lkml.org 
[lkml]   [2020]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH RFC v2 10/21] kasan: inline random_tag for HW_TAGS
    On Fri, Oct 30, 2020 at 4:48 PM Andrey Konovalov <andreyknvl@google.com> wrote:
    >
    > On Wed, Oct 28, 2020 at 12:08 PM Dmitry Vyukov <dvyukov@google.com> wrote:
    > >
    > > On Thu, Oct 22, 2020 at 3:19 PM Andrey Konovalov <andreyknvl@google.com> wrote:
    > > >
    > > > Using random_tag() currently results in a function call. Move its
    > > > definition to mm/kasan/kasan.h and turn it into a static inline function
    > > > for hardware tag-based mode to avoid uneeded function call.
    > > >
    > > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
    > > > Link: https://linux-review.googlesource.com/id/Iac5b2faf9a912900e16cca6834d621f5d4abf427
    > > > ---
    > > > mm/kasan/hw_tags.c | 5 -----
    > > > mm/kasan/kasan.h | 37 ++++++++++++++++++++-----------------
    > > > 2 files changed, 20 insertions(+), 22 deletions(-)
    > > >
    > > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
    > > > index c3a0e83b5e7a..4c24bfcfeff9 100644
    > > > --- a/mm/kasan/hw_tags.c
    > > > +++ b/mm/kasan/hw_tags.c
    > > > @@ -36,11 +36,6 @@ void kasan_unpoison_memory(const void *address, size_t size)
    > > > round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
    > > > }
    > > >
    > > > -u8 random_tag(void)
    > > > -{
    > > > - return get_random_tag();
    > > > -}
    > > > -
    > > > bool check_invalid_free(void *addr)
    > > > {
    > > > u8 ptr_tag = get_tag(addr);
    > > > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
    > > > index 0ccbb3c4c519..94ba15c2f860 100644
    > > > --- a/mm/kasan/kasan.h
    > > > +++ b/mm/kasan/kasan.h
    > > > @@ -188,6 +188,12 @@ static inline bool addr_has_metadata(const void *addr)
    > > >
    > > > #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
    > > >
    > > > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
    > > > +void print_tags(u8 addr_tag, const void *addr);
    > > > +#else
    > > > +static inline void print_tags(u8 addr_tag, const void *addr) { }
    > > > +#endif
    > > > +
    > > > bool check_invalid_free(void *addr);
    > > >
    > > > void *find_first_bad_addr(void *addr, size_t size);
    > > > @@ -223,23 +229,6 @@ static inline void quarantine_reduce(void) { }
    > > > static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
    > > > #endif
    > > >
    > > > -#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
    > > > -
    > > > -void print_tags(u8 addr_tag, const void *addr);
    > > > -
    > > > -u8 random_tag(void);
    > > > -
    > > > -#else
    > > > -
    > > > -static inline void print_tags(u8 addr_tag, const void *addr) { }
    > > > -
    > > > -static inline u8 random_tag(void)
    > > > -{
    > > > - return 0;
    > > > -}
    > > > -
    > > > -#endif
    > > > -
    > > > #ifndef arch_kasan_set_tag
    > > > static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
    > > > {
    > > > @@ -273,6 +262,20 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
    > > > #define get_mem_tag(addr) arch_get_mem_tag(addr)
    > > > #define set_mem_tag_range(addr, size, tag) arch_set_mem_tag_range((addr), (size), (tag))
    > > >
    > > > +#ifdef CONFIG_KASAN_SW_TAGS
    > > > +u8 random_tag(void);
    > > > +#elif defined(CONFIG_KASAN_HW_TAGS)
    > > > +static inline u8 random_tag(void)
    > > > +{
    > > > + return get_random_tag();
    > >
    > > What's the difference between random_tag() and get_random_tag()? Do we
    > > need both?
    >
    > Not really. Will simplify this in the next version and give cleaner names.

    Actually I think I'll keep both for the next version, but rename
    get_random_tag() into hw_get_random_tag() along with other hw-specific
    calls. The idea is to have hw_*() calls for things that are
    implemented by the hardware for HW_TAGS, and then define random_tag()
    based on that for HW_TAGS and based on a software implementation for
    SW_TAGS.

    \
     
     \ /
      Last update: 2020-10-30 17:07    [W:3.078 / U:0.200 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site