Re: [PATCH v8 1/8] ppc64 (le): prepare for -mprofile-kernel

2016-02-17 Thread Michael Ellerman
On Wed, 2016-02-17 at 12:30 +0100, Torsten Duwe wrote: > On Wed, Feb 17, 2016 at 09:55:40PM +1100, Michael Ellerman wrote: > > > > On a kernel built with the 2 instruction version this will fault when the > > function we're looking at is located at the beginning of a page. Because > > instruction[

Re: [PATCH v8 1/8] ppc64 (le): prepare for -mprofile-kernel

2016-02-17 Thread Torsten Duwe
On Wed, Feb 17, 2016 at 09:55:40PM +1100, Michael Ellerman wrote: > On Wed, 2016-02-10 at 17:21 +0100, Torsten Duwe wrote: > > > --- a/arch/powerpc/kernel/module_64.c > > +++ b/arch/powerpc/kernel/module_64.c > > @@ -476,17 +474,44 @@ static unsigned long stub_for_addr(Elf64_Shdr > > *sechdrs, >

Re: [PATCH v8 1/8] ppc64 (le): prepare for -mprofile-kernel

2016-02-17 Thread Michael Ellerman
On Wed, 2016-02-10 at 17:21 +0100, Torsten Duwe wrote: > The gcc switch -mprofile-kernel, available for ppc64 on gcc > 4.8.5, > allows to call _mcount very early in the function, which low-level > ASM code and code patching functions need to consider. > Especially the link register and the paramet

[PATCH v8 1/8] ppc64 (le): prepare for -mprofile-kernel

2016-02-10 Thread Torsten Duwe
The gcc switch -mprofile-kernel, available for ppc64 on gcc > 4.8.5, allows to call _mcount very early in the function, which low-level ASM code and code patching functions need to consider. Especially the link register and the parameter registers are still alive and not yet saved into a new stack