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Message-ID: <1301783301.2837.77.camel@edumazet-laptop>
Date: Sun, 03 Apr 2011 00:28:21 +0200
From: Eric Dumazet <eric.dumazet@...il.com>
To: David Miller <davem@...emloft.net>
Cc: netdev <netdev@...r.kernel.org>,
Arnaldo Carvalho de Melo <acme@...radead.org>
Subject: [PATCH v1] net: filter: Just In Time compiler
In order to speedup packet filtering, here is an implementation of a JIT
compiler for x86_64
It is disabled by default, and must be enabled by the admin.
echo 1 >/proc/sys/net/core/bpf_jit_enable
It uses module_alloc() and module_free() to get memory in the 2GB text
kernel range since we call helpers functions from the generated code.
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)
r9d : skb->len - skb->data_len (headlen)
r8 : skb->data
To get a trace of generated code, use :
echo 2 >/proc/sys/net/core/bpf_jit_enable
Example of generated code :
flen=14 proglen=139 pass=3 image=ffffffffa00d5000
JIT code: ffffffffa00d5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60
JIT code: ffffffffa00d5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00
JIT code: ffffffffa00d5020: e8 24 1b 2f e1 3d 00 08 00 00 75 24 be 1a 00 00
JIT code: ffffffffa00d5030: 00 e8 fe 1a 2f e1 3d 01 00 a8 c0 74 43 be 1e 00
JIT code: ffffffffa00d5040: 00 00 e8 ed 1a 2f e1 3d 01 00 a8 c0 74 32 eb 37
JIT code: ffffffffa00d5050: 3d 06 08 00 00 74 07 3d 35 80 00 00 75 29 be 1c
JIT code: ffffffffa00d5060: 00 00 00 e8 cc 1a 2f e1 3d 01 00 a8 c0 74 11 be
JIT code: ffffffffa00d5070: 26 00 00 00 e8 bb 1a 2f e1 3d 01 00 a8 c0 75 07
JIT code: ffffffffa00d5080: b8 ff ff 00 00 eb 02 31 c0 c9 c3
# tcpdump -p -n -s 0 -i eth1 host 192.168.0.1 -d
(000) ldh [12]
(001) jeq #0x800 jt 2 jf 6
(002) ld [26]
(003) jeq #0xc0a80001 jt 12 jf 4
(004) ld [30]
(005) jeq #0xc0a80001 jt 12 jf 13
(006) jeq #0x806 jt 8 jf 7
(007) jeq #0x8035 jt 8 jf 13
(008) ld [28]
(009) jeq #0xc0a80001 jt 12 jf 10
(010) ld [38]
(011) jeq #0xc0a80001 jt 12 jf 13
(012) ret #65535
(013) ret #0
Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
Cc: Arnaldo Carvalho de Melo <acme@...radead.org>
---
perf tool might need some changes to take into account JIT.
Documentation/sysctl/net.txt | 11
include/linux/filter.h | 76 +++
include/linux/netdevice.h | 1
net/Kconfig | 5
net/core/Makefile | 2
net/core/bpf_jit.S | 142 +++++++
net/core/bpf_jit_comp.c | 636 +++++++++++++++++++++++++++++++++
net/core/filter.c | 65 ---
net/core/sysctl_net_core.c | 9
net/packet/af_packet.c | 2
10 files changed, 888 insertions(+), 61 deletions(-)
diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
index cbd05ff..3201a70 100644
--- a/Documentation/sysctl/net.txt
+++ b/Documentation/sysctl/net.txt
@@ -32,6 +32,17 @@ Table : Subdirectories in /proc/sys/net
1. /proc/sys/net/core - Network core options
-------------------------------------------------------
+bpf_jit_enable
+--------------
+
+This enables Berkeley Packet Filter Just in Time compiler.
+Currently supported on x86_64 architecture, bpf_jit provides a framework
+to speed packet filtering, the one used by tcpdump/libpcap for example.
