bpf: Lock bpf_trace_printk's tmp buf before it is written to
authorFlorent Revest <revest@chromium.org>
Tue, 27 Apr 2021 11:29:58 +0000 (13:29 +0200)
committerAlexei Starovoitov <ast@kernel.org>
Tue, 27 Apr 2021 15:04:34 +0000 (08:04 -0700)
commit38d26d89b31d0766d431471572cc9b007ca19c98
tree2a4348b2fd79659c65fdade471284cd6108b58ff
parent927315041828fcbead6d2ace38c6dee5af95e40f
bpf: Lock bpf_trace_printk's tmp buf before it is written to

bpf_trace_printk uses a shared static buffer to hold strings before they
are printed. A recent refactoring moved the locking of that buffer after
it gets filled by mistake.

Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf")
Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210427112958.773132-1-revest@chromium.org
kernel/trace/bpf_trace.c