[PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall

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* [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall
@ 2025-09-05 20:57 Jiri Olsa
  2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Jiri Olsa @ 2025-09-05 20:57 UTC (permalink / raw)
  To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko
  Cc: bpf, linux-kernel, linux-trace-kernel, x86, Song Liu,
	Yonghong Song, John Fastabend, Hao Luo, Steven Rostedt,
	Masami Hiramatsu, Alan Maguire, David Laight,
	Thomas Weißschuh, Ingo Molnar, Jann Horn, Alejandro Colomar

hi,
as suggested by Andrii [1] it'd be helpful for uprobe syscall
detection to return error value for the !in_uprobe_trampoline
check instead of forcing SIGILL.

This way we could just call uprobe syscall and based on return
value we will find out if the kernel supports it.

Alejandro,
I included the full man page change from [2], because IIUC this
was not applied yet, and as usual I butchered the wording, so I'd
appreciate your review on that.

thanks,
jirka


[1] https://lore.kernel.org/bpf/CAEf4BzaxtW_W1M94e3q0Qw4vM_heHqU7zFeH-fFHOQBwy5+7LQ@mail.gmail.com/
[2] https://lore.kernel.org/bpf/20250720112133.244369-23-jolsa@kernel.org/
---
Jiri Olsa (2):
      uprobes/x86: Return error from uprobe syscall when not called from trampoline
      selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value

 arch/x86/kernel/uprobes.c                               |  2 +-
 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 34 ++++++----------------------------
 2 files changed, 7 insertions(+), 29 deletions(-)

Jiri Olsa (1):
      man2: Add uprobe syscall page

 man/man2/uprobe.2    |  1 +
 man/man2/uretprobe.2 | 42 +++++++++++++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 13 deletions(-)
 create mode 100644 man/man2/uprobe.2

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline
  2025-09-05 20:57 [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Jiri Olsa
@ 2025-09-05 20:57 ` Jiri Olsa
  2025-09-08 11:25   ` Oleg Nesterov
  2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
  2025-09-05 20:57 ` [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value Jiri Olsa
                   ` (2 subsequent siblings)
  3 siblings, 2 replies; 9+ messages in thread
From: Jiri Olsa @ 2025-09-05 20:57 UTC (permalink / raw)
  To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko
  Cc: bpf, linux-kernel, linux-trace-kernel, x86, Song Liu,
	Yonghong Song, John Fastabend, Hao Luo, Steven Rostedt,
	Masami Hiramatsu, Alan Maguire, David Laight,
	Thomas Weißschuh, Ingo Molnar, Jann Horn, Alejandro Colomar

Currently uprobe syscall handles all errors with forcing SIGILL to current
process. As suggested by Andrii it'd be helpful for uprobe syscall detection
to return error value for the !in_uprobe_trampoline check.

This way we could just call uprobe syscall and based on return value we will
find out if the kernel has it.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 arch/x86/kernel/uprobes.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 0a8c0a4a5423..845aeaf36b8d 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -810,7 +810,7 @@ SYSCALL_DEFINE0(uprobe)
 
 	/* Allow execution only from uprobe trampolines. */
 	if (!in_uprobe_trampoline(regs->ip))
-		goto sigill;
+		return -ENXIO;
 
 	err = copy_from_user(&args, (void __user *)regs->sp, sizeof(args));
 	if (err)
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline
  2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
@ 2025-09-08 11:25   ` Oleg Nesterov
  2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
  1 sibling, 0 replies; 9+ messages in thread
From: Oleg Nesterov @ 2025-09-08 11:25 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Peter Zijlstra, Andrii Nakryiko, bpf, linux-kernel,
	linux-trace-kernel, x86, Song Liu, Yonghong Song, John Fastabend,
	Hao Luo, Steven Rostedt, Masami Hiramatsu, Alan Maguire,
	David Laight, Thomas Weißschuh, Ingo Molnar, Jann Horn,
	Alejandro Colomar

On 09/05, Jiri Olsa wrote:
>
> Currently uprobe syscall handles all errors with forcing SIGILL to current
> process. As suggested by Andrii it'd be helpful for uprobe syscall detection
> to return error value for the !in_uprobe_trampoline check.
>
> This way we could just call uprobe syscall and based on return value we will
> find out if the kernel has it.
>
> Suggested-by: Andrii Nakryiko <andrii@kernel.org>
> Acked-by: Andrii Nakryiko <andrii@kernel.org>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  arch/x86/kernel/uprobes.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index 0a8c0a4a5423..845aeaf36b8d 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -810,7 +810,7 @@ SYSCALL_DEFINE0(uprobe)
>
>  	/* Allow execution only from uprobe trampolines. */
>  	if (!in_uprobe_trampoline(regs->ip))
> -		goto sigill;
> +		return -ENXIO;

I agree.

