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x86/fgraph,bpf: Fix ORC stack unwind from kprobe_multi

PATCH Applied Jiri Olsa 3 participants 10 messages Jan 26 – Jan 30

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x86 Kselftest BPF Tracing +2 more subsystems
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Jiri Olsa

author reviewer
#0 lore raw

v2 cover x86/fgraph,bpf: Fix ORC stack unwind from kprobe_multi

hi,
Mahe reported missing function from stack trace on top of kprobe multi program. It turned out the latest fix [1] needs some more fixing.

v2 changes:
- keep the unwind same as for kprobes, attached function
is part of entry probe stacktrace, not kretprobe [Steven]
- several change in trigger bench [Andrii]
- added selftests for standard kprobes and fentry/fexit probes [Andrii]

Note I'll try to add similar stacktrace adjustment for fentry/fexit in separate patchset to not complicate this change.

thanks,
jirka

[1] https://lore.kernel.org/bpf/[email protected]/
---
Jiri Olsa (6):
x86/fgraph: Fix return_to_handler regs.rsp value x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path selftests/bpf: Fix kprobe multi stacktrace_ips test selftests/bpf: Add stacktrace ips test for kprobe/kretprobe selftests/bpf: Add stacktrace ips test for fentry/fexit selftests/bpf: Allow to benchmark trigger with stacktrace

 arch/x86/include/asm/ftrace.h                           |   2 +-
 arch/x86/kernel/ftrace_64.S                             |   5 +++-
 tools/testing/selftests/bpf/bench.c                     |   4 ++++
 tools/testing/selftests/bpf/bench.h                     |   1 +
 tools/testing/selftests/bpf/benchs/bench_trigger.c      |   1 +
 tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 tools/testing/selftests/bpf/progs/stacktrace_ips.c      |  27 ++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/trigger_bench.c       |  46 +++++++++++++++++++++++++++++--------
 8 files changed, 190 insertions(+), 16 deletions(-)
author reviewer
#1 lore raw

PATCH v2 1/6 x86/fgraph: Fix return_to_handler regs.rsp value

The previous change (Fixes commit) messed up the rsp register value, which is wrong because it's already adjusted with FRAME_SIZE, we need the original rsp value.

This change does not affect fprobe current kernel unwind, the !perf_hw_regs path perf_callchain_kernel:

        if (perf_hw_regs(regs)) {
                if (perf_callchain_store(entry, regs->ip))
                        return;
                unwind_start(&state, current, regs, NULL);
        } else {
                unwind_start(&state, current, NULL, (void *)regs->sp);
        }

which uses pt_regs.sp as first_frame boundary (FRAME_SIZE shift makes no difference, unwind stil stops at the right frame).

This change fixes the other path when we want to unwind directly from pt_regs sp/fp/ip state, which is coming in following change.

Fixes 20a0bc10272f ("x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe")
Signed-off-by Jiri Olsa <[email protected]>
---
 arch/x86/kernel/ftrace_64.S | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
arch/x86/kernel/ftrace_64.S +4 -1
index a132608265f6..62c1c93aa1c6 100644
@@ -364,6 +364,9 @@ SYM_CODE_START(return_to_handler)
 	UNWIND_HINT_UNDEFINED
 	ANNOTATE_NOENDBR
 
+	/* Store original rsp for pt_regs.sp value. */
+	movq %rsp, %rdi
+
 	/* Restore return_to_handler value that got eaten by previous ret instruction. */
 	subq $8, %rsp
 	UNWIND_HINT_FUNC

@@ -374,7 +377,7 @@ SYM_CODE_START(return_to_handler)
 	movq %rax, RAX(%rsp)
 	movq %rdx, RDX(%rsp)
 	movq %rbp, RBP(%rsp)
-	movq %rsp, RSP(%rsp)
+	movq %rdi, RSP(%rsp)
 	movq %rsp, %rdi
 
 	call ftrace_return_to_handler
Signature · 1 line
2.52.0
maintainer Reviewed-by on v2 1/6
#2 lore raw

Re: [PATCHv2 bpf-next 1/6] x86/fgraph: Fix return_to_handler regs.rsp value

Quoted 15 lines · On Mon, 26 Jan 2026 22:18:32 +0100 Jiri Olsa <[email protected]> wrote:

The previous change (Fixes commit) messed up the rsp register value, which is wrong because it's already adjusted with FRAME_SIZE, we need the original rsp value.

