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2011-07-02ARM: entry: data abort: arrange for CPU abort helpers to take pc/psr in r4/r5Russell King1-4/+2
Re-jig the CPU abort helpers to take the PC/PSR in r4/r5 rather than r2/r3. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: prefetch abort: tail-call the main prefetch abort handlerRussell King1-5/+3
Tail-call the main C prefetch abort handler code from the per-CPU helper code. Also note that the helper function becomes ABI compliant in terms of the registers preserved. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: re-allocate registers in irq entry assembly macrosRussell King1-5/+5
This avoids the irq entry assembly corrupting r5, thereby allowing it to be preserved through to the svc exit code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: consolidate trace_hardirqs_off into (svc|usr)_entry macrosRussell King1-39/+8
All handlers now call trace_hardirqs_off, so move this common code into the (svc|usr)_entry assembler macros. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: instrument usr exception handlers with irqsoff tracingRussell King1-1/+16
As we no longer re-enable interrupts in these exception handlers, add the irqsoff tracing calls to them so that the kernel tracks the state more accurately. Note that these calls are conditional on IRQSOFF_TRACER: kernel ----------> user ---------> kernel ^ irqs enabled ^ irqs disabled No kernel code can run on the local CPU until we've re-entered the kernel through one of the exception handlers - and userspace can not take any locks etc. So, the kernel doesn't care about the IRQ mask state while userspace is running unless we're doing IRQ off latency tracing. So, we can (and do) avoid the overhead of updating the IRQ mask state on every kernel->user and user->kernel transition. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: instrument svc undefined exception handler with irqtraceRussell King1-0/+10
Add irqtrace function calls to the undefined exception handler, so that we get sane lockdep traces from locking problems in undefined exception handlers. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: avoid enabling interrupts in prefetch/data abort handlersRussell King3-50/+24
Avoid enabling interrupts if the parent context had interrupts enabled in the abort handler assembly code, and move this into the breakpoint/ page/alignment fault handlers instead. This gets rid of some special-casing for the breakpoint fault handlers from the low level abort handler path. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-30ARM: entry: prefetch abort helper: pass aborted pc in r4 rather than r0Russell King1-1/+1
This avoids unnecessary instructions for CPUs which implement the IFAR (instruction fault address register). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-30ARM: entry: rejig register allocation in exception entry handlersRussell King1-38/+43
This allows us to avoid moving registers twice to work around the clobbered registers when we add calls to trace_hardirqs_{on,off}. Ensure that all SVC handlers return with SPSR in r5 for consistency. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: no need to check parent IRQ mask in IRQ handler returnRussell King1-2/+3
There's no point checking to see whether IRQs were masked in the parent context when returning from IRQ handling - the fact that we're handling an IRQ means that the parent context must have had IRQs unmasked. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: no need to increase preempt count for IRQ handlersRussell King1-23/+4
irq_enter() and irq_exit() already take care of the preempt_count handling for interrupts, which increment and decrement the hardirq bits of the preempt count. So we can remove the preempt count handing in our IRQ entry/exit assembly, like x86 did some 9 years ago. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: prefetch/data abort helpers: avoid corrupting r4Russell King1-4/+4
Replace r4 with ip for calling abort helpers - ip is allowed to be corrupted by called functions in the ABI, so it makes more sense to use such a register. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: prefetch/data abort helpers: convert to macrosRussell King1-50/+35
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-21ARM: SMP: wait for CPU to be marked activeRussell King1-1/+5
