net: filter: x86: internal BPF JIT
Maps all internal BPF instructions into x86_64 instructions.
This patch replaces original BPF x64 JIT with internal BPF x64 JIT.
sysctl net.core.bpf_jit_enable is reused as on/off switch.
Performance:
1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code.
No performance difference is observed for filters that were JIT-able before
Example assembler code for BPF filter "tcpdump port 22"
original BPF -> old JIT: original BPF -> internal BPF -> new JIT:
0: push %rbp 0: push %rbp
1: mov %rsp,%rbp 1: mov %rsp,%rbp
4: sub $0x60,%rsp 4: sub $0x228,%rsp
8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue
12: mov %r13,-0x220(%rbp)
19: mov %r14,-0x218(%rbp)
20: mov %r15,-0x210(%rbp)
27: xor %eax,%eax // clear A
c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X
e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d
12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d
16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10
3b: mov %rdi,%rbx
1d: mov $0xc,%esi 3e: mov $0xc,%esi
22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75
27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax
2c: jne 0x0000000000000069 4f: jne 0x000000000000009a
2e: mov $0x14,%esi 51: mov $0x14,%esi
33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91
38: cmp $0x84,%eax 5b: cmp $0x84,%rax
3d: je 0x0000000000000049 62: je 0x0000000000000074
3f: cmp $0x6,%eax 64: cmp $0x6,%rax
42: je 0x0000000000000049 68: je 0x0000000000000074
44: cmp $0x11,%eax 6a: cmp $0x11,%rax
47: jne 0x00000000000000c6 6e: jne 0x0000000000000117
49: mov $0x36,%esi 74: mov $0x36,%esi
4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75
53: cmp $0x16,%eax 7e: cmp $0x16,%rax
56: je 0x00000000000000bf 82: je 0x0000000000000110
58: mov $0x38,%esi 88: mov $0x38,%esi
5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75
62: cmp $0x16,%eax 92: cmp $0x16,%rax
65: je 0x00000000000000bf 96: je 0x0000000000000110
67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117
69: cmp $0x800,%eax 9a: cmp $0x800,%rax
6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117
70: mov $0x17,%esi a3: mov $0x17,%esi
75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91
7a: cmp $0x84,%eax ad: cmp $0x84,%rax
7f: je 0x000000000000008b b4: je 0x00000000000000c2
81: cmp $0x6,%eax b6: cmp $0x6,%rax
84: je 0x000000000000008b ba: je 0x00000000000000c2
86: cmp $0x11,%eax bc: cmp $0x11,%rax
89: jne 0x00000000000000c6 c0: jne 0x0000000000000117
8b: mov $0x14,%esi c2: mov $0x14,%esi
90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75
95: test $0x1fff,%ax cc: test $0x1fff,%rax
99: jne 0x00000000000000c6 d3: jne 0x0000000000000117
d5: mov %rax,%r14
9b: mov $0xe,%esi d8: mov $0xe,%esi
a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH
e2: and $0xf,%eax
e5: shl $0x2,%eax
e8: mov %rax,%r13
eb: mov %r14,%rax
ee: mov %r13,%rsi
a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi
a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d
ad: cmp $0x16,%eax f9: cmp $0x16,%rax
b0: je 0x00000000000000bf fd: je 0x0000000000000110
ff: mov %r13,%rsi
b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi
b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d
ba: cmp $0x16,%eax 10a: cmp $0x16,%rax
bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117
bf: mov $0xffff,%eax 110: mov $0xffff,%eax
c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c
c6: xor %eax,%eax 117: mov $0x0,%eax
c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue
cc: leaveq 123: mov -0x220(%rbp),%r13
cd: retq 12a: mov -0x218(%rbp),%r14
131: mov -0x210(%rbp),%r15
138: leaveq
139: retq
On fully cached SKBs both JITed functions take 12 nsec to execute.
BPF interpreter executes the program in 30 nsec.
The difference in generated assembler is due to the following:
Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function
inside bpf_jit.S.
New JIT removes the helper and does it explicitly, so ldx_msh cost
is the same for both JITs, but generated code looks longer.
New JIT has 4 registers to save, so prologue/epilogue are larger,
but the cost is within noise on x64.
Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'.
New JIT clears %rax unconditionally.
2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM
extensions. New JIT supports all BPF extensions.
Performance of such filters improves 2-4 times depending on a filter.
The longer the filter the higher performance gain.
Synthetic benchmarks with many ancillary loads see 20x speedup
which seems to be the maximum gain from JIT
Notes:
. net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional
and can be used to see generated assembler
. there are two jit_compile() functions and code flow for classic filters is:
sk_attach_filter() - load classic BPF
bpf_jit_compile() - try to JIT from classic BPF
sk_convert_filter() - convert classic to internal
bpf_int_jit_compile() - JIT from internal BPF
seccomp and tracing filters will just call bpf_int_jit_compile()
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S
index 0149575..6440221 100644
--- a/arch/x86/net/bpf_jit.S
+++ b/arch/x86/net/bpf_jit.S
@@ -12,13 +12,16 @@
/*
* Calling convention :
- * rdi : skb pointer
+ * rbx : skb pointer (callee saved)
* esi : offset of byte(s) to fetch in skb (can be scratched)
- * r8 : copy of skb->data
+ * r10 : copy of skb->data
* r9d : hlen = skb->len - skb->data_len
*/
-#define SKBDATA %r8
+#define SKBDATA %r10
#define SKF_MAX_NEG_OFF $(-0x200000) /* SKF_LL_OFF from filter.h */
+#define MAX_BPF_STACK (512 /* from filter.h */ + \
+ 32 /* space for rbx,r13,r14,r15 */ + \
+ 8 /* space for skb_copy_bits */)
sk_load_word:
.globl sk_load_word
@@ -68,53 +71,31 @@
movzbl (SKBDATA,%rsi),%eax
ret
-/**
- * sk_load_byte_msh - BPF_S_LDX_B_MSH helper
- *
- * Implements BPF_S_LDX_B_MSH : ldxb 4*([offset]&0xf)
- * Must preserve A accumulator (%eax)
- * Inputs : %esi is the offset value
- */
-sk_load_byte_msh:
- .globl sk_load_byte_msh
- test %esi,%esi
- js bpf_slow_path_byte_msh_neg
-
-sk_load_byte_msh_positive_offset:
- .globl sk_load_byte_msh_positive_offset
- cmp %esi,%r9d /* if (offset >= hlen) goto bpf_slow_path_byte_msh */
- jle bpf_slow_path_byte_msh
- movzbl (SKBDATA,%rsi),%ebx
- and $15,%bl
- shl $2,%bl
- ret
-
/* rsi contains offset and can be scratched */
#define bpf_slow_path_common(LEN) \
- push %rdi; /* save skb */ \
+ mov %rbx, %rdi; /* arg1 == skb */ \
push %r9; \
push SKBDATA; \
/* rsi already has offset */ \
mov $LEN,%ecx; /* len */ \
- lea -12(%rbp),%rdx; \
+ lea - MAX_BPF_STACK + 32(%rbp),%rdx; \
call skb_copy_bits; \
test %eax,%eax; \
pop SKBDATA; \
- pop %r9; \
- pop %rdi
+ pop %r9;
bpf_slow_path_word:
bpf_slow_path_common(4)
js bpf_error
- mov -12(%rbp),%eax
+ mov - MAX_BPF_STACK + 32(%rbp),%eax
bswap %eax
ret
bpf_slow_path_half:
