[PATCH v4 10/14] s390: Add support for suppressing warning backtraces
From: Alessandro Carminati <hidden>
Date: 2025-03-13 11:44:54
Also in:
dri-devel, linux-arch, linux-arm-kernel, linux-doc, linux-kselftest, linux-riscv, linux-s390, linux-sh, lkml, loongarch
Subsystem:
s390 architecture, the rest · Maintainers:
Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
From: Guenter Roeck <linux@roeck-us.net> 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). Tested-by: Linux Kernel Functional Testing <redacted> Acked-by: Dan Carpenter <redacted> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Alessandro Carminati <redacted> --- arch/s390/include/asm/bug.h | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h
index c500d45fb465..44d4e9f24ae0 100644
--- a/arch/s390/include/asm/bug.h
+++ b/arch/s390/include/asm/bug.h@@ -8,6 +8,15 @@ #ifdef CONFIG_DEBUG_BUGVERBOSE +#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE +# define HAVE_BUG_FUNCTION +# define __BUG_FUNC_PTR " .long %0-.\n" +# define __BUG_FUNC __func__ +#else +# define __BUG_FUNC_PTR +# define __BUG_FUNC NULL +#endif /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */ + #define __EMIT_BUG(x) do { \ asm_inline volatile( \ "0: mc 0,0\n" \
@@ -17,10 +26,12 @@ ".section __bug_table,\"aw\"\n" \ "2: .long 0b-.\n" \ " .long 1b-.\n" \ - " .short %0,%1\n" \ - " .org 2b+%2\n" \ + __BUG_FUNC_PTR \ + " .short %1,%2\n" \ + " .org 2b+%3\n" \ ".previous\n" \ - : : "i" (__LINE__), \ + : : "i" (__BUG_FUNC), \ + "i" (__LINE__), \ "i" (x), \ "i" (sizeof(struct bug_entry))); \ } while (0)
--
2.34.1