When we bring a CPU online, we should wait for it to become active before entering the idle thread, so we know that the scheduler and thread migration is going to work. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-17ARM: 6963/1: Thumb-2: Relax relocation requirements for non-function symbolsDave Martin1-2/+11
The "Thumb bit" of a symbol is only really meaningful for function symbols (STT_FUNC). However, sometimes a branch is relocated against a non-function symbol; for example, PC-relative branches to anonymous assembler local symbols are typically fixed up against the start-of-section symbol, which is not a function symbol. Some inline assembler generates references of this type, such as fixup code generated by macros in <asm/uaccess.h>. The existing relocation code for R_ARM_THM_CALL/R_ARM_THM_JUMP24 interprets this case as an error, because the target symbol appears to be an ARM symbol; but this is really not the case, since the target symbol is just a base in these cases. The addend defines the precise offset to the target location, but since the addend is encoded in a non-interworking Thumb branch instruction, there is no explicit Thumb bit in the addend. Because these instructions never interwork, the implied Thumb bit in the addend is 1, and the destination is Thumb by definition. This patch removes the extraneous Thumb bit check for non-function symbols, enabling modules containing the affected relocation types to be loaded. No modification to the actual relocation code is required, since this code does not take bit[0] of the location->destination offset into account in any case. Function symbols are always checked for interworking conflicts, as before. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-09ARM: extend Code: line by one 16-bit quantity for Thumb instructionsRussell King1-1/+1
Dump out the following 16-bit instruction to the faulting instruction in the Code: line. This allows Thumb-2 instructions to be properly encoded. Tested-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-09ARM: 6955/1: cmpxchg syscall should data abort if page not writePo-Yu Chuang1-1/+1
If the page to cmpxchg is user mode read only (not write), we should simulate a data abort first. Signed-off-by: Po-Yu Chuang <ratbert@faraday-tech.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-09ARM: 6953/1: DT: don't try to access physical address zeroNicolas Pitre1-0/+3
If the DT physical address is zero, this is equivalent to no DT. Especially when the actual RAM physical address is not located at zero, the result of phys_to_virt() would point to la-la-land and crash the kernel, which crash is completely silent this early during boot. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-06ARM: 6952/1: fix lockdep warning of "unannotated irqs-off"Ming Lei2-1/+7
This patch fixes the lockdep warning of "unannotated irqs-off"[1]. After entering __irq_usr, arm core will disable interrupt automatically, but __irq_usr does not annotate the irq disable, so lockdep may complain the warning if it has chance to check this in irq handler. This patch adds trace_hardirqs_off in __irq_usr before entering irq_handler to handle the irq, also calls ret_to_user_from_irq to avoid calling disable_irq again. This is also a fix for irq off tracer. [1], lockdep warning log of "unannotated irqs-off" [ 13.804687] ------------[ cut here ]------------ [ 13.809570] WARNING: at kernel/lockdep.c:3335 check_flags+0x78/0x1d0() [ 13.816467] Modules linked in: [ 13.819732] Backtrace: [ 13.822357] [<c01cb42c>] (dump_backtrace+0x0/0x100) from [<c06abb14>] (dump_stack+0x20/0x24) [ 13.831268] r6:c07d8c2c r5:00000d07 r4:00000000 r3:00000000 [ 13.837280] [<c06abaf4>] (dump_stack+0x0/0x24) from [<c01ffc04>] (warn_slowpath_common+0x5c/0x74) [ 13.846649] [<c01ffba8>] (warn_slowpath_common+0x0/0x74) from [<c01ffc48>] (warn_slowpath_null+0x2c/0x34) [ 13.856781] r8:00000000 r7:00000000 r6:c18b8194 r5:60000093 r4:ef182000 [ 13.863708] r3:00000009 [ 13.866485] [<c01ffc1c>] (warn_slowpath_null+0x0/0x34) from [<c0237d84>] (check_flags+0x78/0x1d0) [ 13.875823] [<c0237d0c>] (check_flags+0x0/0x1d0) from [<c023afc8>] (lock_acquire+0x4c/0x150) [ 13.884704] [<c023af7c>] (lock_acquire+0x0/0x150) from [<c06af638>] (_raw_spin_lock+0x4c/0x84) [ 13.893798] [<c06af5ec>] (_raw_spin_lock+0x0/0x84) from [<c01f9a44>] (sched_ttwu_pending+0x58/0x8c) [ 13.903320] r6:ef92d040 r5:00000003 r4:c18b8180 [ 13.908233] [<c01f99ec>] (sched_ttwu_pending+0x0/0x8c) from [<c01f9a90>] (scheduler_ipi+0x18/0x1c) [ 