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2019-05-06Merge tag 's390-5.2-1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: - Support for kernel address space layout randomization - Add support for kernel image signature verification - Convert s390 to the generic get_user_pages_fast code - Convert s390 to the stack unwind API analog to x86 - Add support for CPU directed interrupts for PCI devices - Provide support for MIO instructions to the PCI base layer, this will allow the use of direct PCI mappings in user space code - Add the basic KVM guest ultravisor interface for protected VMs - Add AT_HWCAP bits for several new hardware capabilities - Update the CPU measurement facility counter definitions to SVN 6 - Arnds cleanup patches for his quest to get LLVM compiles working - A vfio-ccw update with bug fixes and support for halt and clear - Improvements for the hardware TRNG code - Another round of cleanup for the QDIO layer - Numerous cleanups and bug fixes * tag 's390-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (98 commits) s390/vdso: drop unnecessary cc-ldoption s390: fix clang -Wpointer-sign warnigns in boot code s390: drop CONFIG_VIRT_TO_BUS s390: boot, purgatory: pass $(CLANG_FLAGS) where needed s390: only build for new CPUs with clang s390: simplify disabled_wait s390/ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR s390/unwind: introduce stack unwind API s390/opcodes: add missing instructions to the disassembler s390/bug: add entry size to the __bug_table section s390: use proper expoline sections for .dma code s390/nospec: rename assembler generated expoline thunks s390: add missing ENDPROC statements to assembler functions locking/lockdep: check for freed initmem in static_obj() s390/kernel: add support for kernel address space layout randomization (KASLR) s390/kernel: introduce .dma sections s390/sclp: do not use static sccbs s390/kprobes: use static buffer for insn_page s390/kernel: convert SYSCALL and PGM_CHECK handlers to .quad s390/kernel: build a relocatable kernel ...
2019-05-06Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-84/+183
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Here are the locking changes in this cycle: - rwsem unification and simpler micro-optimizations to prepare for more intrusive (and more lucrative) scalability improvements in v5.3 (Waiman Long) - Lockdep irq state tracking flag usage cleanups (Frederic Weisbecker) - static key improvements (Jakub Kicinski, Peter Zijlstra) - misc updates, cleanups and smaller fixes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) locking/lockdep: Remove unnecessary unlikely() locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred() locking/static_key: Factor out the fast path of static_key_slow_dec() locking/static_key: Add support for deferred static branches locking/lockdep: Test all incompatible scenarios at once in check_irq_usage() locking/lockdep: Avoid bogus Clang warning locking/lockdep: Generate LOCKF_ bit composites locking/lockdep: Use expanded masks on find_usage_*() functions locking/lockdep: Map remaining magic numbers to lock usage mask names locking/lockdep: Move valid_state() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING locking/rwsem: Prevent unneeded warning during locking selftest locking/rwsem: Optimize rwsem structure for uncontended lock acquisition locking/rwsem: Enable lock event counting locking/lock_events: Don't show pvqspinlock events on bare metal locking/lock_events: Make lock_events available for all archs & other locks locking/qspinlock_stat: Introduce generic lockevent_*() counting APIs locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro locking/rwsem: Add debug check for __down_read*() locking/rwsem: Micro-optimize rwsem_try_read_lock_unqueued() locking/rwsem: Move rwsem internal function declarations to rwsem-xadd.h ...
