diff mbox series

[RFC,v2,10/21] kasan: inline random_tag for HW_TAGS

Message ID 56b19be34ee958103481bdfc501978556a168b42.1603372719.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series kasan: hardware tag-based mode for production use on arm64 | expand

Commit Message

Andrey Konovalov Oct. 22, 2020, 1:19 p.m. UTC 
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(-)

Comments

Dmitry Vyukov Oct. 28, 2020, 11:08 a.m. UTC | #1 
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?


> +}
> +#else
> +static inline u8 random_tag(void)
> +{
> +       return 0;
> +}
> +#endif
> +
>  /*
>   * Exported functions for interfaces called from assembly or from generated
>   * code. Declarations here to avoid warning about missing declarations.
> --
> 2.29.0.rc1.297.gfa9743e501-goog
>
Andrey Konovalov Oct. 30, 2020, 3:48 p.m. UTC | #2 
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.
Andrey Konovalov Oct. 30, 2020, 4:07 p.m. UTC | #3 
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.
diff mbox series

Patch

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();
+}
+#else
+static inline u8 random_tag(void)
+{
+	return 0;
+}
+#endif
+
 /*
  * Exported functions for interfaces called from assembly or from generated
  * code. Declarations here to avoid warning about missing declarations.