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Leo Yan c4d5493757 perf lock: Don't free "lock_seq_stat" if read_count isn't zero
[ Upstream commit b0e5a05cc9 ]

When execute command "perf lock report", it hits failure and outputs log
as follows:

  perf: builtin-lock.c:623: report_lock_release_event: Assertion `!(seq->read_count < 0)' failed.
  Aborted

This is an imbalance issue.  The locking sequence structure
"lock_seq_stat" contains the reader counter and it is used to check if
the locking sequence is balance or not between acquiring and releasing.

If the tool wrongly frees "lock_seq_stat" when "read_count" isn't zero,
the "read_count" will be reset to zero when allocate a new structure at
the next time; thus it causes the wrong counting for reader and finally
results in imbalance issue.

To fix this issue, if detects "read_count" is not zero (means still have
read user in the locking sequence), goto the "end" tag to skip freeing
structure "lock_seq_stat".

Fixes: e4cef1f650 ("perf lock: Fix state machine to recognize lock sequence")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20201104094229.17509-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:27:21 +01:00
arch ARM: dts: imx50-evk: Fix the chip select 1 IOMUX 2020-11-24 13:27:21 +01:00
block blk-cgroup: Pre-allocate tree node on blkg_conf_prep 2020-11-10 12:35:59 +01:00
certs
crypto crypto: algif_skcipher - EBUSY on aio should be an error 2020-10-29 09:55:01 +01:00
Documentation powerpc/64s: flush L1D after user accesses 2020-11-22 10:02:26 +01:00
drivers Input: resistive-adc-touch - fix kconfig dependency on IIO_BUFFER 2020-11-24 13:27:21 +01:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:21:29 +01:00
fs vfs: remove lockdep bogosity in __sb_start_write 2020-11-24 13:27:20 +01:00
include random32: make prandom_u32() output unpredictable 2020-11-18 19:18:52 +01:00
init printk: reduce LOG_BUF_SHIFT range for H8300 2020-11-05 11:08:41 +01:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:18:40 +02:00
kernel reboot: fix overflow parsing reboot cpu number 2020-11-18 19:18:52 +01:00
lib random32: make prandom_u32() output unpredictable 2020-11-18 19:18:52 +01:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm page_frag: Recover from memory pressure 2020-11-24 13:27:18 +01:00
net net/ncsi: Fix netlink registration 2020-11-24 13:27:19 +01:00
samples misc: vop: add round_up(x,4) for vring_size to avoid kernel panic 2020-10-30 10:38:29 +01:00
scripts scripts/setlocalversion: make git describe output more reliable 2020-11-05 11:08:31 +01:00
security selinux: Fix error return code in sel_ib_pkey_sid_slow() 2020-11-18 19:18:50 +01:00
sound ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link() 2020-11-18 19:18:42 +01:00
tools perf lock: Don't free "lock_seq_stat" if read_count isn't zero 2020-11-24 13:27:21 +01:00
usr initramfs: restore default compression behavior 2020-04-13 10:44:59 +02:00
virt KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch 2020-10-01 13:14:54 +02:00
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.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
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MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-09-26 18:01:31 +02:00
Makefile Linux 4.19.159 2020-11-22 10:02:27 +01:00
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