[PATCH 07/14] x86: Add support for suppressing warning backtraces
From: Guenter Roeck <linux@roeck-us.net>
Date: 2024-03-12 17:03:30
Also in:
dri-devel, linux-arch, linux-arm-kernel, linux-doc, linux-kselftest, linux-riscv, linux-s390, linux-sh, lkml, loongarch
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 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). Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- arch/x86/include/asm/bug.h | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index a3ec87d198ac..d87bf8bab238 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h@@ -23,18 +23,28 @@ #ifdef CONFIG_DEBUG_BUGVERBOSE +#if IS_ENABLED(CONFIG_KUNIT) +# define HAVE_BUG_FUNCTION +# define __BUG_FUNC_PTR __BUG_REL(%c1) +# define __BUG_FUNC __func__ +#else +# define __BUG_FUNC_PTR +# define __BUG_FUNC NULL +#endif /* IS_ENABLED(CONFIG_KUNIT) */ + #define _BUG_FLAGS(ins, flags, extra) \ do { \ asm_inline volatile("1:\t" ins "\n" \ ".pushsection __bug_table,\"aw\"\n" \ "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ - "\t.word %c1" "\t# bug_entry::line\n" \ - "\t.word %c2" "\t# bug_entry::flags\n" \ - "\t.org 2b+%c3\n" \ + "\t" __BUG_FUNC_PTR "\t# bug_entry::function\n" \ + "\t.word %c2" "\t# bug_entry::line\n" \ + "\t.word %c3" "\t# bug_entry::flags\n" \ + "\t.org 2b+%c4\n" \ ".popsection\n" \ extra \ - : : "i" (__FILE__), "i" (__LINE__), \ + : : "i" (__FILE__), "i" (__BUG_FUNC), "i" (__LINE__),\ "i" (flags), \ "i" (sizeof(struct bug_entry))); \ } while (0)
@@ -80,7 +90,8 @@ do { \ do { \ __auto_type __flags = BUGFLAG_WARNING|(flags); \ instrumentation_begin(); \ - _BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE); \ + if (!IS_SUPPRESSED_WARNING(__func__)) \ + _BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE); \ instrumentation_end(); \ } while (0)
--
2.39.2