bpf: Fix possible race in inc_misses_counter
authorHe Fengqing <hefengqing@huawei.com>
Sat, 22 Jan 2022 10:29:36 +0000 (10:29 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 8 Mar 2022 18:12:40 +0000 (19:12 +0100)
commit07058fb18df8285518236e4625f4f61a4c594703
treee19cf7e11938bcc5505a1a87d145b492c92bcdbf
parentaa5040691cb761a04c206a893e5771a904d22ab7
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>
kernel/bpf/trampoline.c