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charset=us-ascii Content-Disposition: inline In-Reply-To: <20250313114329.284104-7-acarmina@redhat.com> On Thu, Mar 13, 2025 at 11:43:21AM +0000, Alessandro Carminati wrote: > From: Guenter Roeck > > 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 > Acked-by: Dan Carpenter > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Signed-off-by: Guenter Roeck > Signed-off-by: Alessandro Carminati > --- > 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 e85ac0c7c039..f6e13fc675ab 100644 > --- a/arch/x86/include/asm/bug.h > +++ b/arch/x86/include/asm/bug.h > @@ -35,18 +35,28 @@ > > #ifdef CONFIG_DEBUG_BUGVERBOSE > > +#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE > +# 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 /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */ > + > #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) > @@ -92,7 +102,8 @@ do { \ > do { \ > __auto_type __flags = BUGFLAG_WARNING|(flags); \ > instrumentation_begin(); \ > - _BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE(1b)); \ > + if (!KUNIT_IS_SUPPRESSED_WARNING(__func__)) \ > + _BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE(1b)); \ > instrumentation_end(); \ > } while (0) NAK, this grows the BUG site for now appreciable reason.