[PATCH v1 1/3] powerpc/code-patching: Test patch_instructions() during boot

[Benjamin Gray]

On Mon, 2024-03-18 at 08:38 +1100, Benjamin Gray wrote:
> On Fri, 2024-03-15 at 07:14 +0000, Christophe Leroy wrote:
> > 
> > 
> > Le 15/03/2024 à 03:57, Benjamin Gray a écrit :
> > > patch_instructions() introduces new behaviour with a couple of
> > > variations. Test each case of
> > > 
> > >    * a repeated 32-bit instruction,
> > >    * a repeated 64-bit instruction (ppc64), and
> > >    * a copied sequence of instructions
> > > 
> > > for both on a single page and when it crosses a page boundary.
> > > 
> > > Signed-off-by: Benjamin Gray <bgray at linux.ibm.com>
> > > ---
> > >   arch/powerpc/lib/test-code-patching.c | 92
> > > +++++++++++++++++++++++++++
> > >   1 file changed, 92 insertions(+)
> > > 
> > > diff --git a/arch/powerpc/lib/test-code-patching.c
> > > b/arch/powerpc/lib/test-code-patching.c
> > > index c44823292f73..35a3756272df 100644
> > > --- a/arch/powerpc/lib/test-code-patching.c
> > > +++ b/arch/powerpc/lib/test-code-patching.c
> > > @@ -347,6 +347,97 @@ static void __init
> > > test_prefixed_patching(void)
> > >   	check(!memcmp(iptr, expected, sizeof(expected)));
> > >   }
> > >   
> > > +static void __init test_multi_instruction_patching(void)
> > > +{
> > > +	u32 code[256];
> > 
> > Build failure:
> > 
> >    CC      arch/powerpc/lib/test-code-patching.o
> > arch/powerpc/lib/test-code-patching.c: In function 
> > 'test_multi_instruction_patching':
> > arch/powerpc/lib/test-code-patching.c:439:1: error: the frame size
> > of
> > 1040 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
> >    439 | }
> >        | ^
> > cc1: all warnings being treated as errors
> > make[4]: *** [scripts/Makefile.build:243: 
> > arch/powerpc/lib/test-code-patching.o] Error 1
> > 
> > 
> > I have to avoid big arrays on the stack.
> 
> All good, I can do that.
> 
> I do run my patches through a couple of 32-bit configs, but I didn't
> see this error. Is this a standard config I should be testing with?

Specifically pmac32_defconfig and ppc44x_defconfig