1. 20 3月, 2015 1 次提交
  2. 12 8月, 2014 1 次提交
    • D
      sparc64: Fix pcr_ops initialization and usage bugs. · 8bccf5b3
      David S. Miller 提交于
      Christopher reports that perf_event_print_debug() can crash in uniprocessor
      builds.  The crash is due to pcr_ops being NULL.
      
      This happens because pcr_arch_init() is only invoked by smp_cpus_done() which
      only executes in SMP builds.
      
      init_hw_perf_events() is closely intertwined with pcr_ops being setup properly,
      therefore:
      
      1) Call pcr_arch_init() early on from init_hw_perf_events(), instead of
         from smp_cpus_done().
      
      2) Do not hook up a PMU type if pcr_ops is NULL after pcr_arch_init().
      
      3) Move init_hw_perf_events to a later initcall so that it we will be
         sure to invoke pcr_arch_init() after all cpus are brought up.
      
      Finally, guard the one naked sequence of pcr_ops dereferences in
      __global_pmu_self() with an appropriate NULL check.
      Reported-by: NChristopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8bccf5b3
  3. 24 6月, 2014 1 次提交
  4. 19 5月, 2014 1 次提交
  5. 25 3月, 2014 1 次提交
  6. 15 11月, 2013 1 次提交
  7. 01 5月, 2013 2 次提交
    • Z
      sparc/sysrq: fix inconstistent help message of sysrq key · 5452c7f8
      zhangwei(Jovi) 提交于
      Currently help message of /proc/sysrq-trigger highlight its
      upper-case characters, like below:
      
            SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
            memory-full-oom-kill(F) kill-all-tasks(I) ...
      
      this would confuse user trigger sysrq by upper-case character, which is
      inconsistent with the real lower-case character registed key.
      
      This inconsistent help message will also lead more confused when
      26 upper-case letters put into use in future.
      
      This patch fix spare sysrq key: "global-regs(y)"
      Signed-off-by: Nzhangwei(Jovi) <jovi.zhangwei@huawei.com>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5452c7f8
    • T
      dump_stack: unify debug information printed by show_regs() · a43cb95d
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Acked-by: NJesper 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a43cb95d
  8. 14 4月, 2013 1 次提交
  9. 29 11月, 2012 2 次提交
  10. 27 10月, 2012 1 次提交
    • D
      sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. · 517ffce4
      David S. Miller 提交于
      The Montgomery Multiply, Montgomery Square, and Multiple-Precision
      Multiply instructions work by loading a combination of the floating
      point and multiple register windows worth of integer registers
      with the inputs.
      
      These values are 64-bit.  But for 32-bit userland processes we only
      save the low 32-bits of each integer register during a register spill.
      This is because the register window save area is in the user stack and
      has a fixed layout.
      
      Therefore, the only way to use these instruction in 32-bit mode is to
      perform the following sequence:
      
      1) Load the top-32bits of a choosen integer register with a sentinel,
         say "-1".  This will be in the outer-most register window.
      
         The idea is that we're trying to see if the outer-most register
         window gets spilled, and thus the 64-bit values were truncated.
      
      2) Load all the inputs for the montmul/montsqr/mpmul instruction,
         down to the inner-most register window.
      
      3) Execute the opcode.
      
      4) Traverse back up to the outer-most register window.
      
      5) Check the sentinel, if it's still "-1" store the results.
         Otherwise retry the entire sequence.
      
      This retry is extremely troublesome.  If you're just unlucky and an
      interrupt or other trap happens, it'll push that outer-most window to
      the stack and clear the sentinel when we restore it.
      
      We could retry forever and never make forward progress if interrupts
      arrive at a fast enough rate (consider perf events as one example).
      So we have do limited retries and fallback to software which is
      extremely non-deterministic.
      
      Luckily it's very straightforward to provide a mechanism to let
      32-bit applications use a 64-bit stack.  Stacks in 64-bit mode are
      biased by 2047 bytes, which means that the lowest bit is set in the
      actual %sp register value.
      
