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2009-04-06perf_counter: unify and fix delayed counter wakeupPeter Zijlstra
While going over the wakeup code I noticed delayed wakeups only work for hardware counters but basically all software counters rely on them. This patch unifies and generalizes the delayed wakeup to fix this issue. Since we're dealing with NMI context bits here, use a cmpxchg() based single link list implementation to track counters that have pending wakeups. [ This should really be generic code for delayed wakeups, but since we cannot use cmpxchg()/xchg() in generic code, I've let it live in the perf_counter code. -- Eric Dumazet could use it to aggregate the network wakeups. ] Furthermore, the x86 method of using TIF flags was flawed in that its quite possible to end up setting the bit on the idle task, loosing the wakeup. The powerpc method uses per-cpu storage and does appear to be sufficient. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Orig-LKML-Reference: <20090330171023.153932974@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06Merge branch 'linus' into perfcounters/core-v2Ingo Molnar
Merge reason: we have gathered quite a few conflicts, need to merge upstream Conflicts: arch/powerpc/kernel/Makefile arch/x86/ia32/ia32entry.S arch/x86/include/asm/hardirq.h arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/cpu/common.c arch/x86/kernel/irq.c arch/x86/kernel/syscall_table_32.S arch/x86/mm/iomap_32.c include/linux/sched.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-01x86: signal: check sas_ss_size instead of sas_ss_flags()Hiroshi Shimamoto
Impact: fix redundant and incorrect check Oleg Nesterov noticed wrt commit: 14fc9fb: x86: signal: check signal stack overflow properly >> No need to check SA_ONSTACK if we're already using alternate signal stack. > > Yes, but this also mean that we don't need sas_ss_flags() under > "if (!onsigstack)", Checking on_sig_stack() in sas_ss_flags() at get_sigframe() is redundant and not correct on 64 bit. To check sas_ss_size is enough. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: roland@redhat.com LKML-Reference: <49CBB54C.5080201@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-20x86: signal: check signal stack overflow properlyHiroshi Shimamoto
Impact: cleanup Check alternate signal stack overflow with proper stack pointer. The stack pointer of the next signal frame is different if that task has i387 state. On x86_64, redzone would be included. No need to check SA_ONSTACK if we're already using alternate signal stack. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Roland McGrath <roland@redhat.com> LKML-Reference: <49C2874D.3080002@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-03x86, signals: fix xine & firefox bustageHiroshi Shimamoto
Impact: fix bad frame in rt_sigreturn on 64-bit After commit 97286a2b64725aac2d584ddd1f94871f9991d5a1 some applications fail to return from signal handler: [ 145.150133] firefox[3250] bad frame in rt_sigreturn frame:00007f902b44eb28 ip:352e80b307 sp:7f902b44ef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000] [ 665.519017] firefox[5420] bad frame in rt_sigreturn frame:00007faa8deaeb28 ip:352e80b307 sp:7faa8deaef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000] The root cause is forgetting to keep 64 byte aligned value of fpstate for next stack pointer calculation. Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org> Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> LKML-Reference: <49AC85C1.7060600@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: signal: introduce helper align_sigframe()Hiroshi Shimamoto
Impact: cleanup Introduce helper align_sigframe() to align stack pointer for signal frame. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: signal: unify get_sigframe()Hiroshi Shimamoto
Impact: cleanup Unify get_sigframe(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: signal: use 16 bytes boundary for rt_sigframeHiroshi Shimamoto
Impact: cleanup Supporting xsave/xrestore introduces 64 bytes boundary for save_i387_xstate(). 16 bytes boundary is OK for rt_sigframe. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: signal: intrroduce get_sigframe() and replace get_sigstack()Hiroshi Shimamoto
Impact: cleanup Introduce get_sigframe() like 32-bit to replace get_sigstack(). Move the i387 stuff into get_sigframe(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: signal: add __user annotationHiroshi Shimamoto
Impact: cleanup Add missing __user annotation to the parameter of get_sigframe(). Also change cast type to void __user * of *fpstate. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13Merge branch 'x86/core' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/Kconfig arch/x86/kernel/apic.c arch/x86/kernel/setup_percpu.c
2009-02-11x86: merge sys_rt_sigreturn between 32 and 64 bitsH. Peter Anvin
