diff options
| author | Xu Kuohai <xukuohai@huawei.com> | 2024-04-16 14:42:07 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2024-04-16 17:19:30 +0200 |
| commit | dc7d7447b56bcc9cf79a9c22e4edad200a298e4c (patch) | |
| tree | 584898bf8b410c67966a7586f587c09eeb7d0a5c /arch | |
| parent | 37eacb9f6e89fb399a79e952bc9c78eb3e16290e (diff) | |
| download | linux-dc7d7447b56bcc9cf79a9c22e4edad200a298e4c.tar.gz | |
bpf, arm64: Fix incorrect runtime stats
When __bpf_prog_enter() returns zero, the arm64 register x20 that stores
prog start time is not assigned to zero, causing incorrect runtime stats.
To fix it, assign the return value of bpf_prog_enter() to x20 register
immediately upon its return.
Fixes: efc9909fdce0 ("bpf, arm64: Add bpf trampoline for arm64")
Reported-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Ivan Babrou <ivan@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240416064208.2919073-2-xukuohai@huaweicloud.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 122021f9bdfc8..13eac43c632df 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -1844,15 +1844,15 @@ static void invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_link *l, emit_call(enter_prog, ctx); + /* save return value to callee saved register x20 */ + emit(A64_MOV(1, A64_R(20), A64_R(0)), ctx); + /* if (__bpf_prog_enter(prog) == 0) * goto skip_exec_of_prog; */ branch = ctx->image + ctx->idx; emit(A64_NOP, ctx); - /* save return value to callee saved register x20 */ - emit(A64_MOV(1, A64_R(20), A64_R(0)), ctx); - emit(A64_ADD_I(1, A64_R(0), A64_SP, args_off), ctx); if (!p->jited) emit_addr_mov_i64(A64_R(1), (const u64)p->insnsi, ctx); |