1. 26 3月, 2006 3 次提交
  2. 13 2月, 2006 1 次提交
    • J
      [PATCH] arch/x86_64/kernel/traps.c PTRACE_SINGLESTEP oops · a65d17c9
      John Blackwood 提交于
      We found a problem with x86_64 kernels with preemption enabled, where
      having multiple tasks doing ptrace singlesteps around the same time will
      cause the system to 'oops'.  The problem seems that a task can get
      preempted out of the do_debug() processing while it is running on the
      DEBUG_STACK stack.  If another task on that same cpu then enters do_debug()
      and uses the same per-cpu DEBUG_STACK stack, the previous preempted tasks's
      stack contents can be corrupted, and the system will oops when the
      preempted task is context switched back in again.
      
      The typical oops looks like the following:
      
        Unable to handle kernel paging request at ffffffffffffffae RIP: <ffffffff805452a1>{thread_return+34}
        PGD 103027 PUD 102429067 PMD 0
        Oops: 0002 [1] PREEMPT SMP
        CPU 0
        Modules linked in:
        Pid: 3786, comm: ssdd Not tainted 2.6.15.2 #1
        RIP: 0010:[<ffffffff805452a1>] <ffffffff805452a1>{thread_return+34}
        RSP: 0018:ffffffff80824058  EFLAGS: 000136c2
        RAX: ffff81017e12cea0 RBX: 0000000000000000 RCX: 00000000c0000100
        RDX: 0000000000000000 RSI: ffff8100f7856e20 RDI: ffff81017e12cea0
        RBP: 0000000000000046 R08: ffff8100f68a6000 R09: 0000000000000000
        R10: 0000000000000000 R11: ffff81017e12cea0 R12: ffff81000c2d53e8
        R13: ffff81017f5b3be8 R14: ffff81000c0036e0 R15: 000001056cbfc899
        FS:  00002aaaaaad9b00(0000) GS:ffffffff80883800(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
        CR2: ffffffffffffffae CR3: 00000000f6fcf000 CR4: 00000000000006e0
        Process ssdd (pid: 3786, threadinfo ffff8100f68a6000, task ffff8100f7856e20)
        Stack: ffffffff808240d8 ffffffff8012a84a ffff8100055f6c00 0000000000000020
               0000000000000001 ffff81000c0036e0 ffffffff808240b8 0000000000000000
               0000000000000000 0000000000000000
        Call Trace: <#DB>
      	<ffffffff8012a84a>{try_to_wake_up+985}
      	<ffffffff8012c0d3>{kick_process+87}
              <ffffffff8013b262>{signal_wake_up+48}
      	<ffffffff8013b5ce>{specific_send_sig_info+179}
              <ffffffff80546abc>{_spin_unlock_irqrestore+27}
      	<ffffffff8013b67c>{force_sig_info+159}
              <ffffffff801103a0>{do_debug+289} <ffffffff80110278>{sync_regs+103}
              <ffffffff8010ed9a>{paranoid_userspace+35}
        Unable to handle kernel paging request at 00007fffffb7d000 RIP: <ffffffff8010f2e4>{show_trace+465}
        PGD f6f25067 PUD f6fcc067 PMD f6957067 PTE 0
        Oops: 0000 [2] PREEMPT SMP
      
      This patch disables preemptions for the task upon entry to do_debug(), before
      interrupts are reenabled, and then disables preemption before exiting
      do_debug(), after disabling interrupts.  I've noticed that the task can be
      preempted either at the end of an interrupt, or on the call to
      force_sig_info() on the spin_unlock_irqrestore() processing.  It might be
      better to attempt to code a fix in entry.S around the code that calls
      do_debug().
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      a65d17c9
  3. 05 2月, 2006 1 次提交
  4. 13 1月, 2006 2 次提交
  5. 12 1月, 2006 12 次提交
  6. 15 11月, 2005 2 次提交
    • A
      [PATCH] x86_64: Remove CONFIG_CHECKING and add command line option for pagefault tracing · 9e43e1b7
      Andi Kleen 提交于
      CONFIG_CHECKING covered some debugging code used in the early times
      of the port. But it wasn't even SMP safe for quite some time
      and the bugs it checked for seem to be gone.
      
      This patch removes all the code to verify GS at kernel entry. There
      haven't been any new bugs in this area for a long time.
      
      Previously it also covered the sysctl for the page fault tracing.
      That didn't make much sense because that code was unconditionally
      compiled in. I made that a boot option now because it is typically
      only useful at boot.
      Signed-off-by: NAndi Kleen <ak@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9e43e1b7
    • J
      [PATCH] x86_64: Support for AMD specific MCE Threshold. · 89b831ef
      Jacob Shin 提交于
      MC4_MISC - DRAM Errors Threshold Register realized under AMD K8 Rev F.
      This register is used to count correctable and uncorrectable ECC errors that occur during DRAM read operations.
      The user may interface through sysfs files in order to change the threshold configuration.
      
      bank%d/error_count - reads current error count, write to clear.
      bank%d/interrupt_enable - set/clear interrupt enable.
      bank%d/threshold_limit - read/write the threshold limit.
      
      APIC vector 0xF9 in hw_irq.h.
      5 software defined bank ids in mce.h.
      new apic.c function to setup threshold apic lvt.
      defaults to interrupt off, count enabled, and threshold limit max.
      sysfs interface created on /sys/devices/system/threshold.
      
      AK: added some ifdefs to make it compile on UP
      Signed-off-by: NJacob Shin <jacob.shin@amd.com>
      Signed-off-by: NAndi Kleen <ak@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      89b831ef
  7. 13 9月, 2005 4 次提交
  8. 08 9月, 2005 1 次提交
  9. 29 7月, 2005 1 次提交
    • A
      [PATCH] x86_64: cpu hotplug changes kills nmi watchdog · 2a16a300
      Alexander Nyberg 提交于
      When the x86_64 cpu hotplug changes went in it added a check in
      default_do_nmi() which kills NMI delivery on any CPU but the BSP.
      
      The NMI watchdog is brought up quite some time before the online bit is set
      in num_online_cpus so this won't work very well.  The nmi watchdogs on cpus
      that are not BSP will never be reprogrammed and no NMIs.
      
      Why was this check added? How does an offlined cpu receive an NMI?
      Signed-off-by: NAlexander Nyberg <alexn@telia.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Andrew Morton <akpm@osdl.org>
      Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
      Cc: <ashok.raj@intel.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      2a16a300
  10. 26 6月, 2005 1 次提交
  11. 24 6月, 2005 2 次提交
  12. 26 5月, 2005 1 次提交
  13. 17 4月, 2005 7 次提交