bpf_slow_path_common(2)
js bpf_error
- mov -12(%rbp),%ax
+ mov - MAX_BPF_STACK + 32(%rbp),%ax
rol $8,%ax
movzwl %ax,%eax
ret
@@ -122,21 +103,11 @@
bpf_slow_path_byte:
bpf_slow_path_common(1)
js bpf_error
- movzbl -12(%rbp),%eax
- ret
-
-bpf_slow_path_byte_msh:
- xchg %eax,%ebx /* dont lose A , X is about to be scratched */
- bpf_slow_path_common(1)
- js bpf_error
- movzbl -12(%rbp),%eax
- and $15,%al
- shl $2,%al
- xchg %eax,%ebx
+ movzbl - MAX_BPF_STACK + 32(%rbp),%eax
ret
#define sk_negative_common(SIZE) \
- push %rdi; /* save skb */ \
+ mov %rbx, %rdi; /* arg1 == skb */ \
push %r9; \
push SKBDATA; \
/* rsi already has offset */ \
@@ -145,10 +116,8 @@
test %rax,%rax; \
pop SKBDATA; \
pop %r9; \
- pop %rdi; \
jz bpf_error
-
bpf_slow_path_word_neg:
cmp SKF_MAX_NEG_OFF, %esi /* test range */
jl bpf_error /* offset lower -> error */
@@ -179,22 +148,12 @@
movzbl (%rax), %eax
ret
-bpf_slow_path_byte_msh_neg:
- cmp SKF_MAX_NEG_OFF, %esi
- jl bpf_error
-sk_load_byte_msh_negative_offset:
- .globl sk_load_byte_msh_negative_offset
- xchg %eax,%ebx /* dont lose A , X is about to be scratched */
- sk_negative_common(1)
- movzbl (%rax),%eax
- and $15,%al
- shl $2,%al
- xchg %eax,%ebx
- ret
-
bpf_error:
# force a return 0 from jit handler
- xor %eax,%eax
- mov -8(%rbp),%rbx
+ xor %eax,%eax
+ mov - MAX_BPF_STACK(%rbp),%rbx
+ mov - MAX_BPF_STACK + 8(%rbp),%r13
+ mov - MAX_BPF_STACK + 16(%rbp),%r14
+ mov - MAX_BPF_STACK + 24(%rbp),%r15
leaveq
ret
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index c5fa7c9..92aef8fd 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1,6 +1,7 @@
/* bpf_jit_comp.c : BPF JIT compiler
*
* Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com)
+ * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -14,28 +15,16 @@
#include <linux/if_vlan.h>
#include <linux/random.h>
-/*
- * Conventions :
- * EAX : BPF A accumulator
- * EBX : BPF X accumulator
- * RDI : pointer to skb (first argument given to JIT function)
- * RBP : frame pointer (even if CONFIG_FRAME_POINTER=n)
- * ECX,EDX,ESI : scratch registers
- * r9d : skb->len - skb->data_len (headlen)
- * r8 : skb->data
- * -8(RBP) : saved RBX value
- * -16(RBP)..-80(RBP) : BPF_MEMWORDS values
- */
int bpf_jit_enable __read_mostly;
/*
* assembly code in arch/x86/net/bpf_jit.S
*/
-extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
+extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[];
-extern u8 sk_load_byte_positive_offset[], sk_load_byte_msh_positive_offset[];
+extern u8 sk_load_byte_positive_offset[];
extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[];
-extern u8 sk_load_byte_negative_offset[], sk_load_byte_msh_negative_offset[];
+extern u8 sk_load_byte_negative_offset[];
static inline u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
{
@@ -56,30 +45,44 @@
#define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2)
#define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3)
#define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4)
-#define EMIT1_off32(b1, off) do { EMIT1(b1); EMIT(off, 4);} while (0)
-
-#define CLEAR_A() EMIT2(0x31, 0xc0) /* xor %eax,%eax */
-#define CLEAR_X() EMIT2(0x31, 0xdb) /* xor %ebx,%ebx */
+#define EMIT1_off32(b1, off) \
+ do {EMIT1(b1); EMIT(off, 4); } while (0)
+#define EMIT2_off32(b1, b2, off) \
+ do {EMIT2(b1, b2); EMIT(off, 4); } while (0)
+#define EMIT3_off32(b1, b2, b3, off) \
+ do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0)
+#define EMIT4_off32(b1, b2, b3, b4, off) \
+ do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0)
static inline bool is_imm8(int value)
{
return value <= 127 && value >= -128;
}
-static inline bool is_near(int offset)
+static inline bool is_simm32(s64 value)
{
- return offset <= 127 && offset >= -128;
+ return value == (s64) (s32) value;
}
-#define EMIT_JMP(offset) \
-do { \
- if (offset) { \
- if (is_near(offset)) \
- EMIT2(0xeb, offset); /* jmp .+off8 */ \
- else \
- EMIT1_off32(0xe9, offset); /* jmp .+off32 */ \
- } \
-} while (0)
+/* mov A, X */
+#define EMIT_mov(A, X) \
+ do {if (A != X) \
+ EMIT3(add_2mod(0x48, A, X), 0x89, add_2reg(0xC0, A, X)); \
+ } while (0)
+
+static int bpf_size_to_x86_bytes(int bpf_size)
+{
+ if (bpf_size == BPF_W)
+ return 4;
+ else if (bpf_size == BPF_H)
+ return 2;
+ else if (bpf_size == BPF_B)
+ return 1;
+ else if (bpf_size == BPF_DW)
+ return 4; /* imm32 */
+ else
+ return 0;
+}
/* list of x86 cond jumps opcodes (. + s8)
* Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32)
@@ -90,27 +93,8 @@
#define X86_JNE 0x75
#define X86_JBE 0x76
#define X86_JA 0x77
-
-#define EMIT_COND_JMP(op, offset) \
-do { \
- if (is_near(offset)) \
- EMIT2(op, offset); /* jxx .+off8 */ \
- else { \
- EMIT2(0x0f, op + 0x10); \
- EMIT(offset, 4); /* jxx .+off32 */ \
- } \
-} while (0)
-
-#define COND_SEL(CODE, TOP, FOP) \
- case CODE: \
- t_op = TOP; \
- f_op = FOP; \
- goto cond_branch
-
-
-#define SEEN_DATAREF 1 /* might call external helpers */
-#define SEEN_XREG 2 /* ebx is used */
-#define SEEN_MEM 4 /* use mem[] for temporary storage */
+#define X86_JGE 0x7D
+#define X86_JG 0x7F
static inline void bpf_flush_icache(void *start, void *end)
{
@@ -125,26 +109,6 @@
#define CHOOSE_LOAD_FUNC(K, func) \
((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
-/* Helper to find the offset of pkt_type in sk_buff
- * We want to make sure its still a 3bit field starting at a byte boundary.
- */
-#define PKT_TYPE_MAX 7
-static int pkt_type_offset(void)
-{
- struct sk_buff skb_probe = {
- .pkt_type = ~0,
- };
- char *ct = (char *)&skb_probe;
- unsigned int off;
-
- for (off = 0; off < sizeof(struct sk_buff); off++) {
- if (ct[off] == PKT_TYPE_MAX)
- return off;
- }
- pr_err_once("Please fix pkt_type_offset(), as pkt_type couldn't be found\n");
- return -1;
-}
-
struct bpf_binary_header {
unsigned int pages;
/* Note : for security reasons, bpf code will follow a randomly
@@ -178,546 +142,715 @@
return header;
}
+/* pick a register outside of BPF range for JIT internal work */
+#define AUX_REG (MAX_BPF_REG + 1)
+
+/* the following table maps BPF registers to x64 registers.
+ * x64 register r12 is unused, since if used as base address register
+ * in load/store instructions, it always needs an extra byte of encoding
+ */
+static const int reg2hex[] = {
+ [BPF_REG_0] = 0, /* rax */
+ [BPF_REG_1] = 7, /* rdi */
+ [BPF_REG_2] = 6, /* rsi */
+ [BPF_REG_3] = 2, /* rdx */
+ [BPF_REG_4] = 1, /* rcx */
+ [BPF_REG_5] = 0, /* r8 */
+ [BPF_REG_6] = 3, /* rbx callee saved */
+ [BPF_REG_7] = 5, /* r13 callee saved */
+ [BPF_REG_8] = 6, /* r14 callee saved */
+ [BPF_REG_9] = 7, /* r15 callee saved */
+ [BPF_REG_FP] = 5, /* rbp readonly */
+ [AUX_REG] = 3, /* r11 temp register */
+};
+
+/* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15
+ * which need extra byte of encoding.
