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2012-06-01new helper: signal_delivered()Al Viro
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>
2012-06-01most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro
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>
2012-06-01pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01new helper: sigmask_to_save()Al Viro
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>
2012-06-01new helper: restore_saved_sigmask()Al Viro
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>
2012-05-31Merge branch 'for-linus' of ↵Linus Torvalds
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 Vorontsov
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>
2012-05-31um: fix possible race on task->mmAnton Vorontsov
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>
2012-05-31um: should hold tasklist_lock while traversing processesAnton Vorontsov
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>
2012-05-31um/kernel/trap.c: port OOM changes to handle_page_fault()Kautuk Consul
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>
2012-05-23move key_repace_session_keyring() into tracehook_notify_resume()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull first series of signal handling cleanups from Al Viro: "This is just the first part of the queue (about a half of it); assorted fixes all over the place in signal handling. This one ends with all sigsuspend() implementations switched to generic one (->saved_sigmask-based). With this, a bunch of assorted old buglets are fixed and most of the missing bits of NOTIFY_RESUME hookup are in place. Two more fixes sit in arm and um trees respectively, and there's a couple of broken ones that need obvious fixes - parisc and avr32 check TIF_NOTIFY_RESUME only on one of two codepaths; fixes for that will happen in the next series" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (55 commits) unicore32: if there's no handler we need to restore sigmask, syscall or no syscall xtensa: add handling of TIF_NOTIFY_RESUME microblaze: drop 'oldset' argument of do_notify_resume() microblaze: handle TIF_NOTIFY_RESUME score: add handling of NOTIFY_RESUME to do_notify_resume() m68k: add TIF_NOTIFY_RESUME and handle it. sparc: kill ancient comment in sparc_sigaction() h8300: missing checks of __get_user()/__put_user() return values frv: missing checks of __get_user()/__put_user() return values cris: missing checks of __get_user()/__put_user() return values powerpc: missing checks of __get_user()/__put_user() return values sh: missing checks of __get_user()/__put_user() return values sparc: missing checks of __get_user()/__put_user() return values avr32: struct old_sigaction is never used m32r: struct old_sigaction is never used xtensa: xtensa_sigaction doesn't exist alpha: tidy signal delivery up score: don't open-code force_sigsegv() cris: don't open-code force_sigsegv() blackfin: don't open-code force_sigsegv() ...
2012-05-23Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/umlLinus Torvalds
Pull UML updates from Richard Weinberger: "Most changes are bug fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: missing checks of __put_user()/__get_user() return values um: stub_rt_sigsuspend isn't needed these days anymore um/x86: merge (and trim) 32- and 64-bit variants of ptrace.h irq: Remove irq_chip->release() um: Remove CONFIG_IRQ_RELEASE_METHOD um: Remove usage of irq_chip->release() um: Implement um_free_irq() um: Fix __swp_type() um: Implement a custom pte_same() function um: Add BUG() to do_ops()'s error path um: Remove unused variables um: bury unused _TIF_RESTORE_SIGMASK um: wrong sigmask saved in case of multiple sigframes um: add TIF_NOTIFY_RESUME um: ->restart_block.fn needs to be reset on sigreturn
2012-05-21new helper: sigsuspend()Al Viro
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21Merge branch 'for-um' of ↵Richard Weinberger
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal into for-3.5
2012-05-21um/x86: merge (and trim) 32- and 64-bit variants of ptrace.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21um: Remove usage of irq_chip->release()Richard Weinberger
UML does no longer need irq_chip->release(). Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-21um: Implement um_free_irq()Richard Weinberger
Instead of using chip->release() we can achieve the same using a simple wrapper for free_irq(). We have already um_request_irq(), so um_free_irq() is the perfect counterpart. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-21um: Add BUG() to do_ops()'s error pathRichard Weinberger
In case we encounter a bad operation in do_ops() something is really broken and it's better to BUG(). Signed-off-by: Richard Weinberger <richard@nod.at>
2012-05-21um: wrong sigmask saved in case of multiple sigframesAl Viro
we can't just find oldmask once; if there are multiple signals and we loop building sigframes for those, ->saved_mask will be definitely wrong for all but the first one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21um: add TIF_NOTIFY_RESUMEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21um: ->restart_block.fn needs to be reset on sigreturnAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-05um: Use generic init_taskThomas Gleixner
Same code. Use the generic version. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Richard Weinberger <richard@nod.at> Link: http://lkml.kernel.org/r/20120503085035.592937512@linutronix.de
2012-04-26smp: Add task_struct argument to __cpu_up()Thomas Gleixner
Preparatory patch to make the idle thread allocation for secondary cpus generic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Richard Weinberger <richard@nod.at> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
