Re: [RFC PATCH] MIPS: Kconfig: Select ARCH_WANT_FRAME_POINTERS

[Sergei Shtylyov]

Hello!

On 16.11.2020 8:03, Tiezhu Yang wrote:

> Select ARCH_WANT_FRAME_POINTERS to fix the following build error under
> CONFIG_DEBUG_ATOMIC_SLEEP:
>
>    CC      arch/mips/kernel/signal.o
> {standard input}: Assembler messages:
> {standard input}:1775: Error: Unable to parse register name $fp
> scripts/Makefile.build:283: recipe for target 'arch/mips/kernel/signal.o' failed
> make[2]: *** [arch/mips/kernel/signal.o] Error 1
> scripts/Makefile.build:500: recipe for target 'arch/mips/kernel' failed
> make[1]: *** [arch/mips/kernel] Error 2
> Makefile:1799: recipe for target 'arch/mips' failed
> make: *** [arch/mips] Error 2
>
> I think it is useful to get debugging information as described in the
> following texts:
>
> lib/Kconfig.debug
> config FRAME_POINTER
>          bool "Compile the kernel with frame pointers"
>          ...
>          default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
>          help
>            If you say Y here the resulting kernel image will be slightly
>            larger and slower, but it gives very useful debugging information
>            in case of kernel bugs. (precise oopses/stacktraces/warnings)
>
> Documentation/dev-tools/kgdb.rst
> This option inserts code to into the compiled executable which saves

   So to or into? :-)

> the frame information in registers or on the stack at different points
> which allows a debugger such as gdb to more accurately construct stack
> back traces while debugging the kernel.
>
> Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
[...]

MBR, Sergei