The patch titled
Subject: arm64: add support for suppressing warning backtraces
has been added to the -mm mm-nonmm-unstable branch. Its filename is
arm64-add-support-for-suppressing-warning-backtraces.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-add-support-for-suppressing-warning-backtraces.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Guenter Roeck <linux@xxxxxxxxxxxx>
Subject: arm64: add support for suppressing warning backtraces
Date: Thu, 13 Mar 2025 11:43:22 +0000
Add name of functions triggering warning backtraces to the __bug_table
object section to enable support for suppressing WARNING backtraces.
To limit image size impact, the pointer to the function name is only added
to the __bug_table section if both CONFIG_KUNIT_SUPPRESS_BACKTRACE and
CONFIG_DEBUG_BUGVERBOSE are enabled. Otherwise, the __func__ assembly
parameter is replaced with a (dummy) NULL parameter to avoid an image size
increase due to unused __func__ entries (this is necessary because
__func__ is not a define but a virtual variable).
Link: https://lkml.kernel.org/r/20250313114329.284104-8-acarmina@xxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Alessandro Carminati <acarmina@xxxxxxxxxx>
Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Acked-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Arthur Grillo <arthurgrillo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx>
Cc: Charlie Jenkins <charlie@xxxxxxxxxxxx>
Cc: Daniel Diaz <daniel.diaz@xxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Gow <davidgow@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: MaÃra Canal <mcanal@xxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Rae Moar <rmoar@xxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Thomas Zimemrmann <tzimmermann@xxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/asm-bug.h | 27 ++++++++++++++++++---------
arch/arm64/include/asm/bug.h | 8 +++++++-
2 files changed, 25 insertions(+), 10 deletions(-)
--- a/arch/arm64/include/asm/asm-bug.h~arm64-add-support-for-suppressing-warning-backtraces
+++ a/arch/arm64/include/asm/asm-bug.h
@@ -8,37 +8,46 @@
#include <asm/brk-imm.h>
#ifdef CONFIG_DEBUG_BUGVERBOSE
-#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
-#define __BUGVERBOSE_LOCATION(file, line) \
+
+#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE
+# define HAVE_BUG_FUNCTION
+# define __BUG_FUNC_PTR(func) .long func - .;
+#else
+# define __BUG_FUNC_PTR(func)
+#endif
+
+#define _BUGVERBOSE_LOCATION(file, func, line) __BUGVERBOSE_LOCATION(file, func, line)
+#define __BUGVERBOSE_LOCATION(file, func, line) \
.pushsection .rodata.str,"aMS",@progbits,1; \
14472: .string file; \
.popsection; \
\
.long 14472b - .; \
+ __BUG_FUNC_PTR(func) \
.short line;
#else
-#define _BUGVERBOSE_LOCATION(file, line)
+#define _BUGVERBOSE_LOCATION(file, func, line)
#endif
#ifdef CONFIG_GENERIC_BUG
-#define __BUG_ENTRY(flags) \
+#define __BUG_ENTRY(flags, func) \
.pushsection __bug_table,"aw"; \
.align 2; \
14470: .long 14471f - .; \
-_BUGVERBOSE_LOCATION(__FILE__, __LINE__) \
+_BUGVERBOSE_LOCATION(__FILE__, func, __LINE__) \
.short flags; \
.align 2; \
.popsection; \
14471:
#else
-#define __BUG_ENTRY(flags)
+#define __BUG_ENTRY(flags, func)
#endif
-#define ASM_BUG_FLAGS(flags) \
- __BUG_ENTRY(flags) \
+#define ASM_BUG_FLAGS(flags, func) \
+ __BUG_ENTRY(flags, func) \
brk BUG_BRK_IMM
-#define ASM_BUG() ASM_BUG_FLAGS(0)
+#define ASM_BUG() ASM_BUG_FLAGS(0, .)
#endif /* __ASM_ASM_BUG_H */
--- a/arch/arm64/include/asm/bug.h~arm64-add-support-for-suppressing-warning-backtraces
+++ a/arch/arm64/include/asm/bug.h
@@ -11,8 +11,14 @@
#include <asm/asm-bug.h>
+#ifdef HAVE_BUG_FUNCTION
+# define __BUG_FUNC __func__
+#else
+# define __BUG_FUNC NULL
+#endif
+
#define __BUG_FLAGS(flags) \
- asm volatile (__stringify(ASM_BUG_FLAGS(flags)));
+ asm volatile (__stringify(ASM_BUG_FLAGS(flags, %c0)) : : "i" (__BUG_FUNC));
#define BUG() do { \
__BUG_FLAGS(0); \
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxx are
bug-kunit-core-support-for-suppressing-warning-backtraces.patch
kunit-bug-count-suppressed-warning-backtraces.patch
kunit-add-test-cases-for-backtrace-warning-suppression.patch
kunit-add-documentation-for-warning-backtrace-suppression-api.patch
drm-suppress-intentional-warning-backtraces-in-scaling-unit-tests.patch
x86-add-support-for-suppressing-warning-backtraces.patch
arm64-add-support-for-suppressing-warning-backtraces.patch
loongarch-add-support-for-suppressing-warning-backtraces.patch
parisc-add-support-for-suppressing-warning-backtraces.patch
s390-add-support-for-suppressing-warning-backtraces.patch
sh-add-support-for-suppressing-warning-backtraces.patch
sh-move-defines-needed-for-suppressing-warning-backtraces.patch
riscv-add-support-for-suppressing-warning-backtraces.patch
powerpc-add-support-for-suppressing-warning-backtraces.patch
