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Diffstat (limited to 'arch/x86/net')
-rw-r--r--arch/x86/net/bpf_jit_comp.c88
1 files changed, 46 insertions, 42 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index be2e7a2b1..70efcd094 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -246,7 +246,7 @@ static void emit_prologue(u8 **pprog)
* goto out;
* if (++tail_call_cnt > MAX_TAIL_CALL_CNT)
* goto out;
- * prog = array->prog[index];
+ * prog = array->ptrs[index];
* if (prog == NULL)
* goto out;
* goto *(prog->bpf_func + prologue_size);
@@ -284,9 +284,9 @@ static void emit_bpf_tail_call(u8 **pprog)
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */
- /* prog = array->prog[index]; */
+ /* prog = array->ptrs[index]; */
EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */
- offsetof(struct bpf_array, prog));
+ offsetof(struct bpf_array, ptrs));
EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */
/* if (prog == NULL)
@@ -315,6 +315,26 @@ static void emit_bpf_tail_call(u8 **pprog)
*pprog = prog;
}
+
+static void emit_load_skb_data_hlen(u8 **pprog)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ /* r9d = skb->len - skb->data_len (headlen)
+ * r10 = skb->data
+ */
+ /* mov %r9d, off32(%rdi) */
+ EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len));
+
+ /* sub %r9d, off32(%rdi) */
+ EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len));
+
+ /* mov %r10, off32(%rdi) */
+ EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data));
+ *pprog = prog;
+}
+
static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
int oldproglen, struct jit_context *ctx)
{
@@ -329,36 +349,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
emit_prologue(&prog);
- if (seen_ld_abs) {
- /* r9d : skb->len - skb->data_len (headlen)
- * r10 : skb->data
- */
- if (is_imm8(offsetof(struct sk_buff, len)))
- /* mov %r9d, off8(%rdi) */
- EMIT4(0x44, 0x8b, 0x4f,
- offsetof(struct sk_buff, len));
- else
- /* mov %r9d, off32(%rdi) */
- EMIT3_off32(0x44, 0x8b, 0x8f,
- offsetof(struct sk_buff, len));
-
- if (is_imm8(offsetof(struct sk_buff, data_len)))
- /* sub %r9d, off8(%rdi) */
- EMIT4(0x44, 0x2b, 0x4f,
- offsetof(struct sk_buff, data_len));
- else
- EMIT3_off32(0x44, 0x2b, 0x8f,
- offsetof(struct sk_buff, data_len));
-
- if (is_imm8(offsetof(struct sk_buff, data)))
- /* mov %r10, off8(%rdi) */
- EMIT4(0x4c, 0x8b, 0x57,
- offsetof(struct sk_buff, data));
- else
- /* mov %r10, off32(%rdi) */
- EMIT3_off32(0x4c, 0x8b, 0x97,
- offsetof(struct sk_buff, data));
- }
+ if (seen_ld_abs)
+ emit_load_skb_data_hlen(&prog);
for (i = 0; i < insn_cnt; i++, insn++) {
const s32 imm32 = insn->imm;
@@ -367,6 +359,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
u8 b1 = 0, b2 = 0, b3 = 0;
s64 jmp_offset;
u8 jmp_cond;
+ bool reload_skb_data;
int ilen;
u8 *func;
@@ -818,12 +811,18 @@ xadd: if (is_imm8(insn->off))
func = (u8 *) __bpf_call_base + imm32;
jmp_offset = func - (image + addrs[i]);
if (seen_ld_abs) {
- EMIT2(0x41, 0x52); /* push %r10 */
- EMIT2(0x41, 0x51); /* push %r9 */
- /* need to adjust jmp offset, since
- * pop %r9, pop %r10 take 4 bytes after call insn
- */
- jmp_offset += 4;
+ reload_skb_data = bpf_helper_changes_skb_data(func);
+ if (reload_skb_data) {
+ EMIT1(0x57); /* push %rdi */
+ jmp_offset += 22; /* pop, mov, sub, mov */
+ } else {
+ EMIT2(0x41, 0x52); /* push %r10 */
+ EMIT2(0x41, 0x51); /* push %r9 */
+ /* need to adjust jmp offset, since
+ * pop %r9, pop %r10 take 4 bytes after call insn
+ */
+ jmp_offset += 4;
+ }
}
if (!imm32 || !is_simm32(jmp_offset)) {
pr_err("unsupported bpf func %d addr %p image %p\n",
@@ -832,8 +831,13 @@ xadd: if (is_imm8(insn->off))
}
EMIT1_off32(0xE8, jmp_offset);
if (seen_ld_abs) {
- EMIT2(0x41, 0x59); /* pop %r9 */
- EMIT2(0x41, 0x5A); /* pop %r10 */
+ if (reload_skb_data) {
+ EMIT1(0x5F); /* pop %rdi */
+ emit_load_skb_data_hlen(&prog);
+ } else {
+ EMIT2(0x41, 0x59); /* pop %r9 */
+ EMIT2(0x41, 0x5A); /* pop %r10 */
+ }
}
break;
@@ -1099,7 +1103,7 @@ void bpf_int_jit_compile(struct bpf_prog *prog)
}
if (bpf_jit_enable > 1)
- bpf_jit_dump(prog->len, proglen, 0, image);
+ bpf_jit_dump(prog->len, proglen, pass + 1, image);
if (image) {
bpf_flush_icache(header, image + proglen);