Re: [PATCH 11/14] s390: Add support for suppressing warning backtraces

[Guenter Roeck]

On 3/14/24 00:57, Geert Uytterhoeven wrote:
> Hi Günter,
>
> On Tue, Mar 12, 2024 at 6:06 PM Guenter Roeck <linux@xxxxxxxxxxxx> 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).
> >
> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/arch/s390/include/asm/bug.h
> > +++ b/arch/s390/include/asm/bug.h
> > @@ -8,19 +8,30 @@
> >
> >   #ifdef CONFIG_DEBUG_BUGVERBOSE
> >
> > +#if IS_ENABLED(CONFIG_KUNIT)
> > +# 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 /* IS_ENABLED(CONFIG_KUNIT) */
> > +
> >   #define __EMIT_BUG(x) do {                                     \
> >          asm_inline volatile(                                    \
> >                  "0:     mc      0,0\n"                          \
> >                  ".section .rodata.str,\"aMS\",@progbits,1\n"    \
> >                  "1:     .asciz  \""__FILE__"\"\n"               \
> >                  ".previous\n"                                   \
> > -               ".section __bug_table,\"awM\",@progbits,%2\n"   \
> > +               ".section __bug_table,\"awM\",@progbits,%3\n"   \
>
> This change conflicts with commit 3938490e78f443fb ("s390/bug:
> remove entry size from __bug_table section") in linus/master.
> I guess it should just be dropped?

Yes, I know. I'll send v2 rebased to v6.9-rc1 once it is available and,
yes, the change will be gone after that.

Thanks,
Guenter