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* [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false
@ 2016-06-05 11:11 seokhoon.yoon
  2016-06-05 12:49 ` Dmitry Vyukov
  0 siblings, 1 reply; 4+ messages in thread
From: seokhoon.yoon @ 2016-06-05 11:11 UTC (permalink / raw)
  To: Andrey Ryabinin; +Cc: Dmitry Vyukov, kasan-dev, linux-mm, iamyooon, sh.yoon

When Kasan tell memory access is write or not, use true or false.
This expression is simple and convenient.

But I think it is possible to more readable. and so change it.

Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
---
 mm/kasan/kasan.c  | 32 ++++++++++++++++----------------
 mm/kasan/kasan.h  | 12 ++++++++++--
 mm/kasan/report.c | 16 ++++++++--------
 3 files changed, 34 insertions(+), 26 deletions(-)

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 18b6a2b..642d936 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -274,7 +274,7 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
 }
 
 static __always_inline void check_memory_region_inline(unsigned long addr,
-						size_t size, bool write,
+						size_t size, enum acc_type type,
 						unsigned long ret_ip)
 {
 	if (unlikely(size == 0))
@@ -282,39 +282,39 @@ static __always_inline void check_memory_region_inline(unsigned long addr,
 
 	if (unlikely((void *)addr <
 		kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
-		kasan_report(addr, size, write, ret_ip);
+		kasan_report(addr, size, type, ret_ip);
 		return;
 	}
 
 	if (likely(!memory_is_poisoned(addr, size)))
 		return;
 
-	kasan_report(addr, size, write, ret_ip);
+	kasan_report(addr, size, type, ret_ip);
 }
 
 static void check_memory_region(unsigned long addr,
-				size_t size, bool write,
+				size_t size, enum acc_type type,
 				unsigned long ret_ip)
 {
-	check_memory_region_inline(addr, size, write, ret_ip);
+	check_memory_region_inline(addr, size, type, ret_ip);
 }
 
 void kasan_check_read(const void *p, unsigned int size)
 {
-	check_memory_region((unsigned long)p, size, false, _RET_IP_);
+	check_memory_region((unsigned long)p, size, READ_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(kasan_check_read);
 
 void kasan_check_write(const void *p, unsigned int size)
 {
-	check_memory_region((unsigned long)p, size, true, _RET_IP_);
+	check_memory_region((unsigned long)p, size, WRITE_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(kasan_check_write);
 
 #undef memset
 void *memset(void *addr, int c, size_t len)
 {
-	check_memory_region((unsigned long)addr, len, true, _RET_IP_);
+	check_memory_region((unsigned long)addr, len, WRITE_MODE, _RET_IP_);
 
 	return __memset(addr, c, len);
 }
@@ -322,8 +322,8 @@ void *memset(void *addr, int c, size_t len)
 #undef memmove
 void *memmove(void *dest, const void *src, size_t len)
 {
-	check_memory_region((unsigned long)src, len, false, _RET_IP_);
-	check_memory_region((unsigned long)dest, len, true, _RET_IP_);
+	check_memory_region((unsigned long)src, len, READ_MODE, _RET_IP_);
+	check_memory_region((unsigned long)dest, len, WRITE_MODE, _RET_IP_);
 
 	return __memmove(dest, src, len);
 }
@@ -331,8 +331,8 @@ void *memmove(void *dest, const void *src, size_t len)
 #undef memcpy
 void *memcpy(void *dest, const void *src, size_t len)
 {
-	check_memory_region((unsigned long)src, len, false, _RET_IP_);
-	check_memory_region((unsigned long)dest, len, true, _RET_IP_);
+	check_memory_region((unsigned long)src, len, READ_MODE, _RET_IP_);
+	check_memory_region((unsigned long)dest, len, WRITE_MODE, _RET_IP_);
 
 	return __memcpy(dest, src, len);
 }
@@ -709,7 +709,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
 #define DEFINE_ASAN_LOAD_STORE(size)					\
 	void __asan_load##size(unsigned long addr)			\
 	{								\
-		check_memory_region_inline(addr, size, false, _RET_IP_);\
+		check_memory_region_inline(addr, size, READ_MODE, _RET_IP_);\
 	}								\
 	EXPORT_SYMBOL(__asan_load##size);				\
 	__alias(__asan_load##size)					\
@@ -717,7 +717,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
 	EXPORT_SYMBOL(__asan_load##size##_noabort);			\
 	void __asan_store##size(unsigned long addr)			\
 	{								\
-		check_memory_region_inline(addr, size, true, _RET_IP_);	\
+		check_memory_region_inline(addr, size, WRITE_MODE, _RET_IP_);\
 	}								\
 	EXPORT_SYMBOL(__asan_store##size);				\
 	__alias(__asan_store##size)					\
@@ -732,7 +732,7 @@ DEFINE_ASAN_LOAD_STORE(16);
 
 void __asan_loadN(unsigned long addr, size_t size)
 {
-	check_memory_region(addr, size, false, _RET_IP_);
+	check_memory_region(addr, size, READ_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_loadN);
 
@@ -742,7 +742,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
 
 void __asan_storeN(unsigned long addr, size_t size)
 {
-	check_memory_region(addr, size, true, _RET_IP_);
+	check_memory_region(addr, size, WRITE_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_storeN);
 
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 7f7ac51..47cb58c 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -27,11 +27,19 @@
 #define KASAN_ABI_VERSION 1
 #endif
 