2019-05-06Merge branch 'core-stacktrace-for-linus' of ↵Linus Torvalds1-49/+38
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull stack trace updates from Ingo Molnar: "So Thomas looked at the stacktrace code recently and noticed a few weirdnesses, and we all know how such stories of crummy kernel code meeting German engineering perfection end: a 45-patch series to clean it all up! :-) Here's the changes in Thomas's words: 'Struct stack_trace is a sinkhole for input and output parameters which is largely pointless for most usage sites. In fact if embedded into other data structures it creates indirections and extra storage overhead for no benefit. Looking at all usage sites makes it clear that they just require an interface which is based on a storage array. That array is either on stack, global or embedded into some other data structure. Some of the stack depot usage sites are outright wrong, but fortunately the wrongness just causes more stack being used for nothing and does not have functional impact. Another oddity is the inconsistent termination of the stack trace with ULONG_MAX. It's pointless as the number of entries is what determines the length of the stored trace. In fact quite some call sites remove the ULONG_MAX marker afterwards with or without nasty comments about it. Not all architectures do that and those which do, do it inconsistenly either conditional on nr_entries == 0 or unconditionally. The following series cleans that up by: 1) Removing the ULONG_MAX termination in the architecture code 2) Removing the ULONG_MAX fixups at the call sites 3) Providing plain storage array based interfaces for stacktrace and stackdepot. 4) Cleaning up the mess at the callsites including some related cleanups. 5) Removing the struct stack_trace based interfaces This is not changing the struct stack_trace interfaces at the architecture level, but it removes the exposure to the generic code'" * 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) x86/stacktrace: Use common infrastructure stacktrace: Provide common infrastructure lib/stackdepot: Remove obsolete functions stacktrace: Remove obsolete functions livepatch: Simplify stack trace retrieval tracing: Remove the last struct stack_trace usage tracing: Simplify stack trace retrieval tracing: Make ftrace_trace_userstack() static and conditional tracing: Use percpu stack trace buffer more intelligently tracing: Simplify stacktrace retrieval in histograms lockdep: Simplify stack trace handling lockdep: Remove save argument from check_prev_add() lockdep: Remove unused trace argument from print_circular_bug() drm: Simplify stacktrace handling dm persistent data: Simplify stack trace handling dm bufio: Simplify stack trace retrieval btrfs: ref-verify: Simplify stack trace retrieval dma/debug: Simplify stracktrace retrieval fault-inject: Simplify stacktrace retrieval mm/page_owner: Simplify stack trace handling ...
2019-04-29locking/lockdep: Remove unnecessary unlikely()zhengbin1-1/+1
DEBUG_LOCKS_WARN_ON() already contains an unlikely(), there is no need for another one. Signed-off-by: zhengbin <zhengbin13@huawei.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: houtao1@huawei.com Link: http://lkml.kernel.org/r/1556540791-23110-1-git-send-email-zhengbin13@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-29lockdep: Simplify stack trace handlingThomas Gleixner1-27/+28
Replace the indirection through struct stack_trace by using the storage array based interfaces and storing the information is a small lockdep specific data structure. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Potapenko <glider@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: linux-mm@kvack.org Cc: David Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy <robin.murphy@arm.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: David Sterba <dsterba@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: dri-devel@lists.freedesktop.org Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.891724020@linutronix.de
2019-04-29lockdep: Remove save argument from check_prev_add()Thomas Gleixner1-8/+8
There is only one caller which hands in save_trace as function pointer. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Potapenko <glider@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: linux-mm@kvack.org Cc: David Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy <robin.murphy@arm.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: David Sterba <dsterba@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: dri-devel@lists.freedesktop.org Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.803362058@linutronix.de
2019-04-29lockdep: Remove unused trace argument from print_circular_bug()Thomas Gleixner1-5/+4
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Potapenko <glider@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: linux-mm@kvack.org Cc: David Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy <robin.murphy@arm.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: David Sterba <dsterba@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: dri-devel@lists.freedesktop.org Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094802.716274532@linutronix.de
