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* Merge branch 'for-linus' of ↵Linus Torvalds2012-06-0161-1059/+416
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull third pile of signal handling patches from Al Viro: "This time it's mostly helpers and conversions to them; there's a lot of stuff remaining in the tree, but that'll either go in -rc2 (isolated bug fixes, ideally via arch maintainers' trees) or will sit there until the next cycle." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: x86: get rid of calling do_notify_resume() when returning to kernel mode blackfin: check __get_user() return value whack-a-mole with TIF_FREEZE FRV: Optimise the system call exit path in entry.S [ver #2] FRV: Shrink TIF_WORK_MASK [ver #2] FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions new helper: signal_delivered() powerpc: get rid of restore_sigmask() most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set set_restore_sigmask() is never called without SIGPENDING (and never should be) TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set don't call try_to_freeze() from do_signal() pull clearing RESTORE_SIGMASK into block_sigmask() sh64: failure to build sigframe != signal without handler openrisc: tracehook_signal_handler() is supposed to be called on success new helper: sigmask_to_save() new helper: restore_saved_sigmask() new helpers: {clear,test,test_and_clear}_restore_sigmask() HAVE_RESTORE_SIGMASK is defined on all architectures now
| * x86: get rid of calling do_notify_resume() when returning to kernel modeAl Viro2012-06-012-13/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we end up calling do_notify_resume() with !user_mode(refs), it does nothing (do_signal() explicitly bails out and we can't get there with TIF_NOTIFY_RESUME in such situations). Then we jump to resume_userspace_sig, which rechecks the same thing and bails out to resume_kernel, thus breaking the loop. It's easier and cheaper to check *before* calling do_notify_resume() and bail out to resume_kernel immediately. And kill the check in do_signal()... Note that on amd64 we can't get there with !user_mode() at all - asm glue takes care of that. Acked-and-reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * blackfin: check __get_user() return valueAl Viro2012-06-011-16/+14
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * whack-a-mole with TIF_FREEZEAl Viro2012-06-011-2/+0
| | | | | | | | | | | | blackfin has reintroduced it, completely unused. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * FRV: Optimise the system call exit path in entry.S [ver #2]David Howells2012-06-011-6/+7
| | | | | | | | | | | | | | | | Optimise the system call exit path in entry.S by packing some instructions. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * FRV: Shrink TIF_WORK_MASK [ver #2]David Howells2012-06-012-13/+15
| | | | | | | | | | | | | | | | | | Shrink TIF_WORK_MASK so that it will fit in the 12-bit signed immediate operand field of an ANDI instruction. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptionsDavid Howells2012-06-012-11/+3
| | | | | | | | | | | | | | | | | | | | Move the test for kernel mode processing from do_signal() into entry.S to also prevent system call exit tracing and userspace resumption notification handling happening when returning from kernel exceptions. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: signal_delivered()Al Viro2012-06-0132-73/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * powerpc: get rid of restore_sigmask()Al Viro2012-06-014-14/+4
| | | | | | | | | | | | ... it's just a call of set_current_blocked() now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro2012-06-0142-133/+2
| | | | | | | | | | | | | | | | Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * set_restore_sigmask() is never called without SIGPENDING (and never should be)Al Viro2012-06-017-7/+7
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is setAl Viro2012-06-0113-19/+14
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * don't call try_to_freeze() from do_signal()Al Viro2012-06-017-28/+0
| | | | | | | | | | | | get_signal_to_deliver() will handle it itself Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro2012-06-0133-387/+124
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * sh64: failure to build sigframe != signal without handlerAl Viro2012-06-011-1/+1
| | | | | | | | | | | | it's actually "send me SIGSEGV"... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * openrisc: tracehook_signal_handler() is supposed to be called on successAl Viro2012-06-011-14/+6
| | | | | | | | | | | | ... not if sigframe couldn't have been built. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: sigmask_to_save()Al Viro2012-06-0130-250/+84
| | | | | | | | | | | | | | replace boilerplate "should we use ->saved_sigmask or ->blocked?" with calls of obvious inlined helper... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: restore_saved_sigmask()Al Viro2012-06-0131-125/+32
| | | | | | | | | | | | | | | | | | first fruits of ..._restore_sigmask() helpers: now we can take boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK and restore the blocked mask from ->saved_mask" into a common helper. Open-coded instances switched... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helpers: {clear,test,test_and_clear}_restore_sigmask()Al Viro2012-06-017-0/+113
| | | | | | | | | | | | helpers parallel to set_restore_sigmask(), used in the next commits Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-06-0126-100/+14