+/*
+ * Distinguish memory access
+ */
+enum acc_type {
+	READ_MODE,
+	WRITE_MODE
+};
+
 struct kasan_access_info {
 	const void *access_addr;
 	const void *first_bad_addr;
 	size_t access_size;
-	bool is_write;
+	enum acc_type access_type;
 	unsigned long ip;
 };
 
@@ -109,7 +117,7 @@ static inline bool kasan_report_enabled(void)
 }
 
 void kasan_report(unsigned long addr, size_t size,
-		bool is_write, unsigned long ip);
+		enum acc_type type, unsigned long ip);
 
 #ifdef CONFIG_SLAB
 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index b3c122d..e0bee22 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -96,7 +96,7 @@ static void print_error_description(struct kasan_access_info *info)
 		bug_type, (void *)info->ip,
 		info->access_addr);
 	pr_err("%s of size %zu by task %s/%d\n",
-		info->is_write ? "Write" : "Read",
+		info->access_type == WRITE_MODE ? "Write" : "Read",
 		info->access_size, current->comm, task_pid_nr(current));
 }
 
@@ -267,7 +267,7 @@ static void kasan_report_error(struct kasan_access_info *info)
 		pr_err("BUG: KASAN: %s on address %p\n",
 			bug_type, info->access_addr);
 		pr_err("%s of size %zu by task %s/%d\n",
-			info->is_write ? "Write" : "Read",
+			info->access_type == WRITE_MODE ? "Write" : "Read",
 			info->access_size, current->comm,
 			task_pid_nr(current));
 		dump_stack();
@@ -283,7 +283,7 @@ static void kasan_report_error(struct kasan_access_info *info)
 }
 
 void kasan_report(unsigned long addr, size_t size,
-		bool is_write, unsigned long ip)
+		enum acc_type type, unsigned long ip)
 {
 	struct kasan_access_info info;
 
@@ -292,7 +292,7 @@ void kasan_report(unsigned long addr, size_t size,
 
 	info.access_addr = (void *)addr;
 	info.access_size = size;
-	info.is_write = is_write;
+	info.access_type = type;
 	info.ip = ip;
 
 	kasan_report_error(&info);
@@ -302,14 +302,14 @@ void kasan_report(unsigned long addr, size_t size,
 #define DEFINE_ASAN_REPORT_LOAD(size)                     \
 void __asan_report_load##size##_noabort(unsigned long addr) \
 {                                                         \
-	kasan_report(addr, size, false, _RET_IP_);	  \
+	kasan_report(addr, size, READ_MODE, _RET_IP_);	  \
 }                                                         \
 EXPORT_SYMBOL(__asan_report_load##size##_noabort)
 
 #define DEFINE_ASAN_REPORT_STORE(size)                     \
 void __asan_report_store##size##_noabort(unsigned long addr) \
 {                                                          \
-	kasan_report(addr, size, true, _RET_IP_);	   \
+	kasan_report(addr, size, WRITE_MODE, _RET_IP_);	   \
 }                                                          \
 EXPORT_SYMBOL(__asan_report_store##size##_noabort)
 
@@ -326,12 +326,12 @@ DEFINE_ASAN_REPORT_STORE(16);
 
 void __asan_report_load_n_noabort(unsigned long addr, size_t size)
 {
-	kasan_report(addr, size, false, _RET_IP_);
+	kasan_report(addr, size, READ_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_report_load_n_noabort);
 
 void __asan_report_store_n_noabort(unsigned long addr, size_t size)
 {
-	kasan_report(addr, size, true, _RET_IP_);
+	kasan_report(addr, size, WRITE_MODE, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_report_store_n_noabort);
-- 
1.9.1

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false
  2016-06-05 11:11 [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false seokhoon.yoon
@ 2016-06-05 12:49 ` Dmitry Vyukov
  2016-06-05 23:08   ` SeokHoon Yoon
  0 siblings, 1 reply; 4+ messages in thread
From: Dmitry Vyukov @ 2016-06-05 12:49 UTC (permalink / raw)
  To: seokhoon.yoon; +Cc: Andrey Ryabinin, kasan-dev, linux-mm, sh.yoon