+ * rax,rcx,...,rbp have simpler encoding
+ */
+static inline bool is_ereg(u32 reg)
+{
+ if (reg == BPF_REG_5 || reg == AUX_REG ||
+ (reg >= BPF_REG_7 && reg <= BPF_REG_9))
+ return true;
+ else
+ return false;
+}
+
+/* add modifiers if 'reg' maps to x64 registers r8..r15 */
+static inline u8 add_1mod(u8 byte, u32 reg)
+{
+ if (is_ereg(reg))
+ byte |= 1;
+ return byte;
+}
+
+static inline u8 add_2mod(u8 byte, u32 r1, u32 r2)
+{
+ if (is_ereg(r1))
+ byte |= 1;
+ if (is_ereg(r2))
+ byte |= 4;
+ return byte;
+}
+
+/* encode dest register 'a_reg' into x64 opcode 'byte' */
+static inline u8 add_1reg(u8 byte, u32 a_reg)
+{
+ return byte + reg2hex[a_reg];
+}
+
+/* encode dest 'a_reg' and src 'x_reg' registers into x64 opcode 'byte' */
+static inline u8 add_2reg(u8 byte, u32 a_reg, u32 x_reg)
+{
+ return byte + reg2hex[a_reg] + (reg2hex[x_reg] << 3);
+}
+
struct jit_context {
unsigned int cleanup_addr; /* epilogue code offset */
- int pc_ret0; /* bpf index of first RET #0 instruction (if any) */
- u8 seen;
+ bool seen_ld_abs;
};
static int do_jit(struct sk_filter *bpf_prog, int *addrs, u8 *image,
int oldproglen, struct jit_context *ctx)
{
- const struct sock_filter *filter = bpf_prog->insns;
- int flen = bpf_prog->len;
+ struct sock_filter_int *insn = bpf_prog->insnsi;
+ int insn_cnt = bpf_prog->len;
u8 temp[64];
- u8 *prog;
- int ilen, i, proglen;
- int t_offset, f_offset;
- u8 t_op, f_op, seen = 0;
- u8 *func;
- unsigned int cleanup_addr = ctx->cleanup_addr;
- u8 seen_or_pass0 = ctx->seen;
+ int i;
+ int proglen = 0;
+ u8 *prog = temp;
+ int stacksize = MAX_BPF_STACK +
+ 32 /* space for rbx, r13, r14, r15 */ +
+ 8 /* space for skb_copy_bits() buffer */;
- /* no prologue/epilogue for trivial filters (RET something) */
- proglen = 0;
- prog = temp;
+ EMIT1(0x55); /* push rbp */
+ EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */
- if (seen_or_pass0) {
- EMIT4(0x55, 0x48, 0x89, 0xe5); /* push %rbp; mov %rsp,%rbp */
- EMIT4(0x48, 0x83, 0xec, 96); /* subq $96,%rsp */
- /* note : must save %rbx in case bpf_error is hit */
- if (seen_or_pass0 & (SEEN_XREG | SEEN_DATAREF))
- EMIT4(0x48, 0x89, 0x5d, 0xf8); /* mov %rbx, -8(%rbp) */
- if (seen_or_pass0 & SEEN_XREG)
- CLEAR_X(); /* make sure we dont leek kernel memory */
+ /* sub rsp, stacksize */
+ EMIT3_off32(0x48, 0x81, 0xEC, stacksize);
- /*
- * If this filter needs to access skb data,
- * loads r9 and r8 with :
- * r9 = skb->len - skb->data_len
- * r8 = skb->data
- */
- if (seen_or_pass0 & SEEN_DATAREF) {
- if (offsetof(struct sk_buff, len) <= 127)
- /* mov off8(%rdi),%r9d */
- EMIT4(0x44, 0x8b, 0x4f, offsetof(struct sk_buff, len));
- else {
- /* mov off32(%rdi),%r9d */
- EMIT3(0x44, 0x8b, 0x8f);
- EMIT(offsetof(struct sk_buff, len), 4);
- }
- if (is_imm8(offsetof(struct sk_buff, data_len)))
- /* sub off8(%rdi),%r9d */
- EMIT4(0x44, 0x2b, 0x4f, offsetof(struct sk_buff, data_len));
- else {
- EMIT3(0x44, 0x2b, 0x8f);
- EMIT(offsetof(struct sk_buff, data_len), 4);
- }
+ /* all classic BPF filters use R6(rbx) save it */
- if (is_imm8(offsetof(struct sk_buff, data)))
- /* mov off8(%rdi),%r8 */
- EMIT4(0x4c, 0x8b, 0x47, offsetof(struct sk_buff, data));
- else {
- /* mov off32(%rdi),%r8 */
- EMIT3(0x4c, 0x8b, 0x87);
- EMIT(offsetof(struct sk_buff, data), 4);
- }
+ /* mov qword ptr [rbp-X],rbx */
+ EMIT3_off32(0x48, 0x89, 0x9D, -stacksize);
+
+ /* sk_convert_filter() maps classic BPF register X to R7 and uses R8
+ * as temporary, so all tcpdump filters need to spill/fill R7(r13) and
+ * R8(r14). R9(r15) spill could be made conditional, but there is only
+ * one 'bpf_error' return path out of helper functions inside bpf_jit.S
+ * The overhead of extra spill is negligible for any filter other
+ * than synthetic ones. Therefore not worth adding complexity.
+ */
+
+ /* mov qword ptr [rbp-X],r13 */
+ EMIT3_off32(0x4C, 0x89, 0xAD, -stacksize + 8);
+ /* mov qword ptr [rbp-X],r14 */
+ EMIT3_off32(0x4C, 0x89, 0xB5, -stacksize + 16);
+ /* mov qword ptr [rbp-X],r15 */
+ EMIT3_off32(0x4C, 0x89, 0xBD, -stacksize + 24);
+
+ /* clear A and X registers */
+ EMIT2(0x31, 0xc0); /* xor eax, eax */
+ EMIT3(0x4D, 0x31, 0xED); /* xor r13, r13 */
+
+ if (ctx->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));
+ }
+
+ for (i = 0; i < insn_cnt; i++, insn++) {
+ const s32 K = insn->imm;
+ u32 a_reg = insn->a_reg;
+ u32 x_reg = insn->x_reg;
+ u8 b1 = 0, b2 = 0, b3 = 0;
+ s64 jmp_offset;
+ u8 jmp_cond;
+ int ilen;
+ u8 *func;
+
+ switch (insn->code) {
+ /* ALU */
+ case BPF_ALU | BPF_ADD | BPF_X:
+ case BPF_ALU | BPF_SUB | BPF_X:
+ case BPF_ALU | BPF_AND | BPF_X:
+ case BPF_ALU | BPF_OR | BPF_X:
+ case BPF_ALU | BPF_XOR | BPF_X:
+ case BPF_ALU64 | BPF_ADD | BPF_X:
+ case BPF_ALU64 | BPF_SUB | BPF_X:
+ case BPF_ALU64 | BPF_AND | BPF_X:
+ case BPF_ALU64 | BPF_OR | BPF_X:
+ case BPF_ALU64 | BPF_XOR | BPF_X:
+ switch (BPF_OP(insn->code)) {
+ case BPF_ADD: b2 = 0x01; break;
+ case BPF_SUB: b2 = 0x29; break;
+ case BPF_AND: b2 = 0x21; break;
+ case BPF_OR: b2 = 0x09; break;
+ case BPF_XOR: b2 = 0x31; break;
}
- }
-
- switch (filter[0].code) {
- case BPF_S_RET_K:
- case BPF_S_LD_W_LEN:
- case BPF_S_ANC_PROTOCOL:
- case BPF_S_ANC_IFINDEX:
- case BPF_S_ANC_MARK:
- case BPF_S_ANC_RXHASH:
- case BPF_S_ANC_CPU:
- case BPF_S_ANC_VLAN_TAG:
- case BPF_S_ANC_VLAN_TAG_PRESENT:
- case BPF_S_ANC_QUEUE:
- case BPF_S_ANC_PKTTYPE:
- case BPF_S_LD_W_ABS:
- case BPF_S_LD_H_ABS:
- case BPF_S_LD_B_ABS:
- /* first instruction sets A register (or is RET 'constant') */
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ EMIT1(add_2mod(0x48, a_reg, x_reg));
