summaryrefslogtreecommitdiff
path: root/arch/arm/kernel/process.c
AgeCommit message (Collapse)Author
2016-03-21ARM: disable_nonboot_cpus before poweroffColibri_iMX6_LinuxImageV2.6Beta1_20160331Apalis_iMX6_LinuxImageV2.6Beta1_20160331Stefan Agner
If poweroff takes a bit more time (e.g. due to I2C call), it is quite likely that another timer interrupt fires. Timer interrupt get broadcasted through the timer interrupt callback tick_handle_oneshot_broadcast. This code broadcasts the timer interrupt to all CPU's in tick_broadcast_oneshot_mask. The only function which removes CPU from this mask is tick_shutdown_broadcast_oneshot which ultimately get called by _cpu_down (in kernel/cpu.c). The function disable_nonboot_cpus makes sure that the CPU's get properly taken down and _cpu_down gets called. With that no more broadcasts are sent to CPU's which are no longer online. Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
2015-12-26process.c: if power off fails, do at least a haltMax Krummenacher
Otherwise power_machine_power_off() returns and e.g. unexpected interrupts create stack traces. Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com> Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
2015-09-17ARM: Call idle notifiersTodd Poynor
Change-Id: Id833e61c13baa1783705ac9e9046d1f0cc90c95e Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Todd Poynor <toddpoynor@google.com>
2014-10-05ARM: 8148/1: flush TLS and thumbee register state during execNathan Lynch
commit fbfb872f5f417cea48760c535e0ff027c88b507a upstream. The TPIDRURO and TPIDRURW registers need to be flushed during exec; otherwise TLS information is potentially leaked. TPIDRURO in particular needs careful treatment. Since flush_thread basically needs the same code used to set the TLS in arm_syscall, pull that into a common set_tls helper in tls.h and use it in both places. Similarly, TEEHBR needs to be cleared during exec as well. Clearing its save slot in thread_info isn't right as there is no guarantee that a thread switch will occur before the new program runs. Just setting the register directly is sufficient. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-09ARM: 7912/1: check stack pointer in get_wchanKonstantin Khlebnikov
get_wchan() is lockless. Task may wakeup at any time and change its own stack, thus each next stack frame may be overwritten and filled with random stuff. /proc/$pid/stack interface had been disabled for non-current tasks, see [1] But 'wchan' still allows to trigger stack frame unwinding on volatile stack. This patch fixes oops in unwind_frame() by adding stack pointer validation on each step (as x86 code do), unwind_frame() already checks frame pointer. Also I've found another report of this oops on stackoverflow (irony). Link: http://www.spinics.net/lists/arm-kernel/msg110589.html [1] Link: http://stackoverflow.com/questions/18479894/unwind-frame-cause-a-kernel-paging-error Cc: <stable@vger.kernel.org> Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-13Merge branch 'security-fixes' into fixesRussell King
2013-08-07ARM: Fix the world famous typo with is_gate_vma()Russell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-03Merge branch 'security-fixes' into fixesRussell King
2013-08-03ARM: fix a cockup in 48be69a02 (ARM: move signal handlers into a vdso-like page)Russell King
Unfortunately, I never committed the fix to a nasty oops which can occur as a result of that commit: ------------[ cut here ]------------ kernel BUG at /home/olof/work/batch/include/linux/mm.h:414! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 490 Comm: killall5 Not tainted 3.11.0-rc3-00288-gabe0308 #53 task: e90acac0 ti: e9be8000 task.ti: e9be8000 PC is at special_mapping_fault+0xa4/0xc4 LR is at __do_fault+0x68/0x48c This doesn't show up unless you do quite a bit of testing; a simple boot test does not do this, so all my nightly tests were passing fine. The reason for this is that install_special_mapping() expects the page array to stick around, and as this was only inserting one page which was stored on the kernel stack, that's why this was blowing up. Reported-by: Olof Johansson <olof@lixom.net> Tested-by: Olof Johansson <olof@lixom.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01Merge branch 'security-fixes' into fixesRussell King
2013-08-01ARM: 7803/1: Fix deadlock scenario with smp_send_stop()Stephen Boyd