2012-04-10um: uml_setup_stubs': warning: unused variable 'pages'Boaz Harrosh
Fix the following gcc complain arch/um/kernel/skas/mmu.c: In function 'uml_setup_stubs': arch/um/kernel/skas/mmu.c:106:16: warning: unused variable 'pages' [-Wunused-variable] Signed-Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-04-10um: Use asm-generic/switch_to.hRichard Weinberger
Signed-off-by: Richard Weinberger <richard@nod.at>
2012-04-09um: fix linker script generationAl Viro
while we can't just use -U$(SUBARCH), we still need to kill idiotic define (implicit -Di386=1), both for SUBARCH=i386 and SUBARCH=x86/CONFIG_64BIT=n builds. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-29remove references to cpu_*_map in arch/Rusty Russell
This has been obsolescent for a while; time for the final push. In adjacent context, replaced old cpus_* with cpumask_*. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: David S. Miller <davem@davemloft.net> (arch/sparc) Acked-by: Chris Metcalf <cmetcalf@tilera.com> (arch/tile) Cc: user-mode-linux-devel@lists.sourceforge.net Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Kuo <rkuo@codeaurora.org> Cc: linux-hexagon@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: sparclinux@vger.kernel.org
2012-03-27Merge branch 'for-linus-3.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML changes from Richard Weinberger: "Mostly bug fixes and cleanups" * 'for-linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (35 commits) um: Update defconfig um: Switch to large mcmodel on x86_64 MTD: Relax dependencies um: Wire CONFIG_GENERIC_IO up um: Serve io_remap_pfn_range() Introduce CONFIG_GENERIC_IO um: allow SUBARCH=x86 um: most of the SUBARCH uses can be killed um: deadlock in line_write_interrupt() um: don't bother trying to rebuild CHECKFLAGS for USER_OBJS um: use the right ifdef around exports in user_syms.c um: a bunch of headers can be killed by using generic-y um: ptrace-generic.h doesn't need user.h um: kill HOST_TASK_PID um: remove pointless include of asm/fixmap.h from asm/pgtable.h um: asm-offsets.h might as well come from underlying arch... um: merge processor_{32,64}.h a bit... um: switch close_chan() to struct line um: race fix: initialize delayed_work *before* registering IRQ um: line->have_irq is never checked... ...
2012-03-25um: most of the SUBARCH uses can be killedAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [richard@nod.at: Re-export SUBARCH in arch/um/Makefile] Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: kill HOST_TASK_PIDAl Viro
just provide get_current_pid() to the userland side of things instead of get_current() + manual poking in its results Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-25um: irq: Remove IRQF_DISABLEDYong Zhang
Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled], We run all interrupt handlers with interrupts disabled and we even check and yell when an interrupt handler returns with interrupts enabled (see commit [b738a50a: genirq: Warn when handler enables interrupts]). So now this flag is a NOOP and can be removed. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2012-03-23um: use set_current_blocked() and block_sigmask()Matt Fleming
As described in commit e6fa16ab9c1e ("signal: sigprocmask() should do retarget_shared_pending()") the modification of current->blocked is incorrect as we need to check whether the signal we're about to block is pending in the shared queue. Also, use the new helper function introduced in commit 5e6292c0f28f ("signal: add block_sigmask() for adding sigmask to current->blocked") which centralises the code for updating current->blocked after successfully delivering a signal and reduces the amount of duplicate code across architectures. In the past some architectures got this code wrong, so using this helper function should stop that from happening again. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23um: don't restore current->blocked on errorMatt Fleming
If we fail to setup the signal stack frame then we don't need to restore current->blocked because it is not modified by setup_signal_stack_*. Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Richard Weinberger <richard@nod.at> Tested-by: Richard Weinberger <richard@nod.at> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
2012-03-20um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() ↵Al Viro
doesn't hold it ... while calling uml_dup_mmap() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20um: embed ->stub_pages[] into mmu_contextAl Viro
seriously, kmalloc() for two-element array of pointers? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20um: remove the second argument of k[un]map_atomic()Cong Wang
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-01-17audit: inline audit_syscall_entry to reduce burden on archsEric Paris
Every arch calls: if (unlikely(current->audit_context)) audit_syscall_entry() which requires knowledge about audit (the existance of audit_context) in the arch code. Just do it all in static inline in audit.h so that arch's can remain blissfully ignorant. Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17Audit: push audit success and retcode into arch ptrace.hEric Paris
