> diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c
> b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> index 2f22ec61667b..bcc4820c802e 100644
> --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c
> +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> @@ -398,7 +398,7 @@ static void *uprobe_producer_ret(void *input)
> #ifdef __x86_64__
> __nocf_check __weak void uprobe_target_nop5(void)
> {
> - asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00");
> + asm volatile (".byte 0x66, 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00,
> 0x00, 0x00");
> }
>
> static void *uprobe_producer_nop5(void *input)
This isn't a bug, but should the function and benchmark names also be
updated? The function is still called uprobe_target_nop5() and the
benchmark exposes names like uprobe-nop5, uretprobe-nop5,
uprobe-multi-nop5, uretprobe-multi-nop5, and usdt-nop5, but they are
now all testing a 10-byte nop instruction.
[ ... ]
> diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c
> b/tools/testing/selftests/bpf/prog_tests/usdt.c
> index 69759b27794d..a160d7c4fa0d 100644
> --- a/tools/testing/selftests/bpf/prog_tests/usdt.c
> +++ b/tools/testing/selftests/bpf/prog_tests/usdt.c
> @@ -252,7 +252,7 @@ extern void usdt_1(void);
> extern void usdt_2(void);
>
> static unsigned char nop1[1] = { 0x90 };
> -static unsigned char nop1_nop5_combo[6] = { 0x90, 0x0f, 0x1f, 0x44, 0x00,
> 0x00 };
> +static unsigned char nop1_nop10_combo[11] = { 0x90, 0x66, 0x66, 0x0f, 0x1f,
> 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 };
>
> static void *find_instr(void *fn, unsigned char *instr, size_t cnt)
> {
> int i;
>
> for (i = 0; i < 10; i++) {
> if (!memcmp(instr, fn + i, cnt))
> return fn + i;
> }
> return NULL;
> }
Is the loop in find_instr() adequate to find this instruction sequence?
In uprobe_syscall.c, find_nop10() was updated to search up to 128 bytes
to account for compiler-generated prologues. If a modern compiler
generates a prologue longer than 9 bytes for usdt_2(), this will
prematurely terminate and cause the subtest_optimized_attach() test to
fail.
[ ... ]
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/26030080109