+ else if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT1(add_2mod(0x40, a_reg, x_reg));
+ EMIT2(b2, add_2reg(0xC0, a_reg, x_reg));
break;
- default:
- /* make sure we dont leak kernel information to user */
- CLEAR_A(); /* A = 0 */
- }
- for (i = 0; i < flen; i++) {
- unsigned int K = filter[i].k;
+ /* mov A, X */
+ case BPF_ALU64 | BPF_MOV | BPF_X:
+ EMIT_mov(a_reg, x_reg);
+ break;
- switch (filter[i].code) {
- case BPF_S_ALU_ADD_X: /* A += X; */
- seen |= SEEN_XREG;
- EMIT2(0x01, 0xd8); /* add %ebx,%eax */
- break;
- case BPF_S_ALU_ADD_K: /* A += K; */
- if (!K)
- break;
- if (is_imm8(K))
- EMIT3(0x83, 0xc0, K); /* add imm8,%eax */
- else
- EMIT1_off32(0x05, K); /* add imm32,%eax */
- break;
- case BPF_S_ALU_SUB_X: /* A -= X; */
- seen |= SEEN_XREG;
- EMIT2(0x29, 0xd8); /* sub %ebx,%eax */
- break;
- case BPF_S_ALU_SUB_K: /* A -= K */
- if (!K)
- break;
- if (is_imm8(K))
- EMIT3(0x83, 0xe8, K); /* sub imm8,%eax */
- else
- EMIT1_off32(0x2d, K); /* sub imm32,%eax */
- break;
- case BPF_S_ALU_MUL_X: /* A *= X; */
- seen |= SEEN_XREG;
- EMIT3(0x0f, 0xaf, 0xc3); /* imul %ebx,%eax */
- break;
- case BPF_S_ALU_MUL_K: /* A *= K */
- if (is_imm8(K))
- EMIT3(0x6b, 0xc0, K); /* imul imm8,%eax,%eax */
- else {
- EMIT2(0x69, 0xc0); /* imul imm32,%eax */
- EMIT(K, 4);
- }
- break;
- case BPF_S_ALU_DIV_X: /* A /= X; */
- seen |= SEEN_XREG;
- EMIT2(0x85, 0xdb); /* test %ebx,%ebx */
- if (ctx->pc_ret0 > 0) {
- /* addrs[pc_ret0 - 1] is start address of target
- * (addrs[i] - 4) is the address following this jmp
- * ("xor %edx,%edx; div %ebx" being 4 bytes long)
- */
- EMIT_COND_JMP(X86_JE, addrs[ctx->pc_ret0 - 1] -
- (addrs[i] - 4));
- } else {
- EMIT_COND_JMP(X86_JNE, 2 + 5);
- CLEAR_A();
- EMIT1_off32(0xe9, cleanup_addr - (addrs[i] - 4)); /* jmp .+off32 */
- }
- EMIT4(0x31, 0xd2, 0xf7, 0xf3); /* xor %edx,%edx; div %ebx */
- break;
- case BPF_S_ALU_MOD_X: /* A %= X; */
- seen |= SEEN_XREG;
- EMIT2(0x85, 0xdb); /* test %ebx,%ebx */
- if (ctx->pc_ret0 > 0) {
- /* addrs[pc_ret0 - 1] is start address of target
- * (addrs[i] - 6) is the address following this jmp
- * ("xor %edx,%edx; div %ebx;mov %edx,%eax" being 6 bytes long)
- */
- EMIT_COND_JMP(X86_JE, addrs[ctx->pc_ret0 - 1] -
- (addrs[i] - 6));
- } else {
- EMIT_COND_JMP(X86_JNE, 2 + 5);
- CLEAR_A();
- EMIT1_off32(0xe9, cleanup_addr - (addrs[i] - 6)); /* jmp .+off32 */
- }
- EMIT2(0x31, 0xd2); /* xor %edx,%edx */
- EMIT2(0xf7, 0xf3); /* div %ebx */
- EMIT2(0x89, 0xd0); /* mov %edx,%eax */
- break;
- case BPF_S_ALU_MOD_K: /* A %= K; */
- if (K == 1) {
- CLEAR_A();
- break;
- }
- EMIT2(0x31, 0xd2); /* xor %edx,%edx */
- EMIT1(0xb9);EMIT(K, 4); /* mov imm32,%ecx */
- EMIT2(0xf7, 0xf1); /* div %ecx */
- EMIT2(0x89, 0xd0); /* mov %edx,%eax */
- break;
- case BPF_S_ALU_DIV_K: /* A /= K */
- if (K == 1)
- break;
- EMIT2(0x31, 0xd2); /* xor %edx,%edx */
- EMIT1(0xb9);EMIT(K, 4); /* mov imm32,%ecx */
- EMIT2(0xf7, 0xf1); /* div %ecx */
- break;
- case BPF_S_ALU_AND_X:
- seen |= SEEN_XREG;
- EMIT2(0x21, 0xd8); /* and %ebx,%eax */
- break;
- case BPF_S_ALU_AND_K:
- if (K >= 0xFFFFFF00) {
- EMIT2(0x24, K & 0xFF); /* and imm8,%al */
- } else if (K >= 0xFFFF0000) {
- EMIT2(0x66, 0x25); /* and imm16,%ax */
- EMIT(K, 2);
- } else {
- EMIT1_off32(0x25, K); /* and imm32,%eax */
- }
- break;
- case BPF_S_ALU_OR_X:
- seen |= SEEN_XREG;
- EMIT2(0x09, 0xd8); /* or %ebx,%eax */
- break;
- case BPF_S_ALU_OR_K:
- if (is_imm8(K))
- EMIT3(0x83, 0xc8, K); /* or imm8,%eax */
- else
- EMIT1_off32(0x0d, K); /* or imm32,%eax */
- break;
- case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
- case BPF_S_ALU_XOR_X:
- seen |= SEEN_XREG;
- EMIT2(0x31, 0xd8); /* xor %ebx,%eax */
- break;
- case BPF_S_ALU_XOR_K: /* A ^= K; */
- if (K == 0)
- break;
- if (is_imm8(K))
- EMIT3(0x83, 0xf0, K); /* xor imm8,%eax */
- else
- EMIT1_off32(0x35, K); /* xor imm32,%eax */
- break;
- case BPF_S_ALU_LSH_X: /* A <<= X; */
- seen |= SEEN_XREG;
- EMIT4(0x89, 0xd9, 0xd3, 0xe0); /* mov %ebx,%ecx; shl %cl,%eax */
- break;
- case BPF_S_ALU_LSH_K:
- if (K == 0)
- break;
- else if (K == 1)
- EMIT2(0xd1, 0xe0); /* shl %eax */
- else
- EMIT3(0xc1, 0xe0, K);
- break;
- case BPF_S_ALU_RSH_X: /* A >>= X; */
- seen |= SEEN_XREG;
- EMIT4(0x89, 0xd9, 0xd3, 0xe8); /* mov %ebx,%ecx; shr %cl,%eax */
- break;
- case BPF_S_ALU_RSH_K: /* A >>= K; */
- if (K == 0)
- break;
- else if (K == 1)
- EMIT2(0xd1, 0xe8); /* shr %eax */
- else
- EMIT3(0xc1, 0xe8, K);
- break;
- case BPF_S_ALU_NEG:
- EMIT2(0xf7, 0xd8); /* neg %eax */
- break;
- case BPF_S_RET_K:
- if (!K) {
- if (ctx->pc_ret0 == -1)
- ctx->pc_ret0 = i;
- CLEAR_A();
- } else {
- EMIT1_off32(0xb8, K); /* mov $imm32,%eax */
- }
- /* fallinto */
- case BPF_S_RET_A:
- if (seen_or_pass0) {
- if (i != flen - 1) {
- EMIT_JMP(cleanup_addr - addrs[i]);
- break;
- }
- if (seen_or_pass0 & SEEN_XREG)
- EMIT4(0x48, 0x8b, 0x5d, 0xf8); /* mov -8(%rbp),%rbx */
- EMIT1(0xc9); /* leaveq */
- }
- EMIT1(0xc3); /* ret */
- break;
- case BPF_S_MISC_TAX: /* X = A */
- seen |= SEEN_XREG;
- EMIT2(0x89, 0xc3); /* mov %eax,%ebx */
- break;
- case BPF_S_MISC_TXA: /* A = X */
- seen |= SEEN_XREG;
- EMIT2(0x89, 0xd8); /* mov %ebx,%eax */
- break;
- case BPF_S_LD_IMM: /* A = K */
- if (!K)
- CLEAR_A();
- else
- EMIT1_off32(0xb8, K); /* mov $imm32,%eax */
- break;
- case BPF_S_LDX_IMM: /* X = K */
- seen |= SEEN_XREG;
- if (!K)
- CLEAR_X();
- else
- EMIT1_off32(0xbb, K); /* mov $imm32,%ebx */
- break;
- case BPF_S_LD_MEM: /* A = mem[K] : mov off8(%rbp),%eax */
- seen |= SEEN_MEM;
- EMIT3(0x8b, 0x45, 0xf0 - K*4);
- break;
- case BPF_S_LDX_MEM: /* X = mem[K] : mov off8(%rbp),%ebx */
- seen |= SEEN_XREG | SEEN_MEM;
