diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-11 18:27:19 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-11 18:27:19 -0700 |
commit | 9716e57a0195dae356ae1425df121988abd27131 (patch) | |
tree | 27aab1864da1b0c51dc4c0a874e8c5c02016f0df /arch/arm64 | |
parent | b1a62749946ee1956a480ba31e7d4929aa561d30 (diff) | |
parent | 37f8173dd84936ea78000ed1cad24f8b18d48ebb (diff) |
Merge tag 'locking-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull atomics rework from Thomas Gleixner:
"Peter Zijlstras rework of atomics and fallbacks. This solves two
problems:
1) Compilers uninline small atomic_* static inline functions which
can expose them to instrumentation.
2) The instrumentation of atomic primitives was done at the
architecture level while composites or fallbacks were provided at
the generic level. As a result there are no uninstrumented
variants of the fallbacks.
Both issues were in the way of fully isolating fragile entry code
pathes and especially the text poke int3 handler which is prone to an
endless recursion problem when anything in that code path is about to
be instrumented. This was always a problem, but got elevated due to
the new batch mode updates of tracing.
The solution is to mark the functions __always_inline and to flip the
fallback and instrumentation so the non-instrumented variants are at
the architecture level and the instrumentation is done in generic
code.
The latter introduces another fallback variant which will go away once
all architectures have been moved over to arch_atomic_*"
* tag 'locking-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/atomics: Flip fallbacks and instrumentation
asm-generic/atomic: Use __always_inline for fallback wrappers
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/include/asm/atomic.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 9543b5e0534d..a08890da696c 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -101,8 +101,8 @@ static inline long arch_atomic64_dec_if_positive(atomic64_t *v) #define ATOMIC_INIT(i) { (i) } -#define arch_atomic_read(v) READ_ONCE((v)->counter) -#define arch_atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) +#define arch_atomic_read(v) __READ_ONCE((v)->counter) +#define arch_atomic_set(v, i) __WRITE_ONCE(((v)->counter), (i)) #define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed #define arch_atomic_add_return_acquire arch_atomic_add_return_acquire @@ -225,6 +225,6 @@ static inline long arch_atomic64_dec_if_positive(atomic64_t *v) #define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive -#include <asm-generic/atomic-instrumented.h> +#define ARCH_ATOMIC #endif /* __ASM_ATOMIC_H */ |