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs changes from Al Viro. "A lot of misc stuff. The obvious groups: * Miklos' atomic_open series; kills the damn abuse of ->d_revalidate() by NFS, which was the major stumbling block for all work in that area. * ripping security_file_mmap() and dealing with deadlocks in the area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in general. * ->encode_fh() switched to saner API; insane fake dentry in mm/cleancache.c gone. * assorted annotations in fs (endianness, __user) * parts of Artem's ->s_dirty work (jff2 and reiserfs parts) * ->update_time() work from Josef. * other bits and pieces all over the place. Normally it would've been in two or three pull requests, but signal.git stuff had eaten a lot of time during this cycle ;-/" Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the 'truncate_range' inode method was removed by the VM changes, the VFS update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due to sparse fix added twice, with other changes nearby). * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits) nfs: don't open in ->d_revalidate vfs: retry last component if opening stale dentry vfs: nameidata_to_filp(): don't throw away file on error vfs: nameidata_to_filp(): inline __dentry_open() vfs: do_dentry_open(): don't put filp vfs: split __dentry_open() vfs: do_last() common post lookup vfs: do_last(): add audit_inode before open vfs: do_last(): only return EISDIR for O_CREAT vfs: do_last(): check LOOKUP_DIRECTORY vfs: do_last(): make ENOENT exit RCU safe vfs: make follow_link check RCU safe vfs: do_last(): use inode variable vfs: do_last(): inline walk_component() vfs: do_last(): make exit RCU safe vfs: split do_lookup() Btrfs: move over to use ->update_time fs: introduce inode operation ->update_time reiserfs: get rid of resierfs_sync_super reiserfs: mark the superblock as dirty a bit later ...
| * ia64 perfmon: fix get_unmapped_area() use thereAl Viro2012-05-301-8/+2
| | | | | | | | | | | | | | get_unmapped_area() returns -E... on failure, not 0. Moreover, the wrapper around it is completely pointless. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * ia64, sparc64: convert wrappers around do_mremap() to sys_mremap()Al Viro2012-05-302-25/+5
| | | | | | | | | | | | they contain open-coded sys_mremap() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * bury __kernel_nlink_t, make internal nlink_t consistentAl Viro2012-05-3020-60/+0
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * parisc: get rid of nlink_t, switch to explicitly-sized typeAl Viro2012-05-301-2/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * powerpc: get rid of nlink_t uses, switch to explicitly-sized typeAl Viro2012-05-301-2/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * mips: get rid of nlink_t, use explictly-sized type (__u32 in all cases)Al Viro2012-05-291-3/+3
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-3131-68/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull second pile of signal handling patches from Al Viro: "This one is just task_work_add() series + remaining prereqs for it. There probably will be another pull request from that tree this cycle - at least for helpers, to get them out of the way for per-arch fixes remaining in the tree." Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile had brought in commit 97fd75b7b8e0 ("kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printks") which changed one of the pr_err() calls that this merge moves around. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: keys: kill task_struct->replacement_session_keyring keys: kill the dummy key_replace_session_keyring() keys: change keyctl_session_to_parent() to use task_work_add() genirq: reimplement exit_irq_thread() hook via task_work_add() task_work_add: generic process-context callbacks avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers parisc: need to check NOTIFY_RESUME when exiting from syscall move key_repace_session_keyring() into tracehook_notify_resume() TIF_NOTIFY_RESUME is defined on all targets now
| * | avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callersAl Viro2012-05-231-1/+1
| | | | | | | | | | | | | | | | | | we need that not just on syscall returns but on irq ones as well... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | parisc: need to check NOTIFY_RESUME when exiting from syscallAl Viro2012-05-231-1/+1
| | | | | | | | | | | | | | | | | | ... not just on return from interrupt Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | move key_repace_session_keyring() into tracehook_notify_resume()Al Viro2012-05-2329-66/+4
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-05-318-46/+52
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc patches from Andrew Morton: - the "misc" tree - stuff from all over the map - checkpatch updates - fatfs - kmod changes - procfs - cpumask - UML - kexec - mqueue - rapidio - pidns - some checkpoint-restore feature work. Reluctantly. Most of it delayed a release. I'm still rather worried that we don't have a clear roadmap to completion for this work. * emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches) kconfig: update compression algorithm info c/r: prctl: add ability to set new mm_struct::exe_file c/r: prctl: extend PR_SET_MM to set up more mm_struct entries c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat syscalls, x86: add __NR_kcmp syscall fs, proc: introduce /proc/<pid>/task/<tid>/children entry sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector() eventfd: change int to __u64 in eventfd_signal() fs/nls: add Apple NLS pidns: make killed children autoreap pidns: use task_active_pid_ns in do_notify_parent rapidio/tsi721: add DMA engine support rapidio: add DMA engine support for RIO data transfers ipc/mqueue: add rbtree node caching support tools/selftests: add mq_perf_tests ipc/mqueue: strengthen checks on mqueue creation ipc/mqueue: correct mq_attr_ok test ipc/mqueue: improve performance of send/recv selftests: add mq_open_tests ...
