From: Xu Kuohai xukuohai@huawei.com
The two infinite loops in bound check cases added by commit 1a3148fc171f ("selftests/bpf: Check when bounds are not in the 32-bit range") increased the execution time of test_verifier from about 6 seconds to about 9 seconds. Rewrite these two infinite loops to finite loops to get rid of this extra time cost.
Signed-off-by: Xu Kuohai xukuohai@huawei.com --- v2: - rewrite the infinite loops to finite loops instead of removing the test cases
v1: https://lore.kernel.org/bpf/20230327153538.850440-1-xukuohai@huaweicloud.com... --- tools/testing/selftests/bpf/verifier/bounds.c | 24 ++++++++++++------- 1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/bpf/verifier/bounds.c b/tools/testing/selftests/bpf/verifier/bounds.c index 74b1917d4208..43942ce8cf15 100644 --- a/tools/testing/selftests/bpf/verifier/bounds.c +++ b/tools/testing/selftests/bpf/verifier/bounds.c @@ -784,22 +784,26 @@ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)), BPF_MOV64_REG(BPF_REG_1, BPF_REG_2), BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1), - BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 8), + BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 13),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0), BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10), BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_LD_IMM64(BPF_REG_2, 0x8000000000000fff), BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000), BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1), + BPF_JMP_REG(BPF_JSGT, BPF_REG_0, BPF_REG_2, 3), /* r1 signed range is [S64_MIN, S64_MAX] */ - BPF_JMP_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2), + BPF_JMP_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -3), + + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "BPF program is too large", - .result = REJECT, + .result = ACCEPT, .prog_type = BPF_PROG_TYPE_XDP, }, { @@ -856,21 +860,25 @@ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)), BPF_MOV64_REG(BPF_REG_1, BPF_REG_2), BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1), - BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 6), + BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 10),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0), BPF_MOV32_IMM(BPF_REG_0, 0x7fffff10), BPF_ALU32_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_MOV32_IMM(BPF_REG_2, 0x80000fff), BPF_MOV32_IMM(BPF_REG_0, 0x80000000), BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1), + BPF_JMP32_REG(BPF_JSGT, BPF_REG_0, BPF_REG_2, 3), /* r1 signed range is [S32_MIN, S32_MAX] */ - BPF_JMP32_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2), + BPF_JMP32_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -3), + + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr = "BPF program is too large", - .result = REJECT, + .result = ACCEPT, .prog_type = BPF_PROG_TYPE_XDP, },
On Tue, Mar 28, 2023 at 5:11 AM Xu Kuohai xukuohai@huaweicloud.com wrote:
From: Xu Kuohai xukuohai@huawei.com
The two infinite loops in bound check cases added by commit 1a3148fc171f ("selftests/bpf: Check when bounds are not in the 32-bit range") increased the execution time of test_verifier from about 6 seconds to about 9 seconds. Rewrite these two infinite loops to finite loops to get rid of this extra time cost.
Signed-off-by: Xu Kuohai xukuohai@huawei.com
v2:
- rewrite the infinite loops to finite loops instead of removing the test cases
v1: https://lore.kernel.org/bpf/20230327153538.850440-1-xukuohai@huaweicloud.com...
Thanks. On my VM with debug kernel it went from: real 0m37.508s user 0m0.382s sys 0m36.555s
to: real 0m14.547s user 0m0.378s sys 0m13.661s
Applied.
Hello:
This patch was applied to bpf/bpf-next.git (master) by Alexei Starovoitov ast@kernel.org:
On Tue, 28 Mar 2023 21:10:48 -0400 you wrote:
From: Xu Kuohai xukuohai@huawei.com
The two infinite loops in bound check cases added by commit 1a3148fc171f ("selftests/bpf: Check when bounds are not in the 32-bit range") increased the execution time of test_verifier from about 6 seconds to about 9 seconds. Rewrite these two infinite loops to finite loops to get rid of this extra time cost.
[...]
Here is the summary with links: - [bpf-next,v2] selftests/bpf: Rewrite two infinite loops in bound check cases https://git.kernel.org/bpf/bpf-next/c/4ca13d1002f3
You are awesome, thank you!
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