forked from luck/tmp_suning_uos_patched
9716e57a01
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-----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=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
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.