From: Eric Dumazet edumazet@google.com
mainline inclusion from mainline-v5.16-rc1 commit d979617aa84d96acca44c2f5778892b4565e322f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6O293
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 Conflicts: kernel/bpf/trampoline.c Signed-off-by: Pu Lehui pulehui@huawei.com Reviewed-by: Xu Kuohai xukuohai@huawei.com Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- kernel/bpf/trampoline.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 87becf77cc75..02637c6cedde 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -526,11 +526,13 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start) * Hence check that 'start' is not zero. */ start) { + unsigned long flags; + stats = this_cpu_ptr(prog->aux->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); } migrate_enable(); rcu_read_unlock();