+Values :
+ 0 - disable the JIT (default value)
+ 1 - enable the JIT
+ 2 - enable the JIT and ask the compiler to emit traces on kernel log.
+
rmem_default
------------
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 45266b7..4609b85 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -135,6 +135,8 @@ struct sk_filter
{
atomic_t refcnt;
unsigned int len; /* Number of filter blocks */
+ unsigned int (*bpf_func)(const struct sk_buff *skb,
+ const struct sock_filter *filter);
struct rcu_head rcu;
struct sock_filter insns[0];
};
@@ -153,6 +155,80 @@ extern unsigned int sk_run_filter(const struct sk_buff *skb,
extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
extern int sk_detach_filter(struct sock *sk);
extern int sk_chk_filter(struct sock_filter *filter, int flen);
+
+#ifdef CONFIG_BPF_JIT
+extern void bpf_jit_compile(struct sk_filter *fp);
+extern void bpf_jit_free(struct sk_filter *fp);
+#define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns)
+#else
+static inline void bpf_jit_compile(struct sk_filter *fp)
+{
+}
+static inline void bpf_jit_free(struct sk_filter *fp)
+{
+}
+#define SK_RUN_FILTER(FILTER, SKB) sk_run_filter(SKB, FILTER->insns)
+#endif
+
+enum {
+ BPF_S_RET_K = 1,
+ BPF_S_RET_A,
+ BPF_S_ALU_ADD_K,
+ BPF_S_ALU_ADD_X,
+ BPF_S_ALU_SUB_K,
+ BPF_S_ALU_SUB_X,
+ BPF_S_ALU_MUL_K,
+ BPF_S_ALU_MUL_X,
+ BPF_S_ALU_DIV_X,
+ BPF_S_ALU_AND_K,
+ BPF_S_ALU_AND_X,
+ BPF_S_ALU_OR_K,
+ BPF_S_ALU_OR_X,
+ BPF_S_ALU_LSH_K,
+ BPF_S_ALU_LSH_X,
+ BPF_S_ALU_RSH_K,
+ BPF_S_ALU_RSH_X,
+ BPF_S_ALU_NEG,
+ BPF_S_LD_W_ABS,
+ BPF_S_LD_H_ABS,
+ BPF_S_LD_B_ABS,
+ BPF_S_LD_W_LEN,
+ BPF_S_LD_W_IND,
+ BPF_S_LD_H_IND,
+ BPF_S_LD_B_IND,
+ BPF_S_LD_IMM,
+ BPF_S_LDX_W_LEN,
+ BPF_S_LDX_B_MSH,
+ BPF_S_LDX_IMM,
+ BPF_S_MISC_TAX,
+ BPF_S_MISC_TXA,
+ BPF_S_ALU_DIV_K,
+ BPF_S_LD_MEM,
+ BPF_S_LDX_MEM,
+ BPF_S_ST,
+ BPF_S_STX,
+ BPF_S_JMP_JA,
+ BPF_S_JMP_JEQ_K,
+ BPF_S_JMP_JEQ_X,
+ BPF_S_JMP_JGE_K,
+ BPF_S_JMP_JGE_X,
+ BPF_S_JMP_JGT_K,
+ BPF_S_JMP_JGT_X,
+ BPF_S_JMP_JSET_K,
+ BPF_S_JMP_JSET_X,
+ /* Ancillary data */
+ BPF_S_ANC_PROTOCOL,
+ BPF_S_ANC_PKTTYPE,
+ BPF_S_ANC_IFINDEX,
+ BPF_S_ANC_NLATTR,
+ BPF_S_ANC_NLATTR_NEST,
+ BPF_S_ANC_MARK,
+ BPF_S_ANC_QUEUE,
+ BPF_S_ANC_HATYPE,
+ BPF_S_ANC_RXHASH,
+ BPF_S_ANC_CPU,
+};
+
#endif /* __KERNEL__ */
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5eeb2cd..7381196 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2513,6 +2513,7 @@ extern struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
extern int netdev_max_backlog;
extern int netdev_tstamp_prequeue;
extern int weight_p;
+extern int bpf_jit_enable;
extern int netdev_set_master(struct net_device *dev, struct net_device *master);
extern int netdev_set_bond_master(struct net_device *dev,
struct net_device *master);
diff --git a/net/Kconfig b/net/Kconfig