      So if we see bit zero set in a 32-bit application's stack we treat
      it like a 64-bit stack.
      
      Runtime detection of such a facility is tricky, and cumbersome at
      best.  For example, just trying to use a biased stack and seeing if it
      works is hard to recover from (the signal handler will need to use an
      alt stack, plus something along the lines of longjmp).  Therefore, we
      add a system call to report a bitmask of arch specific features like
      this in a cheap and less hairy way.
      
      With help from Andy Polyakov.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      517ffce4
  11. 17 10月, 2012 2 次提交
  12. 15 10月, 2012 3 次提交
  13. 13 10月, 2012 1 次提交
    • J
      vfs: define struct filename and have getname() return it · 91a27b2a
      Jeff Layton 提交于
      getname() is intended to copy pathname strings from userspace into a
      kernel buffer. The result is just a string in kernel space. It would
      however be quite helpful to be able to attach some ancillary info to
      the string.
      
      For instance, we could attach some audit-related info to reduce the
      amount of audit-related processing needed. When auditing is enabled,
      we could also call getname() on the string more than once and not
      need to recopy it from userspace.
      
      This patchset converts the getname()/putname() interfaces to return
      a struct instead of a string. For now, the struct just tracks the
      string in kernel space and the original userland pointer for it.
      
      Later, we'll add other information to the struct as it becomes
      convenient.
      Signed-off-by: NJeff Layton <jlayton@redhat.com>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      91a27b2a
  14. 29 3月, 2012 1 次提交
  15. 01 3月, 2012 2 次提交
  16. 12 12月, 2011 3 次提交
    • F
      nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu() · 1268fbc7
      Frederic Weisbecker 提交于
      Those two APIs were provided to optimize the calls of
      tick_nohz_idle_enter() and rcu_idle_enter() into a single
      irq disabled section. This way no interrupt happening in-between would
      needlessly process any RCU job.
      
      Now we are talking about an optimization for which benefits
      have yet to be measured. Let's start simple and completely decouple
      idle rcu and dyntick idle logics to simplify.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      1268fbc7
    • F
      nohz: Allow rcu extended quiescent state handling seperately from tick stop · 2bbb6817
      Frederic Weisbecker 提交于
      It is assumed that rcu won't be used once we switch to tickless
      mode and until we restart the tick. However this is not always
      true, as in x86-64 where we dereference the idle notifiers after
      the tick is stopped.
      
      To prepare for fixing this, add two new APIs:
      tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().
      
      If no use of RCU is made in the idle loop between
      tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
      must instead call the new *_norcu() version such that the arch doesn't
      need to call rcu_idle_enter() and rcu_idle_exit().
      
      Otherwise the arch must call tick_nohz_enter_idle() and
      tick_nohz_exit_idle() and also call explicitly:
      
      - rcu_idle_enter() after its last use of RCU before the CPU is put
      to sleep.
      - rcu_idle_exit() before the first use of RCU after the CPU is woken
      up.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      2bbb6817
    • F
      nohz: Separate out irq exit and idle loop dyntick logic · 280f0677
      Frederic Weisbecker 提交于
      The tick_nohz_stop_sched_tick() function, which tries to delay
      the next timer tick as long as possible, can be called from two
      places:
      
      - From the idle loop to start the dytick idle mode
      - From interrupt exit if we have interrupted the dyntick
      idle mode, so that we reprogram the next tick event in
      case the irq changed some internal state that requires this
      action.
      
      There are only few minor differences between both that
      are handled by that function, driven by the ts->inidle
      cpu variable and the inidle parameter. The whole guarantees
      that we only update the dyntick mode on irq exit if we actually
      interrupted the dyntick idle mode, and that we enter in RCU extended
      quiescent state from idle loop entry only.
      
      Split this function into:
      
      - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
      dynticks idle mode unconditionally if it can, and enters into RCU
      extended quiescent state.
      
      - tick_nohz_irq_exit() which only updates the dynticks idle mode
      when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).
      
      To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
      into tick_nohz_idle_exit().
      
