imrcpan/erofs-linux
1
0 Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git synced 2026-11-03 16:13:17 +01:00
Code Issues Packages Projects Releases Wiki Activity

perf symbols: Filename__read_build_id should look at .notes section too

Browse Source 
In the kernel we have more than one notes section, so the linker
script combines all and puts them into a ".notes" combined
section. So we need to look at both sections and also traverse
them looking at multiple GElf_Nhdr entries till we find the one
we want, with the build_id.

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frédéric Weisbecker <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Arnaldo Carvalho de Melo authored and Ingo Molnar committed 2009-11-21 14:11:32 +01:00
1 parent 6671cb1674
commit fd7a346ea2
1 file changed
+38 -9
Download Patch File Download Diff File Expand all files Collapse all files
tools/perf/util/symbol.c
+38 -9
View File
@@ -899,13 +899,19 @@ bool dsos__read_build_ids(void)
return have_build_id;
}
/*
* Align offset to 4 bytes as needed for note name and descriptor data.
*/
#define NOTE_ALIGN(n) (((n) + 3) & -4U)
int filename__read_build_id(const char *filename, void *bf, size_t size)
{
int fd, err = -1;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *build_id_data;
Elf_Data *data;
Elf_Scn *sec;
void *ptr;
Elf *elf;
if (size < BUILD_ID_SIZE)
@@ -928,14 +934,37 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note.gnu.build-id", NULL);
if (sec == NULL)
if (sec == NULL) {
sec = elf_section_by_name(elf, &ehdr, &shdr,
".notes", NULL);
if (sec == NULL)
goto out_elf_end;
}
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out_elf_end;
build_id_data = elf_getdata(sec, NULL);
if (build_id_data == NULL)
goto out_elf_end;
memcpy(bf, build_id_data->d_buf + 16, BUILD_ID_SIZE);
err = BUILD_ID_SIZE;
ptr = data->d_buf;
while (ptr < (data->d_buf + data->d_size)) {
GElf_Nhdr *nhdr = ptr;
int namesz = NOTE_ALIGN(nhdr->n_namesz),
descsz = NOTE_ALIGN(nhdr->n_descsz);
const char *name;
ptr += sizeof(*nhdr);
name = ptr;
ptr += namesz;
if (nhdr->n_type == NT_GNU_BUILD_ID &&
nhdr->n_namesz == sizeof("GNU")) {
if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
memcpy(bf, ptr, BUILD_ID_SIZE);
err = BUILD_ID_SIZE;
break;
}
}
ptr += descsz;
}
out_elf_end:
elf_end(elf);
out_close:
@@ -963,8 +992,8 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
break;
namesz = (nhdr.n_namesz + 3) & -4U;
descsz = (nhdr.n_descsz + 3) & -4U;
namesz = NOTE_ALIGN(nhdr.n_namesz);
descsz = NOTE_ALIGN(nhdr.n_descsz);
if (nhdr.n_type == NT_GNU_BUILD_ID &&
nhdr.n_namesz == sizeof("GNU")) {
if (read(fd, bf, namesz) != namesz)