This change does not affect fprobe current kernel unwind, the !perf_hw_regs path perf_callchain_kernel:

        if (perf_hw_regs(regs)) {
                if (perf_callchain_store(entry, regs->ip))
                        return;
                unwind_start(&state, current, regs, NULL);
        } else {
                unwind_start(&state, current, NULL, (void *)regs->sp);
        }
Quoted 8 lines

which uses pt_regs.sp as first_frame boundary (FRAME_SIZE shift makes no difference, unwind stil stops at the right frame).

This change fixes the other path when we want to unwind directly from pt_regs sp/fp/ip state, which is coming in following change.

Fixes 20a0bc10272f ("x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe")
Signed-off-by Jiri Olsa <[email protected]>
Reviewed-by Steven Rostedt (Google) <[email protected]>

(it passed all my tests too)

-- Steve

author reviewer
#3 lore raw

PATCH v2 2/6 x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path

In reply to Jiri Olsa

Mahe reported missing function from stack trace on top of kprobe multi program. The missing function is the very first one in the stacktrace, the one that the bpf program is attached to.

  # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118

('*' is used for kprobe_multi attachment)

The reason is that the previous change (the Fixes commit) fixed stack unwind for tracepoint, but removed attached function address from the stack trace on top of kprobe multi programs, which I also overlooked in the related test (check following patch).

The tracepoint and kprobe_multi have different stack setup, but use same unwind path. I think it's better to keep the previous change, which fixed tracepoint unwind and instead change the kprobe multi unwind as explained below.

The bpf program stack unwind calls perf_callchain_kernel for kernel portion and it follows two unwind paths based on X86_EFLAGS_FIXED bit in pt_regs.flags.

When the bit set we unwind from stack represented by pt_regs argument, otherwise we unwind currently executed stack up to 'first_frame' boundary.

The 'first_frame' value is taken from regs.rsp value, but ftrace_caller and ftrace_regs_caller (ftrace trampoline) functions set the regs.rsp to the previous stack frame, so we skip the attached function entry.

If we switch kprobe_multi unwind to use the X86_EFLAGS_FIXED bit, we set the start of the unwind to the attached function address. As another benefit we also cut extra unwind cycles needed to reach the 'first_frame' boundary.

The speedup can be measured with trigger bench for kprobe_multi program and stacktrace support.

- trigger bench with stacktrace on current code:

        kprobe-multi   :     0.810 ± 0.001M/s
        kretprobe-multi:     0.808 ± 0.001M/s

- and with the fix:

        kprobe-multi   :     1.264 ± 0.001M/s
        kretprobe-multi:     1.401 ± 0.002M/s

With the fix, the entry probe stacktrace:

  # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        __x64_sys_newuname+9
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118

The return probe skips the attached function, because it's no longer on the stack at the point of the unwind and this way is the same how standard kretprobe works.

  # bpftrace -e 'kretprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118
Fixes 6d08340d1e35 ("Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"")
Reported-by Mahe Tardy <[email protected]>
Signed-off-by Jiri Olsa <[email protected]>
---
 arch/x86/include/asm/ftrace.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/include/asm/ftrace.h +1 -1
index b08c95872eed..c56e1e63b893 100644
@@ -57,7 +57,7 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs)
 }
 
 #define arch_ftrace_partial_regs(regs) do {	\
-	regs->flags &= ~X86_EFLAGS_FIXED;	\
+	regs->flags |= X86_EFLAGS_FIXED;	\
 	regs->cs = __KERNEL_CS;			\
 } while (0)
Signature · 1 line
2.52.0
maintainer Acked-by on v2 2/6
#4 lore raw

Re: [PATCHv2 bpf-next 2/6] x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path

arch/x86/include/asm/ftrace.h

Quoted 82 lines · On Mon, 26 Jan 2026 22:18:33 +0100 Jiri Olsa <[email protected]> wrote:

Mahe reported missing function from stack trace on top of kprobe multi program. The missing function is the very first one in the stacktrace, the one that the bpf program is attached to.

  # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118

('*' is used for kprobe_multi attachment)

The reason is that the previous change (the Fixes commit) fixed stack unwind for tracepoint, but removed attached function address from the stack trace on top of kprobe multi programs, which I also overlooked in the related test (check following patch).

The tracepoint and kprobe_multi have different stack setup, but use same unwind path. I think it's better to keep the previous change, which fixed tracepoint unwind and instead change the kprobe multi unwind as explained below.

The bpf program stack unwind calls perf_callchain_kernel for kernel portion and it follows two unwind paths based on X86_EFLAGS_FIXED bit in pt_regs.flags.

When the bit set we unwind from stack represented by pt_regs argument, otherwise we unwind currently executed stack up to 'first_frame' boundary.

The 'first_frame' value is taken from regs.rsp value, but ftrace_caller and ftrace_regs_caller (ftrace trampoline) functions set the regs.rsp to the previous stack frame, so we skip the attached function entry.

If we switch kprobe_multi unwind to use the X86_EFLAGS_FIXED bit, we set the start of the unwind to the attached function address. As another benefit we also cut extra unwind cycles needed to reach the 'first_frame' boundary.

The speedup can be measured with trigger bench for kprobe_multi program and stacktrace support.

- trigger bench with stacktrace on current code:

        kprobe-multi   :     0.810 ± 0.001M/s
        kretprobe-multi:     0.808 ± 0.001M/s

- and with the fix:

        kprobe-multi   :     1.264 ± 0.001M/s
        kretprobe-multi:     1.401 ± 0.002M/s

With the fix, the entry probe stacktrace:

  # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        __x64_sys_newuname+9
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118

The return probe skips the attached function, because it's no longer on the stack at the point of the unwind and this way is the same how standard kretprobe works.

  # bpftrace -e 'kretprobe:__x64_sys_newuname* { print(kstack)}'
  Attaching 1 probe...
        do_syscall_64+134
        entry_SYSCALL_64_after_hwframe+118
Fixes 6d08340d1e35 ("Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"")
Reported-by Mahe Tardy <[email protected]>
Signed-off-by Jiri Olsa <[email protected]>
---
 arch/x86/include/asm/ftrace.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/include/asm/ftrace.h +0 -0
index b08c95872eed..c56e1e63b893 100644
Acked-by Steven Rostedt (Google) <[email protected]>

(it passed all my tests too)

-- Steve

author reviewer
#5 lore raw

PATCH v2 3/6 selftests/bpf: Fix kprobe multi stacktrace_ips test

In reply to Jiri Olsa

We now include the attached function in the stack trace, fixing the test accordingly.

Fixes c9e208fa93cd ("selftests/bpf: Add stacktrace ips test for kprobe_multi/kretprobe_multi")
Signed-off-by Jiri Olsa <[email protected]>
---
 .../selftests/bpf/prog_tests/stacktrace_ips.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)
tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c +14 -5
index c9efdd2a5b18..c93718dafd9b 100644
@@ -74,11 +74,20 @@ static void test_stacktrace_ips_kprobe_multi(bool retprobe)
 
 	load_kallsyms();
 
-	check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 4,
-			     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
-			     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
-			     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
-			     ksym_get_addr("bpf_testmod_test_read"));
+	if (retprobe) {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 4,
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	} else {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 5,
+				     ksym_get_addr("bpf_testmod_stacktrace_test"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	}
 
 cleanup:
 	stacktrace_ips__destroy(skel);
Signature · 1 line
2.52.0
author reviewer
#6 lore raw

PATCH v2 4/6 selftests/bpf: Add stacktrace ips test for kprobe/kretprobe

In reply to Jiri Olsa

Adding test that attaches kprobe/kretprobe and verifies the ORC stacktrace matches expected functions.