On Sun, Jun 5, 2016 at 1:11 PM, seokhoon.yoon <iamyooon@gmail.com> wrote:
> When Kasan tell memory access is write or not, use true or false.
> This expression is simple and convenient.
>
> But I think it is possible to more readable. and so change it.
>
> Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
> ---
>  mm/kasan/kasan.c  | 32 ++++++++++++++++----------------
>  mm/kasan/kasan.h  | 12 ++++++++++--
>  mm/kasan/report.c | 16 ++++++++--------
>  3 files changed, 34 insertions(+), 26 deletions(-)
>
> diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
> index 18b6a2b..642d936 100644
> --- a/mm/kasan/kasan.c
> +++ b/mm/kasan/kasan.c
> @@ -274,7 +274,7 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
>  }
>
>  static __always_inline void check_memory_region_inline(unsigned long addr,
> -                                               size_t size, bool write,
> +                                               size_t size, enum acc_type type,
>                                                 unsigned long ret_ip)
>  {
>         if (unlikely(size == 0))
> @@ -282,39 +282,39 @@ static __always_inline void check_memory_region_inline(unsigned long addr,
>
>         if (unlikely((void *)addr <
>                 kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
> -               kasan_report(addr, size, write, ret_ip);
> +               kasan_report(addr, size, type, ret_ip);
>                 return;
>         }
>
>         if (likely(!memory_is_poisoned(addr, size)))
>                 return;
>
> -       kasan_report(addr, size, write, ret_ip);
> +       kasan_report(addr, size, type, ret_ip);
>  }
>
>  static void check_memory_region(unsigned long addr,
> -                               size_t size, bool write,
> +                               size_t size, enum acc_type type,
>                                 unsigned long ret_ip)
>  {
> -       check_memory_region_inline(addr, size, write, ret_ip);
> +       check_memory_region_inline(addr, size, type, ret_ip);
>  }
>
>  void kasan_check_read(const void *p, unsigned int size)
>  {
> -       check_memory_region((unsigned long)p, size, false, _RET_IP_);
> +       check_memory_region((unsigned long)p, size, READ_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(kasan_check_read);
>
>  void kasan_check_write(const void *p, unsigned int size)
>  {
> -       check_memory_region((unsigned long)p, size, true, _RET_IP_);
> +       check_memory_region((unsigned long)p, size, WRITE_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(kasan_check_write);
>
>  #undef memset
>  void *memset(void *addr, int c, size_t len)
>  {
> -       check_memory_region((unsigned long)addr, len, true, _RET_IP_);
> +       check_memory_region((unsigned long)addr, len, WRITE_MODE, _RET_IP_);
>
>         return __memset(addr, c, len);
>  }
> @@ -322,8 +322,8 @@ void *memset(void *addr, int c, size_t len)
>  #undef memmove
>  void *memmove(void *dest, const void *src, size_t len)
>  {
> -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
> -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
> +       check_memory_region((unsigned long)src, len, READ_MODE, _RET_IP_);
> +       check_memory_region((unsigned long)dest, len, WRITE_MODE, _RET_IP_);
>
>         return __memmove(dest, src, len);
>  }
> @@ -331,8 +331,8 @@ void *memmove(void *dest, const void *src, size_t len)
>  #undef memcpy
>  void *memcpy(void *dest, const void *src, size_t len)
>  {
> -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
> -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
> +       check_memory_region((unsigned long)src, len, READ_MODE, _RET_IP_);
> +       check_memory_region((unsigned long)dest, len, WRITE_MODE, _RET_IP_);
>
>         return __memcpy(dest, src, len);
>  }
> @@ -709,7 +709,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
>  #define DEFINE_ASAN_LOAD_STORE(size)                                   \
>         void __asan_load##size(unsigned long addr)                      \
>         {                                                               \
> -               check_memory_region_inline(addr, size, false, _RET_IP_);\
> +               check_memory_region_inline(addr, size, READ_MODE, _RET_IP_);\
>         }                                                               \
>         EXPORT_SYMBOL(__asan_load##size);                               \
>         __alias(__asan_load##size)                                      \
> @@ -717,7 +717,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
>         EXPORT_SYMBOL(__asan_load##size##_noabort);                     \
>         void __asan_store##size(unsigned long addr)                     \
>         {                                                               \
> -               check_memory_region_inline(addr, size, true, _RET_IP_); \
