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2012-10-01Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molnar: 0. 'idle RCU': Adds RCU APIs that allow non-idle tasks to enter RCU idle mode and provides x86 code to make use of them, allowing RCU to treat user-mode execution as an extended quiescent state when the new RCU_USER_QS kernel configuration parameter is specified. (Work is in progress to port this to a few other architectures, but is not part of this series.) 1. A fix for a latent bug that has been in RCU ever since the addition of CPU stall warnings. This bug results in false-positive stall warnings, but thus far only on embedded systems with severely cut-down userspace configurations. 2. Further reductions in latency spikes for huge systems, along with additional boot-time adaptation to the actual hardware. This is a large change, as it moves RCU grace-period initialization and cleanup, along with quiescent-state forcing, from softirq to a kthread. However, it appears to be in quite good shape (famous last words). 3. Updates to documentation and rcutorture, the latter category including keeping statistics on CPU-hotplug latencies and fixing some initialization-time races. 4. CPU-hotplug fixes and improvements. 5. Idle-loop fixes that were omitted on an earlier submission. 6. Miscellaneous fixes and improvements In certain RCU configurations new kernel threads will show up (rcu_bh, rcu_sched), showing RCU processing overhead. * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (90 commits) rcu: Apply micro-optimization and int/bool fixes to RCU's idle handling rcu: Userspace RCU extended QS selftest x86: Exit RCU extended QS on notify resume x86: Use the new schedule_user API on userspace preemption rcu: Exit RCU extended QS on user preemption rcu: Exit RCU extended QS on kernel preemption after irq/exception x86: Exception hooks for userspace RCU extended QS x86: Unspaghettize do_general_protection() x86: Syscall hooks for userspace RCU extended QS rcu: Switch task's syscall hooks on context switch rcu: Ignore userspace extended quiescent state by default rcu: Allow rcu_user_enter()/exit() to nest rcu: Settle config for userspace extended quiescent state rcu: Make RCU_FAST_NO_HZ handle adaptive ticks rcu: New rcu_user_enter_after_irq() and rcu_user_exit_after_irq() APIs rcu: New rcu_user_enter() and rcu_user_exit() APIs ia64: Add missing RCU idle APIs on idle loop xtensa: Add missing RCU idle APIs on idle loop score: Add missing RCU idle APIs on idle loop parisc: Add missing RCU idle APIs on idle loop ...
2012-10-01sanitize tsk_is_polling()Al Viro1-3/+0
Make default just return 0. The current default (checking TIF_POLLING_NRFLAG) is taken to architectures that need it; ones that don't do polling in their idle threads don't need to defined TIF_POLLING_NRFLAG at all. ia64 defined both TS_POLLING (used by its tsk_is_polling()) and TIF_POLLING_NRFLAG (not used at all). Killed the latter... Signed-off-by: Al Viro <[email protected]>
2012-09-30um: switch to generic kernel_thread()Al Viro2-16/+3
Signed-off-by: Al Viro <[email protected]>
2012-09-30x86, um/x86: switch to generic sys_execve and kernel_execveAl Viro3-41/+2
32bit wrapper is lost on that; 64bit one is *not*, since we need to arrange for full pt_regs on stack when we call sys_execve() and we need to load callee-saved ones from there afterwards. Signed-off-by: Al Viro <[email protected]>
2012-09-27um: Preinclude include/linux/kern_levels.hGeert Uytterhoeven3-11/+12
The userspace part of UML uses the asm-offsets.h generator mechanism to create definitions for UM_KERN_<LEVEL> that match the in-kernel KERN_<LEVEL> constant definitions. As of commit 04d2c8c83d0e3ac5f78aeede51babb3236200112 ("printk: convert the format for KERN_<LEVEL> to a 2 byte pattern"), KERN_<LEVEL> is no longer expanded to the literal '"<LEVEL>"', but to '"\001" "LEVEL"', i.e. it contains two parts. However, the combo of DEFINE_STR() in arch/x86/um/shared/sysdep/kernel-offsets.h and sed-y in Kbuild doesn't support string literals consisting of multiple parts. Hence for all UM_KERN_<LEVEL> definitions, only the SOH character is retained in the actual definition, while the remainder ends up in the comment. E.g. in include/generated/asm-offsets.h we get #define UM_KERN_INFO "\001" /* "6" KERN_INFO */ instead of #define UM_KERN_INFO "\001" "6" /* KERN_INFO */ This causes spurious '^A' output in some kernel messages: Calibrating delay loop... 4640.76 BogoMIPS (lpj=23203840) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 256 ^AChecking that