@@ -28,6 +28,7 @@
#include "session.h"
#include "perf_regs.h"
#include "unwind.h"
+#include "symbol.h"
#include "util.h"
extern int
@@ -158,23 +159,6 @@ static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val,
__v; \
})
-static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
- GElf_Shdr *shp, const char *name)
-{
- Elf_Scn *sec = NULL;
-
- while ((sec = elf_nextscn(elf, sec)) != NULL) {
- char *str;
-
- gelf_getshdr(sec, shp);
- str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
- if (!strcmp(name, str))
- break;
- }
-
- return sec;
-}
-
static u64 elf_section_offset(int fd, const char *name)
{
Elf *elf;
@@ -190,7 +174,7 @@ static u64 elf_section_offset(int fd, const char *name)
if (gelf_getehdr(elf, &ehdr) == NULL)
break;
- if (!elf_section_by_name(elf, &ehdr, &shdr, name))
+ if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL))
break;
offset = shdr.sh_offset;
--
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