Acked-by: Oleg Nesterov <oleg@redhat.com>


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [tip: perf/core] uprobes/x86: Return error from uprobe syscall when not called from trampoline
  2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
  2025-09-08 11:25   ` Oleg Nesterov
@ 2025-09-16 11:37   ` tip-bot2 for Jiri Olsa
  1 sibling, 0 replies; 9+ messages in thread
From: tip-bot2 for Jiri Olsa @ 2025-09-16 11:37 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Andrii Nakryiko, Jiri Olsa, Peter Zijlstra (Intel), Oleg Nesterov,
	x86, linux-kernel

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     d3aeb6d97b22272bb4783c6d4309d81bb0a4527c
Gitweb:        https://git.kernel.org/tip/d3aeb6d97b22272bb4783c6d4309d81bb0a4527c
Author:        Jiri Olsa <jolsa@kernel.org>
AuthorDate:    Fri, 05 Sep 2025 22:57:29 +02:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 15 Sep 2025 13:46:29 +02:00

uprobes/x86: Return error from uprobe syscall when not called from trampoline

Currently uprobe syscall handles all errors with forcing SIGILL to current
process. As suggested by Andrii it'd be helpful for uprobe syscall detection
to return error value for the !in_uprobe_trampoline check.

This way we could just call uprobe syscall and based on return value we will
find out if the kernel has it.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
---
 arch/x86/kernel/uprobes.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 0a8c0a4..845aeaf 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -810,7 +810,7 @@ SYSCALL_DEFINE0(uprobe)
 
 	/* Allow execution only from uprobe trampolines. */
 	if (!in_uprobe_trampoline(regs->ip))
-		goto sigill;
+		return -ENXIO;
 
 	err = copy_from_user(&args, (void __user *)regs->sp, sizeof(args));
 	if (err)

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value
  2025-09-05 20:57 [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Jiri Olsa
  2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
@ 2025-09-05 20:57 ` Jiri Olsa
  2025-09-05 21:40   ` Andrii Nakryiko
  2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
  2025-09-05 20:57 ` [PATCH 3/3] man2: Add uprobe syscall page Jiri Olsa
  2025-09-15 11:47 ` [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Peter Zijlstra
  3 siblings, 2 replies; 9+ messages in thread
From: Jiri Olsa @ 2025-09-05 20:57 UTC (permalink / raw)
  To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko
  Cc: bpf, linux-kernel, linux-trace-kernel, x86, Song Liu,
	Yonghong Song, John Fastabend, Hao Luo, Steven Rostedt,
	Masami Hiramatsu, Alan Maguire, David Laight,
	Thomas Weißschuh, Ingo Molnar, Jann Horn, Alejandro Colomar

The uprobe syscall now returns -ENXIO errno when called outside
kernel trampoline, fixing the current sigill test to reflect that
and renaming it to uprobe_error.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 .../selftests/bpf/prog_tests/uprobe_syscall.c | 34 ++++---------------
 1 file changed, 6 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
index 5da0b49eeaca..6d75ede16e7c 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
@@ -757,34 +757,12 @@ static void test_uprobe_race(void)
 #define __NR_uprobe 336
 #endif
 
-static void test_uprobe_sigill(void)
+static void test_uprobe_error(void)
 {
-	int status, err, pid;
+	long err = syscall(__NR_uprobe);
 
