diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-10-27 00:41:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:16:42 +0300 |
| commit | 677c9ad9839ced509be7a91cbff4cb7027a9f8de (patch) | |
| tree | c17f21c06f69ec0c99789f0b1adbe924e40a7d62 /kernel/bpf | |
| parent | ae1fffdf3b95d7ef2dbcc5aeab80db2a2ce06cb5 (diff) | |
| download | linux-677c9ad9839ced509be7a91cbff4cb7027a9f8de.tar.xz | |
bpf: Fixes possible race in update_prog_stats() for 32bit arches
[ Upstream commit d979617aa84d96acca44c2f5778892b4565e322f ]
It seems update_prog_stats() suffers from same issue fixed
in the prior patch:
As it can run while interrupts are enabled, it could
be re-entered and the u64_stats syncp could be mangled.
Fixes: fec56f5890d9 ("bpf: Introduce BPF trampoline")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-3-eric.dumazet@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/trampoline.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index fe1e857324e6..d3a307a8c42b 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -585,11 +585,13 @@ static void notrace update_prog_stats(struct bpf_prog *prog, * Hence check that 'start' is valid. */ start > NO_START_TIME) { + unsigned long flags; + stats = this_cpu_ptr(prog->stats); - u64_stats_update_begin(&stats->syncp); + flags = u64_stats_update_begin_irqsave(&stats->syncp); stats->cnt++; stats->nsecs += sched_clock() - start; - u64_stats_update_end(&stats->syncp); + u64_stats_update_end_irqrestore(&stats->syncp, flags); } } |