13.917663] r6:ef183fb0 r5:00000003 r4:00000000 r3:00000001 [ 13.923645] [<c01f9a78>] (scheduler_ipi+0x0/0x1c) from [<c01bc458>] (do_IPI+0x9c/0xfc) [ 13.932006] [<c01bc3bc>] (do_IPI+0x0/0xfc) from [<c06b0888>] (__irq_usr+0x48/0xe0) [ 13.939971] Exception stack(0xef183fb0 to 0xef183ff8) [ 13.945281] 3fa0: ffffffc3 0001500c 00000001 0001500c [ 13.953948] 3fc0: 00000050 400b45f0 400d9000 00000000 00000001 400d9600 6474e552 bea05b3c [ 13.962585] 3fe0: 400d96c0 bea059c0 400b6574 400b65d8 20000010 ffffffff [ 13.969573] r6:00000403 r5:fa240100 r4:ffffffff r3:20000010 [ 13.975585] ---[ end trace efc4896ab0fb62cb ]--- [ 13.980468] possible reason: unannotated irqs-off. [ 13.985534] irq event stamp: 1610 [ 13.989044] hardirqs last enabled at (1610): [<c01c703c>] no_work_pending+0x8/0x2c [ 13.997131] hardirqs last disabled at (1609): [<c01c7024>] ret_slow_syscall+0xc/0x1c [ 14.005371] softirqs last enabled at (0): [<c01fe5e4>] copy_process+0x2cc/0xa24 [ 14.013183] softirqs last disabled at (0): [< (null)>] (null) Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-28Merge branch 'setns'Linus Torvalds1-0/+1
* setns: ns: Wire up the setns system call Done as a merge to make it easier to fix up conflicts in arm due to addition of sendmmsg system call
2011-05-28ns: Wire up the setns system callEric W. Biederman1-0/+1
32bit and 64bit on x86 are tested and working. The rest I have looked at closely and I can't find any problems. setns is an easy system call to wire up. It just takes two ints so I don't expect any weird architecture porting problems. While doing this I have noticed that we have some architectures that are very slow to get new system calls. cris seems to be the slowest where the last system calls wired up were preadv and pwritev. avr32 is weird in that recvmmsg was wired up but never declared in unistd.h. frv is behind with perf_event_open being the last syscall wired up. On h8300 the last system call wired up was epoll_wait. On m32r the last system call wired up was fallocate. mn10300 has recvmmsg as the last system call wired up. The rest seem to at least have syncfs wired up which was new in the 2.6.39. v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com> v4: Moved wiring up of the system call to another patch v5: ported to v2.6.39-rc6 v6: rebased onto parisc-next and net-next to avoid syscall conflicts. v7: ported to Linus's latest post 2.6.39 tree. >  arch/blackfin/include/asm/unistd.h     |    3 ++- >  arch/blackfin/mach-common/entry.S      |    1 + Acked-by: Mike Frysinger <vapier@gentoo.org> Oh - ia64 wiring looks good. Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-27Merge branches 'devel', 'devel-stable' and 'fixes' into for-linusRussell King7-44/+233
2011-05-26ARM: 6942/1: mm: make TTBR1 always point to swapper_pg_dir on ARMv6/7Catalin Marinas2-2/+6
This patch makes TTBR1 point to swapper_pg_dir so that global, kernel mappings can be used exclusively on v6 and v7 cores where they are needed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26ARM: add sendmmsg syscallRussell King1-0/+1
Commit 228e548e (net: Add sendmmsg socket system call) added the new sendmmsg syscall. Add this to the syscall table for ARM. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2Dave Martin3-44/+52
* To remove the risk of inconvenient register allocation decisions by the compiler, these functions are separated out as pure assembler. * The apcs frame manipulation code is not applicable for Thumb-2 (and also not easily compatible). Since it's not essential to have a full frame on these leaf assembler functions, the frame manipulation is removed, in the interests of simplicity. * Split up ldm/stm instructions to be compatible with Thumb-2, as well as avoiding instruction forms deprecated on >= ARMv7. Signed-off-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26Merge branch 'for-rmk' of git://github.com/at91linux/linux-2.6-at91 into ↵Russell King1-1/+1
devel-stable
2011-05-25Merge branch 'devicetree/arm-next' of git://git.secretlab.ca/git/linux-2.6 ↵Russell King5-42/+226
into devel-stable
2011-05-24Merge branch 'for-2.6.40' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: Unify input section names percpu: Avoid extra NOP in percpu_cmpxchg16b_double percpu: Cast away printk format warning percpu: Always align percpu output section to PAGE_SIZE Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun
2011-05-23Merge branches 'consolidate', 'ep93xx', 'fixes', 'misc', 'mmci', 'remove' ↵Russell King3-118/+248
