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Filename Latest commit message Latest commit date
Qi Liu 7fc7942f52 drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling
[ Upstream commit bdc5c744c7b6457d18a95c26769dad0e7f480a08 ]

When users try to remove PMU modules during perf sampling, kernel panic
will happen because the pmu->read() is a NULL pointer here.

INFO on HiSilicon hip08 platform as follow:
pc : hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu]
lr : hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu]
sp : ffff800010103e90
x29: ffff800010103e90 x28: ffff0027db0c0e40
x27: ffffa29a76f129d8 x26: ffffa29a77ceb000
x25: ffffa29a773a5000 x24: ffffa29a77392000
x23: ffffddffe5943f08 x22: ffff002784285960
x21: ffff002784285800 x20: ffff0027d2e76c80
x19: ffff0027842859e0 x18: ffff80003498bcc8
x17: ffffa29a76afe910 x16: ffffa29a7583f530
x15: 16151a1512061a1e x14: 0000000000000000
x13: ffffa29a76f1e238 x12: 0000000000000001
x11: 0000000000000400 x10: 00000000000009f0
x9 : ffff8000107b3e70 x8 : ffff0027db0c1890
x7 : ffffa29a773a7000 x6 : 00000007f5131013
x5 : 00000007f5131013 x4 : 09f257d417c00000
x3 : 00000002187bd7ce x2 : ffffa29a38f0f0d8
x1 : ffffa29a38eae268 x0 : ffff0027d2e76c80
Call trace:
hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu]
hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu]
__perf_event_read+0x1a0/0x1f8
flush_smp_call_function_queue+0xa0/0x160
generic_smp_call_function_single_interrupt+0x18/0x20
handle_IPI+0x31c/0x4dc
gic_handle_irq+0x2c8/0x310
el1_irq+0xcc/0x180
arch_cpu_idle+0x4c/0x20c
default_idle_call+0x20/0x30
do_idle+0x1b4/0x270
cpu_startup_entry+0x28/0x30
secondary_start_kernel+0x1a4/0x1fc

To solve the above issue, current module should be registered to kernel,
so that try_module_get() can be invoked when perf sampling starts. This
adds the reference counting of module and could prevent users from removing
modules during sampling.

Reported-by: Haifeng Wang <wang.wanghaifeng@huawei.com>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1594891165-8228-1-git-send-email-liuqi115@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-29 10:18:40 +02:00
arch ARM: dts: n900: remove mmc1 card detect gpio 2020-07-29 10:18:36 +02:00
block block: fix get_max_segment_size() overflow on 32bit arch 2020-07-22 09:33:17 +02:00
certs
crypto keys: asymmetric: fix error return code in software_key_query() 2020-07-22 09:33:04 +02:00
Documentation doc: dt: bindings: usb: dwc3: Update entries for disabling SS instances in park mode 2020-07-22 09:32:59 +02:00
drivers drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling 2020-07-29 10:18:40 +02:00
fs nfsd4: fix NULL dereference in nfsd/clients display code 2020-07-29 10:18:34 +02:00
include Input: add SW_MACHINE_COVER 2020-07-29 10:18:36 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression 2020-07-29 10:18:29 +02:00
lib test_objagg: Fix potential memory leak in error handling 2020-06-30 15:37:04 -04:00
LICENSES
mm mm, compaction: make capture control handling safe wrt interrupts 2020-07-09 09:37:57 +02:00
net ipvs: fix the connection sync failed in some cases 2020-07-29 10:18:34 +02:00
samples samples/vfs: avoid warning in statx override 2020-07-09 09:37:54 +02:00
scripts scripts/gdb: fix lx-symbols 'gdb.error' while loading modules 2020-07-29 10:18:35 +02:00
security apparmor: ensure that dfa state tables have entries 2020-07-22 09:33:05 +02:00
sound ALSA: hda/realtek - fixup for yet another Intel reference board 2020-07-29 10:18:39 +02:00
tools perf stat: Zero all the 'ena' and 'run' array slot stats for interval mode 2020-07-22 09:33:05 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Save the host's PtrAuth keys in non-preemptible context 2020-06-17 16:40:38 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 17:22:19 +01:00
Makefile Linux 5.4.53 2020-07-22 09:33:18 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.