diff options
author | Adrian Hunter <adrian.hunter@intel.com> | 2015-09-24 13:05:22 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-09-25 16:45:50 +0300 |
commit | b5cabbcbd157a4bf5a92dfc85134999a3b55342d (patch) | |
tree | 48871ad6649fa8e34a3c9fe6e4683e088f781b5a /tools/perf/util/symbol-elf.c | |
parent | 597ee40722bf05195f91a41e88e15b79bdab152c (diff) | |
download | linux-b5cabbcbd157a4bf5a92dfc85134999a3b55342d.tar.xz |
perf tools: Fix copying of /proc/kcore
A copy of /proc/kcore containing the kernel text can be made to the
buildid cache. e.g.
perf buildid-cache -v -k /proc/kcore
To workaround objdump limitations, a copy is also made when annotating
against /proc/kcore.
The copying process stops working from libelf about v1.62 onwards (the
problem was found with v1.63).
The cause is that a call to gelf_getphdr() in kcore__add_phdr() fails
because additional validation has been added to gelf_getphdr().
The use of gelf_getphdr() is a misguided attempt to get default
initialization of the Gelf_Phdr structure. That should not be
necessary because every member of the Gelf_Phdr structure is
subsequently assigned. So just remove the call to gelf_getphdr().
Similarly, a call to gelf_getehdr() in gelf_kcore__init() can be
removed also.
Committer notes:
Note to stable@kernel.org, from Adrian in the cover letter for this
patchkit:
The "Fix copying of /proc/kcore" problem goes back to v3.13 if you think
it is important enough for stable.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1443089122-19082-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/symbol-elf.c')
-rw-r--r-- | tools/perf/util/symbol-elf.c | 35 |
1 files changed, 13 insertions, 22 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index f78ea3dc4c08..475d88d0a1c9 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1271,8 +1271,6 @@ out_close: static int kcore__init(struct kcore *kcore, char *filename, int elfclass, bool temp) { - GElf_Ehdr *ehdr; - kcore->elfclass = elfclass; if (temp) @@ -1289,9 +1287,7 @@ static int kcore__init(struct kcore *kcore, char *filename, int elfclass, if (!gelf_newehdr(kcore->elf, elfclass)) goto out_end; - ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); - if (!ehdr) - goto out_end; + memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr)); return 0; @@ -1348,23 +1344,18 @@ static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count) static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset, u64 addr, u64 len) { - GElf_Phdr gphdr; - GElf_Phdr *phdr; - - phdr = gelf_getphdr(kcore->elf, idx, &gphdr); - if (!phdr) - return -1; - - phdr->p_type = PT_LOAD; - phdr->p_flags = PF_R | PF_W | PF_X; - phdr->p_offset = offset; - phdr->p_vaddr = addr; - phdr->p_paddr = 0; - phdr->p_filesz = len; - phdr->p_memsz = len; - phdr->p_align = page_size; - - if (!gelf_update_phdr(kcore->elf, idx, phdr)) + GElf_Phdr phdr = { + .p_type = PT_LOAD, + .p_flags = PF_R | PF_W | PF_X, + .p_offset = offset, + .p_vaddr = addr, + .p_paddr = 0, + .p_filesz = len, + .p_memsz = len, + .p_align = page_size, + }; + + if (!gelf_update_phdr(kcore->elf, idx, &phdr)) return -1; return 0; |