index 79cabf1..04a1726 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -232,6 +232,11 @@ config XPS
depends on SMP && SYSFS && USE_GENERIC_SMP_HELPERS
default y
+config BPF_JIT
+ boolean
+ depends on X86_64
+ default y
+
menu "Network testing"
config NET_PKTGEN
diff --git a/net/core/Makefile b/net/core/Makefile
index 8a04dd2..a217995 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -19,3 +19,5 @@ obj-$(CONFIG_FIB_RULES) += fib_rules.o
obj-$(CONFIG_TRACEPOINTS) += net-traces.o
obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o
obj-$(CONFIG_NETWORK_PHY_TIMESTAMPING) += timestamping.o
+obj-$(CONFIG_X86_64) += bpf_jit.o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o
diff --git a/net/core/bpf_jit.S b/net/core/bpf_jit.S
new file mode 100644
index 0000000..a0a9843
--- /dev/null
+++ b/net/core/bpf_jit.S
@@ -0,0 +1,142 @@
+/* bpf_jit.S : BPF JIT helper functions
+ *
+ * Copyright (C) 2011 Eric Dumazet (eric.dumazet@...il.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+#include <linux/linkage.h>
+#include <asm/dwarf2.h>
+
+/*
+ * Calling convention :
+ * rdi : skb pointer
+ * esi : offset of byte(s) to fetch in skb (can be scratched)
+ * r8 : copy of skb->data
+ * r9d : hlen = skb->len - skb->data_len
+ */
+#define SKBDATA %r8
+
+sk_load_word_ind:
+ .globl sk_load_word_ind
+
+ add %ebx,%esi /* offset += X */
+# test %esi,%esi /* if (offset < 0) goto bpf_error; */
+ js bpf_error
+
+sk_load_word:
+ .globl sk_load_word
+
+ mov %r9d,%eax # hlen
+ sub %esi,%eax # hlen - offset
+ cmp $3,%eax
+ jle bpf_slow_path_word
+ mov (SKBDATA,%rsi),%eax
+ bswap %eax /* ntohl() */
+ ret
+
+
+sk_load_half_ind:
+ .globl sk_load_half_ind
+
+ add %ebx,%esi /* offset += X */
+ js bpf_error
+
+sk_load_half:
+ .globl sk_load_half
+
+ mov %r9d,%eax
+ sub %esi,%eax # hlen - offset
+ cmp $1,%eax
+ jle bpf_slow_path_half
+ movzwl (SKBDATA,%rsi),%eax
+ rol $8,%ax # ntohs()
+ ret
+
+sk_load_byte_ind:
+ .globl sk_load_byte_ind
+ add %ebx,%esi /* offset += X */
+ js bpf_error
+
+sk_load_byte:
+ .globl sk_load_byte
+
+ cmp %esi,%r9d /* if (offset >= hlen) goto bpf_slow_path_byte */
+ jle bpf_slow_path_byte
+ 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, already known positive
+ */
+ENTRY(sk_load_byte_msh)
+ CFI_STARTPROC
+ 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
+ CFI_ENDPROC
+ENDPROC(sk_load_byte_msh)
+
+bpf_error:
+# force a return 0 from jit handler
+ xor %eax,%eax
+ mov -8(%rbp),%rbx
+ leaveq
+ ret
+
+/* rsi contains offset and can be scratched */
+#define bpf_slow_path_common(LEN) \
+ push %rdi; /* save skb */ \
+ push %r9; \
+ push SKBDATA; \
+/* rsi already has offset */ \
+ mov $LEN,%ecx; /* len */ \
+ lea -12(%rbp),%rdx; \
+ call skb_copy_bits; \
+ test %eax,%eax; \
+ pop SKBDATA; \
+ pop %r9; \
+ pop %rdi
+
+
+bpf_slow_path_word:
+ bpf_slow_path_common(4)
+ js bpf_error
+ mov -12(%rbp),%eax
