[tip: perf/core] x86/unwind_user: Guard unwind_user_word_size() by UNWIND_USER

From: tip-bot2 for Jens Remus
Date: Wed Dec 17 2025 - 07:49:59 EST


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

Commit-ID: aa6047ef7204ea1faa346b9123439abed0546f7e
Gitweb: https://git.kernel.org/tip/aa6047ef7204ea1faa346b9123439abed0546f7e
Author: Jens Remus <jremus@xxxxxxxxxxxxx>
AuthorDate: Mon, 08 Dec 2025 17:03:51 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 17 Dec 2025 13:31:08 +01:00

x86/unwind_user: Guard unwind_user_word_size() by UNWIND_USER

The unwind user framework in general requires an architecture-specific
implementation of unwind_user_word_size() to be present for any unwind
method, whether that is fp or a future other method, such as potentially
sframe.

Guard unwind_user_word_size() by the availability of the UNWIND_USER
framework instead of the specific HAVE_UNWIND_USER_FP method.

This facilitates to selectively disable HAVE_UNWIND_USER_FP on x86
(e.g. for test purposes) once a new unwind method is added to unwind
user.

Signed-off-by: Jens Remus <jremus@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://patch.msgid.link/20251208160352.1363040-4-jremus@xxxxxxxxxxxxx
---
arch/x86/include/asm/unwind_user.h | 30 ++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwind_user.h
index 971ffe9..7f1229b 100644
--- a/arch/x86/include/asm/unwind_user.h
+++ b/arch/x86/include/asm/unwind_user.h
@@ -2,23 +2,11 @@
#ifndef _ASM_X86_UNWIND_USER_H
#define _ASM_X86_UNWIND_USER_H

-#ifdef CONFIG_HAVE_UNWIND_USER_FP
+#ifdef CONFIG_UNWIND_USER

#include <asm/ptrace.h>
#include <asm/uprobes.h>

-#define ARCH_INIT_USER_FP_FRAME(ws) \
- .cfa_off = 2*(ws), \
- .ra_off = -1*(ws), \
- .fp_off = -2*(ws), \
- .use_fp = true,
-
-#define ARCH_INIT_USER_FP_ENTRY_FRAME(ws) \
- .cfa_off = 1*(ws), \
- .ra_off = -1*(ws), \
- .fp_off = 0, \
- .use_fp = false,
-
static inline int unwind_user_word_size(struct pt_regs *regs)
{
/* We can't unwind VM86 stacks */
@@ -31,6 +19,22 @@ static inline int unwind_user_word_size(struct pt_regs *regs)
return sizeof(long);
}

+#endif /* CONFIG_UNWIND_USER */
+
+#ifdef CONFIG_HAVE_UNWIND_USER_FP
+
+#define ARCH_INIT_USER_FP_FRAME(ws) \
+ .cfa_off = 2*(ws), \
+ .ra_off = -1*(ws), \
+ .fp_off = -2*(ws), \
+ .use_fp = true,
+
+#define ARCH_INIT_USER_FP_ENTRY_FRAME(ws) \
+ .cfa_off = 1*(ws), \
+ .ra_off = -1*(ws), \
+ .fp_off = 0, \
+ .use_fp = false,
+
static inline bool unwind_user_at_function_start(struct pt_regs *regs)
{
return is_uprobe_at_func_entry(regs);