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Merge branch 'ebpf'

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Alexei Starovoitov says:

====================
load imm64 insn and uapi/linux/bpf.h

V9->V10
- no changes, added Daniel's ack

Note they're on top of Hannes's patch in the same area [1]

V8 thread with 'why' reasoning and end goal [2]

Original set [3] of ~28 patches I'm planning to present in 4 stages:

  I. this 2 patches to fork off llvm upstreaming
 II. bpf syscall with manpage and map implementation
III. bpf program load/unload with verifier testsuite (1st user of
     instruction macros from bpf.h and 1st user of load imm64 insn)
 IV. tracing, etc

[1] http://patchwork.ozlabs.org/patch/385266/
[2] https://lkml.org/lkml/2014/8/27/628
[3] https://lkml.org/lkml/2014/8/26/859
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2014-09-09 10:27:22 -07:00
commit afddacc3cc
7 changed files with 135 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Documentation/networking/filter.txt
View File

@ -951,7 +951,7 @@ Size modifier is one of ...
Mode modifier is one of:
BPF_IMM 0x00 /* classic BPF only, reserved in eBPF */
BPF_IMM 0x00 /* used for 32-bit mov in classic BPF and 64-bit in eBPF */
BPF_ABS 0x20
BPF_IND 0x40
BPF_MEM 0x60
@ -995,6 +995,12 @@ BPF_XADD | BPF_DW | BPF_STX: lock xadd *(u64 *)(dst_reg + off16) += src_reg
Where size is one of: BPF_B or BPF_H or BPF_W or BPF_DW. Note that 1 and
2 byte atomic increments are not supported.
eBPF has one 16-byte instruction: BPF_LD | BPF_DW | BPF_IMM which consists
of two consecutive 'struct bpf_insn' 8-byte blocks and interpreted as single
instruction that loads 64-bit immediate value into a dst_reg.
Classic BPF has similar instruction: BPF_LD | BPF_W | BPF_IMM which loads
32-bit immediate value into a register.
Testing
-------

17
arch/x86/net/bpf_jit_comp.c
View File

@ -393,6 +393,23 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
EMIT1_off32(add_1reg(0xB8, dst_reg), imm32);
break;
case BPF_LD | BPF_IMM | BPF_DW:
if (insn[1].code != 0 || insn[1].src_reg != 0 ||
insn[1].dst_reg != 0 || insn[1].off != 0) {
/* verifier must catch invalid insns */
pr_err("invalid BPF_LD_IMM64 insn\n");
return -EINVAL;
}
/* movabsq %rax, imm64 */
EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg));
EMIT(insn[0].imm, 4);
EMIT(insn[1].imm, 4);
insn++;
i++;
break;
/* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */
case BPF_ALU | BPF_MOD | BPF_X:
case BPF_ALU | BPF_DIV | BPF_X:

74
include/linux/filter.h
View File

@ -10,58 +10,12 @@
#include <linux/workqueue.h>
#include <uapi/linux/filter.h>
#include <asm/cacheflush.h>
#include <uapi/linux/bpf.h>
struct sk_buff;
struct sock;
struct seccomp_data;
/* Internally used and optimized filter representation with extended
* instruction set based on top of classic BPF.
*/
/* instruction classes */
#define BPF_ALU64 0x07 /* alu mode in double word width */
/* ld/ldx fields */
#define BPF_DW 0x18 /* double word */
#define BPF_XADD 0xc0 /* exclusive add */
/* alu/jmp fields */
#define BPF_MOV 0xb0 /* mov reg to reg */
#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
/* change endianness of a register */
#define BPF_END 0xd0 /* flags for endianness conversion: */
#define BPF_TO_LE 0x00 /* convert to little-endian */
#define BPF_TO_BE 0x08 /* convert to big-endian */
#define BPF_FROM_LE BPF_TO_LE
#define BPF_FROM_BE BPF_TO_BE
#define BPF_JNE 0x50 /* jump != */
#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
#define BPF_CALL 0x80 /* function call */
#define BPF_EXIT 0x90 /* function return */
/* Register numbers */
enum {
BPF_REG_0 = 0,
BPF_REG_1,
BPF_REG_2,
BPF_REG_3,
BPF_REG_4,
BPF_REG_5,
BPF_REG_6,
BPF_REG_7,
BPF_REG_8,
BPF_REG_9,
BPF_REG_10,
__MAX_BPF_REG,
};
/* BPF has 10 general purpose 64-bit registers and stack frame. */
#define MAX_BPF_REG __MAX_BPF_REG
/* ArgX, context and stack frame pointer register positions. Note,
* Arg1, Arg2, Arg3, etc are used as argument mappings of function
* calls in BPF_CALL instruction.
@ -166,6 +120,24 @@ enum {
.off = 0, \
.imm = IMM })
/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
#define BPF_LD_IMM64(DST, IMM) \
BPF_LD_IMM64_RAW(DST, 0, IMM)
#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
((struct bpf_insn) { \
.code = BPF_LD | BPF_DW | BPF_IMM, \
.dst_reg = DST, \
.src_reg = SRC, \
.off = 0, \
.imm = (__u32) (IMM) }), \
((struct bpf_insn) { \
.code = 0, /* zero is reserved opcode */ \
.dst_reg = 0, \
.src_reg = 0, \
.off = 0, \
.imm = ((__u64) (IMM)) >> 32 })
/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
@ -304,14 +276,6 @@ enum {
#define SK_RUN_FILTER(filter, ctx) \
(*filter->prog->bpf_func)(ctx, filter->prog->insnsi)
struct bpf_insn {
__u8 code; /* opcode */
__u8 dst_reg:4; /* dest register */
__u8 src_reg:4; /* source register */
__s16 off; /* signed offset */
__s32 imm; /* signed immediate constant */
};
#ifdef CONFIG_COMPAT
/* A struct sock_filter is architecture independent. */
struct compat_sock_fprog {