+ bswap %eax
+ ret
+
+bpf_slow_path_half:
+ bpf_slow_path_common(2)
+ js bpf_error
+ mov -12(%rbp),%ax
+ rol $8,%ax
+ movzwl %ax,%eax
+ ret
+
+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
+ ret
+
+
diff --git a/net/core/bpf_jit_comp.c b/net/core/bpf_jit_comp.c
new file mode 100644
index 0000000..bd90315
--- /dev/null
+++ b/net/core/bpf_jit_comp.c
@@ -0,0 +1,636 @@
+/* bpf_jit_comp.c : BPF JIT compiler
+ *
+ * Copyright (C) 2011 Eric Dumazet (eric.dumazet@...il.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+#include <linux/moduleloader.h>
+#include <asm/cacheflush.h>
+#include <linux/netdevice.h>
+#include <linux/filter.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)
+ * r9d : skb->len - skb->data_len (headlen)
+ * r8 : skb->data
+ */
+int bpf_jit_enable __read_mostly;
+
+/*
+ * assembly code in net/core/bpf_jit.S
+ */
+extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
+extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[];
+
+static inline u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
+{
+ if (len == 1)
+ *ptr = bytes;
+ else if (len == 2)
+ *(u16 *)ptr = bytes;
+ else {
+ *(u32 *)ptr = bytes;
+ barrier();
+ }
+ return ptr + len;
+}
+
+#define EMIT(bytes, len) do { prog = emit_code(prog, bytes, len); } while (0)
+
+#define EMIT1(b1) EMIT(b1, 1)
+#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 */
+
+static inline bool is_imm8(int value)
+{
+ return value <= 127 && value >= -128;
+}
+
+static inline bool is_near(int offset)
+{
+ return offset <= 127 && offset >= -128;
+}
+
+#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)
+
+/* list of x86 cond jumps (. + s8)
+ * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32)
+ */
+#define X86_JB 0x72
+#define X86_JAE 0x73
+#define X86_JE 0x74
+#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 */
+
+static inline void bpf_flush_icache(void *start, void *end)
+{
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ smp_wmb();
+ flush_icache_range((unsigned long)start, (unsigned long)end);
+ set_fs(old_fs);
+}
+
+
+void bpf_jit_compile(struct sk_filter *fp)
+{
+ u8 temp[64];
+ u8 *prog;
+ unsigned int proglen, oldproglen = 0;
+ int ilen, i;
+ int t_offset, f_offset;
+ u8 t_op, f_op, seen = 0, pass;
+ u8 *image = NULL;
+ u8 *func;
+ int pc_ret0 = -1; /* bpf index of first RET #0 instruction (if any) */
+ unsigned int cleanup_addr;
+ unsigned int *addrs;
+ const struct sock_filter *filter = fp->insns;
+ int flen = fp->len;
+
+ if (!bpf_jit_enable)
+ return;
+
+ addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL);
+ if (addrs == NULL)
+ return;
+
+ /* Before first pass, make a rough estimation of addrs[]
+ * each bpf instruction is translated to less than 64 bytes
+ */
+ for (proglen = 0, i = 0; i < flen; i++) {
+ proglen += 64;
+ addrs[i] = proglen;
+ }
