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  1. 18 Mar, 2009 10 commits
  3. 17 Mar, 2009 7 commits
    • Linus Torvalds's avatar
      Avoid 64-bit "switch()" statements on 32-bit architectures · ee568b25
      Linus Torvalds authored 
      Commit ee6f779b ("filp->f_pos not
correctly updated in proc_task_readdir") changed the proc code to use
filp->f_pos directly, rather than through a temporary variable.  In the
process, that caused the operations to be done on the full 64 bits, even
though the offset is never that big.

That's all fine and dandy per se, but for some unfathomable reason gcc
generates absolutely horrid code when using 64-bit values in switch()
statements.  To the point of actually calling out to gcc helper
functions like __cmpdi2 rather than just doing the trivial comparisons
directly the way gcc does for normal compares.  At which point we get
link failures, because we really don't want to support that kind of
crazy code.

Fix this by just casting the f_pos value to "unsigned long", which
is plenty big enough for /proc, and avoids the gcc code generation issue.
Reported-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Le <r0bertz@gentoo.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ee568b25
    • Masami Hiramatsu's avatar
      prevent boosting kprobes on exception address · 30390880
      Masami Hiramatsu authored 
      Don't boost at the addresses which are listed on exception tables,
because major page fault will occur on those addresses.  In that case,
kprobes can not ensure that when instruction buffer can be freed since
some processes will sleep on the buffer.

kprobes-ia64 already has same check.
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      30390880
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm · 18439c39
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm crypt: wait for endio to complete before destruction
  dm crypt: fix kcryptd_async_done parameter
  dm io: respect BIO_MAX_PAGES limit
  dm table: rework reference counting fix
  dm ioctl: validate name length when renaming
      18439c39
    • Linus Torvalds's avatar
      Fast TSC calibration: calculate proper frequency error bounds · 9e8912e0
      Linus Torvalds authored 
      In order for ntpd to correctly synchronize the clocks, the frequency of
the system clock must not be off by more than 500 ppm (or, put another
way, 1:2000), or ntpd will end up giving up on trying to synchronize
properly, and ends up reseting the clock in jumps instead.

The fast TSC PIT calibration sometimes failed this test - it was
assuming that the PIT reads always took about one microsecond each (2us
for the two reads to get a 16-bit timer), and that calibrating TSC to
the PIT over 15ms should thus be sufficient to get much closer than
500ppm (max 2us error on both sides giving 4us over 15ms: a 270 ppm
error value).

However, that assumption does not always hold: apparently some hardware
is either very much slower at reading the PIT registers, or there was
other noise causing at least one machine to get 700+ ppm errors.

So instead of using a fixed 15ms timing loop, this changes the fast PIT
calibration to read the TSC delta over the individual PIT timer reads,
and use the result to calculate the error bars on the PIT read timing
properly.  We then successfully calibrate the TSC only if the maximum
error bars fall below 500ppm.

In the process, we also relax the timing to allow up to 25ms for the
calibration, although it can happen much faster depending on hardware.
Reported-and-tested-by: default avatarJesper Krogh <jesper@krogh.cc>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9e8912e0
    • Linus Torvalds's avatar
      Fix potential fast PIT TSC calibration startup glitch · a6a80e1d
      Linus Torvalds authored 
      During bootup, when we reprogram the PIT (programmable interval timer)
to start counting down from 0xffff in order to use it for the fast TSC
calibration, we should also make sure to delay a bit afterwards to allow
the PIT hardware to actually start counting with the new value.

That will happens at the next CLK pulse (1.193182 MHz), so the easiest
way to do that is to just wait at least one microsecond after
programming the new PIT counter value.  We do that by just reading the
counter value back once - which will take about 2us on PC hardware.
Reported-and-tested-by: default avatarjohn stultz <johnstul@us.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a6a80e1d
    • Krzysztof Helt's avatar
      ALSA: opl3sa2 - Fix NULL dereference when suspending snd_opl3sa2 · dde332b6
      Krzysztof Helt authored 
      Fix the OOPS during a opl3sa2 card suspend
and resume if the driver is loaded but the card
is not found.
Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: <stable@kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      dde332b6
    • Eric Sandeen's avatar
      ext4: fix bb_prealloc_list corruption due to wrong group locking · d33a1976
      Eric Sandeen authored 
      This is for Red Hat bug 490026: EXT4 panic, list corruption in
ext4_mb_new_inode_pa

ext4_lock_group(sb, group) is supposed to protect this list for
each group, and a common code flow to remove an album is like
this:

    ext4_get_group_no_and_offset(sb, pa->pa_pstart, &grp, NULL);
    ext4_lock_group(sb, grp);
    list_del(&pa->pa_group_list);
    ext4_unlock_group(sb, grp);

so it's critical that we get the right group number back for
this prealloc context, to lock the right group (the one 
associated with this pa) and prevent concurrent list manipulation.

however, ext4_mb_put_pa() passes in (pa->pa_pstart - 1) with a 
comment, "-1 is to protect from crossing allocation group".

This makes sense for the group_pa, where pa_pstart is advanced
by the length which has been used (in ext4_mb_release_context()),
and when the entire length has been used, pa_pstart has been
advanced to the first block of the next group.

However, for inode_pa, pa_pstart is never advanced; it's just
set once to the first block in the group and not moved after
that.  So in this case, if we subtract one in ext4_mb_put_pa(),
we are actually locking the *previous* group, and opening the
race with the other threads which do not subtract off the extra
block.
Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      d33a1976
  5. 16 Mar, 2009 23 commits
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