The audit system previously expected arches calling to audit_syscall_exit to supply as arguments if the syscall was a success and what the return code was. Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things by converting from negative retcodes to an audit internal magic value stating success or failure. This helper was wrong and could indicate that a valid pointer returned to userspace was a failed syscall. The fix is to fix the layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it in turns calls back into arch code to collect the return value and to determine if the syscall was a success or failure. We also define a generic is_syscall_success() macro which determines success/failure based on if the value is < -MAX_ERRNO. This works for arches like x86 which do not use a separate mechanism to indicate syscall failure. We make both the is_syscall_success() and regs_return_value() static inlines instead of macros. The reason is because the audit function must take a void* for the regs. (uml calls theirs struct uml_pt_regs instead of just struct pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit function takes a void* we need to use static inlines to cast it back to the arch correct structure to dereference it. The other major change is that on some arches, like ia64, MIPS and ppc, we change regs_return_value() to give us the negative value on syscall failure. THE only other user of this macro, kretprobe_example.c, won't notice and it makes the value signed consistently for the audit functions across all archs. In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old audit code as the return value. But the ptrace_64.h code defined the macro regs_return_value() as regs[3]. I have no idea which one is correct, but this patch now uses the regs_return_value() function, so it now uses regs[3]. For powerpc we previously used regs->result but now use the regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is always positive so the regs_return_value(), much like ia64 makes it negative before calling the audit code when appropriate. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion] Acked-by: Tony Luck <tony.luck@intel.com> [for ia64] Acked-by: Richard Weinberger <richard@nod.at> [for uml] Acked-by: David S. Miller <davem@davemloft.net> [for sparc] Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
2012-01-06Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, tsc: Skip TSC synchronization checks for tsc=reliable clocksource: Convert tcb_clksrc to use clocksource_register_hz/khz clocksource: cris: Convert to clocksource_register_khz clocksource: xtensa: Convert to clocksource_register_hz/khz clocksource: um: Convert to clocksource_register_hz/khz clocksource: parisc: Convert to clocksource_register_hz/khz clocksource: m86k: Convert to clocksource_register_hz/khz time: x86: Replace LATCH with PIT_LATCH in i8253 clocksource driver time: x86: Remove CLOCK_TICK_RATE from acpi_pm clocksource driver time: x86: Remove CLOCK_TICK_RATE from mach_timer.h time: x86: Remove CLOCK_TICK_RATE from tsc code time: Fix spelling mistakes in new comments time: fix bogus comment in timekeeping_get_ns_raw
2011-12-11nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu()Frederic Weisbecker
Those two APIs were provided to optimize the calls of tick_nohz_idle_enter() and rcu_idle_enter() into a single irq disabled section. This way no interrupt happening in-between would needlessly process any RCU job. Now we are talking about an optimization for which benefits have yet to be measured. Let's start simple and completely decouple idle rcu and dyntick idle logics to simplify. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11nohz: Allow rcu extended quiescent state handling seperately from tick stopFrederic Weisbecker
It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11nohz: Separate out irq exit and idle loop dyntick logicFrederic Weisbecker
The tick_nohz_stop_sched_tick() function, which tries to delay the next timer tick as long as possible, can be called from two places: - From the idle loop to start the dytick idle mode - From interrupt exit if we have interrupted the dyntick idle mode, so that we reprogram the next tick event in case the irq changed some internal state that requires this action. There are only few minor differences between both that are handled by that function, driven by the ts->inidle cpu variable and the inidle parameter. The whole guarantees that we only update the dyntick mode on irq exit if we actually interrupted the dyntick idle mode, and that we enter in RCU extended quiescent state from idle loop entry only. Split this function into: - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters dynticks idle mode unconditionally if it can, and enters into RCU extended quiescent state. - tick_nohz_irq_exit() which only updates the dynticks idle mode when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called). To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed into tick_nohz_idle_exit(). This simplifies the code and micro-optimize the irq exit path (no need for local_irq_save there). This also prepares for the split between dynticks and rcu extended quiescent state logics. We'll need this split to further fix illegal uses of RCU in extended quiescent states in the idle loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-05Merge branch 'fortglx/3.3/tip/timers/core' of ↵Thomas Gleixner
git://git.linaro.org/people/jstultz/linux into timers/core
2011-11-21clocksource: um: Convert to clocksource_register_hz/khzJohn Stultz
This converts the um clocksource to use clocksource_register_hz/khz This is untested, so any assistance in testing would be appreciated! CC: Jeff Dike <jdike@addtoit.com> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com>
2011-11-02um: distribute exports to where exported stuff is definedAl Viro
ksyms.c is down to the stuff defined in various USER_OBJS Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02um: fix gcov build breakageAl Viro
a) exports in gmon_syms.c duplicate kernel/gcov/* ones b) excluding -pg in vdso compile is not enough - -fprofile-arcs and -ftest-coverage also needs to be excluded Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02um: kill shared/tlb.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02um: make flush_tlb_kernel_range_common() staticAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>