+ cleanup_addr = proglen; /* epilogue address */
+
+ for (pass = 0; pass < 10; pass++) {
+ /* no prologue/epilogue for trivial filters (RET something) */
+ proglen = 0;
+ prog = temp;
+
+ if (seen) {
+ 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 & (SEEN_XREG | SEEN_DATAREF))
+ EMIT4(0x48, 0x89, 0x5d, 0xf8); /* mov %rbx, -8(%rbp) */
+ if (seen & SEEN_XREG)
+ CLEAR_X(); /* make sure we dont leek kernel memory */
+
+ /*
+ * If this filter needs to access skb data,
+ * loads r9 and r8 with :
+ * r9 = skb->len - skb->data_len
+ * r8 = skb->data
+ */
+ if (seen & 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);
+ }
+
+ 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);
+ }
+ }
+ }
+
+ 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_LD_W_ABS:
+ case BPF_S_LD_H_ABS:
+ case BPF_S_LD_B_ABS:
+ /* first instruction sets A register (or is RET 'constant') */
+ break;
+ default:
+ CLEAR_A(); /* A = 0 */
+ }
+
+ for (i = 0; i < flen; i++) {
+ unsigned int K = filter[i].k;
+
+ 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 (pc_ret0 != -1)
+ EMIT_COND_JMP(X86_JE, addrs[pc_ret0] - (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_DIV_K: /* A = reciprocal_divide(A, K); */
+ EMIT3(0x48, 0x69, 0xc0); /* imul imm32,%rax,%rax */
+ EMIT(K, 4);
+ EMIT4(0x48, 0xc1, 0xe8, 0x20); /* shr $0x20,%rax */
+ break;
+ case BPF_S_ALU_AND_X:
+ seen |= SEEN_XREG;
+ EMIT2(0x21, 0xd8); /* and %ebx,%eax */
+ break;
+ case BPF_S_ALU_AND_K:
+ if (is_imm8(K))
+ EMIT3(0x83, 0xe0, K); /* and imm8,%eax */
+ 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_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 (pc_ret0 == -1)
+ pc_ret0 = i;
+ CLEAR_A();
+ } else {
+ EMIT1_off32(0xb8, K); /* mov $imm32,%eax */
+ }
+ /* fallinto */
+ case BPF_S_RET_A:
+ if (seen) {
+ if (i != flen - 1) {
+ EMIT_JMP(cleanup_addr - addrs[i]);
+ break;
+ }
+ if (seen & 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, rxhash) != 4);
+ if (is_imm8(offsetof(struct sk_buff, rxhash))) {
+ /* mov off8(%rdi),%eax */
+ EMIT3(0x8b, 0x47, offsetof(struct sk_buff, rxhash));
+ } else {
+ EMIT2(0x8b, 0x87);
+ EMIT(offsetof(struct sk_buff, rxhash), 4);
+ }
+ break;
+ case BPF_S_ANC_CPU:
+#ifdef CONFIG_SMP
+ EMIT4(0x65, 0x8b, 0x04, 0x25); /* mov %gs:off32,%eax */
+ EMIT((u32)&cpu_number, 4); /* A = smp_processor_id(); */
+#else
+ CLEAR_A();
+#endif
+ break;
+ case BPF_S_LD_W_ABS:
+ func = sk_load_word;
+common_load: seen |= SEEN_DATAREF;
+ if ((int)K < 0)
+ goto out;
+ t_offset = func - (image + addrs[i]);
+ EMIT1_off32(0xbe, K); /* mov imm32,%esi */
+ EMIT1_off32(0xe8, t_offset); /* call */
+ break;
+ case BPF_S_LD_H_ABS:
+ func = sk_load_half;
+ goto common_load;
+ case BPF_S_LD_B_ABS:
+ func = sk_load_byte;
+ goto common_load;
+ case BPF_S_LDX_B_MSH:
+ if ((int)K < 0) {
+ if (pc_ret0 != -1) {
+ EMIT_JMP(addrs[pc_ret0] - addrs[i]);
