From 62e8a3258bda118f24ff462fe04cfbe75b8189b5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 18 Sep 2015 11:13:10 +0200 Subject: atomic, arch: Audit atomic_{read,set}() This patch makes sure that atomic_{read,set}() are at least {READ,WRITE}_ONCE(). We already had the 'requirement' that atomic_read() should use ACCESS_ONCE(), and most archs had this, but a few were lacking. All are now converted to use READ_ONCE(). And, by a symmetry and general paranoia argument, upgrade atomic_set() to use WRITE_ONCE(). Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Dmitry Vyukov Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: james.hogan@imgtec.com Cc: linux-kernel@vger.kernel.org Cc: oleg@redhat.com Cc: will.deacon@arm.com Signed-off-by: Ingo Molnar diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index e8c9560..572b228 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -17,11 +17,11 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic64_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic64_read(v) READ_ONCE((v)->counter) -#define atomic_set(v,i) ((v)->counter = (i)) -#define atomic64_set(v,i) ((v)->counter = (i)) +#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) +#define atomic64_set(v,i) WRITE_ONCE((v)->counter, (i)) /* * To get proper branch prediction for the main line, we must branch diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index c3ecda0..7730d30 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -17,11 +17,11 @@ #include #include -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) #ifdef CONFIG_ARC_HAS_LLSC -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #ifdef CONFIG_ARC_STAR_9000923308 @@ -107,7 +107,7 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ #ifndef CONFIG_SMP /* violating atomic_xxx API locking protocol in UP for optimization sake */ -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #else @@ -125,7 +125,7 @@ static inline void atomic_set(atomic_t *v, int i) unsigned long flags; atomic_ops_lock(flags); - v->counter = i; + WRITE_ONCE(v->counter, i); atomic_ops_unlock(flags); } diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index fe3ef39..2bf80af 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -27,8 +27,8 @@ * strex/ldrex monitor on some implementations. The reason we can use it for * atomic_set() is the clrex or dummy strex done on every exception return. */ -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v,i) (((v)->counter) = (i)) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i)) #if __LINUX_ARM_ARCH__ >= 6 diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 35a6778..1e247ac 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -54,7 +54,7 @@ #define ATOMIC_INIT(i) { (i) } #define atomic_read(v) READ_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #define atomic_xchg(v, new) xchg(&((v)->counter), (new)) #define atomic_cmpxchg(v, old, new) cmpxchg(&((v)->counter), (old), (new)) diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h index 97c9bdf..d74fd8c 100644 --- a/arch/avr32/include/asm/atomic.h +++ b/arch/avr32/include/asm/atomic.h @@ -19,8 +19,8 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = i) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #define ATOMIC_OP_RETURN(op, asm_op, asm_con) \ static inline int __atomic_##op##_return(int i, atomic_t *v) \ diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h index 0da689d..64f02d4 100644 --- a/arch/frv/include/asm/atomic.h +++ b/arch/frv/include/asm/atomic.h @@ -32,8 +32,8 @@ */ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) static inline int atomic_inc_return(atomic_t *v) { diff --git a/arch/h8300/include/asm/atomic.h b/arch/h8300/include/asm/atomic.h index 702ee53..4435a44 100644 --- a/arch/h8300/include/asm/atomic.h +++ b/arch/h8300/include/asm/atomic.h @@ -11,8 +11,8 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = i) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #include diff --git a/arch/hexagon/include/asm/atomic.h b/arch/hexagon/include/asm/atomic.h index 811d61f..55696c4 100644 --- a/arch/hexagon/include/asm/atomic.h +++ b/arch/hexagon/include/asm/atomic.h @@ -48,7 +48,7 @@ static inline void atomic_set(atomic_t *v, int new) * * Assumes all word reads on our architecture are atomic. