Re: [PATCHv3 08/12] selftests/bpf: Change uprobe syscall tests to use nop10

[Jiri Olsa <olsajiri@gmail.com>]

On Fri, May 22, 2026 at 11:57:04AM -0700, Andrii Nakryiko wrote:
> On Thu, May 21, 2026 at 5:45 AM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > Optimized uprobes are now on top of 10-bytes nop instructions,
> > reflect that in existing tests.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  .../selftests/bpf/benchs/bench_trigger.c      |  2 +-
> >  .../selftests/bpf/prog_tests/uprobe_syscall.c | 28 ++++++++++---------
> >  tools/testing/selftests/bpf/prog_tests/usdt.c | 25 ++++++++++-------
> >  tools/testing/selftests/bpf/usdt_2.c          |  2 +-
> >  4 files changed, 32 insertions(+), 25 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> > index 2f22ec61667b..a60b8173cdc4 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)
> 
> heh, nop5 -> nop_a_lot ;)
> 
> 
> >  {
> > -       asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00");
> > +       asm volatile (".byte 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00");
> >  }
> >
> 
> [...]
> 
> > @@ -420,7 +421,8 @@ static void *check_attach(struct uprobe_syscall_executed *skel, trigger_t trigge
> >         ASSERT_EQ(skel->bss->executed, executed, "executed");
> >
> >         /* .. and check the trampoline is as expected. */
> > -       call = (struct __arch_relative_insn *) addr;
> > +       ASSERT_OK(memcmp(addr, lea_rsp, 5), "lea_rsp");
> > +       call = (struct __arch_relative_insn *)(addr + 5);
> >         tramp = (void *) (call + 1) + call->raddr;
> >         ASSERT_EQ(call->op, 0xe8, "call");
> >         ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline");
> > @@ -432,7 +434,7 @@ static void check_detach(void *addr, void *tramp)
> >  {
> >         /* [uprobes_trampoline] stays after detach */
> >         ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline");
> > -       ASSERT_OK(memcmp(addr, nop5, 5), "nop5");
> > +       ASSERT_OK(memcmp(addr, jmp2B, 2), "jmp2B");
> 
> yeah, not jump anymore?

mixed up the selftest change.. I had it fixed already,
new version will have both fixes ;-)

thanks,
jirka

> 
> >  }
> >
> >  static void check(struct uprobe_syscall_executed *skel, struct bpf_link *link,
> 
> [...]