- EMIT3(0x8b, 0x5d, 0xf0 - K*4);
- break;
- case BPF_S_ST: /* mem[K] = A : mov %eax,off8(%rbp) */
- seen |= SEEN_MEM;
- EMIT3(0x89, 0x45, 0xf0 - K*4);
- break;
- case BPF_S_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */
- seen |= SEEN_XREG | SEEN_MEM;
- EMIT3(0x89, 0x5d, 0xf0 - K*4);
- break;
- case BPF_S_LD_W_LEN: /* A = skb->len; */
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
- if (is_imm8(offsetof(struct sk_buff, len)))
- /* mov off8(%rdi),%eax */
- EMIT3(0x8b, 0x47, offsetof(struct sk_buff, len));
- else {
- EMIT2(0x8b, 0x87);
- EMIT(offsetof(struct sk_buff, len), 4);
- }
- break;
- case BPF_S_LDX_W_LEN: /* X = skb->len; */
- seen |= SEEN_XREG;
- if (is_imm8(offsetof(struct sk_buff, len)))
- /* mov off8(%rdi),%ebx */
- EMIT3(0x8b, 0x5f, offsetof(struct sk_buff, len));
- else {
- EMIT2(0x8b, 0x9f);
- EMIT(offsetof(struct sk_buff, len), 4);
- }
- break;
- case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
- if (is_imm8(offsetof(struct sk_buff, protocol))) {
- /* movzwl off8(%rdi),%eax */
- EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, protocol));
- } else {
- EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
- EMIT(offsetof(struct sk_buff, protocol), 4);
- }
- EMIT2(0x86, 0xc4); /* ntohs() : xchg %al,%ah */
- break;
- case BPF_S_ANC_IFINDEX:
- if (is_imm8(offsetof(struct sk_buff, dev))) {
- /* movq off8(%rdi),%rax */
- EMIT4(0x48, 0x8b, 0x47, offsetof(struct sk_buff, dev));
- } else {
- EMIT3(0x48, 0x8b, 0x87); /* movq off32(%rdi),%rax */
- EMIT(offsetof(struct sk_buff, dev), 4);
- }
- EMIT3(0x48, 0x85, 0xc0); /* test %rax,%rax */
- EMIT_COND_JMP(X86_JE, cleanup_addr - (addrs[i] - 6));
- BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
- EMIT2(0x8b, 0x80); /* mov off32(%rax),%eax */
- EMIT(offsetof(struct net_device, ifindex), 4);
- break;
- case BPF_S_ANC_MARK:
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
- if (is_imm8(offsetof(struct sk_buff, mark))) {
- /* mov off8(%rdi),%eax */
- EMIT3(0x8b, 0x47, offsetof(struct sk_buff, mark));
- } else {
- EMIT2(0x8b, 0x87);
- EMIT(offsetof(struct sk_buff, mark), 4);
- }
- break;
- case BPF_S_ANC_RXHASH:
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
- if (is_imm8(offsetof(struct sk_buff, hash))) {
- /* mov off8(%rdi),%eax */
- EMIT3(0x8b, 0x47, offsetof(struct sk_buff, hash));
- } else {
- EMIT2(0x8b, 0x87);
- EMIT(offsetof(struct sk_buff, hash), 4);
- }
- break;
- case BPF_S_ANC_QUEUE:
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
- if (is_imm8(offsetof(struct sk_buff, queue_mapping))) {
- /* movzwl off8(%rdi),%eax */
- EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, queue_mapping));
- } else {
- EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
- EMIT(offsetof(struct sk_buff, queue_mapping), 4);
- }
- break;
- case BPF_S_ANC_CPU:
-#ifdef CONFIG_SMP
- EMIT4(0x65, 0x8b, 0x04, 0x25); /* mov %gs:off32,%eax */
- EMIT((u32)(unsigned long)&cpu_number, 4); /* A = smp_processor_id(); */
-#else
- CLEAR_A();
-#endif
- break;
- case BPF_S_ANC_VLAN_TAG:
- case BPF_S_ANC_VLAN_TAG_PRESENT:
- BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
- if (is_imm8(offsetof(struct sk_buff, vlan_tci))) {
- /* movzwl off8(%rdi),%eax */
- EMIT4(0x0f, 0xb7, 0x47, offsetof(struct sk_buff, vlan_tci));
- } else {
- EMIT3(0x0f, 0xb7, 0x87); /* movzwl off32(%rdi),%eax */
- EMIT(offsetof(struct sk_buff, vlan_tci), 4);
- }
- BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
- if (filter[i].code == BPF_S_ANC_VLAN_TAG) {
- EMIT3(0x80, 0xe4, 0xef); /* and $0xef,%ah */
- } else {
- EMIT3(0xc1, 0xe8, 0x0c); /* shr $0xc,%eax */
- EMIT3(0x83, 0xe0, 0x01); /* and $0x1,%eax */
- }
- break;
- case BPF_S_ANC_PKTTYPE:
- {
- int off = pkt_type_offset();
+ /* mov32 A, X */
+ case BPF_ALU | BPF_MOV | BPF_X:
+ if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT1(add_2mod(0x40, a_reg, x_reg));
+ EMIT2(0x89, add_2reg(0xC0, a_reg, x_reg));
+ break;
- if (off < 0)
- return -EINVAL;
- if (is_imm8(off)) {
- /* movzbl off8(%rdi),%eax */
- EMIT4(0x0f, 0xb6, 0x47, off);
- } else {
- /* movbl off32(%rdi),%eax */
- EMIT3(0x0f, 0xb6, 0x87);
- EMIT(off, 4);
- }
- EMIT3(0x83, 0xe0, PKT_TYPE_MAX); /* and $0x7,%eax */
+ /* neg A */
+ case BPF_ALU | BPF_NEG:
+ case BPF_ALU64 | BPF_NEG:
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ EMIT1(add_1mod(0x48, a_reg));
+ else if (is_ereg(a_reg))
+ EMIT1(add_1mod(0x40, a_reg));
+ EMIT2(0xF7, add_1reg(0xD8, a_reg));
+ break;
+
+ case BPF_ALU | BPF_ADD | BPF_K:
+ case BPF_ALU | BPF_SUB | BPF_K:
+ case BPF_ALU | BPF_AND | BPF_K:
+ case BPF_ALU | BPF_OR | BPF_K:
+ case BPF_ALU | BPF_XOR | BPF_K:
+ case BPF_ALU64 | BPF_ADD | BPF_K:
+ case BPF_ALU64 | BPF_SUB | BPF_K:
+ case BPF_ALU64 | BPF_AND | BPF_K:
+ case BPF_ALU64 | BPF_OR | BPF_K:
+ case BPF_ALU64 | BPF_XOR | BPF_K:
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ EMIT1(add_1mod(0x48, a_reg));
+ else if (is_ereg(a_reg))
+ EMIT1(add_1mod(0x40, a_reg));
+
+ switch (BPF_OP(insn->code)) {
+ case BPF_ADD: b3 = 0xC0; break;
+ case BPF_SUB: b3 = 0xE8; break;
+ case BPF_AND: b3 = 0xE0; break;
+ case BPF_OR: b3 = 0xC8; break;
+ case BPF_XOR: b3 = 0xF0; break;
+ }
+
+ if (is_imm8(K))
+ EMIT3(0x83, add_1reg(b3, a_reg), K);
+ else
+ EMIT2_off32(0x81, add_1reg(b3, a_reg), K);
+ break;
+
+ case BPF_ALU64 | BPF_MOV | BPF_K:
+ /* optimization: if imm32 is positive,
+ * use 'mov eax, imm32' (which zero-extends imm32)
+ * to save 2 bytes
+ */
+ if (K < 0) {
+ /* 'mov rax, imm32' sign extends imm32 */
+ b1 = add_1mod(0x48, a_reg);
+ b2 = 0xC7;
+ b3 = 0xC0;
+ EMIT3_off32(b1, b2, add_1reg(b3, a_reg), K);
break;
