Re: [PATCH 10/14] parisc: Add support for suppressing warning backtraces

Helge Deller
2024-03-15T11:46:33Z

On 3/12/24 18:03, Guenter Roeck wrote:
> 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).
>
> While at it, declare assembler parameters as constants where possible.
> Refine .blockz instructions to calculate the necessary padding instead
> of using fixed values.
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Acked-by: Helge Deller <deller@gmx.de>

Helge

> ---
> arch/parisc/include/asm/bug.h | 29 +++++++++++++++++++++--------
> 1 file changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/arch/parisc/include/asm/bug.h b/arch/parisc/include/asm/bug.h
> index 833555f74ffa..792dacc2a653 100644
> --- a/arch/parisc/include/asm/bug.h
> +++ b/arch/parisc/include/asm/bug.h
> @@ -23,8 +23,17 @@
> # define __BUG_REL(val) ".word " __stringify(val)
> #endif
>
> -
> #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() \
> do { \
> asm volatile("\n" \
> @@ -33,10 +42,12 @@
> "\t.align 4\n" \
> "2:\t" __BUG_REL(1b) "\n" \
> "\t" __BUG_REL(%c0) "\n" \
> - "\t.short %1, %2\n" \
> - "\t.blockz %3-2*4-2*2\n" \
> + "\t" __BUG_FUNC_PTR "\n" \
> + "\t.short %c2, %c3\n" \
> + "\t.blockz %c4-(.-2b)\n" \
> "\t.popsection" \
> - : : "i" (__FILE__), "i" (__LINE__), \
> + : : "i" (__FILE__), "i" (__BUG_FUNC), \
> + "i" (__LINE__), \
> "i" (0), "i" (sizeof(struct bug_entry)) ); \
> unreachable(); \
> } while(0)
> @@ -58,10 +69,12 @@
> "\t.align 4\n" \
> "2:\t" __BUG_REL(1b) "\n" \
> "\t" __BUG_REL(%c0) "\n" \
> - "\t.short %1, %2\n" \
> - "\t.blockz %3-2*4-2*2\n" \
> + "\t" __BUG_FUNC_PTR "\n" \
> + "\t.short %c2, %3\n" \
> + "\t.blockz %c4-(.-2b)\n" \
> "\t.popsection" \
> - : : "i" (__FILE__), "i" (__LINE__), \
> + : : "i" (__FILE__), "i" (__BUG_FUNC), \
> + "i" (__LINE__), \
> "i" (BUGFLAG_WARNING|(flags)), \
> "i" (sizeof(struct bug_entry)) ); \
> } while(0)
> @@ -74,7 +87,7 @@
> "\t.align 4\n" \
> "2:\t" __BUG_REL(1b) "\n" \
> "\t.short %0\n" \
> - "\t.blockz %1-4-2\n" \
> + "\t.blockz %c1-(.-2b)\n" \
> "\t.popsection" \
> : : "i" (BUGFLAG_WARNING|(flags)), \
> "i" (sizeof(struct bug_entry)) ); \