If one process calls sys_reboot and that process then stops other CPUs while those CPUs are within a spin_lock() region we can potentially encounter a deadlock scenario like below. CPU 0 CPU 1 ----- ----- spin_lock(my_lock) smp_send_stop() <send IPI> handle_IPI() disable_preemption/irqs while(1); <PREEMPT> spin_lock(my_lock) <--- Waits forever We shouldn't attempt to run any other tasks after we send a stop IPI to a CPU so disable preemption so that this task runs to completion. We use local_irq_disable() here for cross-arch consistency with x86. Reported-by: Sundarajan Srinivasan <sundaraj@codeaurora.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01ARM: make vectors page inaccessible from userspaceRussell King
If kuser helpers are not provided by the kernel, disable user access to the vectors page. With the kuser helpers gone, there is no reason for this page to be visible to userspace. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01ARM: move signal handlers into a vdso-like pageRussell King
Move the signal handlers into a VDSO page rather than keeping them in the vectors page. This allows us to place them randomly within this page, and also map the page at a random location within userspace further protecting these code fragments from ROP attacks. The new VDSO page is also poisoned in the same way as the vector page. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-09reboot: move arch/x86 reboot= handling to generic kernelRobin Holt
Merge together the unicore32, arm, and x86 reboot= command line parameter handling. Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09reboot: arm: change reboot_mode to use enum reboot_modeRobin Holt
Preparing to move the parsing of reboot= to generic kernel code forces the change in reboot_mode handling to use the enum. [akpm@linux-foundation.org: fix arch/arm/mach-socfpga/socfpga.c] Signed-off-by: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09reboot: arm: prepare reboot_mode for moving to generic kernel codeRobin Holt
Prepare for the moving the parsing of reboot= to the generic kernel code by making reboot_mode into a more generic form. Signed-off-by: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-29Merge branches 'fixes', 'mcpm', 'misc' and 'mmci' into for-nextRussell King
2013-06-24ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and forkAndré Hentschel
Since commit 6a1c53124aa1 the user writeable TLS register was zeroed to prevent it from being used as a covert channel between two tasks. There are more and more applications coming to Windows RT, Wine could support them, but mostly they expect to have the thread environment block (TEB) in TPIDRURW. This patch preserves that register per thread instead of clearing it. Unlike the TPIDRURO, which is already switched, the TPIDRURW can be updated from userspace so needs careful treatment in the case that we modify TPIDRURW and call fork(). To avoid this we must always read TPIDRURW in copy_thread. Signed-off-by: André Hentschel <nerv@dawncrow.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-17ARM: 7759/1: decouple CPU offlining from reboot/shutdownStephen Warren
Add comments to machine_shutdown()/halt()/power_off()/restart() that describe their purpose and/or requirements re: CPUs being active/not. In machine_shutdown(), replace the call to smp_send_stop() with a call to disable_nonboot_cpus(). This completely disables all but one CPU, thus satisfying the requirement that only a single CPU be active for kexec. Adjust Kconfig dependencies for this change. In machine_halt()/power_off()/restart(), call smp_send_stop() directly, rather than via machine_shutdown(); these functions don't need to completely de-activate all CPUs using hotplug, but rather just quiesce them. Remove smp_kill_cpus(), and its call from smp_send_stop(). smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling smp_ops.cpu_die() on the target CPUs first. At least some implementations of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra, for example. Since smp_send_stop() is only used for shutdown, halt, and power-off, there is no need to attempt any kind of CPU hotplug here. Adjust Kconfig to reflect that machine_shutdown() (and hence kexec) relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee that hotplug will work, or even that hotplug is implemented for a particular piece of HW that a multi-platform zImage runs on. Hence, add error-checking to machine_kexec() to determine whether it did work. Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Zhangfei Gao <zhangfei.gao@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-05-22ARM: 7727/1: remove the .vm_mm value from gate_vmaSteven Capper
