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authorAlexei Starovoitov <ast@kernel.org>2018-12-13 11:42:31 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2018-12-15 01:28:32 +0100
commitb233920c97a6201eb47fbafd78365c6946e6d7b6 (patch)
treeb12e159f1af740aea1e6ea95a6944e2341689e09 /kernel/bpf
parenteb415c98980fd13618c64b0d88c2439103b4a627 (diff)
bpf: speed up stacksafe check
Don't check the same stack liveness condition 8 times. once is enough. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ba8e3134bbc2..0c6deb3f2be4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5204,9 +5204,11 @@ static bool stacksafe(struct bpf_func_state *old,
for (i = 0; i < old->allocated_stack; i++) {
spi = i / BPF_REG_SIZE;
- if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ))
+ if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) {
+ i += BPF_REG_SIZE - 1;
/* explored state didn't use this */
continue;
+ }
if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID)
continue;