}
- case BPF_S_LD_W_ABS:
- func = CHOOSE_LOAD_FUNC(K, sk_load_word);
-common_load: seen |= SEEN_DATAREF;
- t_offset = func - (image + addrs[i]);
- EMIT1_off32(0xbe, K); /* mov imm32,%esi */
- EMIT1_off32(0xe8, t_offset); /* call */
+
+ case BPF_ALU | BPF_MOV | BPF_K:
+ /* mov %eax, imm32 */
+ if (is_ereg(a_reg))
+ EMIT1(add_1mod(0x40, a_reg));
+ EMIT1_off32(add_1reg(0xB8, a_reg), K);
+ break;
+
+ /* A %= X, A /= X, A %= K, A /= K */
+ case BPF_ALU | BPF_MOD | BPF_X:
+ case BPF_ALU | BPF_DIV | BPF_X:
+ case BPF_ALU | BPF_MOD | BPF_K:
+ case BPF_ALU | BPF_DIV | BPF_K:
+ case BPF_ALU64 | BPF_MOD | BPF_X:
+ case BPF_ALU64 | BPF_DIV | BPF_X:
+ case BPF_ALU64 | BPF_MOD | BPF_K:
+ case BPF_ALU64 | BPF_DIV | BPF_K:
+ EMIT1(0x50); /* push rax */
+ EMIT1(0x52); /* push rdx */
+
+ if (BPF_SRC(insn->code) == BPF_X)
+ /* mov r11, X */
+ EMIT_mov(AUX_REG, x_reg);
+ else
+ /* mov r11, K */
+ EMIT3_off32(0x49, 0xC7, 0xC3, K);
+
+ /* mov rax, A */
+ EMIT_mov(BPF_REG_0, a_reg);
+
+ /* xor edx, edx
+ * equivalent to 'xor rdx, rdx', but one byte less
+ */
+ EMIT2(0x31, 0xd2);
+
+ if (BPF_SRC(insn->code) == BPF_X) {
+ /* if (X == 0) return 0 */
+
+ /* cmp r11, 0 */
+ EMIT4(0x49, 0x83, 0xFB, 0x00);
+
+ /* jne .+9 (skip over pop, pop, xor and jmp) */
+ EMIT2(X86_JNE, 1 + 1 + 2 + 5);
+ EMIT1(0x5A); /* pop rdx */
+ EMIT1(0x58); /* pop rax */
+ EMIT2(0x31, 0xc0); /* xor eax, eax */
+
+ /* jmp cleanup_addr
+ * addrs[i] - 11, because there are 11 bytes
+ * after this insn: div, mov, pop, pop, mov
+ */
+ jmp_offset = ctx->cleanup_addr - (addrs[i] - 11);
+ EMIT1_off32(0xE9, jmp_offset);
+ }
+
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ /* div r11 */
+ EMIT3(0x49, 0xF7, 0xF3);
+ else
+ /* div r11d */
+ EMIT3(0x41, 0xF7, 0xF3);
+
+ if (BPF_OP(insn->code) == BPF_MOD)
+ /* mov r11, rdx */
+ EMIT3(0x49, 0x89, 0xD3);
+ else
+ /* mov r11, rax */
+ EMIT3(0x49, 0x89, 0xC3);
+
+ EMIT1(0x5A); /* pop rdx */
+ EMIT1(0x58); /* pop rax */
+
+ /* mov A, r11 */
+ EMIT_mov(a_reg, AUX_REG);
+ break;
+
+ case BPF_ALU | BPF_MUL | BPF_K:
+ case BPF_ALU | BPF_MUL | BPF_X:
+ case BPF_ALU64 | BPF_MUL | BPF_K:
+ case BPF_ALU64 | BPF_MUL | BPF_X:
+ EMIT1(0x50); /* push rax */
+ EMIT1(0x52); /* push rdx */
+
+ /* mov r11, A */
+ EMIT_mov(AUX_REG, a_reg);
+
+ if (BPF_SRC(insn->code) == BPF_X)
+ /* mov rax, X */
+ EMIT_mov(BPF_REG_0, x_reg);
+ else
+ /* mov rax, K */
+ EMIT3_off32(0x48, 0xC7, 0xC0, K);
+
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ EMIT1(add_1mod(0x48, AUX_REG));
+ else if (is_ereg(AUX_REG))
+ EMIT1(add_1mod(0x40, AUX_REG));
+ /* mul(q) r11 */
+ EMIT2(0xF7, add_1reg(0xE0, AUX_REG));
+
+ /* mov r11, rax */
+ EMIT_mov(AUX_REG, BPF_REG_0);
+
+ EMIT1(0x5A); /* pop rdx */
+ EMIT1(0x58); /* pop rax */
+
+ /* mov A, r11 */
+ EMIT_mov(a_reg, AUX_REG);
+ break;
+
+ /* shifts */
+ case BPF_ALU | BPF_LSH | BPF_K:
+ case BPF_ALU | BPF_RSH | BPF_K:
+ case BPF_ALU | BPF_ARSH | BPF_K:
+ case BPF_ALU64 | BPF_LSH | BPF_K:
+ case BPF_ALU64 | BPF_RSH | BPF_K:
+ case BPF_ALU64 | BPF_ARSH | BPF_K:
+ if (BPF_CLASS(insn->code) == BPF_ALU64)
+ EMIT1(add_1mod(0x48, a_reg));
+ else if (is_ereg(a_reg))
+ EMIT1(add_1mod(0x40, a_reg));
+
+ switch (BPF_OP(insn->code)) {
+ case BPF_LSH: b3 = 0xE0; break;
+ case BPF_RSH: b3 = 0xE8; break;
+ case BPF_ARSH: b3 = 0xF8; break;
+ }
+ EMIT3(0xC1, add_1reg(b3, a_reg), K);
+ break;
+
+ case BPF_ALU | BPF_END | BPF_FROM_BE:
+ switch (K) {
+ case 16:
+ /* emit 'ror %ax, 8' to swap lower 2 bytes */
+ EMIT1(0x66);
+ if (is_ereg(a_reg))
+ EMIT1(0x41);
+ EMIT3(0xC1, add_1reg(0xC8, a_reg), 8);
break;
- case BPF_S_LD_H_ABS:
- func = CHOOSE_LOAD_FUNC(K, sk_load_half);
- goto common_load;
- case BPF_S_LD_B_ABS:
- func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
- goto common_load;
- case BPF_S_LDX_B_MSH:
- func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh);
- seen |= SEEN_DATAREF | SEEN_XREG;
- t_offset = func - (image + addrs[i]);
- EMIT1_off32(0xbe, K); /* mov imm32,%esi */
- EMIT1_off32(0xe8, t_offset); /* call sk_load_byte_msh */
+ case 32:
+ /* emit 'bswap eax' to swap lower 4 bytes */
+ if (is_ereg(a_reg))
+ EMIT2(0x41, 0x0F);
+ else
+ EMIT1(0x0F);
+ EMIT1(add_1reg(0xC8, a_reg));
break;
- case BPF_S_LD_W_IND:
- func = sk_load_word;
-common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG;
- t_offset = func - (image + addrs[i]);
+ case 64:
+ /* emit 'bswap rax' to swap 8 bytes */
+ EMIT3(add_1mod(0x48, a_reg), 0x0F,
+ add_1reg(0xC8, a_reg));
+ break;
+ }
+ break;
+
+ case BPF_ALU | BPF_END | BPF_FROM_LE:
+ break;
+
+ /* ST: *(u8*)(a_reg + off) = imm */
+ case BPF_ST | BPF_MEM | BPF_B:
+ if (is_ereg(a_reg))
+ EMIT2(0x41, 0xC6);
+ else
+ EMIT1(0xC6);
+ goto st;
+ case BPF_ST | BPF_MEM | BPF_H:
+ if (is_ereg(a_reg))
+ EMIT3(0x66, 0x41, 0xC7);
+ else
+ EMIT2(0x66, 0xC7);
+ goto st;
+ case BPF_ST | BPF_MEM | BPF_W:
+ if (is_ereg(a_reg))
+ EMIT2(0x41, 0xC7);
+ else
+ EMIT1(0xC7);
+ goto st;
+ case BPF_ST | BPF_MEM | BPF_DW:
+ EMIT2(add_1mod(0x48, a_reg), 0xC7);
+
+st: if (is_imm8(insn->off))
+ EMIT2(add_1reg(0x40, a_reg), insn->off);
+ else
+ EMIT1_off32(add_1reg(0x80, a_reg), insn->off);
+
+ EMIT(K, bpf_size_to_x86_bytes(BPF_SIZE(insn->code)));
+ break;
+
+ /* STX: *(u8*)(a_reg + off) = x_reg */
+ case BPF_STX | BPF_MEM | BPF_B:
+ /* emit 'mov byte ptr [rax + off], al' */
+ if (is_ereg(a_reg) || is_ereg(x_reg) ||
+ /* have to add extra byte for x86 SIL, DIL regs */
+ x_reg == BPF_REG_1 || x_reg == BPF_REG_2)
+ EMIT2(add_2mod(0x40, a_reg, x_reg), 0x88);
+ else
+ EMIT1(0x88);
+ goto stx;
+ case BPF_STX | BPF_MEM | BPF_H:
+ if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT3(0x66, add_2mod(0x40, a_reg, x_reg), 0x89);