> +               check_memory_region_inline(addr, size, WRITE_MODE, _RET_IP_);\
>         }                                                               \
>         EXPORT_SYMBOL(__asan_store##size);                              \
>         __alias(__asan_store##size)                                     \
> @@ -732,7 +732,7 @@ DEFINE_ASAN_LOAD_STORE(16);
>
>  void __asan_loadN(unsigned long addr, size_t size)
>  {
> -       check_memory_region(addr, size, false, _RET_IP_);
> +       check_memory_region(addr, size, READ_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(__asan_loadN);
>
> @@ -742,7 +742,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
>
>  void __asan_storeN(unsigned long addr, size_t size)
>  {
> -       check_memory_region(addr, size, true, _RET_IP_);
> +       check_memory_region(addr, size, WRITE_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(__asan_storeN);
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 7f7ac51..47cb58c 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -27,11 +27,19 @@
>  #define KASAN_ABI_VERSION 1
>  #endif
>
> +/*
> + * Distinguish memory access
> + */
> +enum acc_type {
> +       READ_MODE,
> +       WRITE_MODE
> +};
> +
>  struct kasan_access_info {
>         const void *access_addr;
>         const void *first_bad_addr;
>         size_t access_size;
> -       bool is_write;
> +       enum acc_type access_type;
>         unsigned long ip;
>  };
>
> @@ -109,7 +117,7 @@ static inline bool kasan_report_enabled(void)
>  }
>
>  void kasan_report(unsigned long addr, size_t size,
> -               bool is_write, unsigned long ip);
> +               enum acc_type type, unsigned long ip);
>
>  #ifdef CONFIG_SLAB
>  void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index b3c122d..e0bee22 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -96,7 +96,7 @@ static void print_error_description(struct kasan_access_info *info)
>                 bug_type, (void *)info->ip,
>                 info->access_addr);
>         pr_err("%s of size %zu by task %s/%d\n",
> -               info->is_write ? "Write" : "Read",
> +               info->access_type == WRITE_MODE ? "Write" : "Read",
>                 info->access_size, current->comm, task_pid_nr(current));
>  }
>
> @@ -267,7 +267,7 @@ static void kasan_report_error(struct kasan_access_info *info)
>                 pr_err("BUG: KASAN: %s on address %p\n",
>                         bug_type, info->access_addr);
>                 pr_err("%s of size %zu by task %s/%d\n",
> -                       info->is_write ? "Write" : "Read",
> +                       info->access_type == WRITE_MODE ? "Write" : "Read",
>                         info->access_size, current->comm,
>                         task_pid_nr(current));
>                 dump_stack();
> @@ -283,7 +283,7 @@ static void kasan_report_error(struct kasan_access_info *info)
>  }
>
>  void kasan_report(unsigned long addr, size_t size,
> -               bool is_write, unsigned long ip)
> +               enum acc_type type, unsigned long ip)
>  {
>         struct kasan_access_info info;
>
> @@ -292,7 +292,7 @@ void kasan_report(unsigned long addr, size_t size,
>
>         info.access_addr = (void *)addr;
>         info.access_size = size;
> -       info.is_write = is_write;
> +       info.access_type = type;
>         info.ip = ip;
>
>         kasan_report_error(&info);
> @@ -302,14 +302,14 @@ void kasan_report(unsigned long addr, size_t size,
>  #define DEFINE_ASAN_REPORT_LOAD(size)                     \
>  void __asan_report_load##size##_noabort(unsigned long addr) \
>  {                                                         \
> -       kasan_report(addr, size, false, _RET_IP_);        \
> +       kasan_report(addr, size, READ_MODE, _RET_IP_);    \
>  }                                                         \
>  EXPORT_SYMBOL(__asan_report_load##size##_noabort)
>
>  #define DEFINE_ASAN_REPORT_STORE(size)                     \
>  void __asan_report_store##size##_noabort(unsigned long addr) \
>  {                                                          \
> -       kasan_report(addr, size, true, _RET_IP_);          \
> +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);    \
>  }                                                          \
>  EXPORT_SYMBOL(__asan_report_store##size##_noabort)
>
> @@ -326,12 +326,12 @@ DEFINE_ASAN_REPORT_STORE(16);
>
>  void __asan_report_load_n_noabort(unsigned long addr, size_t size)
>  {
> -       kasan_report(addr, size, false, _RET_IP_);
> +       kasan_report(addr, size, READ_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(__asan_report_load_n_noabort);
>
>  void __asan_report_store_n_noabort(unsigned long addr, size_t size)
>  {
> -       kasan_report(addr, size, true, _RET_IP_);
> +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);
>  }
>  EXPORT_SYMBOL(__asan_report_store_n_noabort);


