linux/tools
Namhyung Kim 4a86d41404 perf tools: Allow build-id with trailing zeros
Currently perf saves a build-id with size but old versions assumes the
size of 20.  In case the build-id is less than 20 (like for MD5), it'd
fill the rest with 0s.

I saw a problem when old version of perf record saved a binary in the
build-id cache and new version of perf reads the data.  The symbols
should be read from the build-id cache (as the path no longer has the
same binary) but it failed due to mismatch in the build-id.

  symsrc__init: build id mismatch for /home/namhyung/.debug/.build-id/53/e4c2f42a4c61a2d632d92a72afa08f00000000/elf.

The build-id event in the data has 20 byte build-ids, but it saw a
different size (16) when it reads the build-id of the elf file in the
build-id cache.

  $ readelf -n ~/.debug/.build-id/53/e4c2f42a4c61a2d632d92a72afa08f00000000/elf

  Displaying notes found in: .note.gnu.build-id
    Owner                Data size 	Description
    GNU                  0x00000010	NT_GNU_BUILD_ID (unique build ID bitstring)
      Build ID: 53e4c2f42a4c61a2d632d92a72afa08f

Let's fix this by allowing trailing zeros if the size is different.

Fixes: 39be8d0115 ("perf tools: Pass build_id object to dso__build_id_equal()")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210910224630.1084877-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-09-11 16:04:47 -03:00
..
accounting
arch tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources 2021-09-10 18:15:22 -03:00
bootconfig tools/bootconfig: Show whole test command for each test case 2021-09-08 15:29:16 -04:00
bpf Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-07-31 11:23:26 -07:00
build perf cs-etm: Update OpenCSD decoder for ETE 2021-09-03 08:16:00 -03:00
cgroup
debugging tools: Fix "the the" in a message in kernel-chktaint 2021-06-13 17:01:17 -06:00
edid
firewire
firmware
gpio
hv
iio
include tools include UAPI: Update linux/mount.h copy 2021-09-10 18:15:22 -03:00
io_uring tools/io_uring/io_uring-cp: sync with liburing example 2021-08-13 08:58:11 -06:00
kvm/kvm_stat tools/kvm_stat: Fix documentation typo 2021-05-07 06:06:22 -04:00
laptop
leds
lib perf tools changes for v5.15: 2021-09-05 11:56:18 -07:00
memory-model tools/memory-model: Document data_race(READ_ONCE()) 2021-07-27 11:48:55 -07:00
objtool A single ELF format fix for a section flags mismatch bug that breaks 2021-06-28 11:35:55 -07:00
pci tools: PCI: Zero-initialize param 2021-08-05 11:01:30 +01:00
pcmcia
perf perf tools: Allow build-id with trailing zeros 2021-09-11 16:04:47 -03:00
power tools/power/x86/intel-speed-select: v1.10 release 2021-06-18 15:29:32 +02:00
rcu tools/rcu: Add drgn script to dump number of RCU callbacks 2021-05-10 15:39:19 -07:00
scripts tools build: Fix quiet cmd indentation 2021-05-17 12:10:03 +09:00
spi
testing More tracing updates for 5.15: 2021-09-09 13:11:15 -07:00
thermal/tmon
time
tracing
usb treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
virtio tools/virtio: fix build 2021-08-11 06:44:24 -04:00
vm tools/vm/page_owner_sort.c: check malloc() return 2021-06-29 10:53:47 -07:00
wmi
Makefile