-	pid = fork();
-	if (!ASSERT_GE(pid, 0, "fork"))
-		return;
-	/* child */
-	if (pid == 0) {
-		asm volatile (
-			"pushq %rax\n"
-			"pushq %rcx\n"
-			"pushq %r11\n"
-			"movq $" __stringify(__NR_uprobe) ", %rax\n"
-			"syscall\n"
-			"popq %r11\n"
-			"popq %rcx\n"
-			"retq\n"
-		);
-		exit(0);
-	}
-
-	err = waitpid(pid, &status, 0);
-	ASSERT_EQ(err, pid, "waitpid");
-
-	/* verify the child got killed with SIGILL */
-	ASSERT_EQ(WIFSIGNALED(status), 1, "WIFSIGNALED");
-	ASSERT_EQ(WTERMSIG(status), SIGILL, "WTERMSIG");
+	ASSERT_EQ(err, -1, "error");
+	ASSERT_EQ(errno, ENXIO, "errno");
 }
 
 static void __test_uprobe_syscall(void)
@@ -805,8 +783,8 @@ static void __test_uprobe_syscall(void)
 		test_uprobe_usdt();
 	if (test__start_subtest("uprobe_race"))
 		test_uprobe_race();
-	if (test__start_subtest("uprobe_sigill"))
-		test_uprobe_sigill();
+	if (test__start_subtest("uprobe_error"))
+		test_uprobe_error();
 	if (test__start_subtest("uprobe_regs_equal"))
 		test_uprobe_regs_equal(false);
 	if (test__start_subtest("regs_change"))
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value
  2025-09-05 20:57 ` [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value Jiri Olsa
@ 2025-09-05 21:40   ` Andrii Nakryiko
  2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
  1 sibling, 0 replies; 9+ messages in thread
From: Andrii Nakryiko @ 2025-09-05 21:40 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko, bpf, linux-kernel,
	linux-trace-kernel, x86, Song Liu, Yonghong Song, John Fastabend,
	Hao Luo, Steven Rostedt, Masami Hiramatsu, Alan Maguire,
	David Laight, Thomas Weißschuh, Ingo Molnar, Jann Horn,
	Alejandro Colomar

On Fri, Sep 5, 2025 at 1:58 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> The uprobe syscall now returns -ENXIO errno when called outside
> kernel trampoline, fixing the current sigill test to reflect that
> and renaming it to uprobe_error.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  .../selftests/bpf/prog_tests/uprobe_syscall.c | 34 ++++---------------
>  1 file changed, 6 insertions(+), 28 deletions(-)
>

Acked-by: Andrii Nakryiko <andrii@kernel.org>

> diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> index 5da0b49eeaca..6d75ede16e7c 100644
> --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> @@ -757,34 +757,12 @@ static void test_uprobe_race(void)
>  #define __NR_uprobe 336
>  #endif
>
> -static void test_uprobe_sigill(void)
> +static void test_uprobe_error(void)
>  {
> -       int status, err, pid;
> +       long err = syscall(__NR_uprobe);
>
> -       pid = fork();
> -       if (!ASSERT_GE(pid, 0, "fork"))
> -               return;
> -       /* child */
> -       if (pid == 0) {
> -               asm volatile (
> -                       "pushq %rax\n"
> -                       "pushq %rcx\n"
> -                       "pushq %r11\n"
> -                       "movq $" __stringify(__NR_uprobe) ", %rax\n"
> -                       "syscall\n"
> -                       "popq %r11\n"
> -                       "popq %rcx\n"
> -                       "retq\n"
> -               );
> -               exit(0);
> -       }
> -
> -       err = waitpid(pid, &status, 0);
> -       ASSERT_EQ(err, pid, "waitpid");
> -
> -       /* verify the child got killed with SIGILL */
> -       ASSERT_EQ(WIFSIGNALED(status), 1, "WIFSIGNALED");
> -       ASSERT_EQ(WTERMSIG(status), SIGILL, "WTERMSIG");
> +       ASSERT_EQ(err, -1, "error");
> +       ASSERT_EQ(errno, ENXIO, "errno");
>  }
>
>  static void __test_uprobe_syscall(void)
> @@ -805,8 +783,8 @@ static void __test_uprobe_syscall(void)
>                 test_uprobe_usdt();
>         if (test__start_subtest("uprobe_race"))
>                 test_uprobe_race();
> -       if (test__start_subtest("uprobe_sigill"))
> -               test_uprobe_sigill();
> +       if (test__start_subtest("uprobe_error"))
> +               test_uprobe_error();
>         if (test__start_subtest("uprobe_regs_equal"))
>                 test_uprobe_regs_equal(false);
>         if (test__start_subtest("regs_change"))
> --
> 2.51.0
>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [tip: perf/core] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value
  2025-09-05 20:57 ` [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value Jiri Olsa
  2025-09-05 21:40   ` Andrii Nakryiko
@ 2025-09-16 11:37   ` tip-bot2 for Jiri Olsa
  1 sibling, 0 replies; 9+ messages in thread
From: tip-bot2 for Jiri Olsa @ 2025-09-16 11:37 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Jiri Olsa, Peter Zijlstra (Intel), Andrii Nakryiko, x86,
	linux-kernel

