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| author | He Fengqing <hefengqing@huawei.com> | 2022-01-22 10:29:36 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-08 19:12:40 +0100 |
| commit | 07058fb18df8285518236e4625f4f61a4c594703 (patch) | |
| tree | e19cf7e11938bcc5505a1a87d145b492c92bcdbf | |
| parent | aa5040691cb761a04c206a893e5771a904d22ab7 (diff) | |
| download | linux-stable-07058fb18df8285518236e4625f4f61a4c594703.tar.gz linux-stable-07058fb18df8285518236e4625f4f61a4c594703.tar.bz2 linux-stable-07058fb18df8285518236e4625f4f61a4c594703.zip | |
bpf: Fix possible race in inc_misses_counter
[ Upstream commit 0e3135d3bfa5dfb658145238d2bc723a8e30c3a3 ]
It seems inc_misses_counter() suffers from same issue fixed in
the commit d979617aa84d ("bpf: Fixes possible race in update_prog_stats()
for 32bit arches"):
As it can run while interrupts are enabled, it could
be re-entered and the u64_stats syncp could be mangled.
Fixes: 9ed9e9ba2337 ("bpf: Count the number of times recursion was prevented")
Signed-off-by: He Fengqing <hefengqing@huawei.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20220122102936.1219518-1-hefengqing@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/bpf/trampoline.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 6933a9bfee63..2660fbced9ad 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -541,11 +541,12 @@ static u64 notrace bpf_prog_start_time(void) static void notrace inc_misses_counter(struct bpf_prog *prog) { struct bpf_prog_stats *stats; + unsigned int flags; stats = this_cpu_ptr(prog->stats); - u64_stats_update_begin(&stats->syncp); + flags = u64_stats_update_begin_irqsave(&stats->syncp); u64_stats_inc(&stats->misses); - u64_stats_update_end(&stats->syncp); + u64_stats_update_end_irqrestore(&stats->syncp, flags); } /* The logic is similar to bpf_prog_run(), but with an explicit |