diff options
| author | Alexei Starovoitov <ast@fb.com> | 2017-05-30 23:31:35 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-01 02:29:48 +0300 |
| commit | 2960ae48c4636778761610dd49187691c3774465 (patch) | |
| tree | 7578aae05af40cd063fa3cd8679effc13a28863b | |
| parent | 177366bf7ceb35860281a6ebe824e42bf96fd95d (diff) | |
| download | linux-2960ae48c4636778761610dd49187691c3774465.tar.xz | |
bpf: take advantage of stack_depth tracking in x64 JIT
Take advantage of stack_depth tracking in x64 JIT.
Round up allocated stack by 8 bytes to make sure it stays aligned
for functions called from JITed bpf program.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index c96dac838f3e..617eac9c4511 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -206,7 +206,7 @@ struct jit_context { /* emit x64 prologue code for BPF program and check it's size. * bpf_tail_call helper will skip it while jumping into another program */ -static void emit_prologue(u8 **pprog) +static void emit_prologue(u8 **pprog, u32 stack_depth) { u8 *prog = *pprog; int cnt = 0; @@ -214,8 +214,9 @@ static void emit_prologue(u8 **pprog) EMIT1(0x55); /* push rbp */ EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ - /* sub rsp, MAX_BPF_STACK + AUX_STACK_SPACE */ - EMIT3_off32(0x48, 0x81, 0xEC, MAX_BPF_STACK + AUX_STACK_SPACE); + /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ + EMIT3_off32(0x48, 0x81, 0xEC, + round_up(stack_depth, 8) + AUX_STACK_SPACE); /* sub rbp, AUX_STACK_SPACE */ EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); @@ -363,7 +364,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, int proglen = 0; u8 *prog = temp; - emit_prologue(&prog); + emit_prologue(&prog, bpf_prog->aux->stack_depth); if (seen_ld_abs) emit_load_skb_data_hlen(&prog); |