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  1. 09 Dec, 2014 4 commits
  3. 01 Dec, 2014 3 commits
  5. 27 Nov, 2014 2 commits
    • Jeff Layton's avatar
      sunrpc: add a debugfs rpc_xprt directory with an info file in it · 388f0c77
      Jeff Layton authored 
      Add a new directory heirarchy under the debugfs sunrpc/ directory:

    sunrpc/
        rpc_xprt/
            <xprt id>/

Within that directory, we can put files that give info about the
xprts. We do have the (minor) problem that there is no succinct,
unique identifier for rpc_xprts. So we generate them synthetically
with a static atomic_t counter.

For now, this directory just holds an "info" file, but we may add
other files to it in the future.
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      388f0c77
    • Jeff Layton's avatar
      sunrpc: add debugfs file for displaying client rpc_task queue · b4b9d2cc
      Jeff Layton authored 
      It's possible to get a dump of the RPC task queue by writing a value to
/proc/sys/sunrpc/rpc_debug. If you write any value to that file, you get
a dump of the RPC client task list into the log buffer. This is a rather
inconvenient interface however, and makes it hard to get immediate info
about the task queue.

Add a new directory hierarchy under debugfs:

    sunrpc/
        rpc_clnt/
            <clientid>/

Within each clientid directory we create a new "tasks" file that will
dump info similar to what shows up in the log buffer, but with a few
small differences -- we avoid printing raw kernel addresses in favor of
symbolic names and the XID is also displayed.
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      b4b9d2cc
  7. 26 Nov, 2014 2 commits
  9. 25 Nov, 2014 15 commits
  11. 24 Nov, 2014 11 commits
  13. 23 Nov, 2014 3 commits
    • Linus Torvalds's avatar
      Linux 3.18-rc6 · 5d01410f
      Linus Torvalds authored
      5d01410f
    • Andy Lutomirski's avatar
      uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME · 82975bc6
      Andy Lutomirski authored 
      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: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      82975bc6
    • Thomas Gleixner's avatar
      sched: Provide update_curr callbacks for stop/idle scheduling classes · 90e362f4
      Thomas Gleixner authored 
      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: default avatarChris Mason <clm@fb.com>
Reported-and-tested-by: default avatarBorislav Petkov <bp@alien8.de>
Signed-off-by: default avatarThomas 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      90e362f4
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