Hello seokhoon.yoon,


Where exactly do you hit readability problems?
I would say that the only problematic place is where we initialize the value:

    kasan_report(addr, size, true, _RET_IP_);
    check_memory_region(addr, size, true, _RET_IP_);

Here it is really difficult to say what true/false mean. Even if you
know that it is access type, you don't necessary remember if true
means write or read. That could be solved by adding comments:

    kasan_report(addr, size, /* write = */ true, _RET_IP_);

In all other places one sees that we are talking about "write".

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false
  2016-06-05 12:49 ` Dmitry Vyukov
@ 2016-06-05 23:08   ` SeokHoon Yoon
  2016-06-06 14:33     ` Dmitry Vyukov
  0 siblings, 1 reply; 4+ messages in thread
From: SeokHoon Yoon @ 2016-06-05 23:08 UTC (permalink / raw)
  To: Dmitry Vyukov; +Cc: Andrey Ryabinin, kasan-dev, linux-mm, sh.yoon

[-- Attachment #1: Type: text/plain, Size: 11167 bytes --]

2016-06-05 21:49 GMT+09:00 Dmitry Vyukov <dvyukov@google.com>:

> On Sun, Jun 5, 2016 at 1:11 PM, seokhoon.yoon <iamyooon@gmail.com> wrote:
> > When Kasan tell memory access is write or not, use true or false.
> > This expression is simple and convenient.
> >
> > But I think it is possible to more readable. and so change it.
> >
> > Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
> > ---
> >  mm/kasan/kasan.c  | 32 ++++++++++++++++----------------
> >  mm/kasan/kasan.h  | 12 ++++++++++--
> >  mm/kasan/report.c | 16 ++++++++--------
> >  3 files changed, 34 insertions(+), 26 deletions(-)
> >
> > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
> > index 18b6a2b..642d936 100644
> > --- a/mm/kasan/kasan.c
> > +++ b/mm/kasan/kasan.c
> > @@ -274,7 +274,7 @@ static __always_inline bool
> memory_is_poisoned(unsigned long addr, size_t size)
> >  }
> >
> >  static __always_inline void check_memory_region_inline(unsigned long
> addr,
> > -                                               size_t size, bool write,
> > +                                               size_t size, enum
> acc_type type,
> >                                                 unsigned long ret_ip)
> >  {
> >         if (unlikely(size == 0))
> > @@ -282,39 +282,39 @@ static __always_inline void
> check_memory_region_inline(unsigned long addr,
> >
> >         if (unlikely((void *)addr <
> >                 kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
> > -               kasan_report(addr, size, write, ret_ip);
> > +               kasan_report(addr, size, type, ret_ip);
> >                 return;
> >         }
> >
> >         if (likely(!memory_is_poisoned(addr, size)))
> >                 return;
> >
> > -       kasan_report(addr, size, write, ret_ip);
> > +       kasan_report(addr, size, type, ret_ip);
> >  }
> >
> >  static void check_memory_region(unsigned long addr,
> > -                               size_t size, bool write,
> > +                               size_t size, enum acc_type type,
> >                                 unsigned long ret_ip)
> >  {
> > -       check_memory_region_inline(addr, size, write, ret_ip);
> > +       check_memory_region_inline(addr, size, type, ret_ip);
> >  }
> >
> >  void kasan_check_read(const void *p, unsigned int size)
> >  {
> > -       check_memory_region((unsigned long)p, size, false, _RET_IP_);
> > +       check_memory_region((unsigned long)p, size, READ_MODE, _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(kasan_check_read);
> >
> >  void kasan_check_write(const void *p, unsigned int size)
> >  {
> > -       check_memory_region((unsigned long)p, size, true, _RET_IP_);
> > +       check_memory_region((unsigned long)p, size, WRITE_MODE,
> _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(kasan_check_write);
> >
> >  #undef memset
> >  void *memset(void *addr, int c, size_t len)
> >  {
> > -       check_memory_region((unsigned long)addr, len, true, _RET_IP_);
> > +       check_memory_region((unsigned long)addr, len, WRITE_MODE,
> _RET_IP_);
> >
> >         return __memset(addr, c, len);
> >  }
> > @@ -322,8 +322,8 @@ void *memset(void *addr, int c, size_t len)
> >  #undef memmove
> >  void *memmove(void *dest, const void *src, size_t len)
> >  {
> > -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
> > -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
> > +       check_memory_region((unsigned long)src, len, READ_MODE,
> _RET_IP_);
> > +       check_memory_region((unsigned long)dest, len, WRITE_MODE,
> _RET_IP_);
> >
> >         return __memmove(dest, src, len);
> >  }
> > @@ -331,8 +331,8 @@ void *memmove(void *dest, const void *src, size_t
> len)
> >  #undef memcpy
> >  void *memcpy(void *dest, const void *src, size_t len)
> >  {
> > -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
> > -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
> > +       check_memory_region((unsigned long)src, len, READ_MODE,
> _RET_IP_);
> > +       check_memory_region((unsigned long)dest, len, WRITE_MODE,
> _RET_IP_);
> >
> >         return __memcpy(dest, src, len);
> >  }
> > @@ -709,7 +709,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
> >  #define DEFINE_ASAN_LOAD_STORE(size)                                   \
> >         void __asan_load##size(unsigned long addr)                      \
> >         {                                                               \
> > -               check_memory_region_inline(addr, size, false, _RET_IP_);\
> > +               check_memory_region_inline(addr, size, READ_MODE,
> _RET_IP_);\
> >         }                                                               \
> >         EXPORT_SYMBOL(__asan_load##size);                               \
> >         __alias(__asan_load##size)                                      \
