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bpf: verifier: Use copy_array for jmp_history

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Eliminate a couple needless kfree / kmalloc cycles by using
copy_array for jmp_history.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210429134656.122225-3-lmb@cloudflare.com
This commit is contained in:
Lorenz Bauer 2021-04-29 14:46:55 +01:00 committed by Alexei Starovoitov
parent c69431aab6
commit 06ab6a5055
1 changed files with 5 additions and 8 deletions
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13
kernel/bpf/verifier.c
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@ -926,16 +926,13 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
const struct bpf_verifier_state *src)
{
struct bpf_func_state *dst;
u32 jmp_sz = sizeof(struct bpf_idx_pair) * src->jmp_history_cnt;
int i, err;
if (dst_state->jmp_history_cnt < src->jmp_history_cnt) {
kfree(dst_state->jmp_history);
dst_state->jmp_history = kmalloc(jmp_sz, GFP_USER);
if (!dst_state->jmp_history)
return -ENOMEM;
}
memcpy(dst_state->jmp_history, src->jmp_history, jmp_sz);
dst_state->jmp_history = copy_array(dst_state->jmp_history, src->jmp_history,
src->jmp_history_cnt, sizeof(struct bpf_idx_pair),
GFP_USER);
if (!dst_state->jmp_history)
return -ENOMEM;
dst_state->jmp_history_cnt = src->jmp_history_cnt;
/* if dst has more stack frames then src frame, free them */