and 'spear' into for-linus
2011-05-23Merge branches 'consolidate-clksrc', 'consolidate-flash', ↵Russell King1-0/+7
'consolidate-generic', 'consolidate-smp', 'consolidate-stmp' and 'consolidate-zones' into consolidate
2011-05-23ARM: consolidate SMP cross call implementationRussell King1-0/+7
Rather than having each platform class provide a mach/smp.h header for smp_cross_call(), arrange for them to register the function with the core ARM SMP code instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23arm/dt: probe for platforms via the device treeGrant Likely2-4/+117
If a dtb is passed to the kernel then the kernel needs to iterate through compiled-in mdescs looking for one that matches and move the dtb data to a safe location before it gets accidentally overwritten by the kernel. This patch creates a new function, setup_machine_fdt() which is analogous to the setup_machine_atags() created in the previous patch. It does all the early setup needed to use a device tree machine description. v5: - Print warning with neither dtb nor atags are passed to the kernel - Fix bug in setting of __machine_arch_type to the selected machine, not just the last machine in the list. Reported-by: Tixy <tixy@yxit.co.uk> - Copy command line directly into boot_command_line instead of cmd_line v4: - Dump some output when a matching machine_desc cannot be found v3: - Added processing of reserved list. - Backed out the v2 change that copied instead of reserved the dtb. dtb is reserved again and the real problem was fixed by using alloc_bootmem_align() for early allocation of RAM for unflattening the tree. - Moved cmd_line and initrd changes to earlier patch to make series bisectable. v2: Changed to save the dtb by copying into an allocated buffer. - Since the dtb will very likely be passed in the first 16k of ram where the interrupt vectors live, memblock_reserve() is insufficient to protect the dtb data. [based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>] Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-23arm/dt: consolidate atags setup into setup_machine_atagsGrant Likely1-29/+40
In preparation for adding device tree support, this patch consolidates all of the atag-specific setup into a single function. v5: - drop double printk("Machine; %s\n", ...); call. - leave copying boot_command_line in setup_arch() since it isn't atags specific. v4: - adapt to the removal of lookup_machine_type() - break out dump of machine_desc table into dump_machine_table() because the device tree probe code will use it. - Add for_each_machine_desc() macro Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-20ARM: 6902/1: perf: Remove erroneous check on active_eventsMark Rutland1-5/+0
When initialising a PMU, there is a check to protect against races with other CPUs filling all of the available event slots. Since armpmu_add checks that an event can be scheduled, we do not need to do this at initialisation time. Furthermore the current code is broken because it assumes that atomic_inc_not_zero will unconditionally increment active_counts and then tries to decrement it again on failure. This patch removes the broken, redundant code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-19Merge branch 'driver-core-next' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits) debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning sysfs: remove "last sysfs file:" line from the oops messages drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION" memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION SYSFS: Fix erroneous comments for sysfs_update_group(). driver core: remove the driver-model structures from the documentation driver core: Add the device driver-model structures to kerneldoc Translated Documentation/email-clients.txt RAW driver: Remove call to kobject_put(). reboot: disable usermodehelper to prevent fs access efivars: prevent oops on unload when efi is not enabled Allow setting of number of raw devices as a module parameter Introduce CONFIG_GOOGLE_FIRMWARE driver: Google Memory Console driver: Google EFI SMI x86: Better comments for get_bios_ebda() x86: get_bios_ebda_length() misc: fix ti-st build issues params.c: Use new strtobool function to process boolean inputs debugfs: move to new strtobool ... Fix up trivial conflicts in fs/debugfs/file.c due to the same patch being applied twice, and an unrelated cleanup nearby.