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     6d48436560e91be858158e227f21aab71698814e
Gitweb:        https://git.kernel.org/tip/6d48436560e91be858158e227f21aab71698814e
Author:        Jiri Olsa <jolsa@kernel.org>
AuthorDate:    Fri, 05 Sep 2025 22:57:30 +02:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 15 Sep 2025 13:46:29 +02:00

selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value

The uprobe syscall now returns -ENXIO errno when called outside
kernel trampoline, fixing the current sigill test to reflect that
and renaming it to uprobe_error.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 34 +-------
 1 file changed, 6 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
index 5da0b49..6d75ede 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
@@ -757,34 +757,12 @@ cleanup:
 #define __NR_uprobe 336
 #endif
 
-static void test_uprobe_sigill(void)
+static void test_uprobe_error(void)
 {
-	int status, err, pid;
+	long err = syscall(__NR_uprobe);
 
-	pid = fork();
-	if (!ASSERT_GE(pid, 0, "fork"))
-		return;
-	/* child */
-	if (pid == 0) {
-		asm volatile (
-			"pushq %rax\n"
-			"pushq %rcx\n"
-			"pushq %r11\n"
-			"movq $" __stringify(__NR_uprobe) ", %rax\n"
-			"syscall\n"
-			"popq %r11\n"
-			"popq %rcx\n"
-			"retq\n"
-		);
-		exit(0);
-	}
-
-	err = waitpid(pid, &status, 0);
-	ASSERT_EQ(err, pid, "waitpid");
-
-	/* verify the child got killed with SIGILL */
-	ASSERT_EQ(WIFSIGNALED(status), 1, "WIFSIGNALED");
-	ASSERT_EQ(WTERMSIG(status), SIGILL, "WTERMSIG");
+	ASSERT_EQ(err, -1, "error");
+	ASSERT_EQ(errno, ENXIO, "errno");
 }
 
 static void __test_uprobe_syscall(void)
@@ -805,8 +783,8 @@ static void __test_uprobe_syscall(void)
 		test_uprobe_usdt();
 	if (test__start_subtest("uprobe_race"))
 		test_uprobe_race();
-	if (test__start_subtest("uprobe_sigill"))
-		test_uprobe_sigill();
+	if (test__start_subtest("uprobe_error"))
+		test_uprobe_error();
 	if (test__start_subtest("uprobe_regs_equal"))
 		test_uprobe_regs_equal(false);
 	if (test__start_subtest("regs_change"))

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 3/3] man2: Add uprobe syscall page
  2025-09-05 20:57 [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Jiri Olsa
  2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
  2025-09-05 20:57 ` [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value Jiri Olsa
@ 2025-09-05 20:57 ` Jiri Olsa
  2025-09-15 11:47 ` [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Peter Zijlstra
  3 siblings, 0 replies; 9+ messages in thread
From: Jiri Olsa @ 2025-09-05 20:57 UTC (permalink / raw)
  To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko
  Cc: Alejandro Colomar, bpf, linux-kernel, linux-trace-kernel, x86,
	Song Liu, Yonghong Song, John Fastabend, Hao Luo, Steven Rostedt,
	Masami Hiramatsu, Alan Maguire, David Laight,
	Thomas Weißschuh, Ingo Molnar, Jann Horn

Changing uretprobe syscall man page to be shared with new
uprobe syscall man page.