The test is only for ORC unwinder to keep it simple.

Signed-off-by Jiri Olsa <[email protected]>
---
 .../selftests/bpf/prog_tests/stacktrace_ips.c | 50 +++++++++++++++++++
 .../selftests/bpf/progs/stacktrace_ips.c      |  7 +++
 2 files changed, 57 insertions(+)
tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c +50 -0
index c93718dafd9b..852830536109 100644
@@ -137,6 +137,52 @@ static void test_stacktrace_ips_raw_tp(void)
 	stacktrace_ips__destroy(skel);
 }
 
+static void test_stacktrace_ips_kprobe(bool retprobe)
+{
+	LIBBPF_OPTS(bpf_kprobe_opts, opts,
+		.retprobe = retprobe
+	);
+	LIBBPF_OPTS(bpf_test_run_opts, topts);
+	struct stacktrace_ips *skel;
+
+	skel = stacktrace_ips__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "stacktrace_ips__open_and_load"))
+		return;
+
+	if (!skel->kconfig->CONFIG_UNWINDER_ORC) {
+		test__skip();
+		goto cleanup;
+	}
+
+	skel->links.kprobe_test = bpf_program__attach_kprobe_opts(
+						skel->progs.kprobe_test,
+						"bpf_testmod_stacktrace_test", &opts);
+	if (!ASSERT_OK_PTR(skel->links.kprobe_test, "bpf_program__attach_kprobe_opts"))
+		goto cleanup;
+
+	trigger_module_test_read(1);
+
+	load_kallsyms();
+
+	if (retprobe) {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 4,
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	} else {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 5,
+				     ksym_get_addr("bpf_testmod_stacktrace_test"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	}
+
+cleanup:
+	stacktrace_ips__destroy(skel);
+}
+
 static void __test_stacktrace_ips(void)
 {
 	if (test__start_subtest("kprobe_multi"))

@@ -145,6 +191,10 @@ static void __test_stacktrace_ips(void)
 		test_stacktrace_ips_kprobe_multi(true);
 	if (test__start_subtest("raw_tp"))
 		test_stacktrace_ips_raw_tp();
+	if (test__start_subtest("kprobe"))
+		test_stacktrace_ips_kprobe(false);
+	if (test__start_subtest("kretprobe"))
+		test_stacktrace_ips_kprobe(true);
 }
 #else
 static void __test_stacktrace_ips(void)
tools/testing/selftests/bpf/progs/stacktrace_ips.c +7 -0
index a96c8150d7f5..cae077a4061b 100644
@@ -31,6 +31,13 @@ int unused(void)
 
 __u32 stack_key;
 
+SEC("kprobe")
+int kprobe_test(struct pt_regs *ctx)
+{
+	stack_key = bpf_get_stackid(ctx, &stackmap, 0);
+	return 0;
+}
+
 SEC("kprobe.multi")
 int kprobe_multi_test(struct pt_regs *ctx)
 {
Signature · 1 line
2.52.0
author reviewer
#7 lore raw

PATCH v2 5/6 selftests/bpf: Add stacktrace ips test for fentry/fexit

In reply to Jiri Olsa

Adding test that attaches fentry/fexitand verifies the ORC stacktrace matches expected functions.

The test is only for ORC unwinder to keep it simple.

