Re: [PATCH] powerpc/ftrace: fix syscall tracing on PPC64_ELF_ABI_V1

[Christophe Leroy]

Le 07/12/2022 à 16:18, Mathieu Desnoyers a écrit :
> On 2022-12-06 21:09, Michael Ellerman wrote:
>> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> writes:
>>> On 2022-12-05 17:50, Michael Ellerman wrote:
>>> IMHO the second option would be better because it does not increase the
>>> kernel image size as much as KALLSYMS_ALL.
>>
>> Yes I agree.
>>
>> Even if that did break something, any breakage would be limited to
>> arches which uses function descriptors, which are now all rare.
> 
> Yes, it would only impact those arches using function descriptors, which 
> are broken today with respect to system call tracing. Are you aware of 
> other architectures other than PPC64 ELF ABI v1 supported by the Linux 
> kernel that use function descriptors ?

$ git grep "select HAVE_FUNCTION_DESCRIPTORS" arch/
arch/ia64/Kconfig:      select HAVE_FUNCTION_DESCRIPTORS
arch/parisc/Kconfig:    select HAVE_FUNCTION_DESCRIPTORS if 64BIT
arch/powerpc/Kconfig:   select HAVE_FUNCTION_DESCRIPTORS        if 
PPC64_ELF_ABI_V1


Christophe