Cc: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 man/man2/uprobe.2    |  1 +
 man/man2/uretprobe.2 | 42 +++++++++++++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 13 deletions(-)
 create mode 100644 man/man2/uprobe.2

diff --git a/man/man2/uprobe.2 b/man/man2/uprobe.2
new file mode 100644
index 000000000000..ea5ccf901591
--- /dev/null
+++ b/man/man2/uprobe.2
@@ -0,0 +1 @@
+.so man2/uretprobe.2
diff --git a/man/man2/uretprobe.2 b/man/man2/uretprobe.2
index c81d4c5313a3..a1e4a1fa56f4 100644
--- a/man/man2/uretprobe.2
+++ b/man/man2/uretprobe.2
@@ -2,46 +2,62 @@
 .\"
 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
 .\"
-.TH uretprobe 2 (date) "Linux man-pages (unreleased)"
+.TH uprobe 2 (date) "Linux man-pages (unreleased)"
 .SH NAME
+uprobe,
 uretprobe
 \-
-execute pending return uprobes
+execute pending entry or return uprobes
 .SH SYNOPSIS
 .nf
+.B int uprobe(void);
 .B int uretprobe(void);
 .fi
 .SH DESCRIPTION
+.BR uprobe ()
+is an alternative to breakpoint instructions
+for triggering entry uprobe consumers.
+.P
 .BR uretprobe ()
 is an alternative to breakpoint instructions
 for triggering return uprobe consumers.
 .P
 Calls to
-.BR uretprobe ()
+these system calls
 are only made from the user-space trampoline provided by the kernel.
 Calls from any other place result in a
-.BR SIGILL .
+.BR SIGILL
+or error value (see below).
+
 .SH RETURN VALUE
 The return value is architecture-specific.
 .SH ERRORS
 .TP
 .B SIGILL
-.BR uretprobe ()
-was called by a user-space program.
+uretprobe() was called by a user-space program.
+.TP
+.B ENXIO
+uprobe() was called by a user-space program.
 .SH VERSIONS
 The behavior varies across systems.
 .SH STANDARDS
 None.
 .SH HISTORY
+.TP
+.BR uprobe ()
+TBD
+.TP
+.BR uretprobe ()
 Linux 6.11.
 .P
-.BR uretprobe ()
-was initially introduced for the x86_64 architecture
-where it was shown to be faster than breakpoint traps.
-It might be extended to other architectures.
+These system calls
+were initially introduced for the x86_64 architecture
+where they were shown to be faster than breakpoint traps.
+They might be extended to other architectures.
 .SH CAVEATS
-.BR uretprobe ()
-exists only to allow the invocation of return uprobe consumers.
-It should
+These system calls
+exist only to allow the invocation of
+entry or return uprobe consumers.
+They should
 .B never
 be called directly.
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall
  2025-09-05 20:57 [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Jiri Olsa
                   ` (2 preceding siblings ...)
  2025-09-05 20:57 ` [PATCH 3/3] man2: Add uprobe syscall page Jiri Olsa
@ 2025-09-15 11:47 ` Peter Zijlstra
  3 siblings, 0 replies; 9+ messages in thread
From: Peter Zijlstra @ 2025-09-15 11:47 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Oleg Nesterov, Andrii Nakryiko, bpf, linux-kernel,
	linux-trace-kernel, x86, Song Liu, Yonghong Song, John Fastabend,
	Hao Luo, Steven Rostedt, Masami Hiramatsu, Alan Maguire,
	David Laight, Thomas Weißschuh, Ingo Molnar, Jann Horn,
	Alejandro Colomar

On Fri, Sep 05, 2025 at 10:57:28PM +0200, Jiri Olsa wrote:

> Jiri Olsa (2):
>       uprobes/x86: Return error from uprobe syscall when not called from trampoline
>       selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value
> 
>  arch/x86/kernel/uprobes.c                               |  2 +-
>  tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 34 ++++++----------------------------
>  2 files changed, 7 insertions(+), 29 deletions(-)

Thanks!

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2025-09-16 11:37 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-05 20:57 [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Jiri Olsa
2025-09-05 20:57 ` [PATCH perf/core 1/3] uprobes/x86: Return error from uprobe syscall when not called from trampoline Jiri Olsa
2025-09-08 11:25   ` Oleg Nesterov
2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
2025-09-05 20:57 ` [PATCH perf/core 2/3] selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value Jiri Olsa
2025-09-05 21:40   ` Andrii Nakryiko
2025-09-16 11:37   ` [tip: perf/core] " tip-bot2 for Jiri Olsa
2025-09-05 20:57 ` [PATCH 3/3] man2: Add uprobe syscall page Jiri Olsa
2025-09-15 11:47 ` [PATCH perf/core 0/3] uprobes/x86: change error path for uprobe syscall Peter Zijlstra

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