If one reads /proc/$PID/smaps, the mmap_sem belonging to the address space of the task being examined is locked for reading. All the pages of the vmas belonging to the task's address space are then walked with this lock held. If a gate_vma is present in the architecture, it too is examined by the fs/proc/task_mmu.c code. As gate_vma doesn't belong to the address space of the task though, its pages are not walked. A recent cleanup (commit f6604efe) of the gate_vma initialisation code set the vm_mm value to &init_mm. Unfortunately a non-NULL vm_mm value in the gate_vma will cause the task_mmu code to attempt to walk the pages of the gate_vma (with no mmap-sem lock held). If one enables Transparent Huge Page support and vm debugging, this will then cause OOPses as pmd_trans_huge_lock is called without mmap_sem being locked. This patch removes the .vm_mm value from gate_vma, restoring the original behaviour of the task_mmu code. Signed-off-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-05-03Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: "The major items included in here are: - MCPM, multi-cluster power management, part of the infrastructure required for ARMs big.LITTLE support. - A rework of the ARM KVM code to allow re-use by ARM64. - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes of that stuff for arch/arm - Preparatory patches for Cortex-M3 support from Uwe Kleine-König. There is also a set of three patches in here from Hugh/Catalin to address freeing of inappropriate page tables on LPAE. You already have these from akpm, but they were already part of my tree at the time he sent them, so unfortunately they'll end up with duplicate commits" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits) ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE() ARM: IMX: remove unnecessary use of IS_ERR_VALUE() ARM: OMAP: use consistent error checking ARM: cleanup: OMAP hwmod error checking ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels ARM: 7700/2: Make cpu_init() notrace ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE ARM: 7701/1: mm: Allow arch code to control the user page table ceiling ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum() ARM: mcpm: provide an interface to set the SMP ops at run time ARM: mcpm: generic SMP secondary bringup and hotplug support ARM: mcpm_head.S: vlock-based first man election ARM: mcpm: Add baremetal voting mutexes ARM: mcpm: introduce helpers for platform coherency exit/setup ARM: mcpm: introduce the CPU/cluster power API ARM: multi-cluster PM: secondary kernel entry code ARM: cacheflush: add synchronization helpers for mixed cache state accesses ARM: cpu hotplug: remove majority of cache flushing from platforms ARM: smp: flush L1 cache in cpu_die() ARM: tegra: remove tegra specific cpu_disable() ...
2013-05-02Merge branch 'cleanup' into for-linusRussell King
Conflicts: arch/arm/plat-omap/dmtimer.c
2013-04-30dump_stack: unify debug information printed by show_regs()Tejun Heo
show_regs() is inherently arch-dependent but it does make sense to print generic debug information and some archs already do albeit in slightly different forms. This patch introduces a generic function to print debug information from show_regs() so that different archs print out the same information and it's much easier to modify what's printed. show_regs_print_info() prints out the same debug info as dump_stack() does plus task and thread_info pointers. * Archs which didn't print debug info now do. alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r, metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc, um, xtensa * Already prints debug info. Replaced with show_regs_print_info(). The printed information is superset of what used to be there. arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86 * s390 is special in that it used to print arch-specific information along with generic debug info. Heiko and Martin think that the arch-specific extra isn't worth keeping s390 specfic implementation. Converted to use the generic version. Note that now all archs print the debug info before actual register dumps. An example BUG() dump follows. kernel BUG at /work/os/work/kernel/workqueue.c:4841! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000 RIP: 0010:[<ffffffff8234a07e>] [<ffffffff8234a07e>] init_workqueues+0x4/0x6 RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760 Call Trace: [<ffffffff81000312>] do_one_initcall+0x122/0x170 [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8 [<ffffffff81c47760>] ? rest_init+0x140/0x140 [<ffffffff81c4776e>] kernel_init+0xe/0xf0 [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0 [<ffffffff81c47760>] ? rest_init+0x140/0x140 ... v2: Typo fix in x86-32. v3: CPU number dropped from show_regs_print_info() as dump_stack_print_info() has been updated to print it. s390 specific implementation dropped as requested by s390 maintainers. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-08arm: Use generic idle loopThomas Gleixner