2011-05-19Merge branches 'sched-core-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds1-4/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) sched: Fix and optimise calculation of the weight-inverse sched: Avoid going ahead if ->cpus_allowed is not changed sched, rt: Update rq clock when unthrottling of an otherwise idle CPU sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched: Shorten the construction of the span cpu mask of sched domain sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG sched: Remove unused 'this_best_prio arg' from balance_tasks() sched: Remove noop in alloc_rt_sched_group() sched: Get rid of lock_depth sched: Remove obsolete comment from scheduler_tick() sched: Fix sched_domain iterations vs. RCU sched: Next buddy hint on sleep and preempt path sched: Make set_*_buddy() work on non-task entities sched: Remove need_migrate_task() sched: Move the second half of ttwu() to the remote cpu sched: Restructure ttwu() some more sched: Rename ttwu_post_activation() to ttwu_do_wakeup() sched: Remove rq argument from ttwu_stat() sched: Remove rq->lock from the first half of ttwu() sched: Drop rq->lock from sched_exec() ... * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix rt_rq runtime leakage bug
2011-05-17Merge branch 'syscore' into for-linusRafael J. Wysocki2-35/+28
* syscore: PM: Remove sysdev suspend, resume and shutdown operations PM / PowerPC: Use struct syscore_ops instead of sysdevs for PM PM / UNICORE32: Use struct syscore_ops instead of sysdevs for PM PM / AVR32: Use struct syscore_ops instead of sysdevs for PM PM / Blackfin: Use struct syscore_ops instead of sysdevs for PM ARM / Samsung: Use struct syscore_ops for "core" power management ARM / PXA: Use struct syscore_ops for "core" power management ARM / SA1100: Use struct syscore_ops for "core" power management ARM / Integrator: Use struct syscore_ops for core PM ARM / OMAP: Use struct syscore_ops for "core" power management ARM: Use struct syscore_ops instead of sysdevs for PM in common code
2011-05-14ARM: 6883/1: ptrace: Migrate to regsets frameworkDave Martin1-109/+239
This patch migrates the implementation of the ptrace interface for the core integer registers, legacy FPA registers and VFP registers to use the regsets framework. As an added bonus, all this stuff gets included in coredumps at no extra cost. Without this patch, coredumps contained no VFP state. Third-party extension register sets (iwmmx, crunch) are not migrated by this patch, and continue to use the old implementation; these should be migratable without much extra work. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Will Deacon <Will.Deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-13sysfs: remove "last sysfs file:" line from the oops messagesGreg Kroah-Hartman1-1/+0
On some arches (x86, sh, arm, unicore, powerpc) the oops message would print out the last sysfs file accessed. This was very useful in finding a number of sysfs and driver core bugs in the 2.5 and early 2.6 development days, but it has been a number of years since this file has actually helped in debugging anything that couldn't also be trivially determined from the stack traceback. So it's time to delete the line. This is good as we need all the space we can get for oops messages at times on consoles. Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-12Merge branch 'fixes' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds1-37/+53
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm: ARM: 6870/1: The mandatory barrier rmb() must be a dsb() in for device accesses ARM: 6892/1: handle ptrace requests to change PC during interrupted system calls ARM: 6890/1: memmap: only free allocated memmap entries when using SPARSEMEM ARM: zImage: the page table memory must be considered before relocation ARM: zImage: make sure not to relocate on top of the relocation code ARM: zImage: Fix bad SP address after relocating kernel ARM: zImage: make sure the stack is 64-bit aligned ARM: RiscPC: acornfb: fix section mismatches ARM: RiscPC: etherh: fix section mismatches
2011-05-12ARM: 6892/1: handle ptrace requests to change PC during interrupted system callsArnd Bergmann1-37/+53
GDB's interrupt.exp test cases currenly fail on ARM. The problem is how do_signal handled restarting interrupted system calls: The entry.S assembler code determines that we come from a system call; and that information is passed as "syscall" parameter to do_signal. That routine then calls get_signal_to_deliver [*] and if a signal is to be delivered, calls into handle_signal. If a system call is to be restarted either after the signal handler returns, or if no handler is to be called in the first place, the PC is updated after the get_signal_to_deliver call, either in handle_signal (if we have a handler) or at the end of do_signal (otherwise). Now the problem is that during [*], the call to get_signal_to_deliver, a ptrace intercept may happen. During this intercept, the debugger may change registers, including the PC. This is done by GDB if it wants to execute an "inferior call", i.e. the execution of some code in the debugged program triggered by GDB. To this purpose, GDB will save all registers, allocate a stack frame, set up PC and arguments as appropriate for the call, and point the link register to a dummy breakpoint instruction. Once the process is restarted, it will execute the call and then trap back to the debugger, at which point GDB will restore all registers and continue original execution. This generally works fine. However, now consider what happens when GDB attempts to do exactly that while the process was interrupted during execution of a to-be- restarted system call: do_signal is called with the