[PATCH v2 11/14] s390: Add support for suppressing warning backtraces
From: Guenter Roeck <linux@roeck-us.net>
Date: 2024-03-25 17:53:15
Also in:
dri-devel, linux-arch, linux-arm-kernel, linux-doc, linux-kselftest, linux-riscv, linux-s390, linux-sh, lkml, loongarch, netdev
Subsystem:
s390 architecture, the rest · Maintainers:
Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
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>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
- Rebased to v6.9-rc1 (simplified assembler changes after upstream commit
3938490e78f4 ("s390/bug: remove entry size from __bug_table section")
- Added Tested-by:, Acked-by:, and Reviewed-by: tags
- Introduced KUNIT_SUPPRESS_BACKTRACE configuration option
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)
--
2.39.2