      This simplifies the code and micro-optimize the irq exit path (no need
      for local_irq_save there). This also prepares for the split between
      dynticks and rcu extended quiescent state logics. We'll need this split to
      further fix illegal uses of RCU in extended quiescent states in the idle
      loop.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
      280f0677
  17. 01 11月, 2011 1 次提交
  18. 21 9月, 2011 1 次提交
  19. 20 8月, 2010 1 次提交
  20. 18 8月, 2010 1 次提交
    • D
      Make do_execve() take a const filename pointer · d7627467
      David Howells 提交于
      Make do_execve() take a const filename pointer so that kernel_execve() compiles
      correctly on ARM:
      
      arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
      
      This also requires the argv and envp arguments to be consted twice, once for
      the pointer array and once for the strings the array points to.  This is
      because do_execve() passes a pointer to the filename (now const) to
      copy_strings_kernel().  A simpler alternative would be to cast the filename
      pointer in do_execve() when it's passed to copy_strings_kernel().
      
      do_execve() may not change any of the strings it is passed as part of the argv
      or envp lists as they are some of them in .rodata, so marking these strings as
      const should be fine.
      
      Further kernel_execve() and sys_execve() need to be changed to match.
      
      This has been test built on x86_64, frv, arm and mips.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Tested-by: NRalf Baechle <ralf@linux-mips.org>
      Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d7627467
  21. 21 4月, 2010 1 次提交
  22. 04 3月, 2010 1 次提交
  23. 10 2月, 2010 1 次提交
  24. 30 1月, 2010 1 次提交
  25. 03 8月, 2009 1 次提交
    • I
      debug lockups: Improve lockup detection, fix generic arch fallback · 47cab6a7
      Ingo Molnar 提交于
      As Andrew noted, my previous patch ("debug lockups: Improve lockup
      detection") broke/removed SysRq-L support from architecture that do
      not provide a __trigger_all_cpu_backtrace implementation.
      
      Restore a fallback path and clean up the SysRq-L machinery a bit:
      
       - Rename the arch method to arch_trigger_all_cpu_backtrace()
      
       - Simplify the define
      
       - Document the method a bit - in the hope of more architectures
         adding support for it.
      
      [ The patch touches Sparc code for the rename. ]
      
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      LKML-Reference: <20090802140809.7ec4bb6b.akpm@linux-foundation.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      47cab6a7
  26. 03 4月, 2009 1 次提交
  27. 03 2月, 2009 1 次提交
    • D
      sparc64: On non-Niagara, need to touch NMI watchdog in NOHZ mode. · 802c64b3
      David S. Miller 提交于
      When we're idling in NOHZ mode, timer interrupts are not running.
      
      Evidence of processing timer interrupts is what the NMI watchdog
      uses to determine if the CPU is stuck.
      
      On Niagara, we'll yield the cpu.  This will make the cpu, at
      worst, hang out in the hypervisor until an interrupt arrives.
      This will prevent the NMI watchdog timer from firing.
      
      However on non-Niagara we just loop executing instructions
      which will cause the NMI watchdog to keep firing.  It won't
      see timer interrupts happening so it will think the cpu is
      stuck.
      
      Fix this by touching the NMI watchdog in the cpu idle loop
      on non-Niagara machines.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      802c64b3
  28. 09 1月, 2009 1 次提交
  29. 05 12月, 2008 1 次提交
    • S
      sparc,sparc64: unify kernel/ · a88b5ba8
      Sam Ravnborg 提交于
      o Move all files from sparc64/kernel/ to sparc/kernel
        - rename as appropriate
      o Update sparc/Makefile to the changes
      o Update sparc/kernel/Makefile to include the sparc64 files
      
      NOTE: This commit changes link order on sparc64!
      
      Link order had to change for either of sparc32 and sparc64.
      And assuming sparc64 see more testing than sparc32 change link
      order on sparc64 where issues will be caught faster.
      Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a88b5ba8
  30. 12 9月, 2008 1 次提交
  31. 02 9月, 2008 1 次提交
  32. 13 8月, 2008 1 次提交