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) /** * atomic_xchg - atomic diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h index be4beeb..8dfb5f6 100644 --- a/arch/ia64/include/asm/atomic.h +++ b/arch/ia64/include/asm/atomic.h @@ -21,11 +21,11 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic64_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic64_read(v) READ_ONCE((v)->counter) -#define atomic_set(v,i) (((v)->counter) = (i)) -#define atomic64_set(v,i) (((v)->counter) = (i)) +#define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i)) +#define atomic64_set(v,i) WRITE_ONCE(((v)->counter), (i)) #define ATOMIC_OP(op, c_op) \ static __inline__ int \ diff --git a/arch/m32r/include/asm/atomic.h b/arch/m32r/include/asm/atomic.h index 025e2a1..ea35160 100644 --- a/arch/m32r/include/asm/atomic.h +++ b/arch/m32r/include/asm/atomic.h @@ -28,7 +28,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) /** * atomic_set - set atomic variable @@ -37,7 +37,7 @@ * * Atomically sets the value of @v to @i. */ -#define atomic_set(v,i) (((v)->counter) = (i)) +#define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i)) #ifdef CONFIG_CHIP_M32700_TS1 #define __ATOMIC_CLOBBER , "r4" diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h index 039fac1..4858178 100644 --- a/arch/m68k/include/asm/atomic.h +++ b/arch/m68k/include/asm/atomic.h @@ -17,8 +17,8 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = i) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) /* * The ColdFire parts cannot do some immediate to memory operations, diff --git a/arch/metag/include/asm/atomic_lnkget.h b/arch/metag/include/asm/atomic_lnkget.h index 21c4c26..a625818 100644 --- a/arch/metag/include/asm/atomic_lnkget.h +++ b/arch/metag/include/asm/atomic_lnkget.h @@ -3,7 +3,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_set(v, i) ((v)->counter = (i)) +#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i)) #include diff --git a/arch/metag/include/asm/atomic_lock1.h b/arch/metag/include/asm/atomic_lock1.h index f8efe38..0295d9b 100644 --- a/arch/metag/include/asm/atomic_lock1.h +++ b/arch/metag/include/asm/atomic_lock1.h @@ -10,7 +10,7 @@ static inline int atomic_read(const atomic_t *v) { - return (v)->counter; + return READ_ONCE((v)->counter); } /* diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 4c42fd9..f82d3af 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -30,7 +30,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) /* * atomic_set - set atomic variable @@ -39,7 +39,7 @@ * * Atomically sets the value of @v to @i. */ -#define atomic_set(v, i) ((v)->counter = (i)) +#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i)) #define ATOMIC_OP(op, c_op, asm_op) \ static __inline__ void atomic_##op(int i, atomic_t * v) \ @@ -315,14 +315,14 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) * @v: pointer of type atomic64_t * */ -#define atomic64_read(v) ACCESS_ONCE((v)->counter) +#define atomic64_read(v) READ_ONCE((v)->counter) /* * atomic64_set - set atomic variable * @v: pointer of type atomic64_t * @i: required value */ -#define atomic64_set(v, i) ((v)->counter = (i)) +#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i)) #define ATOMIC64_OP(op, c_op, asm_op) \ static __inline__ void atomic64_##op(long i, atomic64_t * v) \ diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h index 375e591..ce318d5 100644 --- a/arch/mn10300/include/asm/atomic.h +++ b/arch/mn10300/include/asm/atomic.h @@ -34,7 +34,7 @@ * * Atomically reads the value of @v. Note that the guaranteed */ -#define atomic_read(v) (ACCESS_ONCE((v)->counter)) +#define atomic_read(v) READ_ONCE((v)->counter) /** * atomic_set - set atomic variable @@ -43,7 +43,7 @@ * * Atomically sets the value of @v to @i. Note that the guaranteed */ -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #define ATOMIC_OP(op) \ static inline void atomic_##op(int i, atomic_t *v) \ diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index 2536965..1d10999 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -67,7 +67,7 @@ static __inline__ void