The patch titled
Subject: loongarch: add support for suppressing warning backtraces
has been added to the -mm mm-nonmm-unstable branch. Its filename is
loongarch-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/loongarch-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: loongarch: add support for suppressing warning backtraces
Date: Thu, 13 Mar 2025 11:43:23 +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/20250313114329.284104-9-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: Huacai Chen <chenhuacai@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: Catalin Marinas <catalin.marinas@xxxxxxx>
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: 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: Will Deacon <will@xxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/include/asm/bug.h | 42 ++++++++++++++++++++---------
1 file changed, 29 insertions(+), 13 deletions(-)
--- a/arch/loongarch/include/asm/bug.h~loongarch-add-support-for-suppressing-warning-backtraces
+++ a/arch/loongarch/include/asm/bug.h
@@ -3,49 +3,65 @@
#define __ASM_BUG_H
#include <asm/break.h>
+#include <kunit/bug.h>
#include <linux/stringify.h>
#include <linux/objtool.h>
#ifndef CONFIG_DEBUG_BUGVERBOSE
-#define _BUGVERBOSE_LOCATION(file, line)
+#define _BUGVERBOSE_LOCATION(file, func, line)
#else
-#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 /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
+
+#define __BUGVERBOSE_LOCATION(file, func, line) \
.pushsection .rodata.str, "aMS", @progbits, 1; \
10002: .string file; \
.popsection; \
\
.long 10002b - .; \
+ __BUG_FUNC_PTR(func) \
.short line;
-#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line)
+#define _BUGVERBOSE_LOCATION(file, func, line) __BUGVERBOSE_LOCATION(file, func, line)
#endif
#ifndef CONFIG_GENERIC_BUG
-#define __BUG_ENTRY(flags)
+#define __BUG_ENTRY(flags, func)
#else
-#define __BUG_ENTRY(flags) \
+#define __BUG_ENTRY(flags, func) \
.pushsection __bug_table, "aw"; \
.align 2; \
10000: .long 10001f - .; \
- _BUGVERBOSE_LOCATION(__FILE__, __LINE__) \
+ _BUGVERBOSE_LOCATION(__FILE__, func, __LINE__) \
.short flags; \
.popsection; \
10001:
#endif
-#define ASM_BUG_FLAGS(flags) \
- __BUG_ENTRY(flags) \
+#define ASM_BUG_FLAGS(flags, func) \
+ __BUG_ENTRY(flags, func) \
break BRK_BUG;
-#define ASM_BUG() ASM_BUG_FLAGS(0)
+#define ASM_BUG() ASM_BUG_FLAGS(0, .)
+
+#ifdef HAVE_BUG_FUNCTION
+# define __BUG_FUNC __func__
+#else
+# define __BUG_FUNC NULL
+#endif
-#define __BUG_FLAGS(flags, extra) \
- asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags)) \
- extra);
+#define __BUG_FLAGS(flags, extra) \
+ asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags, %0)) \
+ extra : : "i" (__BUG_FUNC) );
#define __WARN_FLAGS(flags) \
do { \
instrumentation_begin(); \
- __BUG_FLAGS(BUGFLAG_WARNING|(flags), ANNOTATE_REACHABLE(10001b));\
+ if (!KUNIT_IS_SUPPRESSED_WARNING(__func__)) \
+ __BUG_FLAGS(BUGFLAG_WARNING|(flags), ANNOTATE_REACHABLE(10001b));\
instrumentation_end(); \
} while (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