host ptys support output SIGIO...Yes ^AChecking that host ptys support SIGIO on close...No, enabling workaround ^AUsing 2.6 host AIO NET: Registered protocol family 16 bio: create slab <bio-0> at 0 Switching to clocksource itimer To fix this: - Move the mapping from UM_KERN_<LEVEL> to KERN_<LEVEL> from arch/um/include/shared/common-offsets.h to arch/um/include/shared/user.h, which is preincluded for all userspace parts, - Preinclude include/linux/kern_levels.h for all userspace parts, to obtain the in-kernel KERN_<LEVEL> constant definitions. This doesn't violate the kernel/userspace separation, as include/linux/kern_levels.h is self-contained and doesn't expose any other kernel internals. - Remove the now unused STR() and DEFINE_STR() macros. Signed-off-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-09-27um: kill thread->forkingAl Viro3-25/+16
we only use that to tell copy_thread() done by syscall from that done by kernel_thread(). However, it's easier to do simply by checking PF_KTHREAD in thread flags. Merge sys_clone() guts for 32bit and 64bit, while we are at it... Signed-off-by: Al Viro <[email protected]>
2012-09-27um: let signal_delivered() do SIGTRAP on singlestepping into handlerAl Viro1-1/+5
... rather than duplicating that in sigframe setup code (and doing that inconsistently, at that) Signed-off-by: Al Viro <[email protected]>
2012-09-27um: don't leak floating point state and segment registers on execve()Al Viro1-0/+1
Signed-off-by: Al Viro <[email protected]>
2012-09-27um: take cleaning singlestep to start_thread()Al Viro1-19/+5
... assuming it's needed to be done at all Signed-off-by: Al Viro <[email protected]>
2012-09-26um: resurrect the right variant of mconsole_proc()Al Viro1-78/+21
Signed-off-by: Al Viro <[email protected]>
2012-09-26rcu: Switch task's syscall hooks on context switchFrederic Weisbecker1-0/+1
Clear the syscalls hook of a task when it's scheduled out so that if the task migrates, it doesn't run the syscall slow path on a CPU that might not need it. Also set the syscalls hook on the next task if needed. Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Alessio Igor Bogani <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Avi Kivity <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Geoff Levand <[email protected]> Cc: Gilad Ben Yossef <[email protected]> Cc: Hakan Akkan <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Kevin Hilman <[email protected]> Cc: Max Krasnyansky <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephen Hemminger <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Sven-Thorsten Dietrich <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Reviewed-by: Josh Triplett <[email protected]>
2012-09-20um: kill thread->forkingAl Viro3-25/+16
we only use that to tell copy_thread() done by syscall from that done by kernel_thread(). However, it's easier to do simply by checking PF_KTHREAD in thread flags. Merge sys_clone() guts for 32bit and 64bit, while we are at it... Signed-off-by: Al Viro <[email protected]>
2012-09-20um: let signal_delivered() do SIGTRAP on singlestepping into handlerAl Viro1-1/+5
... rather than duplicating that in sigframe setup code (and doing that inconsistently, at that) Signed-off-by: Al Viro <[email protected]>
2012-09-20um: don't leak floating point state and segment registers on execve()Al Viro1-0/+1
Signed-off-by: Al Viro <[email protected]>
2012-09-20um: take cleaning singlestep to start_thread()Al Viro1-19/+5
... assuming it's needed to be done at all Signed-off-by: Al Viro <[email protected]>
2012-09-16Merge 3.6-rc6 into tty-nextGreg Kroah-Hartman1-1/+1
This pulls in the fixes in 3.6-rc6 Signed-off-by: Greg Kroah-Hartman <[email protected]>
2012-09-05uml: fix compile error in deliver_alarm()Miklos Szeredi1-1/+1
Fix the following compile error on UML. arch/um/os-Linux/time.c: In function 'deliver_alarm': arch/um/os-Linux/time.c:117:3: error: too few arguments to function 'alarm_handler' arch/um/os-Linux/internal.h:1:6: note: declared here The error was introduced by commit d3c1cfcd ("um: pass siginfo to guest process") in 3.6-rc1. Signed-off-by: Miklos Szeredi <[email protected]> CC: Martin Pärtel <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2012-08-13TTY: use tty_port_register_deviceJiri Slaby1-1/+2