Impact: cleanup With the recent changes in the 32-bit code to make system calls which use struct pt_regs take a pointer, sys_rt_sigreturn() have become identical between 32 and 64 bits, and both are empty wrappers around do_rt_sigreturn(). Remove both wrappers and rename both to sys_rt_sigreturn(). Cc: Brian Gerst <brgerst@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11x86: use regparm(3) for passed-in pt_regs pointerBrian Gerst
Some syscalls need to access the pt_regs structure, either to copy user register state or to modifiy it. This patch adds stubs to load the address of the pt_regs struct into the %eax register, and changes the syscalls to take the pointer as an argument instead of relying on the assumption that the pt_regs structure overlaps the function arguments. Drop the use of regparm(1) due to concern about gcc bugs, and to move in the direction of the eventual removal of regparm(0) for asmlinkage. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11x86: pass in pt_regs pointer for syscalls that need itBrian Gerst
Some syscalls need to access the pt_regs structure, either to copy user register state or to modifiy it. This patch adds stubs to load the address of the pt_regs struct into the %eax register, and changes the syscalls to regparm(1) to receive the pt_regs pointer as the first argument. Signed-off-by: Brian Gerst <brgerst@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11Merge commit 'v2.6.29-rc4' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/setup_percpu.c arch/x86/mm/fault.c drivers/acpi/processor_idle.c kernel/irq/handle.c
2009-02-10x86: add %gs accessors for x86_32Tejun Heo
Impact: cleanup On x86_32, %gs is handled lazily. It's not saved and restored on kernel entry/exit but only when necessary which usually is during task switch but there are few other places. Currently, it's done by calling savesegment() and loadsegment() explicitly. Define get_user_gs(), set_user_gs() and task_user_gs() and use them instead. While at it, clean up register access macros in signal.c. This cleans up code a bit and will help future changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10Merge branch 'x86/uaccess' into core/percpuIngo Molnar
2009-01-23x86: signal: use {get|put}_user_try and catchHiroshi Shimamoto
Impact: use new framework Use {get|put}_user_try, catch, and _ex in arch/x86/kernel/signal.c. Note: this patch contains "WARNING: line over 80 characters", because when introducing new block I insert an indent to avoid mistakes by edit. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-21Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"Ingo Molnar
This reverts commit 4217458dafaa57d8e26a46f5d05ab8c53cf64191. Justin Madru bisected this commit, it was causing weird Firefox crashes. The reason is that GCC mis-optimizes (re-uses) the on-stack parameters of the calling frame, which corrupts the syscall return pt_regs state and thus corrupts user-space register state. So we go back to the slightly less clean but more optimization-safe method of getting to pt_regs. Also add a comment to explain this. Resolves: http://bugzilla.kernel.org/show_bug.cgi?id=12505 Reported-and-bisected-by: Justin Madru <jdm64@gawab.com> Tested-by: Justin Madru <jdm64@gawab.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: fs/exec.c include/linux/init_task.h Simple context conflicts.
2008-12-18x86: signal: move sigframe.h to arch/x86/include/asmHiroshi Shimamoto
Impact: cleanup, move header file Move arch/x86/kernel/sigframe.h to arch/x86/include/asm/sigframe.h. It will be used in arch/x86/ia32/ia32_signal.c. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18x86: signal: move ia32 func declarations into arch/x86/kernel/signal.cHiroshi Shimamoto
Impact: cleanup Move declarations of ia32_setup_rt_frame() and ia32_setup_frame() into arch/x86/kernel/signal.c. This is for future use of sigframe.h. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16x86: signal: use signal_fault() in sys_sigreturn()Hiroshi Shimamoto
Impact: cleanup Call signal_fault() in error route of sys_sigreturn(). Change log level to KERN_EMERG if current is init. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08performance counters: x86 supportIngo Molnar
Implement performance counters for x86 Intel CPUs. It's simplified right now: the PERFMON CPU feature is assumed, which is available in Core2 and later Intel CPUs. The design is flexible to be extended to more CPU types as well. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08x86: signal: change type of paramter for sys_rt_sigreturn()Hiroshi Shimamoto
Impact: cleanup on 32-bit Peter pointed this parameter can be changed. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26x86: signal: unify signal_{32|64}.cHiroshi Shimamoto
Impact: cleanup Unify signal_{32|64}.c! Mechanic unification - the two files are the same. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>