+ else
+ EMIT2(0x66, 0x89);
+ goto stx;
+ case BPF_STX | BPF_MEM | BPF_W:
+ if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT2(add_2mod(0x40, a_reg, x_reg), 0x89);
+ else
+ EMIT1(0x89);
+ goto stx;
+ case BPF_STX | BPF_MEM | BPF_DW:
+ EMIT2(add_2mod(0x48, a_reg, x_reg), 0x89);
+stx: if (is_imm8(insn->off))
+ EMIT2(add_2reg(0x40, a_reg, x_reg), insn->off);
+ else
+ EMIT1_off32(add_2reg(0x80, a_reg, x_reg),
+ insn->off);
+ break;
+
+ /* LDX: a_reg = *(u8*)(x_reg + off) */
+ case BPF_LDX | BPF_MEM | BPF_B:
+ /* emit 'movzx rax, byte ptr [rax + off]' */
+ EMIT3(add_2mod(0x48, x_reg, a_reg), 0x0F, 0xB6);
+ goto ldx;
+ case BPF_LDX | BPF_MEM | BPF_H:
+ /* emit 'movzx rax, word ptr [rax + off]' */
+ EMIT3(add_2mod(0x48, x_reg, a_reg), 0x0F, 0xB7);
+ goto ldx;
+ case BPF_LDX | BPF_MEM | BPF_W:
+ /* emit 'mov eax, dword ptr [rax+0x14]' */
+ if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT2(add_2mod(0x40, x_reg, a_reg), 0x8B);
+ else
+ EMIT1(0x8B);
+ goto ldx;
+ case BPF_LDX | BPF_MEM | BPF_DW:
+ /* emit 'mov rax, qword ptr [rax+0x14]' */
+ EMIT2(add_2mod(0x48, x_reg, a_reg), 0x8B);
+ldx: /* if insn->off == 0 we can save one extra byte, but
+ * special case of x86 r13 which always needs an offset
+ * is not worth the hassle
+ */
+ if (is_imm8(insn->off))
+ EMIT2(add_2reg(0x40, x_reg, a_reg), insn->off);
+ else
+ EMIT1_off32(add_2reg(0x80, x_reg, a_reg),
+ insn->off);
+ break;
+
+ /* STX XADD: lock *(u32*)(a_reg + off) += x_reg */
+ case BPF_STX | BPF_XADD | BPF_W:
+ /* emit 'lock add dword ptr [rax + off], eax' */
+ if (is_ereg(a_reg) || is_ereg(x_reg))
+ EMIT3(0xF0, add_2mod(0x40, a_reg, x_reg), 0x01);
+ else
+ EMIT2(0xF0, 0x01);
+ goto xadd;
+ case BPF_STX | BPF_XADD | BPF_DW:
+ EMIT3(0xF0, add_2mod(0x48, a_reg, x_reg), 0x01);
+xadd: if (is_imm8(insn->off))
+ EMIT2(add_2reg(0x40, a_reg, x_reg), insn->off);
+ else
+ EMIT1_off32(add_2reg(0x80, a_reg, x_reg),
+ insn->off);
+ break;
+
+ /* call */
+ case BPF_JMP | BPF_CALL:
+ func = (u8 *) __bpf_call_base + K;
+ jmp_offset = func - (image + addrs[i]);
+ if (ctx->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;
+ }
+ if (!K || !is_simm32(jmp_offset)) {
+ pr_err("unsupported bpf func %d addr %p image %p\n",
+ K, func, image);
+ return -EINVAL;
+ }
+ EMIT1_off32(0xE8, jmp_offset);
+ if (ctx->seen_ld_abs) {
+ EMIT2(0x41, 0x59); /* pop %r9 */
+ EMIT2(0x41, 0x5A); /* pop %r10 */
+ }
+ break;
+
+ /* cond jump */
+ case BPF_JMP | BPF_JEQ | BPF_X:
+ case BPF_JMP | BPF_JNE | BPF_X:
+ case BPF_JMP | BPF_JGT | BPF_X:
+ case BPF_JMP | BPF_JGE | BPF_X:
+ case BPF_JMP | BPF_JSGT | BPF_X:
+ case BPF_JMP | BPF_JSGE | BPF_X:
+ /* cmp a_reg, x_reg */
+ EMIT3(add_2mod(0x48, a_reg, x_reg), 0x39,
+ add_2reg(0xC0, a_reg, x_reg));
+ goto emit_cond_jmp;
+
+ case BPF_JMP | BPF_JSET | BPF_X:
+ /* test a_reg, x_reg */
+ EMIT3(add_2mod(0x48, a_reg, x_reg), 0x85,
+ add_2reg(0xC0, a_reg, x_reg));
+ goto emit_cond_jmp;
+
+ case BPF_JMP | BPF_JSET | BPF_K:
+ /* test a_reg, imm32 */
+ EMIT1(add_1mod(0x48, a_reg));
+ EMIT2_off32(0xF7, add_1reg(0xC0, a_reg), K);
+ goto emit_cond_jmp;
+
+ case BPF_JMP | BPF_JEQ | BPF_K:
+ case BPF_JMP | BPF_JNE | BPF_K:
+ case BPF_JMP | BPF_JGT | BPF_K:
+ case BPF_JMP | BPF_JGE | BPF_K:
+ case BPF_JMP | BPF_JSGT | BPF_K:
+ case BPF_JMP | BPF_JSGE | BPF_K:
+ /* cmp a_reg, imm8/32 */
+ EMIT1(add_1mod(0x48, a_reg));
+
+ if (is_imm8(K))
+ EMIT3(0x83, add_1reg(0xF8, a_reg), K);
+ else
+ EMIT2_off32(0x81, add_1reg(0xF8, a_reg), K);
+
+emit_cond_jmp: /* convert BPF opcode to x86 */
+ switch (BPF_OP(insn->code)) {
+ case BPF_JEQ:
+ jmp_cond = X86_JE;
+ break;
+ case BPF_JSET:
+ case BPF_JNE:
+ jmp_cond = X86_JNE;
+ break;
+ case BPF_JGT:
+ /* GT is unsigned '>', JA in x86 */
+ jmp_cond = X86_JA;
+ break;
+ case BPF_JGE:
+ /* GE is unsigned '>=', JAE in x86 */
+ jmp_cond = X86_JAE;
+ break;
+ case BPF_JSGT:
+ /* signed '>', GT in x86 */
+ jmp_cond = X86_JG;
+ break;
+ case BPF_JSGE:
+ /* signed '>=', GE in x86 */
+ jmp_cond = X86_JGE;
+ break;
+ default: /* to silence gcc warning */
+ return -EFAULT;
+ }
+ jmp_offset = addrs[i + insn->off] - addrs[i];
+ if (is_imm8(jmp_offset)) {
+ EMIT2(jmp_cond, jmp_offset);
+ } else if (is_simm32(jmp_offset)) {
+ EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
+ } else {
+ pr_err("cond_jmp gen bug %llx\n", jmp_offset);
+ return -EFAULT;
+ }
+
+ break;
+
+ case BPF_JMP | BPF_JA:
+ jmp_offset = addrs[i + insn->off] - addrs[i];
+ if (!jmp_offset)
+ /* optimize out nop jumps */
+ break;
+emit_jmp:
+ if (is_imm8(jmp_offset)) {
+ EMIT2(0xEB, jmp_offset);
+ } else if (is_simm32(jmp_offset)) {
+ EMIT1_off32(0xE9, jmp_offset);
+ } else {
+ pr_err("jmp gen bug %llx\n", jmp_offset);
+ return -EFAULT;
+ }
+ break;
+
+ case BPF_LD | BPF_IND | BPF_W:
+ func = sk_load_word;
+ goto common_load;
+ case BPF_LD | BPF_ABS | BPF_W:
+ func = CHOOSE_LOAD_FUNC(K, sk_load_word);
+common_load: ctx->seen_ld_abs = true;
+ jmp_offset = func - (image + addrs[i]);
+ if (!func || !is_simm32(jmp_offset)) {
+ pr_err("unsupported bpf func %d addr %p image %p\n",
+ K, func, image);
+ return -EINVAL;
+ }
+ if (BPF_MODE(insn->code) == BPF_ABS) {
+ /* mov %esi, imm32 */
+ EMIT1_off32(0xBE, K);
+ } else {
+ /* mov %rsi, x_reg */
+ EMIT_mov(BPF_REG_2, x_reg);
if (K) {
- if (is_imm8(K)) {
- EMIT3(0x8d, 0x73, K); /* lea imm8(%rbx), %esi */
- } else {
- EMIT2(0x8d, 0xb3); /* lea imm32(%rbx),%esi */
- EMIT(K, 4);
- }
- } else {
- EMIT2(0x89,0xde); /* mov %ebx,%esi */
- }
- EMIT1_off32(0xe8, t_offset); /* call sk_load_xxx_ind */
- break;
- case BPF_S_LD_H_IND:
- func = sk_load_half;