Currently we have no way to assign tty->port while performing tty installation. There are two ways to provide the link tty_struct => tty_port. Either by calling tty_port_install from tty->ops->install or tty_port_register_device called instead of tty_register_device when the device is being set up after connected. In this patch we modify most of the drivers to do the latter. When the drivers use tty_register_device and we have tty_port already, we switch to tty_port_register_device. So we have the tty_struct => tty_port link for free for those. Signed-off-by: Jiri Slaby <[email protected]> Acked-by: Alan Cox <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2012-08-01Merge branch 'for-linus-3.6-rc1' of ↵Linus Torvalds21-299/+202
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML fixes from Richard Weinberger: "This patch set contains mostly fixes and cleanups. The UML tty driver uses now tty_port and is no longer broken like hell :-)" * 'for-linus-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: Add arch/x86/um to MAINTAINERS um: pass siginfo to guest process um: fix ubd_file_size for read-only files um: pull interrupt_end() into userspace() um: split syscall_trace(), pass pt_regs to it um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regs um: set BLK_CGROUP=y in defconfig um: remove count_lock um: fully use tty_port um: Remove dead code um: remove line_ioctl() TTY: um/line, use tty from tty_port TTY: um/line, add tty_port
2012-08-02um: pass siginfo to guest processMartin Pärtel10-34/+71
UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE, SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct where previously they were si_addr = NULL and si_code = 128. Signed-off-by: Martin Pärtel <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-08-02um: fix ubd_file_size for read-only filesMartin Pärtel1-1/+1
Made ubd_file_size not request write access. Fixes use of read-only images. Signed-off-by: Martin Pärtel <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-08-02um: pull interrupt_end() into userspace()Al Viro2-8/+6
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-08-02um: split syscall_trace(), pass pt_regs to itAl Viro3-43/+34
Signed-off-by: Al Viro <[email protected]> [[email protected]: Fixed some minor build issues] Signed-off-by: Richard Weinberger <[email protected]>
2012-08-01um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regsAl Viro2-2/+2
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-07-31Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds1-4/+4
Merge Andrew's second set of patches: - MM - a few random fixes - a couple of RTC leftovers * emailed patches from Andrew Morton <[email protected]>: (120 commits) rtc/rtc-88pm80x: remove unneed devm_kfree rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables tmpfs: distribute interleave better across nodes mm: remove redundant initialization mm: warn if pg_data_t isn't initialized with zero mips: zero out pg_data_t when it's allocated memcg: gix memory accounting scalability in shrink_page_list mm/sparse: remove index_init_lock mm/sparse: more checks on mem_section number mm/sparse: optimize sparse_index_alloc memcg: add mem_cgroup_from_css() helper memcg: further prevent OOM with too many dirty pages memcg: prevent OOM with too many dirty pages mm: mmu_notifier: fix freed page still mapped in secondary MMU mm: memcg: only check anon swapin page charges for swap cache mm: memcg: only check swap cache pages for repeated charging mm: memcg: split swapin charge function into private and public part mm: memcg: remove needless !mm fixup to init_mm when charging mm: memcg: remove unneeded shmem charge type ...
2012-07-31Merge tag 'random_for_linus' of ↵Linus Torvalds6-19/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random subsystem patches from Ted Ts'o: "This patch series contains a major revamp of how we collect entropy from interrupts for /dev/random and /dev/urandom. The goal is to addresses weaknesses discussed in the paper "Mining your Ps and Qs: Detection of Widespread Weak Keys in Network Devices", by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will be published in the Proceedings of the 21st Usenix Security Symposium, August 2012. (See https://factorable.net for more information and an extended version of the paper.)" Fix up trivial conflicts due to nearby changes in drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c} * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits) random: mix in architectural randomness in extract_buf() dmi: Feed DMI table to /dev/random driver random: Add comment to random_initialize() random: final removal of IRQF_SAMPLE_RANDOM um: remove IRQF_SAMPLE_RANDOM which is now a no-op sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op [ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op ...