2019-04-29locking/lockdep: check for freed initmem in static_obj()Gerald Schaefer1-0/+3
The following warning occurred on s390: WARNING: CPU: 0 PID: 804 at kernel/locking/lockdep.c:1025 lockdep_register_key+0x30/0x150 This is because the check in static_obj() assumes that all memory within [_stext, _end] belongs to static objects, which at least for s390 isn't true. The init section is also part of this range, and freeing it allows the buddy allocator to allocate memory from it. We have virt == phys for the kernel on s390, so that such allocations would then have addresses within the range [_stext, _end]. To fix this, introduce arch_is_kernel_initmem_freed(), similar to arch_is_kernel_text/data(), and add it to the checks in static_obj(). This will always return 0 on architectures that do not define arch_is_kernel_initmem_freed. On s390, it will return 1 if initmem has been freed and the address is in the range [__init_begin, __init_end]. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29locking/lockdep: Test all incompatible scenarios at once in check_irq_usage()Frederic Weisbecker1-67/+161
check_prev_add_irq() tests all incompatible scenarios one after the other while adding a lock (@next) to a tree dependency (@prev): LOCK_USED_IN_HARDIRQ vs LOCK_ENABLED_HARDIRQ LOCK_USED_IN_HARDIRQ_READ vs LOCK_ENABLED_HARDIRQ LOCK_USED_IN_SOFTIRQ vs LOCK_ENABLED_SOFTIRQ LOCK_USED_IN_SOFTIRQ_READ vs LOCK_ENABLED_SOFTIRQ Also for these four scenarios, we must at least iterate the @prev backward dependency. Then if it matches the relevant LOCK_USED_* bit, we must also iterate the @next forward dependency. Therefore in the best case we iterate 4 times, in the worst case 8 times. A different approach can let us divide the number of branch iterations by 4: 1) Iterate through @prev backward dependencies and accumulate all the IRQ uses in a single mask. In the best case where the current lock hasn't been used in IRQ, we stop here. 2) Iterate through @next forward dependencies and try to find a lock whose usage is exclusive to the accumulated usages gathered in the previous step. If we find one (call it @lockA), we have found an incompatible use, otherwise we stop here. Only bad locking scenario go further. So a sane verification stop here. 3) Iterate again through @prev backward dependency and find the lock whose usage matches @lockA in term of incompatibility. Call that lock @lockB. 4) Report the incompatible usages of @lockA and @lockB If no incompatible use is found, the verification never goes beyond step 2 which means at most two iterations. The following compares the execution measurements of the function check_prev_add_irq(): Number of calls | Avg (ns) | Stdev (ns) | Total time (ns) ------------------------------------------------------------------------ Mainline 8452 | 2652 | 11962 | 22415143 This patch 8452 | 1518 | 7090 | 12835602 Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190402160244.32434-5-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-18locking/lockdep: Use expanded masks on find_usage_*() functionsFrederic Weisbecker1-10/+10
In order to optimize check_irq_usage() and factorize all the IRQ usage validations we'll need to be able to check multiple lock usage bits at once. Prepare the low level usage mask check functions for that purpose. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190402160244.32434-4-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-18locking/lockdep: Map remaining magic numbers to lock usage mask namesFrederic Weisbecker1-4/+7
Clarify the code with mapping some more constant numbers that haven't been named after their corresponding LOCK_USAGE_* symbol. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190402160244.32434-3-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-18locking/lockdep: Move valid_state() inside CONFIG_TRACE_IRQFLAGS && ↵Frederic Weisbecker1-4/+6
CONFIG_PROVE_LOCKING valid_state() and print_usage_bug*() functions are not used beyond irq locking correctness checks under CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING. Sadly the "unused function" warning wouldn't fire because valid_state() is inline so the unused case has remained unseen until now. So move them inside the appropriate CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING section. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190402160244.32434-2-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-16locking/lockdep: Make lockdep_unregister_key() honor 'debug_locks' againBart Van Assche1-4/+5
If lockdep_register_key() and lockdep_unregister_key() are called with debug_locks == false then the following warning is reported: WARNING: CPU: 2 PID: 15145 at kernel/locking/lockdep.c:4920 lockdep_unregister_key+0x1ad/0x240 That warning is reported because lockdep_unregister_key() ignores the value of 'debug_locks' and because the behavior of lockdep_register_key() depends on whether or not 'debug_locks' is set. Fix this inconsistency by making lockdep_unregister_key() take 'debug_locks' again into account. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: shenghui <shhuiw@foxmail.com> Fixes: 90c1cba2b3b3 ("locking/lockdep: Zap lock classes even with lock debugging disabled") Link: http://lkml.kernel.org/r/20190415170538.23491-1-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-14lockdep: Remove the ULONG_MAX stack trace hackeryThomas Gleixner1-11/+0
