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2011-10-03ARM: 7091/1: errata: D-cache line maintenance operation by MVA may not succeedWill Deacon
commit f630c1bdfbf8fe423325beaf60027cfc7fd7c610 upstream. This patch implements a workaround for erratum 764369 affecting Cortex-A9 MPCore with two or more processors (all current revisions). Under certain timing circumstances, a data cache line maintenance operation by MVA targeting an Inner Shareable memory region may fail to proceed up to either the Point of Coherency or to the Point of Unification of the system. This workaround adds a DSB instruction before the relevant cache maintenance functions and sets a specific bit in the diagnostic control register of the SCU. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-07ARM: 6994/1: smp_twd: Fix typo in 'twd_timer_rate' printingVitaly Kuzmichev
To get hundredths of MHz the rate needs to be divided by 10'000. Here is an example: twd_timer_rate = 123456789 Before the patch: twd_timer_rate / 1000000 = 123 (twd_timer_rate / 1000000) % 100 = 23 Result: 123.23MHz. After being fixed: twd_timer_rate / 1000000 = 123 (twd_timer_rate / 10000) % 100 = 45 Result: 123.45MHz. Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-05ARM: move memory layout sanity checking before meminfo initializationRussell King
Ensure that the meminfo array is sanity checked before we pass the memory to memblock. This helps to ensure that memblock and meminfo agree on the dimensions of memory, especially when more memory is passed than the kernel can deal with. Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-05ARM: 6989/1: perf: do not start the PMU when no events are presentWill Deacon
armpmu_enable can be called in situations where no events are present (for example, from the event rotation tick after a profiled task has exited). In this case, we currently start the PMU anyway which may leave it active inevitably without any events being monitored. This patch adds a simple check to the enabling code so that we avoid starting the PMU when no events are present. Cc: <stable@kernel.org> Reported-by: Ashwin Chaugle <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-21ARM: SMP: wait for CPU to be marked activeRussell King
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 Martin
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 King
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 Chuang
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 Pitre
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 Lei
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 Torvalds
* 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. Biederman
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 King
2011-05-26ARM: 6942/1: mm: make TTBR1 always point to swapper_pg_dir on ARMv6/7Catalin Marinas
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 King
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 Martin
* 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 King
devel-stable
2011-05-25Merge branch 'devicetree/arm-next' of git://git.secretlab.ca/git/linux-2.6 ↵Russell King
into devel-stable
2011-05-24Merge branch 'for-2.6.40' of ↵Linus Torvalds
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 King
and 'spear' into for-linus
2011-05-23Merge branches 'consolidate-clksrc', 'consolidate-flash', ↵Russell King
'consolidate-generic', 'consolidate-smp', 'consolidate-stmp' and 'consolidate-zones' into consolidate
2011-05-23ARM: consolidate SMP cross call implementationRussell King
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 Likely
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 Likely
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 Rutland
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 Torvalds
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 Torvalds
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. Wysocki
* 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 Martin
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-Hartman
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 Torvalds
* '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 Bergmann
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 Boivie
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 Molnar
2011-05-11arm/dt: Allow CONFIG_OF on ARMGrant Likely
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 Likely
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 Molnar
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 Rosenberg
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 King
2011-04-28ARM: kprobes: Tidy-up kprobes-decode.cJon Medhurst
- 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 Medhurst
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>
2011-04-28ARM: kprobes: Add emulation of SBFX, UBFX, BFI and BFC instructionsJon Medhurst
These bit field manipulation instructions occur several thousand times in an ARMv7 kernel. 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 MOVW and MOVT instructionsJon Medhurst
The MOVW and MOVT instructions account for approximately 7% of all instructions in a ARMv7 kernel as GCC uses them instead of a literal pool. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Reject probing of undefined data processing instructionsJon Medhurst
The instruction decoding in space_cccc_000x needs to reject probing of instructions with undefined patterns as they may in future become defined and then emulated faultily - as has already happened with the SMC instruction. This fix is achieved by testing for the instruction patterns we want to probe and making the the default fall-through paths reject probes. This also allows us to remove some explicit tests for instructions that we wish to reject, as that is now the default action. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Remove redundant code in space_1111Jon Medhurst
The tests to explicitly reject probing CPS, RFE and SRS instructions are redundant as the default case is now to reject undecoded patterns. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Fix emulation of PLD instructionsJon Medhurst
The PLD instructions wasn't being decoded correctly and the emulation code wasn't adjusting PC correctly. As the PLD instruction is only a performance hint we emulate it as a simple nop, and we can broaden the instruction decoding to take into account newer PLI and PLDW instructions. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Reject probing of SETEND instructionsJon Medhurst
The emulation of SETEND was broken as it changed the endianess for the running kprobes handling code. Rather than adding a new simulation routine to fix this we'll just reject probing of SETEND as these should be very rare in the kernel. Note, the function emulate_none is now unused but it is left in the source code as future patches will use it. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Consolidate stub decoding functionsJon Medhurst
Following the change to remove support for coprocessor instructions we are left with three stub functions which can be consolidated. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Reject probing of all coprocessor instructionsJon Medhurst
The kernel doesn't currently support VFP or Neon code, and probing of code with CP15 operations is fraught with bad consequences. Therefore we don't need the ability to probe coprocessor instructions and the code to support this can be removed. The removed code also had at least two bugs: - MRC into R15 should set CPSR not trash PC - LDC and STC which use PC as base register needed the address offset by 8 Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-04-28ARM: kprobes: Fix emulation of USAD8 instructionsJon Medhurst
The USAD8 instruction wasn't being explicitly decoded leading to the incorrect emulation routine being called. It can be correctly decoded in the same way as the signed multiply instructions so we move the decoding there. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>