Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and misc x86 updates from Ingo Molnar:
"Lots of changes in this cycle - in part because locking/core attracted
a number of related x86 low level work which was easier to handle in a
single tree:
- Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E.
McKenney, Andrea Parri)
- lockdep scalability improvements and micro-optimizations (Waiman
Long)
- rwsem improvements (Waiman Long)
- spinlock micro-optimization (Matthew Wilcox)
- qspinlocks: Provide a liveness guarantee (more fairness) on x86.
(Peter Zijlstra)
- Add support for relative references in jump tables on arm64, x86
and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens)
- Be a lot less permissive on weird (kernel address) uaccess faults
on x86: BUG() when uaccess helpers fault on kernel addresses (Jann
Horn)
- macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav
Amit)
- ... and a handful of other smaller changes as well"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
locking/lockdep: Make global debug_locks* variables read-mostly
locking/lockdep: Fix debug_locks off performance problem
locking/pvqspinlock: Extend node size when pvqspinlock is configured
locking/qspinlock_stat: Count instances of nested lock slowpaths
locking/qspinlock, x86: Provide liveness guarantee
x86/asm: 'Simplify' GEN_*_RMWcc() macros
locking/qspinlock: Rework some comments
locking/qspinlock: Re-order code
locking/lockdep: Remove duplicated 'lock_class_ops' percpu array
x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y
futex: Replace spin_is_locked() with lockdep
locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y
x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs
x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs
x86/extable: Macrofy inline assembly code to work around GCC inlining bugs
x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops
x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs
x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs
x86/refcount: Work around GCC inlining bug
x86/objtool: Use asm macros to work around GCC inlining bugs
...
This commit is contained in:
@@ -14,41 +14,33 @@
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* We use a brcl 0,2 instruction for jump labels at compile time so it
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* can be easily distinguished from a hotpatch generated instruction.
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*/
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static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
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static inline bool arch_static_branch(struct static_key *key, bool branch)
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{
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asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
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".pushsection __jump_table, \"aw\"\n"
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".balign 8\n"
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".quad 0b, %l[label], %0\n"
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".popsection\n"
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: : "X" (&((char *)key)[branch]) : : label);
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asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
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".pushsection __jump_table,\"aw\"\n"
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".balign 8\n"
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".long 0b-.,%l[label]-.\n"
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".quad %0-.\n"
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".popsection\n"
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: : "X" (&((char *)key)[branch]) : : label);
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return false;
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label:
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return true;
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}
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static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
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static inline bool arch_static_branch_jump(struct static_key *key, bool branch)
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{
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asm_volatile_goto("0: brcl 15, %l[label]\n"
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".pushsection __jump_table, \"aw\"\n"
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".balign 8\n"
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".quad 0b, %l[label], %0\n"
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".popsection\n"
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: : "X" (&((char *)key)[branch]) : : label);
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asm_volatile_goto("0: brcl 15,%l[label]\n"
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".pushsection __jump_table,\"aw\"\n"
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".balign 8\n"
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".long 0b-.,%l[label]-.\n"
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".quad %0-.\n"
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".popsection\n"
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: : "X" (&((char *)key)[branch]) : : label);
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return false;
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label:
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return true;
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}
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typedef unsigned long jump_label_t;
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struct jump_entry {
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jump_label_t code;
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jump_label_t target;
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jump_label_t key;
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};
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#endif /* __ASSEMBLY__ */
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#endif
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