| * | | syscalls, x86: add __NR_kcmp syscallCyrill Gorcunov2012-05-312-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While doing the checkpoint-restore in the user space one need to determine whether various kernel objects (like mm_struct-s of file_struct-s) are shared between tasks and restore this state. The 2nd step can be solved by using appropriate CLONE_ flags and the unshare syscall, while there's currently no ways for solving the 1st one. One of the ways for checking whether two tasks share e.g. mm_struct is to provide some mm_struct ID of a task to its proc file, but showing such info considered to be not that good for security reasons. Thus after some debates we end up in conclusion that using that named 'comparison' syscall might be the best candidate. So here is it -- __NR_kcmp. It takes up to 5 arguments - the pids of the two tasks (which characteristics should be compared), the comparison type and (in case of comparison of files) two file descriptors. Lookups for pids are done in the caller's PID namespace only. At moment only x86 is supported and tested. [akpm@linux-foundation.org: fix up selftests, warnings] [akpm@linux-foundation.org: include errno.h] [akpm@linux-foundation.org: tweak comment text] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Glauber Costa <glommer@parallels.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tejun Heo <tj@kernel.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Valdis.Kletnieks@vt.edu Cc: Michal Marek <mmarek@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | um: properly check all process' threads for a live mmAnton Vorontsov2012-05-311-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kill_off_processes() might miss a valid process, this is because checking for process->mm is not enough. Process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To catch this we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | um: fix possible race on task->mmAnton Vorontsov2012-05-311-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Checking for task->mm is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so let's take the task lock while we care about its mm. Note that we should also use find_lock_task_mm() to check all process' threads for a valid mm, but for uml we'll do it in a separate patch. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | um: should hold tasklist_lock while traversing processesAnton Vorontsov2012-05-311-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Traversing the tasks requires holding tasklist_lock, otherwise it is unsafe. p.s. However, I'm not sure that calling os_kill_ptraced_process() in the atomic context is correct. It seem to work, but please take a closer look. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | blackfin: fix possible deadlock in decode_address()Anton Vorontsov2012-05-311-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Oleg Nesterov found an interesting deadlock possibility: > sysrq_showregs_othercpus() does smp_call_function(showacpu) > and showacpu() show_stack()->decode_address(). Now suppose that IPI > interrupts the task holding read_lock(tasklist). To fix this, blackfin should not grab the write_ variant of the tasklist lock, read_ one is enough. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | blackfin: a couple of task->mm handling fixesAnton Vorontsov2012-05-311-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch fixes two problems: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we have to take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To catch this we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | sh: use clear_tasks_mm_cpumask()Anton Vorontsov2012-05-311-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has the issue fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | powerpc: use clear_tasks_mm_cpumask()Anton Vorontsov2012-05-311-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current CPU hotplug code has some task->mm handling issues: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we must take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has all the issues fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | arm: use clear_tasks_mm_cpumask()Anton Vorontsov2012-05-311-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has this issue fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | um/kernel/trap.c: port OOM changes to handle_page_fault()Kautuk Consul2012-05-311-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d065bd810b6d ("mm: retry page fault when blocking on disk transfer") and commit 37b23e0525d3 ("x86,mm: make pagefault killable") introduced changes into the x86 pagefault handler for making the page fault handler retryable as well as killable. These changes reduce the mmap_sem hold time, which is crucial during OOM killer invocation. Port these changes to um. Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2012-05-311-2/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull two small kvm fixes from Avi Kivity: "A build fix for non-kvm archs and a transparent hugepage refcount bugfix on hosts with 4M pages." * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: Export asm-generic/kvm_para.h KVM: MMU: fix huge page adapted on non-PAE host