No architecture terminates the stack trace with ULONG_MAX anymore. Remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Potapenko <glider@google.com> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190410103644.485737321@linutronix.de
2019-04-10locking/lockdep: Zap lock classes even with lock debugging disabledBart Van Assche1-17/+12
The following commit: a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use") changed the behavior of lockdep_free_key_range() from unconditionally zapping lock classes into only zapping lock classes if debug_lock == true. Not zapping lock classes if debug_lock == false leaves dangling pointers in several lockdep datastructures, e.g. lock_class::name in the all_lock_classes list. The shell command "cat /proc/lockdep" causes the kernel to iterate the all_lock_classes list. Hence the "unable to handle kernel paging request" cash that Shenghui encountered by running cat /proc/lockdep. Since the new behavior can cause cat /proc/lockdep to crash, restore the pre-v5.1 behavior. This patch avoids that cat /proc/lockdep triggers the following crash with debug_lock == false: BUG: unable to handle kernel paging request at fffffbfff40ca448 RIP: 0010:__asan_load1+0x28/0x50 Call Trace: string+0xac/0x180 vsnprintf+0x23e/0x820 seq_vprintf+0x82/0xc0 seq_printf+0x92/0xb0 print_name+0x34/0xb0 l_show+0x184/0x200 seq_read+0x59e/0x6c0 proc_reg_read+0x11f/0x170 __vfs_read+0x4d/0x90 vfs_read+0xc5/0x1f0 ksys_read+0xab/0x130 __x64_sys_read+0x43/0x50 do_syscall_64+0x71/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: shenghui <shhuiw@foxmail.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Fixes: a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use") # v5.1-rc1. Link: https://lkml.kernel.org/r/20190403233552.124673-1-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-09locking/lockdep: Only call init_rcu_head() after RCU has been initializedBart Van Assche1-4/+11
init_data_structures_once() is called for the first time before RCU has been initialized. Make sure that init_rcu_head() is called before the RCU head is used and after RCU has been initialized. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: longman@redhat.com Link: https://lkml.kernel.org/r/c20aa0f0-42ab-a884-d931-7d4ec2bf0cdc@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-09locking/lockdep: Avoid a Clang warningArnd Bergmann1-1/+3
Clang warns about a tentative array definition without a length: kernel/locking/lockdep.c:845:12: error: tentative array definition assumed to have one element [-Werror] There is no real reason to do this here, so just set the same length as in the real definition later in the same file. It has to be hidden in an #ifdef or annotated __maybe_unused though, to avoid the unused-variable warning if CONFIG_PROVE_LOCKING is disabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190307075222.3424524-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-06Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Lots of tooling updates - too many to list, here's a few highlights: - Various subcommand updates to 'perf trace', 'perf report', 'perf record', 'perf annotate', 'perf script', 'perf test', etc. - CPU and NUMA topology and affinity handling improvements, - HW tracing and HW support updates: - Intel PT updates - ARM CoreSight updates - vendor HW event updates - BPF updates - Tons of infrastructure updates, both on the build system and the library support side - Documentation updates. - ... and lots of other changes, see the changelog for details. Kernel side updates: - Tighten up kprobes blacklist handling, reduce the number of places where developers can install a kprobe and hang/crash the system. - Fix/enhance vma address filter handling. - Various PMU driver updates, small fixes and additions. - refcount_t conversions - BPF updates - error code propagation enhancements - misc other changes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (238 commits) perf script python: Add Python3 support to syscall-counts-by-pid.py perf script python: Add Python3 support to syscall-counts.py perf script python: Add Python3 support to stat-cpi.py perf script python: Add Python3 support to stackcollapse.py perf script python: Add Python3 support to sctop.py perf script python: Add Python3 support to powerpc-hcalls.py perf script python: Add Python3 support to net_dropmonitor.py perf script python: Add Python3 support to mem-phys-addr.py perf script python: Add Python3 support to failed-syscalls-by-pid.py perf script python: Add Python3 support to netdev-times.py perf tools: Add perf_exe() helper to find perf binary perf script: Handle missing fields with -F +.. perf data: Add perf_data__open_dir_data function perf data: Add perf_data__(create_dir|close_dir) functions perf data: Fail check_backup in case of error perf data: Make check_backup work over directories perf tools: Add rm_rf_perf_data function perf tools: Add pattern name checking to rm_rf perf tools: Add depth checking to rm_rf perf data: Add global path holder ...