- goto common_load_ind;
- case BPF_S_LD_B_IND:
- func = sk_load_byte;
- goto common_load_ind;
- case BPF_S_JMP_JA:
- t_offset = addrs[i + K] - addrs[i];
- EMIT_JMP(t_offset);
- break;
- COND_SEL(BPF_S_JMP_JGT_K, X86_JA, X86_JBE);
- COND_SEL(BPF_S_JMP_JGE_K, X86_JAE, X86_JB);
- COND_SEL(BPF_S_JMP_JEQ_K, X86_JE, X86_JNE);
- COND_SEL(BPF_S_JMP_JSET_K,X86_JNE, X86_JE);
- COND_SEL(BPF_S_JMP_JGT_X, X86_JA, X86_JBE);
- COND_SEL(BPF_S_JMP_JGE_X, X86_JAE, X86_JB);
- COND_SEL(BPF_S_JMP_JEQ_X, X86_JE, X86_JNE);
- COND_SEL(BPF_S_JMP_JSET_X,X86_JNE, X86_JE);
-
-cond_branch: f_offset = addrs[i + filter[i].jf] - addrs[i];
- t_offset = addrs[i + filter[i].jt] - addrs[i];
-
- /* same targets, can avoid doing the test :) */
- if (filter[i].jt == filter[i].jf) {
- EMIT_JMP(t_offset);
- break;
- }
-
- switch (filter[i].code) {
- case BPF_S_JMP_JGT_X:
- case BPF_S_JMP_JGE_X:
- case BPF_S_JMP_JEQ_X:
- seen |= SEEN_XREG;
- EMIT2(0x39, 0xd8); /* cmp %ebx,%eax */
- break;
- case BPF_S_JMP_JSET_X:
- seen |= SEEN_XREG;
- EMIT2(0x85, 0xd8); /* test %ebx,%eax */
- break;
- case BPF_S_JMP_JEQ_K:
- if (K == 0) {
- EMIT2(0x85, 0xc0); /* test %eax,%eax */
- break;
- }
- case BPF_S_JMP_JGT_K:
- case BPF_S_JMP_JGE_K:
- if (K <= 127)
- EMIT3(0x83, 0xf8, K); /* cmp imm8,%eax */
+ if (is_imm8(K))
+ /* add %esi, imm8 */
+ EMIT3(0x83, 0xC6, K);
else
- EMIT1_off32(0x3d, K); /* cmp imm32,%eax */
- break;
- case BPF_S_JMP_JSET_K:
- if (K <= 0xFF)
- EMIT2(0xa8, K); /* test imm8,%al */
- else if (!(K & 0xFFFF00FF))
- EMIT3(0xf6, 0xc4, K >> 8); /* test imm8,%ah */
- else if (K <= 0xFFFF) {
- EMIT2(0x66, 0xa9); /* test imm16,%ax */
- EMIT(K, 2);
- } else {
- EMIT1_off32(0xa9, K); /* test imm32,%eax */
- }
- break;
+ /* add %esi, imm32 */
+ EMIT2_off32(0x81, 0xC6, K);
}
- if (filter[i].jt != 0) {
- if (filter[i].jf && f_offset)
- t_offset += is_near(f_offset) ? 2 : 5;
- EMIT_COND_JMP(t_op, t_offset);
- if (filter[i].jf)
- EMIT_JMP(f_offset);
- break;
- }
- EMIT_COND_JMP(f_op, f_offset);
- break;
+ }
+ /* skb pointer is in R6 (%rbx), it will be copied into
+ * %rdi if skb_copy_bits() call is necessary.
+ * sk_load_* helpers also use %r10 and %r9d.
+ * See bpf_jit.S
+ */
+ EMIT1_off32(0xE8, jmp_offset); /* call */
+ break;
+
+ case BPF_LD | BPF_IND | BPF_H:
+ func = sk_load_half;
+ goto common_load;
+ case BPF_LD | BPF_ABS | BPF_H:
+ func = CHOOSE_LOAD_FUNC(K, sk_load_half);
+ goto common_load;
+ case BPF_LD | BPF_IND | BPF_B:
+ func = sk_load_byte;
+ goto common_load;
+ case BPF_LD | BPF_ABS | BPF_B:
+ func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
+ goto common_load;
+
+ case BPF_JMP | BPF_EXIT:
+ if (i != insn_cnt - 1) {
+ jmp_offset = ctx->cleanup_addr - addrs[i];
+ goto emit_jmp;
+ }
+ /* update cleanup_addr */
+ ctx->cleanup_addr = proglen;
+ /* mov rbx, qword ptr [rbp-X] */
+ EMIT3_off32(0x48, 0x8B, 0x9D, -stacksize);
+ /* mov r13, qword ptr [rbp-X] */
+ EMIT3_off32(0x4C, 0x8B, 0xAD, -stacksize + 8);
+ /* mov r14, qword ptr [rbp-X] */
+ EMIT3_off32(0x4C, 0x8B, 0xB5, -stacksize + 16);
+ /* mov r15, qword ptr [rbp-X] */
+ EMIT3_off32(0x4C, 0x8B, 0xBD, -stacksize + 24);
+
+ EMIT1(0xC9); /* leave */
+ EMIT1(0xC3); /* ret */
+ break;
+
default:
- /* hmm, too complex filter, give up with jit compiler */
+ /* By design x64 JIT should support all BPF instructions
+ * This error will be seen if new instruction was added
+ * to interpreter, but not to JIT
+ * or if there is junk in sk_filter
+ */
+ pr_err("bpf_jit: unknown opcode %02x\n", insn->code);
return -EINVAL;
}
+
ilen = prog - temp;
if (image) {
if (unlikely(proglen + ilen > oldproglen)) {
- pr_err("bpb_jit_compile fatal error\n");
+ pr_err("bpf_jit_compile fatal error\n");
return -EFAULT;
}
memcpy(image + proglen, temp, ilen);
@@ -726,22 +859,15 @@
addrs[i] = proglen;
prog = temp;
}
- /* last bpf instruction is always a RET :
- * use it to give the cleanup instruction(s) addr
- */
- ctx->cleanup_addr = proglen - 1; /* ret */
- if (seen_or_pass0)
- ctx->cleanup_addr -= 1; /* leaveq */
- if (seen_or_pass0 & SEEN_XREG)
- ctx->cleanup_addr -= 4; /* mov -8(%rbp),%rbx */
-
- ctx->seen = seen;
-
return proglen;
}
void bpf_jit_compile(struct sk_filter *prog)
{
+}
+
+void bpf_int_jit_compile(struct sk_filter *prog)
+{
struct bpf_binary_header *header = NULL;
int proglen, oldproglen = 0;
struct jit_context ctx = {};
@@ -768,8 +894,6 @@
addrs[i] = proglen;
}
ctx.cleanup_addr = proglen;
- ctx.seen = SEEN_XREG | SEEN_DATAREF | SEEN_MEM;
- ctx.pc_ret0 = -1;
for (pass = 0; pass < 10; pass++) {
proglen = do_jit(prog, addrs, image, oldproglen, &ctx);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 4457b38..9d5ae0a 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -207,6 +207,9 @@
void sk_filter_charge(struct sock *sk, struct sk_filter *fp);
void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
+u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+void bpf_int_jit_compile(struct sk_filter *fp);
+
#ifdef CONFIG_BPF_JIT
#include <stdarg.h>
#include <linux/linkage.h>
diff --git a/net/core/filter.c b/net/core/filter.c
index c442a0d..32c5b44 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1524,6 +1524,10 @@
return ERR_PTR(err);
}
+void __weak bpf_int_jit_compile(struct sk_filter *prog)
+{
+}
+
static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp,
struct sock *sk)
{
@@ -1544,9 +1548,12 @@
/* JIT compiler couldn't process this filter, so do the
* internal BPF translation for the optimized interpreter.
*/
- if (!fp->jited)
+ if (!fp->jited) {
fp = __sk_migrate_filter(fp, sk);
+ /* Probe if internal BPF can be jit-ed */
+ bpf_int_jit_compile(fp);
+ }
return fp;
}