user/sven/linux.git/kernel/futex.c, branch v5.8.11

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14Z

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

futex: get rid of a kernel-docs build warning

2020-04-20T21:45:41Z

Adjust whitespaces and blank lines in order to get rid of this: ./kernel/futex.c:491: WARNING: Definition list ends without a blank line; unexpected unindent. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/57788af7889161483e0c97f91c079cfb3986c4b3.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-03-30T23:17:15Z

Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Continued user-access cleanups in the futex code. - percpu-rwsem rewrite that uses its own waitqueue and atomic_t instead of an embedded rwsem. This addresses a couple of weaknesses, but the primary motivation was complications on the -rt kernel. - Introduce raw lock nesting detection on lockdep (CONFIG_PROVE_RAW_LOCK_NESTING=y), document the raw_lock vs. normal lock differences. This too originates from -rt. - Reuse lockdep zapped chain_hlocks entries, to conserve RAM footprint on distro-ish kernels running into the "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" depletion of the lockdep chain-entries pool. - Misc cleanups, smaller fixes and enhancements - see the changelog for details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t Documentation/locking/locktypes: Minor copy editor fixes Documentation/locking/locktypes: Further clarifications and wordsmithing m68knommu: Remove mm.h include from uaccess_no.h x86: get rid of user_atomic_cmpxchg_inatomic() generic arch_futex_atomic_op_inuser() doesn't need access_ok() x86: don't reload after cmpxchg in unsafe_atomic_op2() loop x86: convert arch_futex_atomic_op_inuser() to user_access_begin/user_access_end() objtool: whitelist __sanitizer_cov_trace_switch() [parisc, s390, sparc64] no need for access_ok() in futex handling sh: no need of access_ok() in arch_futex_atomic_op_inuser() futex: arch_futex_atomic_op_inuser() calling conventions change completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() lockdep: Add posixtimer context tracing bits lockdep: Annotate irq_work lockdep: Add hrtimer context tracing bits lockdep: Introduce wait-type checks completion: Use simple wait queues sched/swait: Prepare usage in completions ...

Merge branch 'uaccess.futex' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into locking/core

2020-03-28T10:59:24Z

Pull uaccess futex cleanups for Al Viro: Consolidate access_ok() usage and the futex uaccess function zoo.

futex: arch_futex_atomic_op_inuser() calling conventions change

2020-03-28T03:58:51Z

Move access_ok() in and pagefault_enable()/pagefault_disable() out. Mechanical conversion only - some instances don't really need a separate access_ok() at all (e.g. the ones only using get_user()/put_user(), or architectures where access_ok() is always true); we'll deal with that in followups. Signed-off-by: Al Viro

futex: Unbreak futex hashing

2020-03-09T21:33:09Z

The recent futex inode life time fix changed the ordering of the futex key union struct members, but forgot to adjust the hash function accordingly, As a result the hashing omits the leading 64bit and even hashes beyond the futex key causing a bad hash distribution which led to a ~100% performance regression. Hand in the futex key pointer instead of a random struct member and make the size calculation based of the struct offset. Fixes: 8019ad13ef7f ("futex: Fix inode life-time issue") Reported-by: Rong Chen Decoded-by: Linus Torvalds Signed-off-by: Thomas Gleixner Tested-by: Rong Chen Link: https://lkml.kernel.org/r/87h7yy90ve.fsf@nanos.tec.linutronix.de

futex: Remove {get,drop}_futex_key_refs()

2020-03-06T10:06:19Z

Now that {get,drop}_futex_key_refs() have become a glorified NOP, remove them entirely. The only thing get_futex_key_refs() is still doing is an smp_mb(), and now that we don't need to (ab)use existing atomic ops to obtain them, we can place it explicitly where we need it. Signed-off-by: Peter Zijlstra (Intel)

futex: Remove pointless mmgrap() + mmdrop()

2020-03-06T10:06:18Z

We always set 'key->private.mm' to 'current->mm', getting an extra reference on 'current->mm' is quite pointless, because as long as the task is blocked it isn't going to go away. Signed-off-by: Peter Zijlstra (Intel)

futex: Fix inode life-time issue

2020-03-06T10:06:15Z

As reported by Jann, ihold() does not in fact guarantee inode persistence. And instead of making it so, replace the usage of inode pointers with a per boot, machine wide, unique inode identifier. This sequence number is global, but shared (file backed) futexes are rare enough that this should not become a performance issue. Reported-by: Jann Horn Suggested-by: Linus Torvalds Signed-off-by: Peter Zijlstra (Intel)

futex: Fix kernel-doc notation warning

2020-01-09T12:23:40Z

Fix a kernel-doc warning in kernel/futex.c by adding notation for @ret. ../kernel/futex.c:1187: warning: Function parameter or member 'ret' not described in 'wait_for_owner_exiting' Fixes: 3ef240eaff36 ("futex: Prevent exit livelock") Signed-off-by: Randy Dunlap Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/223be78c-f3c8-52df-836d-c5fb8e7907e9@infradead.org