Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v5 3/3] powerpc/32: Add KASAN support | Date | Mon, 18 Feb 2019 20:27:47 +1100 |
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Christophe Leroy <christophe.leroy@c-s.fr> writes:
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h > index e0637730a8e7..dba2c1038363 100644 > --- a/arch/powerpc/include/asm/ppc_asm.h > +++ b/arch/powerpc/include/asm/ppc_asm.h > @@ -251,6 +251,10 @@ GLUE(.,name): > > #define _GLOBAL_TOC(name) _GLOBAL(name) > > +#define KASAN_OVERRIDE(x, y) \ > + .weak x; \ > + .set x, y > +
Can you add a comment describing what that does and why?
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile > index 879b36602748..fc4c42262694 100644 > --- a/arch/powerpc/kernel/Makefile > +++ b/arch/powerpc/kernel/Makefile > @@ -16,8 +16,9 @@ CFLAGS_prom_init.o += -fPIC > CFLAGS_btext.o += -fPIC > endif > > -CFLAGS_cputable.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) > -CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) > +CFLAGS_early_32.o += -DDISABLE_BRANCH_PROFILING > +CFLAGS_cputable.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) -DDISABLE_BRANCH_PROFILING > +CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) -DDISABLE_BRANCH_PROFILING
Why do we need to disable branch profiling now?
I'd probably be happier if all the CFLAGS changes were done in a leadup patch to make them more obvious.
> diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh > index 667df97d2595..da6bb16e0876 100644 > --- a/arch/powerpc/kernel/prom_init_check.sh > +++ b/arch/powerpc/kernel/prom_init_check.sh > @@ -16,8 +16,16 @@ > # If you really need to reference something from prom_init.o add > # it to the list below: > > +grep CONFIG_KASAN=y .config >/dev/null
Just to be safe "^CONFIG_KASAN=y$" ?
> +if [ $? -eq 0 ] > +then > + MEMFCT="__memcpy __memset" > +else > + MEMFCT="memcpy memset" > +fi
MEM_FUNCS ?
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile > index 3bf9fc6fd36c..ce8d4a9f810a 100644 > --- a/arch/powerpc/lib/Makefile > +++ b/arch/powerpc/lib/Makefile > @@ -8,6 +8,14 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC) > CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE) > > +KASAN_SANITIZE_code-patching.o := n > +KASAN_SANITIZE_feature-fixups.o := n > + > +ifdef CONFIG_KASAN > +CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING > +CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING > +endif
There's that branch profiling again, though here it's only if KASAN is enabled.
> diff --git a/arch/powerpc/mm/kasan_init.c b/arch/powerpc/mm/kasan_init.c > new file mode 100644 > index 000000000000..bd8e0a263e12 > --- /dev/null > +++ b/arch/powerpc/mm/kasan_init.c > @@ -0,0 +1,114 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#define DISABLE_BRANCH_PROFILING > + > +#include <linux/kasan.h> > +#include <linux/printk.h> > +#include <linux/memblock.h> > +#include <linux/sched/task.h> > +#include <asm/pgalloc.h> > + > +void __init kasan_early_init(void) > +{ > + unsigned long addr = KASAN_SHADOW_START; > + unsigned long end = KASAN_SHADOW_END; > + unsigned long next; > + pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(addr), addr), addr);
Can none of those fail?
cheers
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