1. 28 9月, 2012 2 次提交
  2. 26 9月, 2012 4 次提交
    • F
      x86: Use the new schedule_user API on userspace preemption · 0430499c
      Frederic Weisbecker 提交于
      This way we can exit the RCU extended quiescent state before
      we schedule a new task from irq/exception exit.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Alessio Igor Bogani <abogani@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kevin Hilman <khilman@ti.com>
      Cc: Max Krasnyansky <maxk@qualcomm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Hemminger <shemminger@vyatta.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
      0430499c
    • F
      x86: Exception hooks for userspace RCU extended QS · 6ba3c97a
      Frederic Weisbecker 提交于
      Add necessary hooks to x86 exception for userspace
      RCU extended quiescent state support.
      
      This includes traps, page fault, debug exceptions, etc...
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Alessio Igor Bogani <abogani@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kevin Hilman <khilman@ti.com>
      Cc: Max Krasnyansky <maxk@qualcomm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Hemminger <shemminger@vyatta.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      6ba3c97a
    • F
      x86: Syscall hooks for userspace RCU extended QS · bf5a3c13
      Frederic Weisbecker 提交于
      Add syscall slow path hooks to notify syscall entry
      and exit on CPUs that want to support userspace RCU
      extended quiescent state.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Alessio Igor Bogani <abogani@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kevin Hilman <khilman@ti.com>
      Cc: Max Krasnyansky <maxk@qualcomm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Hemminger <shemminger@vyatta.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
      bf5a3c13
    • T
      x86_64: Work around old GAS bug · 1b2b23d8
      Tao Guo 提交于
      GAS in binutils(2.16.91) could not parse parentheses within
      macro parameters unless fully parenthesized, and this is a
      workaround to make old gas work without generating below errors:
      
       arch/x86/kernel/entry_64.S: Assembler messages:
       arch/x86/kernel/entry_64.S:387: Error: too many positional arguments
       arch/x86/kernel/entry_64.S:389: Error: too many positional arguments
       [...]
      Signed-off-by: NTao Guo <glorioustao@gmail.com>
      Reluctantly-Acked-by: NJan Beulich <jbeulich@novell.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Link: http://lkml.kernel.org/r/1348648102-12653-1-git-send-email-glorioustao@gmail.com
      [ Jan argues that these old GAS versions are fragile - which is so, but lets give them a chance. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      1b2b23d8
  3. 22 9月, 2012 1 次提交
    • S
      x86, kvm: fix kvm's usage of kernel_fpu_begin/end() · b1a74bf8
      Suresh Siddha 提交于
      Preemption is disabled between kernel_fpu_begin/end() and as such
      it is not a good idea to use these routines in kvm_load/put_guest_fpu()
      which can be very far apart.
      
      kvm_load/put_guest_fpu() routines are already called with
      preemption disabled and KVM already uses the preempt notifier to save
      the guest fpu state using kvm_put_guest_fpu().
      
      So introduce __kernel_fpu_begin/end() routines which don't touch
      preemption and use them instead of kernel_fpu_begin/end()
      for KVM's use model of saving/restoring guest FPU state.
      
      Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
      state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
      So no need to worry about it. For the traditional lazyFPU restore case,
      change the cr0.TS bit for the host state during vm-exit to be always clear
      and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
      (guest FPU or the host task's FPU) state is not active. This ensures
      that the host/guest FPU state is properly saved, restored
      during context-switch and with interrupts (using irq_fpu_usable()) not
      stomping on the active FPU state.
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
      Cc: Avi Kivity <avi@redhat.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      b1a74bf8
  4. 21 9月, 2012 1 次提交
  5. 19 9月, 2012 11 次提交
  6. 18 9月, 2012 1 次提交
  7. 15 9月, 2012 4 次提交
    • O
      uprobes: Make arch_uprobe_task->saved_trap_nr "unsigned int" · baedbf02
      Oleg Nesterov 提交于
      Make arch_uprobe_task->saved_trap_nr "unsigned int" and move it down
      after ->saved_scratch_register, this changes sizeof() from 24 to 16.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      baedbf02
    • O
      uprobes/x86: Xol should send SIGTRAP if X86_EFLAGS_TF was set · 3a4664aa
      Oleg Nesterov 提交于
      arch_uprobe_disable_step() correctly preserves X86_EFLAGS_TF and
      returns to user-mode. But this means the application gets SIGTRAP
      only after the next insn.
      
      This means that UPROBE_CLEAR_TF logic is not really right. _enable
      should only record the state of X86_EFLAGS_TF, and _disable should
      check it separately from UPROBE_FIX_SETF.
      
      Remove arch_uprobe_task->restore_flags, add ->saved_tf instead, and
      change enable/disable accordingly. This assumes that the probed insn
      was not trapped, see the next patch.
      
      arch_uprobe_skip_sstep() logic has the same problem, change it to
      check X86_EFLAGS_TF and send SIGTRAP as well. We will cleanup this
      all after we fold enable/disable_step into pre/post_hol hooks.
      
