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perf symbols: Export elf_section_by_name and reuse

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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@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140116093949.24403.38093.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2014-01-16 09:39:49 +00:00 committed by Arnaldo Carvalho de Melo
parent e53b00d382
commit 99ca423387
4 changed files with 37 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
tools/perf/util/probe-event.c
View File

@ -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)
{

5
tools/perf/util/symbol-elf.c
View File

@ -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;

5
tools/perf/util/symbol.h
View File

@ -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 */

20
tools/perf/util/unwind.c
View File

@ -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;