From: Alexei Starovoitov <ast@fb•com>
To: "David S . Miller" <davem@davemloft•net>
Cc: Daniel Borkmann <daniel@iogearbox•net>, <netdev@vger•kernel.org>,
<kernel-team@fb•com>
Subject: [PATCH net-next 9/9] bpf: take advantage of stack_depth tracking in x64 JIT
Date: Tue, 30 May 2017 13:31:35 -0700 [thread overview]
Message-ID: <20170530203135.3642768-10-ast@fb.com> (raw)
In-Reply-To: <20170530203135.3642768-1-ast@fb.com>
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>
---
arch/x86/net/bpf_jit_comp.c | 9 +++++----
1 file 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);
--
2.9.3
next prev parent reply other threads:[~2017-05-30 20:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-30 20:31 [PATCH net-next 0/9] bpf: stack depth tracking Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 1/9] bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 2/9] bpf: split bpf core interpreter Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 3/9] bpf: teach verifier to track stack depth Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 4/9] bpf: reconcile bpf_tail_call and stack_depth Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 5/9] bpf: track stack depth of classic bpf programs Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 6/9] bpf: fix stack_depth usage by test_bpf.ko Alexei Starovoitov
2017-05-31 18:15 ` David Miller
2017-05-31 18:39 ` Alexei Starovoitov
2017-05-31 18:43 ` David Miller
2017-05-31 18:45 ` Alexei Starovoitov
2017-05-31 22:41 ` Alexei Starovoitov
2017-05-31 23:30 ` David Miller
2017-06-06 10:19 ` Daniel Borkmann
2017-05-30 20:31 ` [PATCH net-next 7/9] bpf: use different interpreter depending on required stack size Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 8/9] bpf: change x86 JITed program stack layout Alexei Starovoitov
2017-05-30 20:31 ` Alexei Starovoitov [this message]
2017-05-31 23:30 ` [PATCH net-next 0/9] bpf: stack depth tracking David Miller
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