Use the generic idle loop and replace enable/disable_hlt with the respective core functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Tested-by: Kevin Hilman <khilman@linaro.org> # OMAP Link: http://lkml.kernel.org/r/20130321215233.826238797@linutronix.de
2013-04-08arch: Cleanup enable/disable_hltThomas Gleixner
enable/disable_hlt() does not need to be exported and can be killed on architectures which do not use it at all. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.377959540@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-02-23ARM: cleanup gate_vma initializationRussell King
Three's no need to have code initializing this by hand; it's more efficient to initialize the constant structure members directly. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-02-17ARM idle: delete pm_idleLen Brown
pm_idle() on ARM was a synonym for default_idle(), so simply invoke default_idle() directly. Signed-off-by: Len Brown <len.brown@intel.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org>
2012-12-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild
2012-11-28flagday: don't pass regs to copy_thread()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28arm: switch to generic fork/vfork/cloneAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-13ARM: 7574/1: kernel/process.c: include idmap.h instead of redeclaring ↵Nicolas Pitre
setup_mm_for_reboot() Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-18ARM: 7544/1: Add BUG_ON when hlt counter is wrongly usedfwu
1. On ARM platform, "nohlt" can be used to prevent core from idle process, returning immediately. 2. There are two interfaces, exported for other modules, named "disable_hlt" and "enable_hlt" are used to enable/disable the cpuidle mechanism by increasing/decreasing "hlt_counter". Disable_hlt and enable_hlt are paired operation, when you first call disable_hlt and then enable_hlt, the semantics are right. 3. There is no obvious constraint to prevent user(driver/module) code to prevent the case that enable_hlt is ahead of disable_hlt, which is a fatal operation on kernel state change from user, and there is no any WARNING or notification if the case happens in current kernel code. This patch aims to report BUG when the case happens, just like what the kernel do when enable_irq is ahead of disable_irq. Link: https://patchwork.kernel.org/patch/1527881/ Signed-off-by: fwu <fwu@marvell.com> Signed-off-by: YiLu Mao <ylmao@marvell.com> Signed-off-by: Ning Jiang <ning.jiang@marvell.com> Acked-by: Nicolas Pitre Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull third pile of kernel_execve() patches from Al Viro: "The last bits of infrastructure for kernel_thread() et.al., with alpha/arm/x86 use of those. Plus sanitizing the asm glue and do_notify_resume() on alpha, fixing the "disabled irq while running task_work stuff" breakage there. At that point the rest of kernel_thread/kernel_execve/sys_execve work can be done independently for different architectures. The only pending bits that do depend on having all architectures converted are restrictred to fs/* and kernel/* - that'll obviously have to wait for the next cycle. I thought we'd have to wait for all of them done before we start eliminating the longjump-style insanity in kernel_execve(), but it turned out there's a very simple way to do that without flagday-style changes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to saner kernel_execve() semantics arm: switch to saner kernel_execve() semantics x86, um: convert to saner kernel_execve() semantics infrastructure for saner ret_from_kernel_thread semantics make sure that kernel_thread() callbacks call do_exit() themselves make sure that we always have a return path from kernel_execve() ppc: eeh_event should just use kthread_run() don't bother with kernel_thread/kernel_execve for launching linuxrc alpha: get rid of switch_stack argument of do_work_pending() alpha: don't bother passing switch_stack separately from regs alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c alpha: simplify TIF_NEED_RESCHED handling
2012-10-12arm: switch to saner kernel_execve() semanticsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
2012-09-30arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-13Merge branch 'for-arm-soc' of ↵Arnd Bergmann
