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| author | Libing Zhou <libing.zhou@nokia-sbell.com> | 2020-08-20 10:56:41 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-29 10:11:02 +0100 |
| commit | 537a9156a67aeec0a8491000aeb842e9dbfda265 (patch) | |
| tree | b4b4d8fe4b316fbeb0bdad68a1e02095cfb564c6 /arch | |
| parent | 86a891c752af3db9635d429204fc6f8218e95ab8 (diff) | |
| download | linux-stable-537a9156a67aeec0a8491000aeb842e9dbfda265.tar.gz linux-stable-537a9156a67aeec0a8491000aeb842e9dbfda265.tar.bz2 linux-stable-537a9156a67aeec0a8491000aeb842e9dbfda265.zip | |
x86/nmi: Fix nmi_handle() duration miscalculation
[ Upstream commit f94c91f7ba3ba7de2bc8aa31be28e1abb22f849e ]
When nmi_check_duration() is checking the time an NMI handler took to
execute, the whole_msecs value used should be read from the @duration
argument, not from the ->max_duration, the latter being used to store
the current maximal duration.
[ bp: Rewrite commit message. ]
Fixes: 248ed51048c4 ("x86/nmi: Remove irq_work from the long duration NMI handler")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Libing Zhou <libing.zhou@nokia-sbell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Changbin Du <changbin.du@gmail.com>
Link: https://lkml.kernel.org/r/20200820025641.44075-1-libing.zhou@nokia-sbell.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/nmi.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 4fc9954a9560..47381666d6a5 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -102,7 +102,6 @@ fs_initcall(nmi_warning_debugfs); static void nmi_check_duration(struct nmiaction *action, u64 duration) { - u64 whole_msecs = READ_ONCE(action->max_duration); int remainder_ns, decimal_msecs; if (duration < nmi_longest_ns || duration < action->max_duration) @@ -110,12 +109,12 @@ static void nmi_check_duration(struct nmiaction *action, u64 duration) action->max_duration = duration; - remainder_ns = do_div(whole_msecs, (1000 * 1000)); + remainder_ns = do_div(duration, (1000 * 1000)); decimal_msecs = remainder_ns / 1000; printk_ratelimited(KERN_INFO "INFO: NMI handler (%ps) took too long to run: %lld.%03d msecs\n", - action->handler, whole_msecs, decimal_msecs); + action->handler, duration, decimal_msecs); } static int nmi_handle(unsigned int type, struct pt_regs *regs) |