+ break;
+ }
+ CLEAR_A();
+ EMIT_JMP(cleanup_addr - addrs[i]);
+ break;
+ }
+ seen |= SEEN_DATAREF | SEEN_XREG;
+ t_offset = sk_load_byte_msh - (image + addrs[i]);
+ EMIT1_off32(0xbe, K); /* mov imm32,%esi */
+ EMIT1_off32(0xe8, t_offset); /* call sk_load_byte_msh */
+ break;
+ case BPF_S_LD_W_IND:
+ func = sk_load_word_ind;
+common_load_ind: 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_xxx_ind */
+ break;
+ case BPF_S_LD_H_IND:
+ func = sk_load_half_ind;
+ goto common_load_ind;
+ case BPF_S_LD_B_IND:
+ func = sk_load_byte_ind;
+ 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 */
+ 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;
+ }
+ if (filter[i].jt != 0) {
+ if (filter[i].jf)
+ t_offset += is_near(f_offset) ? 2 : 6;
+ EMIT_COND_JMP(t_op, t_offset);
+ if (filter[i].jf)
+ EMIT_JMP(f_offset);
+ break;
+ }
+ EMIT_COND_JMP(f_op, f_offset);
+ break;
+ default:
+ /* hmm, too complex filter, give up with jit compiler */
+ goto out;
+ }
+ ilen = prog - temp;
+ if (image) {
+ if (unlikely(proglen + ilen > oldproglen)) {
+ pr_err("bpb_jit_compile fatal error\n");
+ kfree(addrs);
+ module_free(NULL, image);
+ return;
+ }
+ memcpy(image + proglen, temp, ilen);
+ }
+ proglen += ilen;
+ addrs[i] = proglen;
+ prog = temp;
+ }
+ /* last bpf instruction is always a RET :
+ * use it to give the cleanup instruction(s) addr
+ */
+ cleanup_addr = proglen - 1; /* ret */
+ if (seen)
+ cleanup_addr -= 1; /* leaveq */
+ if (seen & SEEN_XREG)
+ cleanup_addr -= 4; /* mov -8(%rbp),%rbx */
+
+ if (image) {
+ WARN_ON(proglen != oldproglen);
+ break;
+ }
+ if (proglen == oldproglen) {
+ image = module_alloc(max_t(unsigned int,
+ proglen,
+ sizeof(struct work_struct)));
+ if (!image)
+ goto out;
+ }
+ oldproglen = proglen;
+ }
+ if (bpf_jit_enable > 1)
+ pr_err("flen=%d proglen=%u pass=%d image=%p\n",
+ flen, proglen, pass, image);
+
+ if (image) {
+ if (bpf_jit_enable > 1)
+ print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_ADDRESS,
+ 16, 1, image, proglen, false);
+
+ bpf_flush_icache(image, image + proglen);
+
+ fp->bpf_func = (void *)image;
+ }
+out:
+ kfree(addrs);
+ return;
+}
+
+static void jit_free_defer(struct work_struct *arg)
+{
+ module_free(NULL, arg);
+}
+
+/* run from softirq, we must use a work_struct to call
+ * module_free() from process context
+ */
+void bpf_jit_free(struct sk_filter *fp)
+{
+ if (fp->bpf_func != sk_run_filter) {
+ struct work_struct *work = (struct work_struct *)fp->bpf_func;
+
+ INIT_WORK(work, jit_free_defer);
+ schedule_work(work);
+ }
+}
+
diff --git a/net/core/filter.c b/net/core/filter.c
index 232b187..e63a794 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -39,65 +39,6 @@
#include <linux/filter.h>
#include <linux/reciprocal_div.h>
-enum {
- BPF_S_RET_K = 1,
- BPF_S_RET_A,
- BPF_S_ALU_ADD_K,
- BPF_S_ALU_ADD_X,
