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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-11 18:27:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-11 18:27:19 -0700
commit9716e57a0195dae356ae1425df121988abd27131 (patch)
tree27aab1864da1b0c51dc4c0a874e8c5c02016f0df /arch/x86
parentb1a62749946ee1956a480ba31e7d4929aa561d30 (diff)
parent37f8173dd84936ea78000ed1cad24f8b18d48ebb (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/x86')
-rw-r--r--arch/x86/include/asm/atomic.h17
-rw-r--r--arch/x86/include/asm/atomic64_32.h9
-rw-r--r--arch/x86/include/asm/atomic64_64.h15
3 files changed, 34 insertions, 7 deletions
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index 115127c7ad28..a9ae58826074 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -28,7 +28,7 @@ static __always_inline int arch_atomic_read(const atomic_t *v)
* Note for KASAN: we deliberately don't use READ_ONCE_NOCHECK() here,
* it's non-inlined function that increases binary size and stack usage.
*/
- return READ_ONCE((v)->counter);
+ return __READ_ONCE((v)->counter);
}
/**
@@ -40,7 +40,7 @@ static __always_inline int arch_atomic_read(const atomic_t *v)
*/
static __always_inline void arch_atomic_set(atomic_t *v, int i)
{
- WRITE_ONCE(v->counter, i);
+ __WRITE_ONCE(v->counter, i);
}
/**
@@ -166,6 +166,7 @@ static __always_inline int arch_atomic_add_return(int i, atomic_t *v)
{
return i + xadd(&v->counter, i);
}
+#define arch_atomic_add_return arch_atomic_add_return
/**
* arch_atomic_sub_return - subtract integer and return
@@ -178,32 +179,37 @@ static __always_inline int arch_atomic_sub_return(int i, atomic_t *v)
{
return arch_atomic_add_return(-i, v);
}
+#define arch_atomic_sub_return arch_atomic_sub_return
static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
{
return xadd(&v->counter, i);
}
+#define arch_atomic_fetch_add arch_atomic_fetch_add
static __always_inline int arch_atomic_fetch_sub(int i, atomic_t *v)
{
return xadd(&v->counter, -i);
}
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub
static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
{
return arch_cmpxchg(&v->counter, old, new);
}
+#define arch_atomic_cmpxchg arch_atomic_cmpxchg
-#define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
static __always_inline bool arch_atomic_try_cmpxchg(atomic_t *v, int *old, int new)
{
return try_cmpxchg(&v->counter, old, new);
}
+#define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
static inline int arch_atomic_xchg(atomic_t *v, int new)
{
return arch_xchg(&v->counter, new);
}
+#define arch_atomic_xchg arch_atomic_xchg
static inline void arch_atomic_and(int i, atomic_t *v)
{
@@ -221,6 +227,7 @@ static inline int arch_atomic_fetch_and(int i, atomic_t *v)
return val;
}
+#define arch_atomic_fetch_and arch_atomic_fetch_and
static inline void arch_atomic_or(int i, atomic_t *v)
{
@@ -238,6 +245,7 @@ static inline int arch_atomic_fetch_or(int i, atomic_t *v)
return val;
}
+#define arch_atomic_fetch_or arch_atomic_fetch_or
static inline void arch_atomic_xor(int i, atomic_t *v)
{
@@ -255,6 +263,7 @@ static inline int arch_atomic_fetch_xor(int i, atomic_t *v)
return val;
}
+#define arch_atomic_fetch_xor arch_atomic_fetch_xor
#ifdef CONFIG_X86_32
# include <asm/atomic64_32.h>
@@ -262,6 +271,6 @@ static inline int arch_atomic_fetch_xor(int i, atomic_t *v)
# include <asm/atomic64_64.h>
#endif
-#include <asm-generic/atomic-instrumented.h>
+#define ARCH_ATOMIC
#endif /* _ASM_X86_ATOMIC_H */
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 52cfaecb13f9..5efd01b548d1 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -75,6 +75,7 @@ static inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
{
return arch_cmpxchg64(&v->counter, o, n);
}
+#define arch_atomic64_cmpxchg arch_atomic64_cmpxchg
/**
* arch_atomic64_xchg - xchg atomic64 variable
@@ -94,6 +95,7 @@ static inline s64 arch_atomic64_xchg(atomic64_t *v, s64 n)
: "memory");
return o;
}
+#define arch_atomic64_xchg arch_atomic64_xchg
/**
* arch_atomic64_set - set atomic64 variable
@@ -138,6 +140,7 @@ static inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
+#define arch_atomic64_add_return arch_atomic64_add_return
/*
* Other variants with different arithmetic operators:
@@ -149,6 +152,7 @@ static inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
+#define arch_atomic64_sub_return arch_atomic64_sub_return
static inline s64 arch_atomic64_inc_return(atomic64_t *v)
{
@@ -242,6 +246,7 @@ static inline int arch_atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
"S" (v) : "memory");
return (int)a;
}
+#define arch_atomic64_add_unless arch_atomic64_add_unless
static inline int arch_atomic64_inc_not_zero(atomic64_t *v)
{
@@ -281,6 +286,7 @@ static inline s64 arch_atomic64_fetch_and(s64 i, atomic64_t *v)
return old;
}
+#define arch_atomic64_fetch_and arch_atomic64_fetch_and
static inline void arch_atomic64_or(s64 i, atomic64_t *v)
{
@@ -299,6 +305,7 @@ static inline s64 arch_atomic64_fetch_or(s64 i, atomic64_t *v)
return old;
}
+#define arch_atomic64_fetch_or arch_atomic64_fetch_or
static inline void arch_atomic64_xor(s64 i, atomic64_t *v)
{
@@ -317,6 +324,7 @@ static inline s64 arch_atomic64_fetch_xor(s64 i, atomic64_t *v)
return old;
}
+#define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
{
@@ -327,6 +335,7 @@ static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
return old;
}
+#define arch_atomic64_fetch_add arch_atomic64_fetch_add
#define arch_atomic64_fetch_sub(i, v) arch_atomic64_fetch_add(-(i), (v))
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 95c6ceac66b9..809bd010a751 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -19,7 +19,7 @@
*/
static inline s64 arch_atomic64_read(const atomic64_t *v)
{
- return READ_ONCE((v)->counter);
+ return __READ_ONCE((v)->counter);
}
/**
@@ -31,7 +31,7 @@ static inline s64 arch_atomic64_read(const atomic64_t *v)
*/
static inline void arch_atomic64_set(atomic64_t *v, s64 i)
{
- WRITE_ONCE(v->counter, i);
+ __WRITE_ONCE(v->counter, i);
}
/**
@@ -159,37 +159,43 @@ static __always_inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
{
return i + xadd(&v->counter, i);
}
+#define arch_atomic64_add_return arch_atomic64_add_return
static inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
{
return arch_atomic64_add_return(-i, v);
}
+#define arch_atomic64_sub_return arch_atomic64_sub_return
static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
{
return xadd(&v->counter, i);
}
+#define arch_atomic64_fetch_add arch_atomic64_fetch_add
static inline s64 arch_atomic64_fetch_sub(s64 i, atomic64_t *v)
{
return xadd(&v->counter, -i);
}
+#define arch_atomic64_fetch_sub arch_atomic64_fetch_sub
static inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new)
{
return arch_cmpxchg(&v->counter, old, new);
}
+#define arch_atomic64_cmpxchg arch_atomic64_cmpxchg
-#define arch_atomic64_try_cmpxchg arch_atomic64_try_cmpxchg
static __always_inline bool arch_atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new)
{
return try_cmpxchg(&v->counter, old, new);
}
+#define arch_atomic64_try_cmpxchg arch_atomic64_try_cmpxchg
static inline s64 arch_atomic64_xchg(atomic64_t *v, s64 new)
{
return arch_xchg(&v->counter, new);
}
+#define arch_atomic64_xchg arch_atomic64_xchg
static inline void arch_atomic64_and(s64 i, atomic64_t *v)
{
@@ -207,6 +213,7 @@ static inline s64 arch_atomic64_fetch_and(s64 i, atomic64_t *v)
} while (!arch_atomic64_try_cmpxchg(v, &val, val & i));
return val;
}
+#define arch_atomic64_fetch_and arch_atomic64_fetch_and
static inline void arch_atomic64_or(s64 i, atomic64_t *v)
{
@@ -224,6 +231,7 @@ static inline s64 arch_atomic64_fetch_or(s64 i, atomic64_t *v)
} while (!arch_atomic64_try_cmpxchg(v, &val, val | i));
return val;
}
+#define arch_atomic64_fetch_or arch_atomic64_fetch_or
static inline void arch_atomic64_xor(s64 i, atomic64_t *v)
{
@@ -241,5 +249,6 @@ static inline s64 arch_atomic64_fetch_xor(s64 i, atomic64_t *v)
} while (!arch_atomic64_try_cmpxchg(v, &val, val ^ i));
return val;
}
+#define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
#endif /* _ASM_X86_ATOMIC64_64_H */