2019-02-28locking/lockdep: Add module_param to enable consistency checksPeter Zijlstra1-13/+33
And move the whole lot under CONFIG_DEBUG_LOCKDEP. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Add support for dynamic keysBart Van Assche1-8/+113
A shortcoming of the current lockdep implementation is that it requires lock keys to be allocated statically. That forces all instances of lock objects that occur in a given data structure to share a lock key. Since lock dependency analysis groups lock objects per key sharing lock keys can cause false positive lockdep reports. Make it possible to avoid such false positive reports by allowing lock keys to be allocated dynamically. Require that dynamically allocated lock keys are registered before use by calling lockdep_register_key(). Complain about attempts to register the same lock key pointer twice without calling lockdep_unregister_key() between successive registration calls. The purpose of the new lock_keys_hash[] data structure that keeps track of all dynamic keys is twofold: - Verify whether the lockdep_register_key() and lockdep_unregister_key() functions are used correctly. - Avoid that lockdep_init_map() complains when encountering a dynamically allocated key. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-19-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Verify whether lock objects are small enough to be used as ↵Bart Van Assche1-0/+11
class keys Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-18-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Check data structure consistencyBart Van Assche1-0/+167
Debugging lockdep data structure inconsistencies is challenging. Add code that verifies data structure consistency at runtime. That code is disabled by default because it is very CPU intensive. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-17-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Reuse lock chains that have been freedBart Van Assche1-20/+37
A previous patch introduced a lock chain leak. Fix that leak by reusing lock chains that have been freed. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-16-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Fix a comment in add_chain_cache()Bart Van Assche1-1/+1
Reflect that add_chain_cache() is always called with the graph lock held. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-15-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count()Bart Van Assche1-1/+15
This patch does not change any functionality but makes the next patch in this series easier to read. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-14-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Reuse list entries that are no longer in useBart Van Assche1-8/+16
Instead of abandoning elements of list_entries[] that are no longer in use, make alloc_list_entry() reuse array elements that have been freed. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-13-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Free lock classes that are no longer in useBart Van Assche1-48/+348
Instead of leaving lock classes that are no longer in use in the lock_classes array, reuse entries from that array that are no longer in use. Maintain a linked list of free lock classes with list head 'free_lock_class'. Only add freed lock classes to the free_lock_classes list after a grace period to avoid that a lock_classes[] element would be reused while an RCU reader is accessing it. Since the lockdep selftests run in a context where sleeping is not allowed and since the selftests require that lock resetting/zapping works with debug_locks off, make the behavior of lockdep_free_key_range() and lockdep_reset_lock() depend on whether or not these are called from the context of the lockdep selftests. Thanks to Peter for having shown how to modify get_pending_free() such that that function does not have to sleep. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-12-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Update two outdated commentsBart Van Assche1-5/+3
synchronize_sched() has been removed recently. Update the comments that refer to synchronize_sched(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Fixes: 51959d85f32d ("lockdep: Replace synchronize_sched() with synchronize_rcu()") # v5.0-rc1 Link: https://lkml.kernel.org/r/20190214230058.196511-11-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Make it easy to detect whether or not inside a selftestBart Van Assche1-0/+6
The patch that frees unused lock classes will modify the behavior of lockdep_free_key_range() and lockdep_reset_lock() depending on whether or not these functions are called from the context of the lockdep selftests. Hence make it easy to detect whether or not lockdep code is called from the context of a lockdep selftest. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-10-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock()Bart Van Assche1-36/+36