syscall flag set; it calls get_signal_to_deliver, at which point the debugger takes over and changes the PC to point to a completely different place. Now get_signal_to_deliver returns without a signal to deliver; but now do_signal decides it should be restarting a system call, and decrements the PC by 2 or 4 -- so it now points to 2 or 4 bytes before the function GDB wants to call -- which leads to a subsequent crash. To fix this problem, two things need to be supported: - do_signal must be able to recognize that get_signal_to_deliver changed the PC to a different location, and skip the restart-syscall sequence - once the debugger has restored all registers at the end of the inferior call sequence, do_signal must recognize that *now* it needs to restart the pending system call, even though it was now entered from a breakpoint instead of an actual svc instruction This set of issues is solved on other platforms, usually by one of two mechanisms: - The status information "do_signal is handling a system call that may need restarting" is itself carried in some register that can be accessed via ptrace. This is e.g. on Intel the "orig_eax" register; on Sparc the kernel defines a magic extra bit in the flags register for this purpose. This allows GDB to manage that state: reset it when doing an inferior call, and restore it after the call is finished. - On s390, do_signal transparently handles this problem without requiring GDB interaction, by performing system call restarting in the following way: first, adjust the PC as necessary for restarting the call. Then, call get_signal_to_deliver; and finally just continue execution at the PC. This way, if GDB does not change the PC, everything is as before. If GDB *does* change the PC, execution will simply continue there -- and once GDB restores the PC it saved at that point, it will automatically point to the *restarted* system call. (There is the minor twist how to handle system calls that do *not* need restarting -- do_signal will undo the PC change in this case, after get_signal_to_deliver has returned, and only if ptrace did not change the PC during that call.) Because there does not appear to be any obvious register to carry the syscall-restart information on ARM, we'd either have to introduce a new artificial ptrace register just for that purpose, or else handle the issue transparently like on s390. The patch below implements the second option; using this patch makes the interrupt.exp test cases pass on ARM, with no regression in the GDB test suite otherwise. Cc: patches@linaro.org Signed-off-by: Ulrich Weigand <ulrich.weigand@linaro.org> Signed-off-by: Arnd Bergmann <arnd.bergmann@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-12ARM: 6893/1: Allow for kernel command line concatenationVictor Boivie1-4/+9
This patch allows the provided CONFIG_CMDLINE to be concatenated with the one provided by the boot loader. This is useful to merge the static values defined in CONFIG_CMDLINE with the boot loader's (possibly) more dynamic values, such as startup reasons and more. Signed-off-by: Victor Boivie <victor.boivie@sonyericsson.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonyericsson.com> Signed-off-by: Oskar Andero <oskar.andero@sonyericsson.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-12Merge commit 'v2.6.39-rc7' into sched/coreIngo Molnar7-324/+475
2011-05-11arm/dt: Allow CONFIG_OF on ARMGrant Likely3-1/+49
Add some basic empty infrastructure for DT support on ARM. v5: - Fix off-by-one error in size calculation of initrd - Stop mucking with cmd_line, and load command line from dt into boot_command_line instead which matches the behaviour of ATAGS booting v3: - moved cmd_line export and initrd setup to this patch to make the series bisectable. - switched to alloc_bootmem_align() for allocation when unflattening the device tree. memblock_alloc() was not the right interface. Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com> Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-11arm/dt: Make __vet_atags also accept a dtb imageGrant Likely2-10/+22
The dtb is passed to the kernel via register r2, which is the same method that is used to pass an atags pointer. This patch modifies __vet_atags to not clear r2 when it encounters a dtb image. v2: fixed bugs pointed out by Nicolas Pitre Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-04Merge branch 'perf/urgent' of ↵Ingo Molnar1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent
2011-04-29ARM: 6891/1: prevent heap corruption in OABI semtimedopDan Rosenberg1-1/+1
When CONFIG_OABI_COMPAT is set, the wrapper for semtimedop does not bound the nsops argument. A sufficiently large value will cause an integer overflow in allocation size, followed by copying too much data into the allocated buffer. Fix this by restricting nsops to SEMOPM. Untested. Cc: stable@kernel.org Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-29Merge branch 'kprobes' of git://git.linaro.org/people/nico/linux into fixesRussell King2-321/+459
2011-04-28ARM: kprobes: Tidy-up kprobes-decode.cJon Medhurst1-108/+23
- Remove coding standard violations reported by checkpatch.pl - Delete comment about handling of conditional branches which is no longer true. - Delete comment at end of file which lists all ARM instructions. This duplicates data available in the ARM ARM and seems like an unnecessary maintenance burden to keep this up to date and accurate. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Add emulation of hint instructions like NOP and WFIJon Medhurst1-0/+24
Being able to probe NOP instructions is useful for hard-coding probeable locations and is used by the kprobes test code. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>