kernel/git/stable/linux.git/fs/eventpoll.c, branch linux-3.11.y

Revert "epoll: use freezable blocking call"

2013-11-13T03:08:08+00:00

commit c511851de162e8ec03d62e7d7feecbdf590d881d upstream. This reverts commit 1c441e921201 (epoll: use freezable blocking call) which is reported to cause user space memory corruption to happen after suspend to RAM. Since it appears to be extremely difficult to root cause this problem, it is best to revert the offending commit and try to address the original issue in a better way later. References: https://bugzilla.kernel.org/show_bug.cgi?id=61781 Reported-by: Natrio Reported-by: Jeff Pohlmeyer Bisected-by: Leo Wolf Fixes: 1c441e921201 (epoll: use freezable blocking call) Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

Merge branch 'akpm' (updates from Andrew Morton)

2013-07-04T00:12:13+00:00

Merge first patch-bomb from Andrew Morton: - various misc bits - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been distracted. There has been quite a bit of activity. - About half the MM queue - Some backlight bits - Various lib/ updates - checkpatch updates - zillions more little rtc patches - ptrace - signals - exec - procfs - rapidio - nbd - aoe - pps - memstick - tools/testing/selftests updates * emailed patches from Andrew Morton : (445 commits) tools/testing/selftests: don't assume the x bit is set on scripts selftests: add .gitignore for kcmp selftests: fix clean target in kcmp Makefile selftests: add .gitignore for vm selftests: add hugetlbfstest self-test: fix make clean selftests: exit 1 on failure kernel/resource.c: remove the unneeded assignment in function __find_resource aio: fix wrong comment in aio_complete() drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode drivers/memstick/host/r592.c: convert to module_pci_driver drivers/memstick/host/jmb38x_ms: convert to module_pci_driver pps-gpio: add device-tree binding and support drivers/pps/clients/pps-gpio.c: convert to module_platform_driver drivers/pps/clients/pps-gpio.c: convert to devm_* helpers drivers/parport/share.c: use kzalloc Documentation/accounting/getdelays.c: avoid strncpy in accounting tool aoe: update internal version number to v83 aoe: update copyright date aoe: perform I/O completions in parallel ...

signals: eventpoll: do not use sigprocmask()

2013-07-03T23:08:01+00:00

sigprocmask() should die. None of the current callers actually need this strange interface. Change fs/eventpoll.c to use set_current_blocked(). This also means we should not worry about SIGKILL/SIGSTOP. Signed-off-by: Oleg Nesterov Cc: Al Viro Cc: Denys Vlasenko Cc: Eric Wong Cc: Jason Baron Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: use freezable blocking call

2013-05-12T12:16:22+00:00

Avoid waking up every thread sleeping in an epoll_wait call during suspend and resume by calling a freezable blocking call. Previous patches modified the freezer to avoid sending wakeups to threads that are blocked in freezable blocking calls. This call was selected to be converted to a freezable call because it doesn't hold any locks or release any resources when interrupted that might be needed by another freezing task or a kernel driver during suspend, and is a common site where idle userspace tasks are blocked. Acked-by: Tejun Heo Signed-off-by: Colin Cross Signed-off-by: Rafael J. Wysocki

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2013-05-01T14:21:43+00:00

Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions

epoll: cleanup: use RCU_INIT_POINTER when nulling

2013-05-01T00:04:04+00:00

It is always safe to use RCU_INIT_POINTER to NULL a pointer. This results in slightly smaller/faster code. Signed-off-by: Eric Wong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: cleanup: hoist out f_op->poll calls

2013-05-01T00:04:04+00:00

This reduces the amount of code inside the ready list iteration loops for better readability IMHO. Signed-off-by: Eric Wong Cc: Davide Libenzi Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: lock ep->mtx in ep_free to silence lockdep

2013-05-01T00:04:04+00:00

Technically we do not need to hold ep->mtx during ep_free since we are certain there are no other users of ep at that point. However, lockdep complains with a "suspicious rcu_dereference_check() usage!" message; so lock the mutex before ep_remove to silence the warning. Signed-off-by: Eric Wong Cc: Al Viro Cc: Arve Hjønnevåg Cc: Davide Libenzi Cc: Eric Dumazet Cc: NeilBrown , Cc: Rafael J. Wysocki Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: use RCU to protect wakeup_source in epitem

2013-05-01T00:04:04+00:00

This prevents wakeup_source destruction when a user hits the item with EPOLL_CTL_MOD while ep_poll_callback is running. Tested with CONFIG_SPARSE_RCU_POINTER=y and "make fs/eventpoll.o C=2" Signed-off-by: Eric Wong Cc: Alexander Viro Cc: Arve Hjønnevåg Cc: Davide Libenzi Cc: Eric Dumazet Cc: NeilBrown Cc: "Rafael J. Wysocki" Cc: "Paul E. McKenney" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: trim epitem by one cache line

2013-05-01T00:04:04+00:00

It is common for epoll users to have thousands of epitems, so saving a cache line on every allocation leads to large memory savings. Since epitem allocations are cache-aligned, reducing sizeof(struct epitem) from 136 bytes to 128 bytes will allow it to squeeze under a cache line boundary on x86_64. Via /sys/kernel/slab/eventpoll_epi, I see the following changes on my x86_64 Core2 Duo (which has 64-byte cache alignment): object_size : 192 => 128 objs_per_slab: 21 => 32 Also, add a BUILD_BUG_ON() to check for future accidental breakage. [akpm@linux-foundation.org: use __packed, for all architectures] Signed-off-by: Eric Wong Cc: Davide Libenzi Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds