Commit 5cbaefe9 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

kcsan: Improve various small stylistic details 



Tidy up a few bits:

  - Fix typos and grammar, improve wording.

  - Remove spurious newlines that are col80 warning artifacts where the
    resulting line-break is worse than the disease it's curing.

  - Use core kernel coding style to improve readability and reduce
    spurious code pattern variations.

  - Use better vertical alignment for structure definitions and initialization
    sequences.

  - Misc other small details.

No change in functionality intended.

Cc: linux-kernel@vger.kernel.org
Cc: Marco Elver <elver@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8e1d58ae

include/linux/compiler-clang.h

+1 −1
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ 
#define KASAN_ABI_VERSION 5



#if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)

/* emulate gcc's __SANITIZE_ADDRESS__ flag */

/* Emulate GCC's __SANITIZE_ADDRESS__ flag */

#define __SANITIZE_ADDRESS__

#define __no_sanitize_address \

		__attribute__((no_sanitize("address", "hwaddress")))

include/linux/compiler.h

+1 −1
Original line number Diff line number Diff line
@@ -313,7 +313,7 @@ unsigned long read_word_at_a_time(const void *addr) 
#include <linux/kcsan.h>



/*

 * data_race: macro to document that accesses in an expression may conflict with

 * data_race(): macro to document that accesses in an expression may conflict with

 * other concurrent accesses resulting in data races, but the resulting

 * behaviour is deemed safe regardless.

 *

include/linux/kcsan-checks.h

+9 −13
Original line number Diff line number Diff line
@@ -12,13 +12,13 @@ 
#define KCSAN_ACCESS_ATOMIC 0x2



/*

 * __kcsan_*: Always calls into runtime when KCSAN is enabled. This may be used

 * __kcsan_*: Always calls into the runtime when KCSAN is enabled. This may be used

 * even in compilation units that selectively disable KCSAN, but must use KCSAN

 * to validate access to an address. Never use these in header files!

 */

#ifdef CONFIG_KCSAN

/**

 * __kcsan_check_access - check generic access for data race

 * __kcsan_check_access - check generic access for data races

 *

 * @ptr address of access

 * @size size of access
@@ -32,7 +32,7 @@ static inline void __kcsan_check_access(const volatile void *ptr, size_t size, 
#endif



/*

 * kcsan_*: Only calls into runtime when the particular compilation unit has

 * kcsan_*: Only calls into the runtime when the particular compilation unit has

 * KCSAN instrumentation enabled. May be used in header files.

 */

#ifdef __SANITIZE_THREAD__
@@ -77,16 +77,12 @@ static inline void kcsan_check_access(const volatile void *ptr, size_t size, 
	kcsan_check_access(ptr, size, KCSAN_ACCESS_WRITE)



/*

 * Check for atomic accesses: if atomic access are not ignored, this simply

 * aliases to kcsan_check_access, otherwise becomes a no-op.

 * Check for atomic accesses: if atomic accesses are not ignored, this simply

 * aliases to kcsan_check_access(), otherwise becomes a no-op.

 */

#ifdef CONFIG_KCSAN_IGNORE_ATOMICS

#define kcsan_check_atomic_read(...)                                           \

	do {                                                                   \

	} while (0)

#define kcsan_check_atomic_write(...)                                          \

	do {                                                                   \

	} while (0)

#define kcsan_check_atomic_read(...)	do { } while (0)

#define kcsan_check_atomic_write(...)	do { } while (0)

#else

#define kcsan_check_atomic_read(ptr, size)                                     \

	kcsan_check_access(ptr, size, KCSAN_ACCESS_ATOMIC)

include/linux/kcsan.h

+8 −15
Original line number Diff line number Diff line
@@ -95,19 +95,12 @@ void kcsan_atomic_next(int n); 
#else /* CONFIG_KCSAN */



static inline void kcsan_init(void)			{ }



static inline void kcsan_disable_current(void)		{ }



static inline void kcsan_enable_current(void)		{ }



static inline void kcsan_nestable_atomic_begin(void)	{ }



static inline void kcsan_nestable_atomic_end(void)	{ }



static inline void kcsan_flat_atomic_begin(void)	{ }



static inline void kcsan_flat_atomic_end(void)		{ }



static inline void kcsan_atomic_next(int n)		{ }



#endif /* CONFIG_KCSAN */

include/linux/seqlock.h

+4 −4
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ 
 *

 * As a consequence, we take the following best-effort approach for raw usage

 * via seqcount_t under KCSAN: upon beginning a seq-reader critical section,

 * pessimistically mark then next KCSAN_SEQLOCK_REGION_MAX memory accesses as

 * pessimistically mark the next KCSAN_SEQLOCK_REGION_MAX memory accesses as

 * atomics; if there is a matching read_seqcount_retry() call, no following

 * memory operations are considered atomic. Usage of seqlocks via seqlock_t

 * interface is not affected.
@@ -265,7 +265,7 @@ static inline void raw_write_seqcount_end(seqcount_t *s) 
 * usual consistency guarantee. It is one wmb cheaper, because we can

 * collapse the two back-to-back wmb()s.

 *

 * Note that, writes surrounding the barrier should be declared atomic (e.g.

 * Note that writes surrounding the barrier should be declared atomic (e.g.

 * via WRITE_ONCE): a) to ensure the writes become visible to other threads

 * atomically, avoiding compiler optimizations; b) to document which writes are

 * meant to propagate to the reader critical section. This is necessary because
@@ -465,7 +465,7 @@ static inline unsigned read_seqbegin(const seqlock_t *sl) 
{

	unsigned ret = read_seqcount_begin(&sl->seqcount);



	kcsan_atomic_next(0);  /* non-raw usage, assume closing read_seqretry */

	kcsan_atomic_next(0);  /* non-raw usage, assume closing read_seqretry() */

	kcsan_flat_atomic_begin();

	return ret;

}
@@ -473,7 +473,7 @@ static inline unsigned read_seqbegin(const seqlock_t *sl) 
static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)

{

	/*

	 * Assume not nested: read_seqretry may be called multiple times when

	 * Assume not nested: read_seqretry() may be called multiple times when

	 * completing read critical section.

	 */

	kcsan_flat_atomic_end();