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

[Tiezhu Yang]

On 11/16/2020 05:08 PM, Sergei Shtylyov wrote:

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? :-)

Hi Sergei,

Thanks for pointing that out，this may be a typo which should be "into".
I will update the commit message to correct it.

Thanks,
Tiezhu

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 <yangtie...@loongson.cn>

[...]

MBR, Sergei