On Thu, May 28, 2026 at 03:00:05PM +0200, Jakub Sitnicki wrote:
> On Tue, May 26, 2026 at 10:58 PM +02, Jiri Olsa wrote:
> > Adding tests for forked/cloned optimized uprobes and make
> > sure the child can properly execute optimized probe for
> > both fork (dups mm) and clone with CLONE_VM.
> >
> > Signed-off-by: Jiri Olsa <[email protected]>
> > ---
> > .../selftests/bpf/prog_tests/uprobe_syscall.c | 88 +++++++++++++++++++
> > 1 file changed, 88 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> > b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> > index efff0c515184..033d32b4cc27 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> > @@ -4,6 +4,8 @@
> >
> > #ifdef __x86_64__
> >
> > +#define _GNU_SOURCE
> > +#include <sched.h>
> > #include <unistd.h>
> > #include <asm/ptrace.h>
> > #include <linux/compiler.h>
> > @@ -936,6 +938,88 @@ static void test_uprobe_error(void)
> > ASSERT_EQ(errno, EPROTO, "errno");
> > }
> >
> > +__attribute__((aligned(16)))
> > +__nocf_check __weak __naked void uprobe_fork_test(void)
> > +{
> > + asm volatile (
> > + ".byte 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00,
> > 0x00\n" /* nop10 */
> > + "ret\n"
> > + );
> > +}
> > +
> > +static int child_func(void *arg)
>
> Nit: Could annotate with noreturn:
>
> #include <stdnoreturn.h>
>
> /* ... */
>
> static noreturn int child_func(void *arg)
yep, will change, thanks
jirka
>
> > +{
> > + struct uprobe_syscall_executed *skel = arg;
> > +
> > + /* Make sure the child's probe is still there and optimized.. */
> > + if (memcmp(uprobe_fork_test, lea_rsp, sizeof(lea_rsp)))
> > + _exit(1);
> > +
> > + skel->bss->pid = getpid();
> > +
> > + /* .. and it executes properly. */
> > + uprobe_fork_test();
> > +
> > + if (skel->bss->executed != 3)
> > + _exit(2);
> > +
> > + _exit(0);
> > +}
>
> [...]
>
> Reviewed-by: Jakub Sitnicki <[email protected]>