git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds into next/drivers From Bryan Wu <bryan.wu@canonical.com>: Based on Linus Walleij's ARM LED consolidation work, this patchset introduce a new generic led trigger for CPU not only for ARM but also for others. For enabling CPU idle event, CPU arch code should call ledtrig_cpu() stub to trigger idle start or idle end event. These patches convert old style LED driver in arch/arm to gpio_led or new led driver interface. Against 3.5 release and build successfully for all the machines. Test ledtrig-cpu driver on OMAP4 Panda board. v9 --> v10 * fix compiling issue on versatile_defconfig reported by Russell King * rebase to 3.5 kernel and move patches to new git tree v8 --> v9: * use mutex to replace rw_sema pointed out by Tim Gardner * add a new struct led_trigger_cpu * add lock_is_inited to record mutex lock initialization v6 --> v7: * add a patch to unify the led-trigger name * fix some typo pointed * use BUG_ON to detect CPU numbers during building stage v5 --> v6: * replace __get_cpu_var() to per_cpu() * remove smp_processor_id() which is wrong with for_each_possible_cpu() * test on real OMAP4 Panda board * add comments about CPU hotplug in the CPU LED trigger driver v4 --> v5: * rebase all the patches on top of latest linux-next * replace on_each_cpu() with for_each_possible_cpu() * add some description of ledtrig_cpu() API * remove old leds code from driver nwflash.c, which should use a new led trigger then * this trigger driver can be built as module now v3 --> v4: * fix a typo pointed by Jochen Friedrich * fix some building errors * add Reviewed-by and Tested-by into patch log v2 --> v3: * almost rewrote the whole ledtrig-cpu driver, which is more simple * every CPU will have a per-CPU trigger * cpu trigger can be assigned to any leds * fix a lockdep issue in led-trigger common code * other fix according to review v1 --> v2: * remove select operations in Kconfig of every machines * add back supporting of led in core module of mach-integrator * solidate name scheme in ledtrig-cpu.c * add comments of CPU_LED_* cpu led events * fold patches of RealView and Versatile together * add machine_is_ check during assabet led driver init * add some Acked-by in patch logs * remove code for simpad machine in machine-sa11000, since Jochen Friedrich introduced gpiolib and gpio-led driver for simpad * on Assabet and Netwinder machine, LED operations is reversed like: setting bit means turn off leds clearing bit means turn on leds * add a new function to read CM_CTRL register for led driver * 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: ARM: use new LEDS CPU trigger stub to replace old one ARM: mach-sa1100: retire custom LED code ARM: mach-omap1: retire custom LED code ARM: mach-pnx4008: remove including old leds event API header file ARM: plat-samsung: remove including old leds event API header file ARM: mach-pxa: retire custom LED code char: nwflash: remove old led event code ARM: mach-footbridge: retire custom LED code ARM: mach-ebsa110: retire custom LED code ARM: mach-clps711x: retire custom LED code of P720T machine ARM: mach-integrator: retire custom LED code ARM: mach-integrator: move CM_CTRL to header file for accessing by other functions ARM: mach-orion5x: convert custom LED code to gpio_led and LED CPU trigger ARM: mach-shark: retire custom LED code ARM: mach-ks8695: remove leds driver, since nobody use it ARM: mach-realview and mach-versatile: retire custom LED code ARM: at91: convert old leds drivers to gpio_led and led_trigger drivers led-triggers: create a trigger for CPU activity Conflicts: arch/arm/mach-clps711x/p720t.c arch/arm/mach-sa1100/leds-cerf.c arch/arm/mach-sa1100/leds-lart.c Let's hope this is the last time we pull this and it doesn't cause more trouble. I have verified that version 10 causes no build warnings or errors any more, and the patches still look good. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-08-01ARM: use new LEDS CPU trigger stub to replace old oneBryan Wu
Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-31ARM: 7466/1: disable interrupt before spinning endlesslyShawn Guo
The CPU will endlessly spin at the end of machine_halt and machine_restart calls. However, this will lead to a soft lockup warning after about 20 seconds, if CONFIG_LOCKUP_DETECTOR is enabled, as system timer is still alive. Disable interrupt before going to spin endlessly, so that the lockup warning will never be seen. Cc: <stable@vger.kernel.org> Reported-by: Marek Vasut <marex@denx.de> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-08arm: Remove unused cpu_idle_wait()Thomas Gleixner
cpuidle uses a generic function now. Remove the unused code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Link: http://lkml.kernel.org/r/20120507175652.260797846@linutronix.de
2012-03-29Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull more ARM updates from Russell King. This got a fair number of conflicts with the <asm/system.h> split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ...
