Re: [PATCH] riscv: Disable STACKPROTECTOR_PER_TASK if GCC_PLUGIN_RANDSTRUCT is enabled

[Palmer Dabbelt]

On Fri, 23 Jul 2021 17:58:13 PDT (-0700), Palmer Dabbelt wrote:
> On Tue, 06 Jul 2021 09:26:21 PDT (-0700), linux@xxxxxxxxxxxx wrote:
> > riscv uses the value of TSK_STACK_CANARY to set
> > stack-protector-guard-offset. With GCC_PLUGIN_RANDSTRUCT enabled, that
> > value is non-deterministic, and with riscv:allmodconfig often results
> > in build errors such as
> >
> > cc1: error: '8120' is not a valid offset in '-mstack-protector-guard-offset='
> >
> > Enable STACKPROTECTOR_PER_TASK only if GCC_PLUGIN_RANDSTRUCT is disabled
> > to fix the problem.
> >
> > Fixes: fea2fed201ee5 ("riscv: Enable per-task stack canaries")
> > Cc: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > ---
> >  arch/riscv/Kconfig | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index 469a70bd8da6..3afb84fa2190 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -486,6 +486,7 @@ config CC_HAVE_STACKPROTECTOR_TLS
> >
> >  config STACKPROTECTOR_PER_TASK
> >  	def_bool y
> > +	depends on !GCC_PLUGIN_RANDSTRUCT
> >  	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
> >
> >  config PHYS_RAM_BASE_FIXED
>
> Thanks, this is on fixes.  I do an allmodconfig build and haven't seen
> these failures, is there something special I need to do to get this
> working?  I know nothing about GCC plugins...

Sorry, looks like I screwed something up and I didn't actually merge 
this onto fixes.  Not sure what happened, but this time it should 
actually be on fixes.