      Note: send_sig(SIGTRAP) is not actually right, we need send_sigtrap().
      But this needs more changes, handle_swbp() does the same and this is
      equally wrong.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      3a4664aa
    • O
      uprobes/x86: Do not (ab)use TIF_SINGLESTEP/user_*_single_step() for single-stepping · 9bd1190a
      Oleg Nesterov 提交于
      user_enable/disable_single_step() was designed for ptrace, it assumes
      a single user and does unnecessary and wrong things for uprobes. For
      example:
      
      	- arch_uprobe_enable_step() can't trust TIF_SINGLESTEP, an
      	  application itself can set X86_EFLAGS_TF which must be
      	  preserved after arch_uprobe_disable_step().
      
      	- we do not want to set TIF_SINGLESTEP/TIF_FORCED_TF in
      	  arch_uprobe_enable_step(), this only makes sense for ptrace.
      
      	- otoh we leak TIF_SINGLESTEP if arch_uprobe_disable_step()
      	  doesn't do user_disable_single_step(), the application will
      	  be killed after the next syscall.
      
      	- arch_uprobe_enable_step() does access_process_vm() we do
      	  not need/want.
      
      Change arch_uprobe_enable/disable_step() to set/clear X86_EFLAGS_TF
      directly, this is much simpler and more correct. However, we need to
      clear TIF_BLOCKSTEP/DEBUGCTLMSR_BTF before executing the probed insn,
      add set_task_blockstep(false).
      
      Note: with or without this patch, there is another (hopefully minor)
      problem. A probed "pushf" insn can see the wrong X86_EFLAGS_TF set by
      uprobes. Perhaps we should change _disable to update the stack, or
      teach arch_uprobe_skip_sstep() to emulate this insn.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      9bd1190a
    • S
      uprobes/x86: Implement x86 specific arch_uprobe_*_step · bdc1e472
      Sebastian Andrzej Siewior 提交于
      The arch specific implementation behaves like user_enable_single_step()
      except that it does not disable single stepping if it was already
      enabled by ptrace. This allows the debugger to single step over an
      uprobe. The state of block stepping is not restored. It makes only sense
      together with TF and if that was enabled then the debugger is notified.
      
      Note: this is still not correct. For example, TIF_SINGLESTEP check
      is not right, the application itself can set X86_EFLAGS_TF. And otoh
      we leak TIF_SINGLESTEP (set by enable) if the probed insn is "popf".
      See the next patches, we need the changes in arch/x86/kernel/step.c
      first.
      Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      bdc1e472
  8. 13 9月, 2012 3 次提交
  9. 12 9月, 2012 6 次提交
  10. 10 9月, 2012 1 次提交
  11. 05 9月, 2012 4 次提交
  12. 01 9月, 2012 1 次提交
  13. 23 8月, 2012 1 次提交
    • S
      ftrace/x86: Add support for -mfentry to x86_64 · d57c5d51
      Steven Rostedt 提交于
      If the kernel is compiled with gcc 4.6.0 which supports -mfentry,
      then use that instead of mcount.
      
      With mcount, frame pointers are forced with the -pg option and we
      get something like:
      
      <can_vma_merge_before>:
             55                      push   %rbp
             48 89 e5                mov    %rsp,%rbp
             53                      push   %rbx
             41 51                   push   %r9
             e8 fe 6a 39 00          callq  ffffffff81483d00 <mcount>
             31 c0                   xor    %eax,%eax
             48 89 fb                mov    %rdi,%rbx
             48 89 d7                mov    %rdx,%rdi
             48 33 73 30             xor    0x30(%rbx),%rsi
             48 f7 c6 ff ff ff f7    test   $0xfffffffff7ffffff,%rsi
      
      With -mfentry, frame pointers are no longer forced and the call looks
      like this:
      
      <can_vma_merge_before>:
             e8 33 af 37 00          callq  ffffffff81461b40 <__fentry__>
             53                      push   %rbx
             48 89 fb                mov    %rdi,%rbx
             31 c0                   xor    %eax,%eax
             48 89 d7                mov    %rdx,%rdi
             41 51                   push   %r9
             48 33 73 30             xor    0x30(%rbx),%rsi
             48 f7 c6 ff ff ff f7    test   $0xfffffffff7ffffff,%rsi
      
      This adds the ftrace hook at the beginning of the function before a
      frame is set up, and allows the function callbacks to be able to access
      parameters. As kprobes now can use function tracing (at least on x86)
      this speeds up the kprobe hooks that are at the beginning of the
      function.
      
      Link: http://lkml.kernel.org/r/20120807194100.130477900@goodmis.orgAcked-by: NIngo Molnar <mingo@kernel.org>
      Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      d57c5d51