> > @@ -717,7 +717,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
> >         EXPORT_SYMBOL(__asan_load##size##_noabort);                     \
> >         void __asan_store##size(unsigned long addr)                     \
> >         {                                                               \
> > -               check_memory_region_inline(addr, size, true, _RET_IP_); \
> > +               check_memory_region_inline(addr, size, WRITE_MODE,
> _RET_IP_);\
> >         }                                                               \
> >         EXPORT_SYMBOL(__asan_store##size);                              \
> >         __alias(__asan_store##size)                                     \
> > @@ -732,7 +732,7 @@ DEFINE_ASAN_LOAD_STORE(16);
> >
> >  void __asan_loadN(unsigned long addr, size_t size)
> >  {
> > -       check_memory_region(addr, size, false, _RET_IP_);
> > +       check_memory_region(addr, size, READ_MODE, _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(__asan_loadN);
> >
> > @@ -742,7 +742,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
> >
> >  void __asan_storeN(unsigned long addr, size_t size)
> >  {
> > -       check_memory_region(addr, size, true, _RET_IP_);
> > +       check_memory_region(addr, size, WRITE_MODE, _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(__asan_storeN);
> >
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index 7f7ac51..47cb58c 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -27,11 +27,19 @@
> >  #define KASAN_ABI_VERSION 1
> >  #endif
> >
> > +/*
> > + * Distinguish memory access
> > + */
> > +enum acc_type {
> > +       READ_MODE,
> > +       WRITE_MODE
> > +};
> > +
> >  struct kasan_access_info {
> >         const void *access_addr;
> >         const void *first_bad_addr;
> >         size_t access_size;
> > -       bool is_write;
> > +       enum acc_type access_type;
> >         unsigned long ip;
> >  };
> >
> > @@ -109,7 +117,7 @@ static inline bool kasan_report_enabled(void)
> >  }
> >
> >  void kasan_report(unsigned long addr, size_t size,
> > -               bool is_write, unsigned long ip);
> > +               enum acc_type type, unsigned long ip);
> >
> >  #ifdef CONFIG_SLAB
> >  void quarantine_put(struct kasan_free_meta *info, struct kmem_cache
> *cache);
> > diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> > index b3c122d..e0bee22 100644
> > --- a/mm/kasan/report.c
> > +++ b/mm/kasan/report.c
> > @@ -96,7 +96,7 @@ static void print_error_description(struct
> kasan_access_info *info)
> >                 bug_type, (void *)info->ip,
> >                 info->access_addr);
> >         pr_err("%s of size %zu by task %s/%d\n",
> > -               info->is_write ? "Write" : "Read",
> > +               info->access_type == WRITE_MODE ? "Write" : "Read",
> >                 info->access_size, current->comm, task_pid_nr(current));
> >  }
> >
> > @@ -267,7 +267,7 @@ static void kasan_report_error(struct
> kasan_access_info *info)
> >                 pr_err("BUG: KASAN: %s on address %p\n",
> >                         bug_type, info->access_addr);
> >                 pr_err("%s of size %zu by task %s/%d\n",
> > -                       info->is_write ? "Write" : "Read",
> > +                       info->access_type == WRITE_MODE ? "Write" :
> "Read",
> >                         info->access_size, current->comm,
> >                         task_pid_nr(current));
> >                 dump_stack();
> > @@ -283,7 +283,7 @@ static void kasan_report_error(struct
> kasan_access_info *info)
> >  }
> >
> >  void kasan_report(unsigned long addr, size_t size,
> > -               bool is_write, unsigned long ip)
> > +               enum acc_type type, unsigned long ip)
> >  {
> >         struct kasan_access_info info;
> >
> > @@ -292,7 +292,7 @@ void kasan_report(unsigned long addr, size_t size,
> >
> >         info.access_addr = (void *)addr;
> >         info.access_size = size;
> > -       info.is_write = is_write;
> > +       info.access_type = type;
> >         info.ip = ip;
> >
> >         kasan_report_error(&info);
> > @@ -302,14 +302,14 @@ void kasan_report(unsigned long addr, size_t size,
> >  #define DEFINE_ASAN_REPORT_LOAD(size)                     \
> >  void __asan_report_load##size##_noabort(unsigned long addr) \
> >  {                                                         \
> > -       kasan_report(addr, size, false, _RET_IP_);        \
> > +       kasan_report(addr, size, READ_MODE, _RET_IP_);    \
> >  }                                                         \
> >  EXPORT_SYMBOL(__asan_report_load##size##_noabort)
> >
> >  #define DEFINE_ASAN_REPORT_STORE(size)                     \
> >  void __asan_report_store##size##_noabort(unsigned long addr) \
> >  {                                                          \
> > -       kasan_report(addr, size, true, _RET_IP_);          \
> > +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);    \
> >  }                                                          \
> >  EXPORT_SYMBOL(__asan_report_store##size##_noabort)
> >
> > @@ -326,12 +326,12 @@ DEFINE_ASAN_REPORT_STORE(16);
> >
> >  void __asan_report_load_n_noabort(unsigned long addr, size_t size)
> >  {
> > -       kasan_report(addr, size, false, _RET_IP_);
> > +       kasan_report(addr, size, READ_MODE, _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(__asan_report_load_n_noabort);
> >
> >  void __asan_report_store_n_noabort(unsigned long addr, size_t size)
> >  {
> > -       kasan_report(addr, size, true, _RET_IP_);
> > +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);
> >  }
> >  EXPORT_SYMBOL(__asan_report_store_n_noabort);
>
>
> Hello seokhoon.yoon,
>
> Hi Dmitry,
thanks for your replies.