Signed-off-by Jiri Olsa <[email protected]>
---
 .../selftests/bpf/prog_tests/stacktrace_ips.c | 51 +++++++++++++++++++
 .../selftests/bpf/progs/stacktrace_ips.c      | 20 ++++++++
 2 files changed, 71 insertions(+)
tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c +51 -0
index 852830536109..da42b00e3d1f 100644
@@ -183,6 +183,53 @@ static void test_stacktrace_ips_kprobe(bool retprobe)
 	stacktrace_ips__destroy(skel);
 }
 
+static void test_stacktrace_ips_trampoline(bool retprobe)
+{
+	LIBBPF_OPTS(bpf_test_run_opts, topts);
+	struct stacktrace_ips *skel;
+
+	skel = stacktrace_ips__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "stacktrace_ips__open_and_load"))
+		return;
+
+	if (!skel->kconfig->CONFIG_UNWINDER_ORC) {
+		test__skip();
+		goto cleanup;
+	}
+
+	if (retprobe) {
+		skel->links.fexit_test = bpf_program__attach_trace(skel->progs.fexit_test);
+		if (!ASSERT_OK_PTR(skel->links.fexit_test, "bpf_program__attach_trace"))
+			goto cleanup;
+	} else {
+		skel->links.fentry_test = bpf_program__attach_trace(skel->progs.fentry_test);
+		if (!ASSERT_OK_PTR(skel->links.fentry_test, "bpf_program__attach_trace"))
+			goto cleanup;
+	}
+
+	trigger_module_test_read(1);
+
+	load_kallsyms();
+
+	if (retprobe) {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 4,
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	} else {
+		check_stacktrace_ips(bpf_map__fd(skel->maps.stackmap), skel->bss->stack_key, 5,
+				     ksym_get_addr("bpf_testmod_stacktrace_test"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_3"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_2"),
+				     ksym_get_addr("bpf_testmod_stacktrace_test_1"),
+				     ksym_get_addr("bpf_testmod_test_read"));
+	}
+
+cleanup:
+	stacktrace_ips__destroy(skel);
+}
+
 static void __test_stacktrace_ips(void)
 {
 	if (test__start_subtest("kprobe_multi"))

@@ -195,6 +242,10 @@ static void __test_stacktrace_ips(void)
 		test_stacktrace_ips_kprobe(false);
 	if (test__start_subtest("kretprobe"))
 		test_stacktrace_ips_kprobe(true);
+	if (test__start_subtest("fentry"))
+		test_stacktrace_ips_trampoline(false);
+	if (test__start_subtest("fexit"))
+		test_stacktrace_ips_trampoline(true);
 }
 #else
 static void __test_stacktrace_ips(void)
tools/testing/selftests/bpf/progs/stacktrace_ips.c +20 -0
index cae077a4061b..6830f2978613 100644
@@ -53,4 +53,24 @@ int rawtp_test(void *ctx)
 	return 0;
 }
 
+SEC("fentry/bpf_testmod_stacktrace_test")
+int fentry_test(struct pt_regs *ctx)
+{
+	/*
+	 * Skip 2 bpf_program/trampoline stack entries:
+	 * - bpf_prog_bd1f7a949f55fb03_fentry_test
+	 * - bpf_trampoline_182536277701
+	 */
+	stack_key = bpf_get_stackid(ctx, &stackmap, 2);
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_stacktrace_test")
+int fexit_test(struct pt_regs *ctx)
+{
+	/* Skip 2 bpf_program/trampoline stack entries, check fentry_test. */
+	stack_key = bpf_get_stackid(ctx, &stackmap, 2);
+	return 0;
+}
+
 char _license[] SEC("license") = "GPL";
Signature · 1 line
2.52.0
author reviewer
#8 lore raw

PATCH v2 6/6 selftests/bpf: Allow to benchmark trigger with stacktrace

In reply to Jiri Olsa

Adding support to call bpf_get_stackid helper from trigger programs, so far added for kprobe multi.

Adding the --stacktrace/-g option to enable it.

