On Thu, 13 Mar 2025 at 19:44, Alessandro Carminati <acarm...@redhat.com> wrote: > > From: Guenter Roeck <li...@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 <l...@linaro.org> > Acked-by: Dan Carpenter <dan.carpen...@linaro.org> > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Borislav Petkov <b...@alien8.de> > Cc: Dave Hansen <dave.han...@linux.intel.com> > Signed-off-by: Guenter Roeck <li...@roeck-us.net> > Signed-off-by: Alessandro Carminati <acarm...@redhat.com> > ---
Reviewed-by: David Gow <david...@google.com>
Cheers,
-- David
> 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)
>
> --
> 2.34.1
>
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