>
> Where exactly do you hit readability problems?
>

I don`t hit readablity problem,but kasan need to abstract this expression.
I think more abstraction give us more readablity. isn't it? :)


> I would say that the only problematic place is where we initialize the
> value:
>
>     kasan_report(addr, size, true, _RET_IP_);
>     check_memory_region(addr, size, true, _RET_IP_);
>
Here it is really difficult to say what true/false mean. Even if you
> know that it is access type, you don't necessary remember if true

means write or read. That could be solved by adding comments:
>
>     kasan_report(addr, size, /* write = */ true, _RET_IP_);
>
> In all other places one sees that we are talking about "write".


thanks.

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false
  2016-06-05 23:08   ` SeokHoon Yoon
@ 2016-06-06 14:33     ` Dmitry Vyukov
  0 siblings, 0 replies; 4+ messages in thread
From: Dmitry Vyukov @ 2016-06-06 14:33 UTC (permalink / raw)
  To: SeokHoon Yoon; +Cc: Andrey Ryabinin, kasan-dev, linux-mm, sh.yoon

On Mon, Jun 6, 2016 at 1:08 AM, SeokHoon Yoon <iamyooon@gmail.com> wrote:
>
> 2016-06-05 21:49 GMT+09:00 Dmitry Vyukov <dvyukov@google.com>:
>>
>> On Sun, Jun 5, 2016 at 1:11 PM, seokhoon.yoon <iamyooon@gmail.com> wrote:
>> > When Kasan tell memory access is write or not, use true or false.
>> > This expression is simple and convenient.
>> >
>> > But I think it is possible to more readable. and so change it.
>> >
>> > Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
>> > ---
>> >  mm/kasan/kasan.c  | 32 ++++++++++++++++----------------
>> >  mm/kasan/kasan.h  | 12 ++++++++++--
>> >  mm/kasan/report.c | 16 ++++++++--------
>> >  3 files changed, 34 insertions(+), 26 deletions(-)
>> >
>> > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
>> > index 18b6a2b..642d936 100644
>> > --- a/mm/kasan/kasan.c
>> > +++ b/mm/kasan/kasan.c
>> > @@ -274,7 +274,7 @@ static __always_inline bool
>> > memory_is_poisoned(unsigned long addr, size_t size)
>> >  }
>> >
>> >  static __always_inline void check_memory_region_inline(unsigned long
>> > addr,
>> > -                                               size_t size, bool write,
>> > +                                               size_t size, enum
>> > acc_type type,
>> >                                                 unsigned long ret_ip)
>> >  {
>> >         if (unlikely(size == 0))
>> > @@ -282,39 +282,39 @@ static __always_inline void
>> > check_memory_region_inline(unsigned long addr,
>> >
>> >         if (unlikely((void *)addr <
>> >                 kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
>> > -               kasan_report(addr, size, write, ret_ip);
>> > +               kasan_report(addr, size, type, ret_ip);
>> >                 return;
>> >         }
>> >
>> >         if (likely(!memory_is_poisoned(addr, size)))
>> >                 return;
>> >
>> > -       kasan_report(addr, size, write, ret_ip);
>> > +       kasan_report(addr, size, type, ret_ip);
>> >  }
>> >
>> >  static void check_memory_region(unsigned long addr,
>> > -                               size_t size, bool write,
>> > +                               size_t size, enum acc_type type,
>> >                                 unsigned long ret_ip)
>> >  {
>> > -       check_memory_region_inline(addr, size, write, ret_ip);
>> > +       check_memory_region_inline(addr, size, type, ret_ip);
>> >  }
>> >
>> >  void kasan_check_read(const void *p, unsigned int size)
>> >  {
>> > -       check_memory_region((unsigned long)p, size, false, _RET_IP_);
>> > +       check_memory_region((unsigned long)p, size, READ_MODE,
>> > _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(kasan_check_read);
>> >
>> >  void kasan_check_write(const void *p, unsigned int size)
>> >  {
>> > -       check_memory_region((unsigned long)p, size, true, _RET_IP_);
>> > +       check_memory_region((unsigned long)p, size, WRITE_MODE,
>> > _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(kasan_check_write);
>> >
>> >  #undef memset
>> >  void *memset(void *addr, int c, size_t len)
>> >  {
>> > -       check_memory_region((unsigned long)addr, len, true, _RET_IP_);
>> > +       check_memory_region((unsigned long)addr, len, WRITE_MODE,
>> > _RET_IP_);
>> >
>> >         return __memset(addr, c, len);
>> >  }
>> > @@ -322,8 +322,8 @@ void *memset(void *addr, int c, size_t len)
>> >  #undef memmove
>> >  void *memmove(void *dest, const void *src, size_t len)
>> >  {
>> > -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
>> > -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
>> > +       check_memory_region((unsigned long)src, len, READ_MODE,
>> > _RET_IP_);
>> > +       check_memory_region((unsigned long)dest, len, WRITE_MODE,
>> > _RET_IP_);
>> >
>> >         return __memmove(dest, src, len);
>> >  }
>> > @@ -331,8 +331,8 @@ void *memmove(void *dest, const void *src, size_t
>> > len)
>> >  #undef memcpy
>> >  void *memcpy(void *dest, const void *src, size_t len)
>> >  {
>> > -       check_memory_region((unsigned long)src, len, false, _RET_IP_);
>> > -       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
>> > +       check_memory_region((unsigned long)src, len, READ_MODE,
>> > _RET_IP_);
>> > +       check_memory_region((unsigned long)dest, len, WRITE_MODE,
>> > _RET_IP_);
>> >
>> >         return __memcpy(dest, src, len);
>> >  }
>> > @@ -709,7 +709,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
>> >  #define DEFINE_ASAN_LOAD_STORE(size)
>> > \
>> >         void __asan_load##size(unsigned long addr)
>> > \
>> >         {
>> > \
>> > -               check_memory_region_inline(addr, size, false,
>> > _RET_IP_);\
>> > +               check_memory_region_inline(addr, size, READ_MODE,
>> > _RET_IP_);\
>> >         }
>> > \
>> >         EXPORT_SYMBOL(__asan_load##size);
>> > \
>> >         __alias(__asan_load##size)
>> > \
>> > @@ -717,7 +717,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
>> >         EXPORT_SYMBOL(__asan_load##size##_noabort);
>> > \
>> >         void __asan_store##size(unsigned long addr)
>> > \
>> >         {
>> > \
>> > -               check_memory_region_inline(addr, size, true, _RET_IP_);
>> > \
>> > +               check_memory_region_inline(addr, size, WRITE_MODE,
>> > _RET_IP_);\
>> >         }
>> > \
>> >         EXPORT_SYMBOL(__asan_store##size);
>> > \
>> >         __alias(__asan_store##size)
>> > \