atomic_set(atomic_t *v, int i) static __inline__ int atomic_read(const atomic_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } /* exported interface */ diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h index 05b9f74..c399e1c 100644 --- a/arch/sh/include/asm/atomic.h +++ b/arch/sh/include/asm/atomic.h @@ -14,8 +14,8 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic_set(v,i) ((v)->counter = (i)) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) #if defined(CONFIG_GUSA_RB) #include diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h index 917084a..f2fbf9e 100644 --- a/arch/sparc/include/asm/atomic_64.h +++ b/arch/sparc/include/asm/atomic_64.h @@ -14,11 +14,11 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) ACCESS_ONCE((v)->counter) -#define atomic64_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) +#define atomic64_read(v) READ_ONCE((v)->counter) -#define atomic_set(v, i) (((v)->counter) = i) -#define atomic64_set(v, i) (((v)->counter) = i) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) +#define atomic64_set(v, i) WRITE_ONCE(((v)->counter), (i)) #define ATOMIC_OP(op) \ void atomic_##op(int, atomic_t *); \ diff --git a/arch/tile/include/asm/atomic.h b/arch/tile/include/asm/atomic.h index 7097984..9fc0107 100644 --- a/arch/tile/include/asm/atomic.h +++ b/arch/tile/include/asm/atomic.h @@ -34,7 +34,7 @@ */ static inline int atomic_read(const atomic_t *v) { - return ACCESS_ONCE(v->counter); + return READ_ONCE(v->counter); } /** diff --git a/arch/tile/include/asm/atomic_64.h b/arch/tile/include/asm/atomic_64.h index 096a56d..51cabc2 100644 --- a/arch/tile/include/asm/atomic_64.h +++ b/arch/tile/include/asm/atomic_64.h @@ -24,7 +24,7 @@ /* First, the 32-bit atomic ops that are "real" on our 64-bit platform. */ -#define atomic_set(v, i) ((v)->counter = (i)) +#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i)) /* * The smp_mb() operations throughout are to support the fact that @@ -82,8 +82,8 @@ static inline void atomic_xor(int i, atomic_t *v) #define ATOMIC64_INIT(i) { (i) } -#define atomic64_read(v) ((v)->counter) -#define atomic64_set(v, i) ((v)->counter = (i)) +#define atomic64_read(v) READ_ONCE((v)->counter) +#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i)) static inline void atomic64_add(long i, atomic64_t *v) { diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index fb52aa6..ae5fb83 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -24,7 +24,7 @@ */ static __always_inline int atomic_read(const atomic_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } /** @@ -36,7 +36,7 @@ static __always_inline int atomic_read(const atomic_t *v) */ static __always_inline void atomic_set(atomic_t *v, int i) { - v->counter = i; + WRITE_ONCE(v->counter, i); } /** diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h index 50e33ef..0373510 100644 --- a/arch/x86/include/asm/atomic64_64.h +++ b/arch/x86/include/asm/atomic64_64.h @@ -18,7 +18,7 @@ */ static inline long atomic64_read(const atomic64_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } /** @@ -30,7 +30,7 @@ static inline long atomic64_read(const atomic64_t *v) */ static inline void atomic64_set(atomic64_t *v, long i) { - v->counter = i; + WRITE_ONCE(v->counter, i); } /** diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h index 93795d0..fd8017c 100644 --- a/arch/xtensa/include/asm/atomic.h +++ b/arch/xtensa/include/asm/atomic.h @@ -47,7 +47,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) /** * atomic_set - set atomic variable @@ -56,7 +56,7 @@ * * Atomically sets the value of @v to @i. */ -#define atomic_set(v,i) ((v)->counter = (i)) +#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) #if XCHAL_HAVE_S32C1I #define ATOMIC_OP(op) \ diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index d4d7e33..74f1a37 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -127,7 +127,7 @@ ATOMIC_OP(xor, ^) * Atomically reads the value of @v. */ #ifndef atomic_read -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) #endif /** @@ -137,7 +137,7 @@ ATOMIC_OP(xor, ^) * * Atomically sets the value of @v to @i. */ -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #include -- cgit v0.10.2