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  1. 20 4月, 2008 30 次提交
  3. 19 4月, 2008 4 次提交
  5. 18 4月, 2008 6 次提交
    • R
      ptrace_signal subroutine · 18c98b65
      由 Roland McGrath 提交于 
      This breaks out the ptrace handling from get_signal_to_deliver into a
new subroutine.  The actual code there doesn't change, and it gets
inlined into nearly identical compiled code.  This makes the function
substantially shorter and thus easier to read, and it nicely isolates
the ptrace magic.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      18c98b65
    • L
      cgroup: fix a race condition in manipulating tsk->cg_list · 0e04388f
      由 Li Zefan 提交于 
      When I ran a test program to fork mass processes and at the same time
'cat /cgroup/tasks', I got the following oops:

  ------------[ cut here ]------------
  kernel BUG at lib/list_debug.c:72!
  invalid opcode: 0000 [#1] SMP
  Pid: 4178, comm: a.out Not tainted (2.6.25-rc9 #72)
  ...
  Call Trace:
   [<c044a5f9>] ? cgroup_exit+0x55/0x94
   [<c0427acf>] ? do_exit+0x217/0x5ba
   [<c0427ed7>] ? do_group_exit+0.65/0x7c
   [<c0427efd>] ? sys_exit_group+0xf/0x11
   [<c0404842>] ? syscall_call+0x7/0xb
   [<c05e0000>] ? init_cyrix+0x2fa/0x479
  ...
  EIP: [<c04df671>] list_del+0x35/0x53 SS:ESP 0068:ebc7df4
  ---[ end trace caffb7332252612b ]---
  Fixing recursive fault but reboot is needed!

After digging into the code and debugging, I finlly found out a race
situation:

				do_exit()
				  ->cgroup_exit()
				    ->if (!list_empty(&tsk->cg_list))
				        list_del(&tsk->cg_list);

  cgroup_iter_start()
    ->cgroup_enable_task_cg_list()
      ->list_add(&tsk->cg_list, ..);

In this case the list won't be deleted though the process has exited.

We got two bug reports in the past, which seem to be the same bug as
this one:
	http://lkml.org/lkml/2008/3/5/332
	http://lkml.org/lkml/2007/10/17/224

Actually sometimes I got oops on list_del, sometimes oops on list_add.
And I can change my test program a bit to trigger other oops.

The patch has been tested both on x86_32 and x86_64.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0e04388f
    • J
      kgdb: always use icache flush for sw breakpoints · 1a9a3e76
      由 Jason Wessel 提交于 
      On the ppc 4xx architecture the instruction cache must be flushed as
well as the data cache.  This patch just makes it generic for all
architectures where CACHE_FLUSH_IS_SAFE is set to 1.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1a9a3e76
    • J
      kgdb: fix SMP NMI kgdb_handle_exception exit race · 56fb7093
      由 Jason Wessel 提交于 
      Fix the problem of protecting the kgdb handle_exception exit
which had an NMI race condition, while trying to restore
normal system operation.

There was a small window after the master processor sets cpu_in_debug
to zero but before it has set kgdb_active to zero where a
non-master processor in an SMP system could receive an NMI and
re-enter the kgdb_wait() loop.

As long as the master processor sets the cpu_in_debug before sending
the cpu roundup the cpu_in_debug variable can also be used to guard
against the race condition.

The kgdb_wait() function no longer needs to check
kgdb_active because it is done in the arch specific code
and handled along with the nmi traps at the low level.
This also allows kgdb_wait() to exit correctly if it was
entered for some unknown reason due to a spurious NMI that
could not be handled by the arch specific code.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      56fb7093
    • J
      kgdb: fix several kgdb regressions · 737a460f
      由 Jason Wessel 提交于 
      kgdb core fixes:
- Check to see that mm->mmap_cache is not null before calling
  flush_cache_range(), else on arch=ARM it will cause a fatal
  fault.

- Breakpoints should only be restored if they are in the BP_ACTIVE
  state.

- Fix a typo in comments to "kgdb_register_io_module"

x86 kgdb fixes:
- Fix the x86 arch handler such that on a kill or detach that the
  appropriate cleanup on the single stepping flags gets run.

- Add in the DIE_NMIWATCHDOG call for x86_64

- Touch the nmi watchdog before returning the system to normal
  operation after performing any kind of kgdb operation, else
  the possibility exists to trigger the watchdog.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      737a460f
    • J
      kgdb: fix optional arch functions and probe_kernel_* · b4b8ac52
      由 Jason Wessel 提交于 
      Fix two regressions dealing with the kgdb core.

1) kgdb_skipexception and kgdb_post_primary_code are optional
functions that are only required on archs that need special exception
fixups.

2) The kernel address space scope must be set on any probe_kernel_*
function or archs such as ARCH=arm will not allow access to the kernel
memory space.  As an example, it is required to allow the full kernel
address space is when you the kernel debugger to inspect a system
call.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      b4b8ac52