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Disintegrate asm/system.h for ARMDavid Howells
Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org
2012-03-27Merge branch 'devel-stable' into for-linusRussell King
Conflicts: arch/arm/Kconfig.debug arch/arm/plat-versatile/Kconfig Merge fixes: arch/arm/mach-integrator/Kconfig drivers/clocksource/Kconfig
2012-03-24ARM: 7294/1: vectors: use gate_vma for vectors user mappingWill Deacon
The current user mapping for the vectors page is inserted as a `horrible hack vma' into each task via arch_setup_additional_pages. This causes problems with the MM subsystem and vm_normal_page, as described here: https://lkml.org/lkml/2012/1/14/55 Following the suggestion from Hugh in the above thread, this patch uses the gate_vma for the vectors user mapping, therefore consolidating the horrible hack VMAs into one. Acked-and-Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-23Merge branch 'for-armsoc' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull #1 ARM updates from Russell King: "This one covers stuff which Arnd is waiting for me to push, as this is shared between both our trees and probably other trees elsewhere. Essentially, this contains: - AMBA primecell device initializer updates - mostly shrinking the size of the device declarations in platform code to something more reasonable. - Getting rid of the NO_IRQ crap from AMBA primecell stuff. - Nicolas' idle cleanups. This in combination with the restart cleanups from the last merge window results in a great many mach/system.h files being deleted." Yay: ~80 files, ~2000 lines deleted. * 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm: (60 commits) ARM: remove disable_fiq and arch_ret_to_user macros ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLER ARM: rpc: make default fiq handler run-time installed ARM: make arch_ret_to_user macro optional ARM: amba: samsung: use common amba device initializers ARM: amba: spear: use common amba device initializers ARM: amba: nomadik: use common amba device initializers ARM: amba: u300: use common amba device initializers ARM: amba: lpc32xx: use common amba device initializers ARM: amba: netx: use common amba device initializers ARM: amba: bcmring: use common amba device initializers ARM: amba: ep93xx: use common amba device initializers ARM: amba: omap2: use common amba device initializers ARM: amba: integrator: use common amba device initializers ARM: amba: realview: get rid of private platform amba_device initializer ARM: amba: versatile: get rid of private platform amba_device initializer ARM: amba: vexpress: get rid of private platform amba_device initializer ARM: amba: provide common initializers for static amba devices ARM: amba: make use of -1 IRQs warn ARM: amba: u300: get rid of NO_IRQ initializers ...
2012-03-23coredump: remove VM_ALWAYSDUMP flagJason Baron
The motivation for this patchset was that I was looking at a way for a qemu-kvm process, to exclude the guest memory from its core dump, which can be quite large. There are already a number of filter flags in /proc/<pid>/coredump_filter, however, these allow one to specify 'types' of kernel memory, not specific address ranges (which is needed in this case). Since there are no more vma flags available, the first patch eliminates the need for the 'VM_ALWAYSDUMP' flag. The flag is used internally by the kernel to mark vdso and vsyscall pages. However, it is simple enough to check if a vma covers a vdso or vsyscall page without the need for this flag. The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new 'VM_NODUMP' flag, which can be set by userspace using new madvise flags: 'MADV_DONTDUMP', and unset via 'MADV_DODUMP'. The core dump filters continue to work the same as before unless 'MADV_DONTDUMP' is set on the region. The qemu code which implements this features is at: http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch In my testing the qemu core dump shrunk from 383MB -> 13MB with this patch. I also believe that the 'MADV_DONTDUMP' flag might be useful for security sensitive apps, which might want to select which areas are dumped. This patch: The VM_ALWAYSDUMP flag is currently used by the coredump code to indicate that a vma is part of a vsyscall or vdso section. However, we can determine if a vma is in one these sections by checking it against the gate_vma and checking for a non-NULL return value from arch_vma_name(). Thus, freeing a valuable vma bit. Signed-off-by: Jason Baron <jbaron@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-01sched/rt: Use schedule_preempt_disabled()Thomas Gleixner
Coccinelle based conversion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-20ARM: substitute arch_idle()Nicolas Pitre
Now that all implementations of arch_idle() are equivalent to cpu_do_idle() we can just use the later directly and stop including mach/system.h. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com> Acked-by: Tony Lindgren <tony@atomide.com> Tested-by: Stephen Warren <swarren@nvidia.com>
2012-01-20ARM: clean up idle handlersNicolas Pitre
Let's factor out the need_resched() check instead of having it duplicated in every pm_idle implementations to avoid inconsistencies (omap2_pm_idle is missing it already). The forceful re-enablement of IRQs after pm_idle has returned can go. The warning certainly doesn't trigger for existing users. To get rid of the pm_idle calling convention oddity, let's introduce arm_pm_idle() allowing for the local_irq_enable() to be factored out from SOC specific implementations. The default pm_idle function becomes a wrapper for arm_pm_idle and it takes care of enabling IRQs closer to where they are initially disabled. And finally move the comment explaining the reason for that turning off of IRQs to a more proper location. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>