This patch does not change the behavior of these functions but makes the patch that frees unused lock classes easier to read. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-9-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Initialize the locks_before and locks_after lists earlierBart Van Assche1-2/+27
This patch does not change any functionality. A later patch will reuse lock classes that have been freed. In combination with that patch this patch wil have the effect of initializing lock class order lists once instead of every time a lock class structure is reinitialized. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-8-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Make zap_class() remove all matching lock order entriesBart Van Assche1-6/+13
Make sure that all lock order entries that refer to a class are removed from the list_entries[] array when a kernel module is unloaded. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-7-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Avoid that add_chain_cache() adds an invalid chain to the cacheBart Van Assche1-10/+1
Make sure that add_chain_cache() returns 0 and does not modify the chain hash if nr_chain_hlocks == MAX_LOCKDEP_CHAIN_HLOCKS before this function is called. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-5-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Fix reported required memory size (2/2)Bart Van Assche1-1/+2
Lock chains are only tracked with CONFIG_PROVE_LOCKING=y. Do not report the memory required for the lock chain array if CONFIG_PROVE_LOCKING=n. See also commit: ca58abcb4a6d ("lockdep: sanitise CONFIG_PROVE_LOCKING") Include the size of the chain_hlocks[] array. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-4-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Fix reported required memory size (1/2)Bart Van Assche1-7/+7
Change the sizeof(array element time) * (array size) expressions into sizeof(array). This fixes the size computations of the classhash_table[] and chainhash_table[] arrays. The reason is that commit: a63f38cc4ccf ("locking/lockdep: Convert hash tables to hlists") changed the type of the elements of that array from 'struct list_head' into 'struct hlist_head'. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-3-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28locking/lockdep: Fix two 32-bit compiler warningsBart Van Assche1-2/+2
Use %zu to format size_t instead of %lu to avoid that the compiler complains about a mismatch between format specifier and argument on 32-bit systems. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20190214230058.196511-2-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-13kprobes: Prohibit probing on lockdep functionsMasami Hiramatsu1-1/+6
Some lockdep functions can be involved in breakpoint handling and probing on those functions can cause a breakpoint recursion. Prohibit probing on those functions by blacklist. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrea Righi <righi.andrea@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/154998810578.31052.1680977921449292812.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04locking/lockdep: Add debug_locks check in __lock_downgrade()Waiman Long1-0/+3
Tetsuo Handa had reported he saw an incorrect "downgrading a read lock" warning right after a previous lockdep warning. It is likely that the previous warning turned off lock debugging causing the lockdep to have inconsistency states leading to the lock downgrade warning. Fix that by add a check for debug_locks at the beginning of __lock_downgrade(). Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-01-21locking/lockdep: Provide enum lock_usage_bit mask namesFrederic Weisbecker1-22/+11
It makes the code more self-explanatory and tells throughout the code what magic number refers to: - state (Hardirq/Softirq) - direction (used in or enabled above state) - read or write We can even remove some comments that were compensating for the lack of those constant names. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1545973321-24422-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-01-21locking/lockdep: Simplify mark_held_locks()Frederic Weisbecker1-15/+8
The enum mark_type appears a bit artificial here. We can directly pass the base enum lock_usage_bit value to mark_held_locks(). All we need then is to add the read index for each lock if necessary. It makes the code clearer. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1545973321-24422-2-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-01-21locking/lockdep: Add debug_locks check in __lock_downgrade()Waiman Long1-0/+3
Tetsuo Handa had reported he saw an incorrect "downgrading a read lock" warning right after a previous lockdep warning. It is likely that the previous warning turned off lock debugging causing the lockdep to have inconsistency states leading to the lock downgrade warning. Fix that by add a check for debug_locks at the beginning of __lock_downgrade(). Debugged-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-26Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-33/+43
