WSL2-Linux-Kernel/tools
Alexey Budankov bb1835a3b8 perf session: Fix decompression of PERF_RECORD_COMPRESSED records
Avoid termination of trace loading in case the last record in the
decompressed buffer partly resides in the following mmaped
PERF_RECORD_COMPRESSED record.

In this case NULL value returned by fetch_mmaped_event() means to
proceed to the next mmaped record then decompress it and load compressed
events.

The issue can be reproduced like this:

  $ perf record -z -- some_long_running_workload
  $ perf report --stdio -vv
  decomp (B): 44519 to 163000
  decomp (B): 48119 to 174800
  decomp (B): 65527 to 131072
  fetch_mmaped_event: head=0x1ffe0 event->header_size=0x28, mmap_size=0x20000: fuzzed perf.data?
  Error:
  failed to process sample
  ...

Testing:

  71: Zstd perf.data compression/decompression              : Ok

  $ tools/perf/perf report -vv --stdio
  decomp (B): 59593 to 262160
  decomp (B): 4438 to 16512
  decomp (B): 285 to 880
  Looking at the vmlinux_path (8 entries long)
  Using vmlinux for symbols
  decomp (B): 57474 to 261248
  prefetch_event: head=0x3fc78 event->header_size=0x28, mmap_size=0x3fc80: fuzzed or compressed perf.data?
  decomp (B): 25 to 32
  decomp (B): 52 to 120
  ...

Fixes: 57fc032ad6 ("perf session: Avoid infinite loop when seeing invalid header.size")
Link: https://marc.info/?l=linux-kernel&m=156580812427554&w=2
Co-developed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/cf782c34-f3f8-2f9f-d6ab-145cee0d5322@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-19 19:31:55 -03:00
..
accounting
arch x86/insn: Add some Intel instructions to the opcode map 2019-11-18 18:54:45 -03:00
bpf tools: bpf: Use !building_out_of_srctree to determine srctree 2019-09-30 10:53:34 +02:00
build
cgroup iocost_monitor: Report debt 2019-09-10 12:31:39 -06:00
debugging
firewire
firmware
gpio tools: gpio: Use !building_out_of_srctree to determine srctree 2019-10-22 14:42:42 +02:00
hv - First round of vmbus hibernation support from Dexuan Cui. 2019-09-24 12:36:31 -07:00
iio
include tools headers UAPI: Sync sched.h with the kernel 2019-10-15 12:44:00 -03:00
io_uring
kvm/kvm_stat
laptop
leds
lib libtraceevent: Fix parsing of event %o and %X argument types 2019-11-18 13:01:59 -03:00
memory-model
nfsd
objtool KVM: x86: Check kvm_rebooting in kvm_spurious_fault() 2019-09-25 15:23:33 +02:00
pci
pcmcia
perf perf session: Fix decompression of PERF_RECORD_COMPRESSED records 2019-11-19 19:31:55 -03:00
power platform-drivers-x86 for v5.4-2 2019-09-24 12:39:40 -07:00
scripts
spi
testing Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-08 18:21:05 -08:00
thermal/tmon
time
usb usbip: tools: Fix read_usb_vudc_device() error path handling 2019-10-28 17:51:06 +01:00
virtio tools/virtio: xen stub 2019-10-13 09:38:27 -04:00
vm
wmi
Makefile