Signed-off-by Jiri Olsa <[email protected]>
---
 tools/testing/selftests/bpf/bench.c           |  4 ++
 tools/testing/selftests/bpf/bench.h           |  1 +
 .../selftests/bpf/benchs/bench_trigger.c      |  1 +
 .../selftests/bpf/progs/trigger_bench.c       | 46 +++++++++++++++----
 4 files changed, 43 insertions(+), 9 deletions(-)
tools/testing/selftests/bpf/bench.c +4 -0
index bd29bb2e6cb5..8368bd3a0665 100644
@@ -265,6 +265,7 @@ static const struct argp_option opts[] = {
 	{ "verbose", 'v', NULL, 0, "Verbose debug output"},
 	{ "affinity", 'a', NULL, 0, "Set consumer/producer thread affinity"},
 	{ "quiet", 'q', NULL, 0, "Be more quiet"},
+	{ "stacktrace", 's', NULL, 0, "Get stack trace"},
 	{ "prod-affinity", ARG_PROD_AFFINITY_SET, "CPUSET", 0,
 	  "Set of CPUs for producer threads; implies --affinity"},
 	{ "cons-affinity", ARG_CONS_AFFINITY_SET, "CPUSET", 0,

@@ -350,6 +351,9 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 	case 'q':
 		env.quiet = true;
 		break;
+	case 's':
+		env.stacktrace = true;
+		break;
 	case ARG_PROD_AFFINITY_SET:
 		env.affinity = true;
 		if (parse_num_list(arg, &env.prod_cpus.cpus,
tools/testing/selftests/bpf/bench.h +1 -0
index bea323820ffb..7cf21936e7ed 100644
@@ -26,6 +26,7 @@ struct env {
 	bool list;
 	bool affinity;
 	bool quiet;
+	bool stacktrace;
 	int consumer_cnt;
 	int producer_cnt;
 	int nr_cpus;
tools/testing/selftests/bpf/benchs/bench_trigger.c +1 -0
index 34018fc3927f..aeec9edd3851 100644
@@ -146,6 +146,7 @@ static void setup_ctx(void)
 	bpf_program__set_autoload(ctx.skel->progs.trigger_driver, true);
 
 	ctx.skel->rodata->batch_iters = args.batch_iters;
+	ctx.skel->rodata->stacktrace = env.stacktrace;
 }
 
 static void load_ctx(void)
tools/testing/selftests/bpf/progs/trigger_bench.c +37 -9

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2.52.0
CI Applied
#9 lore raw
In reply to Jiri Olsa
This series was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <[email protected]>:

Hello:

This series was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <[email protected]>:

Quoted 11 lines · On Mon, 26 Jan 2026 22:18:31 +0100 you wrote:

hi,
Mahe reported missing function from stack trace on top of kprobe multi program. It turned out the latest fix [1] needs some more fixing.

v2 changes:
- keep the unwind same as for kprobes, attached function
is part of entry probe stacktrace, not kretprobe [Steven]
- several change in trigger bench [Andrii]
- added selftests for standard kprobes and fentry/fexit probes [Andrii]

[...]

Here is the summary with links:
- [PATCHv2,bpf-next,1/6] x86/fgraph: Fix return_to_handler regs.rsp value

    https://git.kernel.org/bpf/bpf-next/c/8bc11700e0d2
  - [PATCHv2,bpf-next,2/6] x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path
    https://git.kernel.org/bpf/bpf-next/c/aea251799998
  - [PATCHv2,bpf-next,3/6] selftests/bpf: Fix kprobe multi stacktrace_ips test
    https://git.kernel.org/bpf/bpf-next/c/0207f94971e7
  - [PATCHv2,bpf-next,4/6] selftests/bpf: Add stacktrace ips test for kprobe/kretprobe
    https://git.kernel.org/bpf/bpf-next/c/7373f97e868a
  - [PATCHv2,bpf-next,5/6] selftests/bpf: Add stacktrace ips test for fentry/fexit
    https://git.kernel.org/bpf/bpf-next/c/e5d532be4a3b
  - [PATCHv2,bpf-next,6/6] selftests/bpf: Allow to benchmark trigger with stacktrace
    https://git.kernel.org/bpf/bpf-next/c/4173b494d93a

You are awesome, thank you!

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