From: Paul Chaignon <paul.chaignon@gmail.com>
Date: Wed, 13 May 2026 19:35:01 +0000 (+0200)
Subject: selftests/bpf: Test reported max stack depth
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a5b22e87ba5aeb5cad8acb1c7d9866981c37d1b;p=thirdparty%2Fkernel%2Flinux.git

selftests/bpf: Test reported max stack depth

This patch tests the maximum stack depth reporting in verifier logs,
with a couple special cases covered: fastcall, private stacks (main
subprog & callee), and rounding up to 16 bytes. For that last one, we
need to skip the test when JIT compilation is disabled as the rounding
is then to 32 bytes.

Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/075d22efd4338385a92f13b7817025cc3f04ec60.1778700777.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
index 0d9e167555b5f..8d7ff38e4c069 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
@@ -799,8 +799,7 @@ __naked int bpf_loop_interaction2(void)
 
 SEC("raw_tp")
 __arch_x86_64
-__log_level(4)
-__msg("stack depth 512+0")
+__log_level(4) __msg("stack depth 512+0 max 512")
 /* just to print xlated version when debugging */
 __xlated("r0 = &(void __percpu *)(r0)")
 __success
diff --git a/tools/testing/selftests/bpf/progs/verifier_private_stack.c b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
index c5078face38da..046f7445a4582 100644
--- a/tools/testing/selftests/bpf/progs/verifier_private_stack.c
+++ b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
@@ -86,6 +86,7 @@ __naked static void cumulative_stack_depth_subprog(void)
 SEC("kprobe")
 __description("Private stack, subtree > MAX_BPF_STACK")
 __success
+__log_level(4) __msg("stack depth 512+32 max 512")
 __arch_x86_64
 /* private stack fp for the main prog */
 __jited("	movabsq	$0x{{.*}}, %r9")
@@ -324,6 +325,8 @@ int private_stack_async_callback_1(void)
 SEC("fentry/bpf_fentry_test9")
 __description("Private stack, async callback, potential nesting")
 __success __retval(0)
+__load_if_JITed()
+__log_level(4) __msg("stack depth 8+0+256+0 max 272")
 __arch_x86_64
 __jited("	subq	$0x100, %rsp")
 __arch_arm64
@@ -344,6 +347,18 @@ int private_stack_async_callback_2(void)
 	return 0;
 }
 
+SEC("fentry/bpf_fentry_test9")
+__description("private stack, max stack depth is private stack")
+__success
+__log_level(4) __msg("stack depth 8+256+0 max 256")
+int private_stack_max_depth(void)
+{
+	int x = 0;
+
+	subprog1(&x);
+	return 0;
+}
+
 #else
 
 SEC("kprobe")