Commit 99ca4233 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarMasami 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e53b00d3

tools/perf/util/probe-event.c

+28 −48
Original line number Diff line number Diff line
@@ -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)

{

tools/perf/util/symbol-elf.c

+2 −3
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/symbol.h

+5 −0
Original line number Diff line number Diff line
@@ -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 */

tools/perf/util/unwind.c

+2 −18
Original line number Diff line number Diff line
@@ -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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