[bpf-next,13/13] selftests/bpf: Add 5-byte nop uprobe trigger bench

Commit Message

Jiri Olsa Dec. 11, 2024, 1:34 p.m. UTC

Add 5-byte nop uprobe trigger bench (x86_64 specific) to measure
uprobes/uretprobes on top of nop5 instruction.

Signed-off-by: Jiri Olsa <[e-mail]>
---
 tools/testing/selftests/bpf/bench.c           | 12 ++++++
 .../selftests/bpf/benchs/bench_trigger.c      | 42 +++++++++++++++++++
 .../selftests/bpf/benchs/run_bench_uprobes.sh |  2 +-
 3 files changed, 55 insertions(+), 1 deletion(-)

Comments

Andrii Nakryiko Dec. 13, 2024, 9:57 p.m. UTC | #1

On Wed, Dec 11, 2024 at 5:36 AM Jiri Olsa <[e-mail]> wrote:
>
> Add 5-byte nop uprobe trigger bench (x86_64 specific) to measure
> uprobes/uretprobes on top of nop5 instruction.
>
> Signed-off-by: Jiri Olsa <[e-mail]>
> ---
>  tools/testing/selftests/bpf/bench.c           | 12 ++++++
>  .../selftests/bpf/benchs/bench_trigger.c      | 42 +++++++++++++++++++
>  .../selftests/bpf/benchs/run_bench_uprobes.sh |  2 +-
>  3 files changed, 55 insertions(+), 1 deletion(-)
>

[...]

>  static void usetup(bool use_retprobe, bool use_multi, void *target_addr)
>  {
>         size_t uprobe_offset;
> @@ -448,6 +462,28 @@ static void uretprobe_multi_ret_setup(void)
>         usetup(true, true /* use_multi */, &uprobe_target_ret);
>  }
>
> +#ifdef __x86_64__
> +static void uprobe_nop5_setup(void)
> +{
> +       usetup(false, false /* !use_multi */, &uprobe_target_nop5);
> +}
> +
> +static void uretprobe_nop5_setup(void)
> +{
> +       usetup(false, false /* !use_multi */, &uprobe_target_nop5);
> +}

true /* use_retprobe */

that's the problem with bench setup, right?

> +
> +static void uprobe_multi_nop5_setup(void)
> +{
> +       usetup(false, true /* use_multi */, &uprobe_target_nop5);
> +}
> +
> +static void uretprobe_multi_nop5_setup(void)
> +{
> +       usetup(false, true /* use_multi */, &uprobe_target_nop5);
> +}
> +#endif
> +
>  const struct bench bench_trig_syscall_count = {
>         .name = "trig-syscall-count",
>         .validate = trigger_validate,

[...]

Jiri Olsa Dec. 16, 2024, 7:56 a.m. UTC | #2

On Fri, Dec 13, 2024 at 01:57:56PM -0800, Andrii Nakryiko wrote:
> On Wed, Dec 11, 2024 at 5:36 AM Jiri Olsa <[e-mail]> wrote:
> >
> > Add 5-byte nop uprobe trigger bench (x86_64 specific) to measure
> > uprobes/uretprobes on top of nop5 instruction.
> >
> > Signed-off-by: Jiri Olsa <[e-mail]>
> > ---
> >  tools/testing/selftests/bpf/bench.c           | 12 ++++++
> >  .../selftests/bpf/benchs/bench_trigger.c      | 42 +++++++++++++++++++
> >  .../selftests/bpf/benchs/run_bench_uprobes.sh |  2 +-
> >  3 files changed, 55 insertions(+), 1 deletion(-)
> >
> 
> [...]
> 
> >  static void usetup(bool use_retprobe, bool use_multi, void *target_addr)
> >  {
> >         size_t uprobe_offset;
> > @@ -448,6 +462,28 @@ static void uretprobe_multi_ret_setup(void)
> >         usetup(true, true /* use_multi */, &uprobe_target_ret);
> >  }
> >
> > +#ifdef __x86_64__
> > +static void uprobe_nop5_setup(void)
> > +{
> > +       usetup(false, false /* !use_multi */, &uprobe_target_nop5);
> > +}
> > +
> > +static void uretprobe_nop5_setup(void)
> > +{
> > +       usetup(false, false /* !use_multi */, &uprobe_target_nop5);
> > +}
> 
> true /* use_retprobe */
> 
> that's the problem with bench setup, right?

yes, but there's more ;-)

we also need change in arch_uretprobe_hijack_return_addr to skip
the extra 3 values (pushed on stack by the uprobe trampoline) when
hijacking the returm value, I'll send new version

jirka

> 
> > +
> > +static void uprobe_multi_nop5_setup(void)
> > +{
> > +       usetup(false, true /* use_multi */, &uprobe_target_nop5);
> > +}
> > +
> > +static void uretprobe_multi_nop5_setup(void)
> > +{
> > +       usetup(false, true /* use_multi */, &uprobe_target_nop5);
> > +}
> > +#endif
> > +
> >  const struct bench bench_trig_syscall_count = {
> >         .name = "trig-syscall-count",
> >         .validate = trigger_validate,
> 
> [...]

