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| author |   Alexei Starovoitov <ast@fb.com> | 2017-05-30 13:31:33 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-05-31 19:29:48 -0400 |
| commit | b870aa901f4be1d32c13faf9e8f40bf2a8562e19 (patch) | |
| tree | 80ea6e90353fd5cff52f5c7f5e80c73b57ce3a15 /kernel | |
| parent | bpf: fix stack_depth usage by test_bpf.ko (diff) | |
| download | linux-dev-b870aa901f4be1d32c13faf9e8f40bf2a8562e19.tar.xz linux-dev-b870aa901f4be1d32c13faf9e8f40bf2a8562e19.zip | |
bpf: use different interpreter depending on required stack size
16 __bpf_prog_run() interpreters for various stack sizes add .text
but not a lot comparing to run-time stack savings
text data bss dec hex filename
26350 10328 624 37302 91b6 kernel/bpf/core.o.before_split
25777 10328 624 36729 8f79 kernel/bpf/core.o.after_split
26970 10328 624 37922 9422 kernel/bpf/core.o.now
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/core.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index abd410d394bc..774069ca18a7 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1218,16 +1218,38 @@ load_byte: } STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ -static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) -{ - u64 stack[MAX_BPF_STACK / sizeof(u64)]; - u64 regs[MAX_BPF_REG]; - - FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; - ARG1 = (u64) (unsigned long) ctx; - return ___bpf_prog_run(regs, insn, stack); +#define PROG_NAME(stack_size) __bpf_prog_run##stack_size +#define DEFINE_BPF_PROG_RUN(stack_size) \ +static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ +{ \ + u64 stack[stack_size / sizeof(u64)]; \ + u64 regs[MAX_BPF_REG]; \ +\ + FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ + ARG1 = (u64) (unsigned long) ctx; \ + return ___bpf_prog_run(regs, insn, stack); \ } +#define EVAL1(FN, X) FN(X) +#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) +#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) +#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) +#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) +#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) + +EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); +EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); +EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); + +#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), + +static unsigned int (*interpreters[])(const void *ctx, + const struct bpf_insn *insn) = { +EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) +EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) +EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) +}; + bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp) { @@ -1275,7 +1297,7 @@ static int bpf_check_tail_call(const struct bpf_prog *fp) */ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) { - fp->bpf_func = (void *) __bpf_prog_run; + fp->bpf_func = interpreters[round_down(fp->aux->stack_depth, 32) / 32]; /* eBPF JITs can rewrite the program in case constant * blinding is active. However, in case of error during |