Linus Torvalds 9716e57a01 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_*. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl7imyETHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoT0wEACcI3mDiK/9hNlfnobIJTup1E8erUdY /EZX8yFc/FgpSSKAMROu3kswZ+rSWmBEyzTJLEtBAaYU6haAuGx77AugoDHfVkYi +CEJvVEpeK7fzsgu9aTb/5B6EDUo/P1fzTFjVTK1I9M9KrGLxbkGRZWYUeX3KRZd RskRJMbp9L4oiNJNAuIP6QKoJ7PK/sL16e8oVZSQR6WW9ZH4uDZbyfl5z0xLjI7u PIsFCoDu7/ig2wpOhtAYRVsL8C6EQ8mSeEUMKeM7A7UFAkVadYB8PTmEJ/QcixW+ 5R0+cnQE/3I/n0KRwfz/7p2gzILJk/cY6XJWVoAsQb990MD2ahjZJPYI4jdknjz6 8bL/QjBq+pZwbHWOhy+IdUntIYGkyjfLKoPLdSoh+uK1kl8Jsg+AlB2lN469BV1D r0NltiCLggvtqXEDLV4YZqxie6H38gvOzPDbH8I6M34+WkOI2sM0D1P/Naqw/Wgl M1Ygx4wYG8X4zDESAYMy9tSXh5lGDIjiF6sjGTOPYWwUIeRlINfWeJkiXKnYNwv/ qTiC8ciCxhlQcDifdyfQjT3mHNcP7YpVKp317TCtU4+WxMSrW1h2SL6m6j74dNI/ P7/J6GKONeLRbt0ZQbQGjqHxSuu6kqUEu69aVs5W9+WjNEoJW1EW4vrJ3TeF5jLh 0Srl4VsyDwzuXw== =Jkzv -----END PGP SIGNATURE----- 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		2020-06-11 18:27:19 -07:00
..
asm	Peter Zijlstras rework of atomics and fallbacks. This solves two problems:	2020-06-11 18:27:19 -07:00
uapi/asm	ARM:	2020-06-03 15:13:47 -07:00