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  1. 10 12月, 2014 3 次提交
  3. 02 12月, 2014 3 次提交
  5. 28 11月, 2014 2 次提交
  7. 27 11月, 2014 2 次提交
  9. 26 11月, 2014 12 次提交
  11. 25 11月, 2014 14 次提交
  13. 24 11月, 2014 4 次提交
    • L
      Linux 3.18-rc6 · 5d01410f
      由 Linus Torvalds 提交于
      5d01410f
    • A
      uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME · 82975bc6
      由 Andy Lutomirski 提交于 
      x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns.  I suspect that this is a mistake and that
the code only works because int3 is paranoid.

Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug.  With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
Reported-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      82975bc6
    • T
      sched: Provide update_curr callbacks for stop/idle scheduling classes · 90e362f4
      由 Thomas Gleixner 提交于 
      Chris bisected a NULL pointer deference in task_sched_runtime() to
commit 6e998916 'sched/cputime: Fix clock_nanosleep()/clock_gettime()
inconsistency'.

Chris observed crashes in atop or other /proc walking programs when he
started fork bombs on his machine.  He assumed that this is a new exit
race, but that does not make any sense when looking at that commit.

What's interesting is that, the commit provides update_curr callbacks
for all scheduling classes except stop_task and idle_task.

While nothing can ever hit that via the clock_nanosleep() and
clock_gettime() interfaces, which have been the target of the commit in
question, the author obviously forgot that there are other code paths
which invoke task_sched_runtime()

do_task_stat(()
 thread_group_cputime_adjusted()
   thread_group_cputime()
     task_cputime()
       task_sched_runtime()
        if (task_current(rq, p) && task_on_rq_queued(p)) {
          update_rq_clock(rq);
          up->sched_class->update_curr(rq);
        }

If the stats are read for a stomp machine task, aka 'migration/N' and
that task is current on its cpu, this will happily call the NULL pointer
of stop_task->update_curr.  Ooops.

Chris observation that this happens faster when he runs the fork bomb
makes sense as the fork bomb will kick migration threads more often so
the probability to hit the issue will increase.

Add the missing update_curr callbacks to the scheduler classes stop_task
and idle_task.  While idle tasks cannot be monitored via /proc we have
other means to hit the idle case.

Fixes: 6e998916 'sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency'
Reported-by: NChris Mason <clm@fb.com>
Reported-and-tested-by: NBorislav Petkov <bp@alien8.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      90e362f4
    • L
      Merge branch 'x86-traps' (trap handling from Andy Lutomirski) · 00c89b2f
      由 Linus Torvalds 提交于 
      Merge x86-64 iret fixes from Andy Lutomirski:
 "This addresses the following issues:

   - an unrecoverable double-fault triggerable with modify_ldt.
   - invalid stack usage in espfix64 failed IRET recovery from IST
     context.
   - invalid stack usage in non-espfix64 failed IRET recovery from IST
     context.

  It also makes a good but IMO scary change: non-espfix64 failed IRET
  will now report the correct error.  Hopefully nothing depended on the
  old incorrect behavior, but maybe Wine will get confused in some
  obscure corner case"

* emailed patches from Andy Lutomirski <luto@amacapital.net>:
  x86_64, traps: Rework bad_iret
  x86_64, traps: Stop using IST for #SS
  x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C
      00c89b2f