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main change in this cycle are initial preparatory bits of dynamic lockdep keys support from Bart Van Assche. There are also misc changes, a comment cleanup and a data structure cleanup" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Clean up comment in nohz_idle_balance() locking/lockdep: Stop using RCU primitives to access 'all_lock_classes' locking/lockdep: Make concurrent lockdep_reset_lock() calls safe locking/lockdep: Remove a superfluous INIT_LIST_HEAD() statement locking/lockdep: Introduce lock_class_cache_is_registered() locking/lockdep: Inline __lockdep_init_map() locking/lockdep: Declare local symbols static tools/lib/lockdep/tests: Test the lockdep_reset_lock() implementation tools/lib/lockdep: Add dummy print_irqtrace_events() implementation tools/lib/lockdep: Rename "trywlock" into "trywrlock" tools/lib/lockdep/tests: Run lockdep tests a second time under Valgrind tools/lib/lockdep/tests: Improve testing accuracy tools/lib/lockdep/tests: Fix shellcheck warnings tools/lib/lockdep/tests: Display compiler warning and error messages locking/lockdep: Remove ::version from lock_class structure
2018-12-11locking/lockdep: Stop using RCU primitives to access 'all_lock_classes'Bart Van Assche1-4/+5
Due to the previous patch all code that accesses the 'all_lock_classes' list holds the graph lock. Hence use regular list primitives instead of their RCU variants to access this list. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-14-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11locking/lockdep: Make concurrent lockdep_reset_lock() calls safeBart Van Assche1-1/+4
Since zap_class() removes items from the all_lock_classes list and the classhash_table, protect all zap_class() calls against concurrent data structure modifications with the graph lock. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-13-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11locking/lockdep: Remove a superfluous INIT_LIST_HEAD() statementBart Van Assche1-1/+0
Initializing a list entry just before it is passed to list_add_tail_rcu() is not necessary because list_add_tail_rcu() overwrites the next and prev pointers anyway. Hence remove the INIT_LIST_HEAD() statement. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-12-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11locking/lockdep: Introduce lock_class_cache_is_registered()Bart Van Assche1-20/+30
This patch does not change any functionality but makes the lockdep_reset_lock() function easier to read. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-11-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11locking/lockdep: Inline __lockdep_init_map()Bart Van Assche1-7/+1
Since the function __lockdep_init_map() only has one caller, inline it into its caller. This patch does not change any functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-10-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11locking/lockdep: Declare local symbols staticBart Van Assche1-0/+3
This patch avoids that sparse complains about a missing declaration for the lock_classes array when building with CONFIG_DEBUG_LOCKDEP=n. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: johannes.berg@intel.com Cc: tj@kernel.org Link: https://lkml.kernel.org/r/20181207011148.251812-9-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-27lockdep: Replace synchronize_sched() with synchronize_rcu()Paul E. McKenney1-1/+1
Now that synchronize_rcu() waits for preempt-disable regions of code as well as RCU read-side critical sections, synchronize_sched() can be replaced by synchronize_rcu(). This commit therefore makes this change. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will.deacon@arm.com>
2018-10-19locking/lockdep: Fix debug_locks off performance problemWaiman Long1-2/+2
It was found that when debug_locks was turned off because of a problem found by the lockdep code, the system performance could drop quite significantly when the lock_stat code was also configured into the kernel. For instance, parallel kernel build time on a 4-socket x86-64 server nearly doubled. Further analysis into the cause of the slowdown traced back to the frequent call to debug_locks_off() from the __lock_acquired() function probably due to some inconsistent lockdep states with debug_locks off. The debug_locks_off() function did an unconditional atomic xchg to write a 0 value into debug_locks which had already been set to 0. This led to severe cacheline contention in the cacheline that held debug_locks. As debug_locks is being referenced in quite a few different places in the kernel, this greatly slow down the system performance. To prevent that trashing of debug_locks cacheline, lock_acquired() and lock_contended() now checks the state of debug_locks before proceeding. The debug_locks_off() function is also modified to check debug_locks before calling __debug_locks_off(). Signed-off-by: Waiman Long <longman@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1539913518-15598-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>