| Message ID | 20220610152141.2148929-4-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kasan: Fix ordering between MTE tag colouring and page->flags | expand |
On Fri, Jun 10, 2022 at 5:21 PM Catalin Marinas <catalin.marinas@arm.com> wrote: > > Currently post_alloc_hook() skips the kasan unpoisoning if the tags will > be zeroed (__GFP_ZEROTAGS) or __GFP_SKIP_KASAN_UNPOISON is passed. Since > __GFP_ZEROTAGS is now accompanied by __GFP_SKIP_KASAN_UNPOISON, remove > the extra check. > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > Cc: Andrey Konovalov <andreyknvl@gmail.com> > Cc: Peter Collingbourne <pcc@google.com> > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > mm/page_alloc.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index f6ed240870bc..bf45a6aa407a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2361,7 +2361,7 @@ static inline bool check_new_pcp(struct page *page, unsigned int order) > } > #endif /* CONFIG_DEBUG_VM */ > > -static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) > +static inline bool should_skip_kasan_unpoison(gfp_t flags) > { > /* Don't skip if a software KASAN mode is enabled. */ > if (IS_ENABLED(CONFIG_KASAN_GENERIC) || > @@ -2373,12 +2373,10 @@ static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) > return true; > > /* > - * With hardware tag-based KASAN enabled, skip if either: > - * > - * 1. Memory tags have already been cleared via tag_clear_highpage(). > - * 2. Skipping has been requested via __GFP_SKIP_KASAN_UNPOISON. > + * With hardware tag-based KASAN enabled, skip if this has been > + * requested via __GFP_SKIP_KASAN_UNPOISON. > */ > - return init_tags || (flags & __GFP_SKIP_KASAN_UNPOISON); > + return flags & __GFP_SKIP_KASAN_UNPOISON; > } > > static inline bool should_skip_init(gfp_t flags) > @@ -2430,7 +2428,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, > /* Note that memory is already initialized by the loop above. */ > init = false; > } > - if (!should_skip_kasan_unpoison(gfp_flags, init_tags)) { > + if (!should_skip_kasan_unpoison(gfp_flags)) { > /* Unpoison shadow memory or set memory tags. */ > kasan_unpoison_pages(page, order, init); > Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
On 6/10/22 16:21, Catalin Marinas wrote: > Currently post_alloc_hook() skips the kasan unpoisoning if the tags will > be zeroed (__GFP_ZEROTAGS) or __GFP_SKIP_KASAN_UNPOISON is passed. Since > __GFP_ZEROTAGS is now accompanied by __GFP_SKIP_KASAN_UNPOISON, remove > the extra check. > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > Cc: Andrey Konovalov <andreyknvl@gmail.com> > Cc: Peter Collingbourne <pcc@google.com> > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > mm/page_alloc.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index f6ed240870bc..bf45a6aa407a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2361,7 +2361,7 @@ static inline bool check_new_pcp(struct page *page, unsigned int order) > } > #endif /* CONFIG_DEBUG_VM */ > > -static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) > +static inline bool should_skip_kasan_unpoison(gfp_t flags) > { > /* Don't skip if a software KASAN mode is enabled. */ > if (IS_ENABLED(CONFIG_KASAN_GENERIC) || > @@ -2373,12 +2373,10 @@ static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) > return true; > > /* > - * With hardware tag-based KASAN enabled, skip if either: > - * > - * 1. Memory tags have already been cleared via tag_clear_highpage(). > - * 2. Skipping has been requested via __GFP_SKIP_KASAN_UNPOISON. > + * With hardware tag-based KASAN enabled, skip if this has been > + * requested via __GFP_SKIP_KASAN_UNPOISON. > */ > - return init_tags || (flags & __GFP_SKIP_KASAN_UNPOISON); > + return flags & __GFP_SKIP_KASAN_UNPOISON; > } > > static inline bool should_skip_init(gfp_t flags) > @@ -2430,7 +2428,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, > /* Note that memory is already initialized by the loop above. */ > init = false; > } > - if (!should_skip_kasan_unpoison(gfp_flags, init_tags)) { > + if (!should_skip_kasan_unpoison(gfp_flags)) { > /* Unpoison shadow memory or set memory tags. */ > kasan_unpoison_pages(page, order, init); >
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index f6ed240870bc..bf45a6aa407a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2361,7 +2361,7 @@ static inline bool check_new_pcp(struct page *page, unsigned int order) } #endif /* CONFIG_DEBUG_VM */ -static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) +static inline bool should_skip_kasan_unpoison(gfp_t flags) { /* Don't skip if a software KASAN mode is enabled. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC) || @@ -2373,12 +2373,10 @@ static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) return true; /* - * With hardware tag-based KASAN enabled, skip if either: - * - * 1. Memory tags have already been cleared via tag_clear_highpage(). - * 2. Skipping has been requested via __GFP_SKIP_KASAN_UNPOISON. + * With hardware tag-based KASAN enabled, skip if this has been + * requested via __GFP_SKIP_KASAN_UNPOISON. */ - return init_tags || (flags & __GFP_SKIP_KASAN_UNPOISON); + return flags & __GFP_SKIP_KASAN_UNPOISON; } static inline bool should_skip_init(gfp_t flags) @@ -2430,7 +2428,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, /* Note that memory is already initialized by the loop above. */ init = false; } - if (!should_skip_kasan_unpoison(gfp_flags, init_tags)) { + if (!should_skip_kasan_unpoison(gfp_flags)) { /* Unpoison shadow memory or set memory tags. */ kasan_unpoison_pages(page, order, init);
Currently post_alloc_hook() skips the kasan unpoisoning if the tags will be zeroed (__GFP_ZEROTAGS) or __GFP_SKIP_KASAN_UNPOISON is passed. Since __GFP_ZEROTAGS is now accompanied by __GFP_SKIP_KASAN_UNPOISON, remove the extra check. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> --- mm/page_alloc.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)