| Message ID | 20170706220114.142438-3-ghackmann@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jul 7, 2017 at 12:01 AM, Greg Hackmann <ghackmann@google.com> wrote: > From: Alexander Potapenko <glider@google.com> > > As a code-size optimization, LLVM builds since r279383 may > bulk-manipulate the shadow region when (un)poisoning large memory > blocks. This requires new callbacks that simply do an uninstrumented > memset(). > > This fixes linking the Clang-built kernel when using KASAN. > > Signed-off-by: Alexander Potapenko <glider@google.com> > [ghackmann@google.com: fix memset() parameters, and tweak > commit message to describe new callbacks] > Signed-off-by: Greg Hackmann <ghackmann@google.com> > --- > mm/kasan/kasan.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c > index 892b626f564b..89911e5c69f9 100644 > --- a/mm/kasan/kasan.c > +++ b/mm/kasan/kasan.c > @@ -828,6 +828,21 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) > } > EXPORT_SYMBOL(__asan_allocas_unpoison); > > +/* Emitted by the compiler to [un]poison local variables. */ > +#define DEFINE_ASAN_SET_SHADOW(byte) \ > + void __asan_set_shadow_##byte(const void *addr, size_t size) \ > + { \ > + __memset((void *)addr, 0x##byte, size); \ > + } \ > + EXPORT_SYMBOL(__asan_set_shadow_##byte) > + > +DEFINE_ASAN_SET_SHADOW(00); > +DEFINE_ASAN_SET_SHADOW(f1); > +DEFINE_ASAN_SET_SHADOW(f2); > +DEFINE_ASAN_SET_SHADOW(f3); > +DEFINE_ASAN_SET_SHADOW(f5); > +DEFINE_ASAN_SET_SHADOW(f8); > + > #ifdef CONFIG_MEMORY_HOTPLUG > static int kasan_mem_notifier(struct notifier_block *nb, > unsigned long action, void *data) Reviewed-by: Dmitry Vyukov <dvyukov@google.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07/07/2017 01:01 AM, Greg Hackmann wrote: > From: Alexander Potapenko <glider@google.com> > > As a code-size optimization, LLVM builds since r279383 may > bulk-manipulate the shadow region when (un)poisoning large memory > blocks. This requires new callbacks that simply do an uninstrumented > memset(). > > This fixes linking the Clang-built kernel when using KASAN. > > Signed-off-by: Alexander Potapenko <glider@google.com> > [ghackmann@google.com: fix memset() parameters, and tweak > commit message to describe new callbacks] > Signed-off-by: Greg Hackmann <ghackmann@google.com> > --- > mm/kasan/kasan.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c > index 892b626f564b..89911e5c69f9 100644 > --- a/mm/kasan/kasan.c > +++ b/mm/kasan/kasan.c > @@ -828,6 +828,21 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) > } > EXPORT_SYMBOL(__asan_allocas_unpoison); > > +/* Emitted by the compiler to [un]poison local variables. */ > +#define DEFINE_ASAN_SET_SHADOW(byte) \ > + void __asan_set_shadow_##byte(const void *addr, size_t size) \ > + { \ > + __memset((void *)addr, 0x##byte, size); \ > + } \ > + EXPORT_SYMBOL(__asan_set_shadow_##byte) > + > +DEFINE_ASAN_SET_SHADOW(00); > +DEFINE_ASAN_SET_SHADOW(f1); > +DEFINE_ASAN_SET_SHADOW(f2); > +DEFINE_ASAN_SET_SHADOW(f3); > +DEFINE_ASAN_SET_SHADOW(f5); > +DEFINE_ASAN_SET_SHADOW(f8); I think we can remove f8 as it should be used only by use-after-return instrumentation. We don't use it in the kernel > + > #ifdef CONFIG_MEMORY_HOTPLUG > static int kasan_mem_notifier(struct notifier_block *nb, > unsigned long action, void *data) > -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 892b626f564b..89911e5c69f9 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -828,6 +828,21 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) } EXPORT_SYMBOL(__asan_allocas_unpoison); +/* Emitted by the compiler to [un]poison local variables. */ +#define DEFINE_ASAN_SET_SHADOW(byte) \ + void __asan_set_shadow_##byte(const void *addr, size_t size) \ + { \ + __memset((void *)addr, 0x##byte, size); \ + } \ + EXPORT_SYMBOL(__asan_set_shadow_##byte) + +DEFINE_ASAN_SET_SHADOW(00); +DEFINE_ASAN_SET_SHADOW(f1); +DEFINE_ASAN_SET_SHADOW(f2); +DEFINE_ASAN_SET_SHADOW(f3); +DEFINE_ASAN_SET_SHADOW(f5); +DEFINE_ASAN_SET_SHADOW(f8); + #ifdef CONFIG_MEMORY_HOTPLUG static int kasan_mem_notifier(struct notifier_block *nb, unsigned long action, void *data)