Patch

diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 1bd403a5ef7b..0fd8c9b0d38f 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -526,6 +526,12 @@  extern const struct bench bench_trig_uprobe_multi_push;
 extern const struct bench bench_trig_uretprobe_multi_push;
 extern const struct bench bench_trig_uprobe_multi_ret;
 extern const struct bench bench_trig_uretprobe_multi_ret;
+#ifdef __x86_64__
+extern const struct bench bench_trig_uprobe_nop5;
+extern const struct bench bench_trig_uretprobe_nop5;
+extern const struct bench bench_trig_uprobe_multi_nop5;
+extern const struct bench bench_trig_uretprobe_multi_nop5;
+#endif
 
 extern const struct bench bench_rb_libbpf;
 extern const struct bench bench_rb_custom;
@@ -586,6 +592,12 @@  static const struct bench *benchs[] = {
 	&bench_trig_uretprobe_multi_push,
 	&bench_trig_uprobe_multi_ret,
 	&bench_trig_uretprobe_multi_ret,
+#ifdef __x86_64__
+	&bench_trig_uprobe_nop5,
+	&bench_trig_uretprobe_nop5,
+	&bench_trig_uprobe_multi_nop5,
+	&bench_trig_uretprobe_multi_nop5,
+#endif
 	/* ringbuf/perfbuf benchmarks */
 	&bench_rb_libbpf,
 	&bench_rb_custom,
diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
index 32e9f194d449..e74289a3270b 100644
--- a/tools/testing/selftests/bpf/benchs/bench_trigger.c
+++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
@@ -333,6 +333,20 @@  static void *uprobe_producer_ret(void *input)
 	return NULL;
 }
 
+#ifdef __x86_64__
+__nocf_check __weak void uprobe_target_nop5(void)
+{
+	asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00");
+}
+
+static void *uprobe_producer_nop5(void *input)
+{
+	while (true)
+		uprobe_target_nop5();
+	return NULL;
+}
+#endif
+
 static void usetup(bool use_retprobe, bool use_multi, void *target_addr)
 {
 	size_t uprobe_offset;
@@ -448,6 +462,28 @@  static void uretprobe_multi_ret_setup(void)
 	usetup(true, true /* use_multi */, &uprobe_target_ret);
 }
 
+#ifdef __x86_64__
+static void uprobe_nop5_setup(void)
+{
+	usetup(false, false /* !use_multi */, &uprobe_target_nop5);
+}
+
+static void uretprobe_nop5_setup(void)
+{
+	usetup(false, false /* !use_multi */, &uprobe_target_nop5);
+}
+
+static void uprobe_multi_nop5_setup(void)
+{
+	usetup(false, true /* use_multi */, &uprobe_target_nop5);
+}
+
+static void uretprobe_multi_nop5_setup(void)
+{
+	usetup(false, true /* use_multi */, &uprobe_target_nop5);
+}
+#endif
+
 const struct bench bench_trig_syscall_count = {
 	.name = "trig-syscall-count",
 	.validate = trigger_validate,
@@ -506,3 +542,9 @@  BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret");
 BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop");
 BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push");
 BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret");
+#ifdef __x86_64__
+BENCH_TRIG_USERMODE(uprobe_nop5, nop5, "uprobe-nop5");
+BENCH_TRIG_USERMODE(uretprobe_nop5, nop5, "uretprobe-nop5");
+BENCH_TRIG_USERMODE(uprobe_multi_nop5, nop5, "uprobe-multi-nop5");
+BENCH_TRIG_USERMODE(uretprobe_multi_nop5, nop5, "uretprobe-multi-nop5");
+#endif
diff --git a/tools/testing/selftests/bpf/benchs/run_bench_uprobes.sh b/tools/testing/selftests/bpf/benchs/run_bench_uprobes.sh
index af169f831f2f..03f55405484b 100755
--- a/tools/testing/selftests/bpf/benchs/run_bench_uprobes.sh
+++ b/tools/testing/selftests/bpf/benchs/run_bench_uprobes.sh
@@ -2,7 +2,7 @@ 
 
 set -eufo pipefail
 
-for i in usermode-count syscall-count {uprobe,uretprobe}-{nop,push,ret}
+for i in usermode-count syscall-count {uprobe,uretprobe}-{nop,push,ret,nop5}
 do
 	summary=$(sudo ./bench -w2 -d5 -a trig-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
 	printf "%-15s: %s\n" $i "$summary"