1
include/uapi/linux/Kbuild
View File

@ -67,6 +67,7 @@ header-y += bfs_fs.h
header-y += binfmts.h
header-y += blkpg.h
header-y += blktrace_api.h
header-y += bpf.h
header-y += bpqether.h
header-y += bsg.h
header-y += btrfs.h

65
include/uapi/linux/bpf.h Normal file
View File

@ -0,0 +1,65 @@
/* 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 version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#ifndef _UAPI__LINUX_BPF_H__
#define _UAPI__LINUX_BPF_H__
#include <linux/types.h>
/* Extended instruction set based on top of classic BPF */
/* instruction classes */
#define BPF_ALU64 0x07 /* alu mode in double word width */
/* ld/ldx fields */
#define BPF_DW 0x18 /* double word */
#define BPF_XADD 0xc0 /* exclusive add */
/* alu/jmp fields */
#define BPF_MOV 0xb0 /* mov reg to reg */
#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
/* change endianness of a register */
#define BPF_END 0xd0 /* flags for endianness conversion: */
#define BPF_TO_LE 0x00 /* convert to little-endian */
#define BPF_TO_BE 0x08 /* convert to big-endian */
#define BPF_FROM_LE BPF_TO_LE
#define BPF_FROM_BE BPF_TO_BE
#define BPF_JNE 0x50 /* jump != */
#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
#define BPF_CALL 0x80 /* function call */
#define BPF_EXIT 0x90 /* function return */
/* Register numbers */
enum {
BPF_REG_0 = 0,
BPF_REG_1,
BPF_REG_2,
BPF_REG_3,
BPF_REG_4,
BPF_REG_5,
BPF_REG_6,
BPF_REG_7,
BPF_REG_8,
BPF_REG_9,
BPF_REG_10,
__MAX_BPF_REG,
};
/* BPF has 10 general purpose 64-bit registers and stack frame. */
#define MAX_BPF_REG __MAX_BPF_REG
struct bpf_insn {
__u8 code; /* opcode */
__u8 dst_reg:4; /* dest register */
__u8 src_reg:4; /* source register */
__s16 off; /* signed offset */
__s32 imm; /* signed immediate constant */
};
#endif /* _UAPI__LINUX_BPF_H__ */

5
kernel/bpf/core.c
View File

@ -242,6 +242,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
[BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
[BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
[BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
[BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
};
void *ptr;
int off;
@ -301,6 +302,10 @@ select_insn:
ALU64_MOV_K:
DST = IMM;
CONT;
LD_IMM_DW:
DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
insn++;
CONT;
ALU64_ARSH_X:
(*(s64 *) &DST) >>= SRC;
CONT;

21
lib/test_bpf.c
View File

@ -1735,6 +1735,27 @@ static struct bpf_test tests[] = {
{ },
{ { 1, 0 } },
},
{
"load 64-bit immediate",
.u.insns_int = {
BPF_LD_IMM64(R1, 0x567800001234L),
BPF_MOV64_REG(R2, R1),
BPF_MOV64_REG(R3, R2),
BPF_ALU64_IMM(BPF_RSH, R2, 32),
BPF_ALU64_IMM(BPF_LSH, R3, 32),
BPF_ALU64_IMM(BPF_RSH, R3, 32),
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R2, 0x5678, 1),
BPF_EXIT_INSN(),
BPF_JMP_IMM(BPF_JEQ, R3, 0x1234, 1),
BPF_EXIT_INSN(),
BPF_ALU64_IMM(BPF_MOV, R0, 1),
BPF_EXIT_INSN(),
},
INTERNAL,
{ },
{ { 0, 1 } }
},
};
static struct net_device dev;