>> > @@ -732,7 +732,7 @@ DEFINE_ASAN_LOAD_STORE(16);
>> >
>> >  void __asan_loadN(unsigned long addr, size_t size)
>> >  {
>> > -       check_memory_region(addr, size, false, _RET_IP_);
>> > +       check_memory_region(addr, size, READ_MODE, _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(__asan_loadN);
>> >
>> > @@ -742,7 +742,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
>> >
>> >  void __asan_storeN(unsigned long addr, size_t size)
>> >  {
>> > -       check_memory_region(addr, size, true, _RET_IP_);
>> > +       check_memory_region(addr, size, WRITE_MODE, _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(__asan_storeN);
>> >
>> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
>> > index 7f7ac51..47cb58c 100644
>> > --- a/mm/kasan/kasan.h
>> > +++ b/mm/kasan/kasan.h
>> > @@ -27,11 +27,19 @@
>> >  #define KASAN_ABI_VERSION 1
>> >  #endif
>> >
>> > +/*
>> > + * Distinguish memory access
>> > + */
>> > +enum acc_type {
>> > +       READ_MODE,
>> > +       WRITE_MODE
>> > +};
>> > +
>> >  struct kasan_access_info {
>> >         const void *access_addr;
>> >         const void *first_bad_addr;
>> >         size_t access_size;
>> > -       bool is_write;
>> > +       enum acc_type access_type;
>> >         unsigned long ip;
>> >  };
>> >
>> > @@ -109,7 +117,7 @@ static inline bool kasan_report_enabled(void)
>> >  }
>> >
>> >  void kasan_report(unsigned long addr, size_t size,
>> > -               bool is_write, unsigned long ip);
>> > +               enum acc_type type, unsigned long ip);
>> >
>> >  #ifdef CONFIG_SLAB
>> >  void quarantine_put(struct kasan_free_meta *info, struct kmem_cache
>> > *cache);
>> > diff --git a/mm/kasan/report.c b/mm/kasan/report.c
>> > index b3c122d..e0bee22 100644
>> > --- a/mm/kasan/report.c
>> > +++ b/mm/kasan/report.c
>> > @@ -96,7 +96,7 @@ static void print_error_description(struct
>> > kasan_access_info *info)
>> >                 bug_type, (void *)info->ip,
>> >                 info->access_addr);
>> >         pr_err("%s of size %zu by task %s/%d\n",
>> > -               info->is_write ? "Write" : "Read",
>> > +               info->access_type == WRITE_MODE ? "Write" : "Read",
>> >                 info->access_size, current->comm, task_pid_nr(current));
>> >  }
>> >
>> > @@ -267,7 +267,7 @@ static void kasan_report_error(struct
>> > kasan_access_info *info)
>> >                 pr_err("BUG: KASAN: %s on address %p\n",
>> >                         bug_type, info->access_addr);
>> >                 pr_err("%s of size %zu by task %s/%d\n",
>> > -                       info->is_write ? "Write" : "Read",
>> > +                       info->access_type == WRITE_MODE ? "Write" :
>> > "Read",
>> >                         info->access_size, current->comm,
>> >                         task_pid_nr(current));
>> >                 dump_stack();
>> > @@ -283,7 +283,7 @@ static void kasan_report_error(struct
>> > kasan_access_info *info)
>> >  }
>> >
>> >  void kasan_report(unsigned long addr, size_t size,
>> > -               bool is_write, unsigned long ip)
>> > +               enum acc_type type, unsigned long ip)
>> >  {
>> >         struct kasan_access_info info;
>> >
>> > @@ -292,7 +292,7 @@ void kasan_report(unsigned long addr, size_t size,
>> >
>> >         info.access_addr = (void *)addr;
>> >         info.access_size = size;
>> > -       info.is_write = is_write;
>> > +       info.access_type = type;
>> >         info.ip = ip;
>> >
>> >         kasan_report_error(&info);
>> > @@ -302,14 +302,14 @@ void kasan_report(unsigned long addr, size_t size,
>> >  #define DEFINE_ASAN_REPORT_LOAD(size)                     \
>> >  void __asan_report_load##size##_noabort(unsigned long addr) \
>> >  {                                                         \
>> > -       kasan_report(addr, size, false, _RET_IP_);        \
>> > +       kasan_report(addr, size, READ_MODE, _RET_IP_);    \
>> >  }                                                         \
>> >  EXPORT_SYMBOL(__asan_report_load##size##_noabort)
>> >
>> >  #define DEFINE_ASAN_REPORT_STORE(size)                     \
>> >  void __asan_report_store##size##_noabort(unsigned long addr) \
>> >  {                                                          \
>> > -       kasan_report(addr, size, true, _RET_IP_);          \
>> > +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);    \
>> >  }                                                          \
>> >  EXPORT_SYMBOL(__asan_report_store##size##_noabort)
>> >
>> > @@ -326,12 +326,12 @@ DEFINE_ASAN_REPORT_STORE(16);
>> >
>> >  void __asan_report_load_n_noabort(unsigned long addr, size_t size)
>> >  {
>> > -       kasan_report(addr, size, false, _RET_IP_);
>> > +       kasan_report(addr, size, READ_MODE, _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(__asan_report_load_n_noabort);
>> >
>> >  void __asan_report_store_n_noabort(unsigned long addr, size_t size)
>> >  {
>> > -       kasan_report(addr, size, true, _RET_IP_);
>> > +       kasan_report(addr, size, WRITE_MODE, _RET_IP_);
>> >  }
>> >  EXPORT_SYMBOL(__asan_report_store_n_noabort);
>>
>>
>> Hello seokhoon.yoon,
>>
> Hi Dmitry,
> thanks for your replies.
>
>>
>>
>> Where exactly do you hit readability problems?
>
>
> I don`t hit readablity problem,but kasan need to abstract this expression.
> I think more abstraction give us more readablity. isn't it? :)

Keeping it simple also gives readability.

>> I would say that the only problematic place is where we initialize the
>> value:
>>
>>     kasan_report(addr, size, true, _RET_IP_);
>>     check_memory_region(addr, size, true, _RET_IP_);
>>
>> Here it is really difficult to say what true/false mean. Even if you
>> know that it is access type, you don't necessary remember if true
>>
>> means write or read. That could be solved by adding comments:
>>
>>     kasan_report(addr, size, /* write = */ true, _RET_IP_);
>>
>> In all other places one sees that we are talking about "write".
>
>
> thanks.

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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2016-06-06 14:34 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2016-06-05 11:11 [PATCH 1/1] mm/kasan: use {READ,WRITE}_MODE not true,false seokhoon.yoon
2016-06-05 12:49 ` Dmitry Vyukov
2016-06-05 23:08   ` SeokHoon Yoon
2016-06-06 14:33     ` Dmitry Vyukov

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