- BPF_S_ALU_SUB_K,
- BPF_S_ALU_SUB_X,
- BPF_S_ALU_MUL_K,
- BPF_S_ALU_MUL_X,
- BPF_S_ALU_DIV_X,
- BPF_S_ALU_AND_K,
- BPF_S_ALU_AND_X,
- BPF_S_ALU_OR_K,
- BPF_S_ALU_OR_X,
- BPF_S_ALU_LSH_K,
- BPF_S_ALU_LSH_X,
- BPF_S_ALU_RSH_K,
- BPF_S_ALU_RSH_X,
- BPF_S_ALU_NEG,
- BPF_S_LD_W_ABS,
- BPF_S_LD_H_ABS,
- BPF_S_LD_B_ABS,
- BPF_S_LD_W_LEN,
- BPF_S_LD_W_IND,
- BPF_S_LD_H_IND,
- BPF_S_LD_B_IND,
- BPF_S_LD_IMM,
- BPF_S_LDX_W_LEN,
- BPF_S_LDX_B_MSH,
- BPF_S_LDX_IMM,
- BPF_S_MISC_TAX,
- BPF_S_MISC_TXA,
- BPF_S_ALU_DIV_K,
- BPF_S_LD_MEM,
- BPF_S_LDX_MEM,
- BPF_S_ST,
- BPF_S_STX,
- BPF_S_JMP_JA,
- BPF_S_JMP_JEQ_K,
- BPF_S_JMP_JEQ_X,
- BPF_S_JMP_JGE_K,
- BPF_S_JMP_JGE_X,
- BPF_S_JMP_JGT_K,
- BPF_S_JMP_JGT_X,
- BPF_S_JMP_JSET_K,
- BPF_S_JMP_JSET_X,
- /* Ancillary data */
- BPF_S_ANC_PROTOCOL,
- BPF_S_ANC_PKTTYPE,
- BPF_S_ANC_IFINDEX,
- BPF_S_ANC_NLATTR,
- BPF_S_ANC_NLATTR_NEST,
- BPF_S_ANC_MARK,
- BPF_S_ANC_QUEUE,
- BPF_S_ANC_HATYPE,
- BPF_S_ANC_RXHASH,
- BPF_S_ANC_CPU,
-};
-
/* No hurry in this branch */
static void *__load_pointer(const struct sk_buff *skb, int k, unsigned int size)
{
@@ -145,7 +86,7 @@ int sk_filter(struct sock *sk, struct sk_buff *skb)
rcu_read_lock();
filter = rcu_dereference(sk->sk_filter);
if (filter) {
- unsigned int pkt_len = sk_run_filter(skb, filter->insns);
+ unsigned int pkt_len = SK_RUN_FILTER(filter, skb);
err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
}
@@ -638,6 +579,7 @@ void sk_filter_release_rcu(struct rcu_head *rcu)
{
struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
+ bpf_jit_free(fp);
kfree(fp);
}
EXPORT_SYMBOL(sk_filter_release_rcu);
@@ -672,6 +614,7 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
atomic_set(&fp->refcnt, 1);
fp->len = fprog->len;
+ fp->bpf_func = sk_run_filter;
err = sk_chk_filter(fp->insns, fp->len);
if (err) {
@@ -679,6 +622,8 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
return err;
}
+ bpf_jit_compile(fp);
+
old_fp = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 385b609..a829e3f 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -122,6 +122,15 @@ static struct ctl_table net_core_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec
},
+#ifdef CONFIG_BPF_JIT
+ {
+ .procname = "bpf_jit_enable",
+ .data = &bpf_jit_enable,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+#endif
{
.procname = "netdev_tstamp_prequeue",
.data = &netdev_tstamp_prequeue,
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index b5362e9..549527b 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -538,7 +538,7 @@ static inline unsigned int run_filter(const struct sk_buff *skb,
rcu_read_lock();
filter = rcu_dereference(sk->sk_filter);
if (filter != NULL)
- res = sk_run_filter(skb, filter->insns);
+ res = SK_RUN_FILTER(filter, skb);
rcu_read_unlock();
return res;
--
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