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  1. Jun 18, 2006
    • Oleg Nesterov's avatar
      [PATCH] run_posix_cpu_timers: remove a bogus BUG_ON() · 30f1e3dd
      Oleg Nesterov authored 
      do_exit() clears ->it_##clock##_expires, but nothing prevents
another cpu to attach the timer to exiting process after that.
arm_timer() tries to protect against this race, but the check
is racy.

After exit_notify() does 'write_unlock_irq(&tasklist_lock)' and
before do_exit() calls 'schedule() local timer interrupt can find
tsk->exit_state != 0. If that state was EXIT_DEAD (or another cpu
does sys_wait4) interrupted task has ->signal == NULL.

At this moment exiting task has no pending cpu timers, they were
cleanuped in __exit_signal()->posix_cpu_timers_exit{,_group}(),
so we can just return from irq.

John Stultz recently confirmed this bug, see

	http://marc.theaimsgroup.com/?l=linux-kernel&m=115015841413687



Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      30f1e3dd
    • Oleg Nesterov's avatar
      [PATCH] check_process_timers: fix possible lockup · 8f17fc20
      Oleg Nesterov authored 
      

If the local timer interrupt happens just after do_exit() sets PF_EXITING
(and before it clears ->it_xxx_expires) run_posix_cpu_timers() will call
check_process_timers() with tasklist_lock + ->siglock held and

	check_process_timers:

		t = tsk;
		do {
			....

			do {
				t = next_thread(t);
			} while (unlikely(t->flags & PF_EXITING));
		} while (t != tsk);

the outer loop will never stop.

Actually, the window is bigger.  Another process can attach the timer
after ->it_xxx_expires was cleared (see the next commit) and the 'if
(PF_EXITING)' check in arm_timer() is racy (see the one after that).

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8f17fc20
    • Stephen Hemminger's avatar
      [PATCH] sky2: netconsole suspend/resume interaction · 88d11360
      Stephen Hemminger authored 
      

A couple of fixes that should prevent crashes when using netconsole and
suspend/resume. First, netconsole poll routine shouldn't run unless the
device is up; second, the NAPI poll should be disabled during suspend.

This is only an issue on sky2, because it has to have one NAPI poll
routine for both ports on dual port boards. Normal drivers use
netif_rx_schedule_prep and that checks for netif_running.

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      88d11360
    • Jens Axboe's avatar
      [PATCH] Fix missing ret assignment in __bio_map_user() error path · 99172157
      Jens Axboe authored 
      

If get_user_pages() returns less pages than what we asked for, we jump
to out_unmap which will return ERR_PTR(ret).  But ret can contain a
positive number just smaller than local_nr_pages, so be sure to set it
to -EFAULT always.

Problem found and diagnosed by Damien Le Moal <damien@sdl.hitachi.co.jp>

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      99172157
    • Jens Axboe's avatar
      [PATCH] fix cdrom open · 16070428
      Jens Axboe authored 
      

Some time ago the cdrom open routine was changed so that we call the
driver's open routine before checking to see if it is read only.  However,
if we discovered that a read write open was not possible and the open
flags required a writable open, we just returned -EROFS without calling
the driver's release routine.   This seems to work for most cdrom drivers,
but breaks the Powerpc iSeries virtual cdrom rather badly.

This just inserts the release call in the error path to balance the call
to "->open()" done by "open_for_data()".

Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      16070428
  3. Jun 15, 2006
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