| * | | | KVM: MMU: fix huge page adapted on non-PAE hostXiao Guangrong2012-05-281-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The huge page size is 4M on non-PAE host, but 2M page size is used in transparent_hugepage_adjust(), so the page we get after adjust the mapping level is not the head page, the BUG_ON() will be triggered Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | | | Merge tag 'please-pull-mce' of ↵Linus Torvalds2012-05-311-15/+16
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras Pull mce cleanup from Tony Luck: "One more mce cleanup before the 3.5 merge window closes" * tag 'please-pull-mce' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: x86/mce: Cleanup timer mess
| * | | | | x86/mce: Cleanup timer messThomas Gleixner2012-05-301-15/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use unsigned long for dealing with jiffies not int. Rename the callback to something sensible. Use __this_cpu_read/write for accessing per cpu data. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-3148-306/+244
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 patches from Heiko Carstens: "A couple of s390 patches for the 3.5 merge window. Just a collection of bug fixes and cleanups." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uaccess: fix access_ok compile warnings s390/cmpxchg: select HAVE_CMPXCHG_LOCAL option s390/cmpxchg: fix sign extension bugs s390/cmpxchg: fix 1 and 2 byte memory accesses s390/cmpxchg: fix compile warnings specific to s390 s390/cmpxchg: add missing memory barrier to cmpxchg64 s390/cpu: remove cpu "capabilities" sysfs attribute s390/kernel: Fix smp_call_ipl_cpu() for offline CPUs s390/kernel: Introduce memcpy_absolute() function s390/headers: replace __s390x__ with CONFIG_64BIT where possible s390/headers: remove #ifdef __KERNEL__ from not exported headers s390/irq: split irq stats for cpu-measurement alert facilities s390/kexec: Move early_pgm_check_handler() to text section s390/kdump: Use real mode for PSW restart and kexec s390/kdump: Account /sys/kernel/kexec_crash_size changes in OS info s390/kernel: Remove OS info init function call and diag 308 for kdump
| * | | | | | s390/uaccess: fix access_ok compile warningsHeiko Carstens2012-05-301-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On s390 access_ok is a macro which discards all parameters and always returns 1. This can result in compile warnings which warn about unused variables like this: fs/read_write.c: In function 'rw_copy_check_uvector': fs/read_write.c:684:16: warning: unused variable 'buf' [-Wunused-variable] Fix this by adding a __range_ok() function which consumes all parameters but still always returns 1. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | | s390/cmpxchg: select HAVE_CMPXCHG_LOCAL optionHeiko Carstens2012-05-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that hopefully all cmpxchg/xchg bugs have been fixed select HAVE_CMPXCHG_LOCAL option which uncovered a couple of bugs on s390. The only call site which is affected seems to be within mm/vmstat.c. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | | s390/cmpxchg: fix sign extension bugsHeiko Carstens2012-05-301-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For 1 and 2 byte operands for xchg and cmpxchg the old and new values get or'ed into the larger 4 byte old value before the compare and swap instruction gets executed. This is done without using the proper byte mask before or'ing the values. If the caller passed in negative old or new values these got sign extended by the caller. Which in turn means that either the old value never matches, or, even worse, unrelated bytes would be changed in memory. Luckily there don't seem to be any callers around yet, since that would have resulted in the specification exception fixed in an earlies patch. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | | s390/cmpxchg: fix 1 and 2 byte memory accessesHeiko Carstens2012-05-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When accessing a 1 or 2 byte memory operand we cannot use the passed address since the compare and swap instruction only works for 4 byte aligned memory operands. Hence we calculate an aligned address so that compare and swap works correctly. However we don't pass the calculated address to the inline assembly. This results in incorrect memory accesses and in a specification exception if used on non 4 byte aligned memory operands. Since this didn't happen until now, there don't seem to be too many users of cmpxchg on unaligned addresses. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>