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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 /scripts/atomic/fallbacks/inc_not_zero
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 'scripts/atomic/fallbacks/inc_not_zero')
-rwxr-xr-xscripts/atomic/fallbacks/inc_not_zero8
1 files changed, 4 insertions, 4 deletions
diff --git a/scripts/atomic/fallbacks/inc_not_zero b/scripts/atomic/fallbacks/inc_not_zero
index a7c45c8d107c..50f2d4d48279 100755
--- a/scripts/atomic/fallbacks/inc_not_zero
+++ b/scripts/atomic/fallbacks/inc_not_zero
@@ -1,14 +1,14 @@
cat <<EOF
/**
- * ${atomic}_inc_not_zero - increment unless the number is zero
+ * ${arch}${atomic}_inc_not_zero - increment unless the number is zero
* @v: pointer of type ${atomic}_t
*
* Atomically increments @v by 1, if @v is non-zero.
* Returns true if the increment was done.
*/
-static inline bool
-${atomic}_inc_not_zero(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_inc_not_zero(${atomic}_t *v)
{
- return ${atomic}_add_unless(v, 1, 0);
+ return ${arch}${atomic}_add_unless(v, 1, 0);
}
EOF