2012-07-31memcg: rename config variablesAndrew Morton1-4/+4
Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [[email protected]: fix missed bits] Cc: Glauber Costa <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Aneesh Kumar K.V <[email protected]> Cc: David Rientjes <[email protected]> Cc: KOSAKI Motohiro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2012-07-28um: set BLK_CGROUP=y in defconfigRichard Weinberger1-1/+1
BLK_CGROUP=m is no longer valid. Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28um: remove count_lockRichard Weinberger2-7/+0
this lock is no longer needed. Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28um: fully use tty_portRichard Weinberger4-78/+65
... use all tty_port helpers Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28um: Remove dead codeRichard Weinberger1-26/+0
Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28um: remove line_ioctl()Richard Weinberger4-90/+0
line_ioctl() has no real function. Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28TTY: um/line, use tty from tty_portJiri Slaby3-9/+21
This means switching to the tty refcounted model so that we will not race with interrupts. Signed-off-by: Jiri Slaby <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: [email protected] Signed-off-by: Richard Weinberger <[email protected]>
2012-07-28TTY: um/line, add tty_portJiri Slaby2-4/+5
And use count from there. Signed-off-by: Jiri Slaby <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: [email protected] Signed-off-by: Richard Weinberger <[email protected]>
2012-07-27Merge branch 'kmap_atomic' of git://github.com/congwang/linuxLinus Torvalds1-17/+1
Pull final kmap_atomic cleanups from Cong Wang: "This should be the final round of cleanup, as the definitions of enum km_type finally get removed from the whole tree. The patches have been in linux-next for a long time." * 'kmap_atomic' of git://github.com/congwang/linux: pipe: remove KM_USER0 from comments vmalloc: remove KM_USER0 from comments feature-removal-schedule.txt: remove kmap_atomic(page, km_type) tile: remove km_type definitions um: remove km_type definitions asm-generic: remove km_type definitions avr32: remove km_type definitions frv: remove km_type definitions powerpc: remove km_type definitions arm: remove km_type definitions highmem: remove the deprecated form of kmap_atomic tile: remove usage of enum km_type frv: remove the second parameter of kmap_atomic_primary() jbd2: remove the second argument of kmap_atomic
2012-07-24um: remove km_type definitionsCong Wang1-17/+1
Signed-off-by: Cong Wang <[email protected]>
2012-07-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+0
Conflicts: drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
2012-07-19um: remove IRQF_SAMPLE_RANDOM which is now a no-opTheodore Ts'o6-19/+12
With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a no-op; interrupt randomness is now collected unconditionally in a very low-overhead fashion; see commit 775f4b297b. The IRQF_SAMPLE_RANDOM flag was scheduled to be removed in 2009 on the feature-removal-schedule, so this patch is preparation for the final removal of this flag. Signed-off-by: "Theodore Ts'o" <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]>
2012-07-16arch: Use eth_random_addrJoe Perches1-1/+1
Convert the existing uses of random_ether_addr to the new eth_random_addr. Signed-off-by: Joe Perches <[email protected]> Acked-by: Mike Frysinger <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2012-07-02Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"Paul E. McKenney1-1/+0
This reverts commit 616c310e83b872024271c915c1b9ab505b9efad9. (Move PREEMPT_RCU preemption to switch_to() invocation). Testing by Sasha Levin <[email protected]> showed that this can result in deadlock due to invoking the scheduler when one of the runqueue locks is held. Because this commit was simply a performance optimization, revert it. Reported-by: Sasha Levin <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Tested-by: Sasha Levin <[email protected]>
2012-06-01new helper: signal_delivered()Al Viro1-1/+1
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 <[email protected]>
2012-06-01most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro2-7/+0
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 <[email protected]>
2012-06-01pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro1-14/+2
Signed-off-by: Al Viro <[email protected]>
2012-06-01new helper: sigmask_to_save()Al Viro1-8/+3
replace boilerplate "should we use ->saved_sigmask or ->blocked?" with calls of obvious inlined helper... Signed-off-by: Al Viro <[email protected]>
2012-06-01new helper: restore_saved_sigmask()Al Viro1-4/+2
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 <[email protected]>
2012-05-31Merge branch 'for-linus' of ↵Linus Torvalds1-4/+1
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
2012-05-31um: properly check all process' threads for a live mmAnton Vorontsov1-6/+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 <[email protected]> Signed-off-by: Anton Vorontsov <[email protected]> Cc: Richard Weinberger <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2012-05-31um: fix possible race on task->mmAnton Vorontsov1-2/+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 <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2012-05-31um: should hold tasklist_lock while traversing processesAnton Vorontsov1-0/+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 <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2012-05-31um/kernel/trap.c: port OOM changes to handle_page_fault()Kautuk Consul1-5/+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 <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>