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  1. 15 May, 2012 1 commit
  3. 14 May, 2012 9 commits
    • Hiroshi DOYU's avatar
      memory: tegra{20,30}-mc: Remove empty *_remove() · 7458eab6
      Hiroshi DOYU authored 
      Remove unnecessary empty functions.
Signed-off-by: default avatarHiroshi DOYU <hdoyu@nvidia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7458eab6
    • Kay Sievers's avatar
      printk() - isolate KERN_CONT users from ordinary complete lines · c313af14
      Kay Sievers authored 
      Arrange the continuation printk() buffering to be fully separated from the
ordinary full line users.

Limit the exposure to races and wrong printk() line merges to users of
continuation only. Ordinary full line users racing against continuation
users will no longer affect each other.

Multiple continuation users from different threads, racing against each
other will not wrongly be merged into a single line, but printed as
separate lines.

Test output of a kernel module which starts two separate threads which
race against each other, one of them printing a single full terminated
line:
  printk("(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)\n");

The other one printing the line, every character separate in a
continuation loop:
  printk("(C");
  for (i = 0; i < 58; i++)
          printk(KERN_CONT "C");
  printk(KERN_CONT "C)\n");

Behavior of single and non-thread-aware printk() buffer:
  # modprobe printk-race
  printk test init
  (CC(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  CC(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  CC(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  CC(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  C(AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC)
  (CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC)

New behavior with separate and thread-aware continuation buffer:
  # modprobe printk-race
  printk test init
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA)
  (CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC)
  (CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC)

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Ingo Molnar  <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: default avatarKay Sievers <kay@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c313af14
    • Alan Stern's avatar
      sysfs: get rid of some lockdep false positives · 356c05d5
      Alan Stern authored 
      This patch (as1554) fixes a lockdep false-positive report.  The
problem arises because lockdep is unable to deal with the
tree-structured locks created by the device core and sysfs.

This particular problem involves a sysfs attribute method that
unregisters itself, not from the device it was called for, but from a
descendant device.  Lockdep doesn't understand the distinction and
reports a possible deadlock, even though the operation is safe.

This is the sort of thing that would normally be handled by using a
nested lock annotation; unfortunately it's not feasible to do that
here.  There's no sensible way to tell sysfs when attribute removal
occurs in the context of a parent attribute method.

As a workaround, the patch adds a new flag to struct attribute
telling sysfs not to inform lockdep when it acquires a readlock on a
sysfs_dirent instance for the attribute.  The readlock is still
acquired, but lockdep doesn't know about it and hence does not
complain about impossible deadlock scenarios.

Also added are macros for static initialization of attribute
structures with the ignore_lockdep flag set.  The three offending
attributes in the USB subsystem are converted to use the new macros.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Acked-by: default avatarTejun Heo <tj@kernel.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      356c05d5
    • K. Y. Srinivasan's avatar
      Drivers: hv: util: Properly handle version negotiations. · c836d0ab
      K. Y. Srinivasan authored 
      The current version negotiation code is not "future proof". Fix this
by allowing each service the flexibility to either specify the highest
version it can support or it can support the highest version number
the host is offering.
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c836d0ab
    • K. Y. Srinivasan's avatar
      Drivers: hv: Get rid of an unnecessary check in vmbus_prep_negotiate_resp() · a3605300
      K. Y. Srinivasan authored 
      The vmbus_prep_negotiate_resp() is only invoked when we are negotiating
the version; so the current check in vmbus_prep_negotiate_resp()
is unnecessary. Get rid of it.
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a3605300
    • Hiroshi DOYU's avatar
      memory: tegra{20,30}-mc: Use dev_err_ratelimited() · 90394482
      Hiroshi DOYU authored 
      Introduce a new dev_*_ratelimited() instead of pr_*_ratelimited() for
better info to print.
Signed-off-by: default avatarHiroshi DOYU <hdoyu@nvidia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      90394482
    • Hiroshi DOYU's avatar
      driver core: Add dev_*_ratelimited() family · 6ca04593
      Hiroshi DOYU authored 
      Add dev_*_ratelimited() family, dev_* version of pr_*_ratelimited().

Using Joe Perches's proposal/implementation.
Signed-off-by: default avatarHiroshi DOYU <hdoyu@nvidia.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6ca04593
    • Hiroshi DOYU's avatar
      Driver Core: don't oops with unregistered driver in driver_find_device() · 094e47e9
      Hiroshi DOYU authored 
      driver_find_device() can be called with an unregistered driver. Need
to check driver_private to see if it's populated or not, especially
under deferrable probe.

In the case that there are 2 drivers, one depends on the other. With
-EPROBE_DEFER, two drivers can use deferred probe to ensure that their
relative probe order doesn't matter. If dependee driver is probed
first, then the dependant's driver_find_device('dependee')
succeeds. If the dependant is probed first, then the dependant's
driver_find_device('dependee') should return NULL, and the dependant
should get -EPROBE_DEFER. driver_find_device() needs to return NULL if
it's not populated.

In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
  http://article.gmane.org/gmane.linux.ports.tegra/4658

"tegra_ahb_driver" may not be populated when it's called.

For more SMMU/AHB specific discussion, refer to the following thread:
  https://lkml.org/lkml/2012/5/10/21Signed-off-by: default avatarHiroshi DOYU <hdoyu@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      094e47e9
    • Kay Sievers's avatar
      printk() - restore prefix/timestamp printing for multi-newline strings · 3ce9a7c0
      Kay Sievers authored 
      Calls like:
  printk("\n *** DEADLOCK ***\n\n");
will print 3 properly indented, separated, syslog + timestamp prefixed lines in
the log output.
Reported-By: default avatarSasha Levin <levinsasha928@gmail.com>
Signed-off-by: default avatarKay Sievers <kay@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3ce9a7c0
  5. 11 May, 2012 5 commits
  7. 10 May, 2012 5 commits
  9. 09 May, 2012 3 commits
  11. 08 May, 2012 8 commits
  13. 07 May, 2012 4 commits
    • Kay Sievers's avatar
      printk: convert byte-buffer to variable-length record buffer · 7ff9554b
      Kay Sievers authored 
      - Record-based stream instead of the traditional byte stream
  buffer. All records carry a 64 bit timestamp, the syslog facility
  and priority in the record header.

- Records consume almost the same amount, sometimes less memory than
  the traditional byte stream buffer (if printk_time is enabled). The record
  header is 16 bytes long, plus some padding bytes at the end if needed.
  The byte-stream buffer needed 3 chars for the syslog prefix, 15 char for
  the timestamp and a newline.

- Buffer management is based on message sequence numbers. When records
  need to be discarded, the reading heads move on to the next full
  record. Unlike the byte-stream buffer, no old logged lines get
  truncated or partly overwritten by new ones. Sequence numbers also
  allow consumers of the log stream to get notified if any message in
  the stream they are about to read gets discarded during the time
  of reading.

- Better buffered IO support for KERN_CONT continuation lines, when printk()
  is called multiple times for a single line. The use of KERN_CONT is now
  mandatory to use continuation; a few places in the kernel need trivial fixes
  here. The buffering could possibly be extended to per-cpu variables to allow
  better thread-safety for multiple printk() invocations for a single line.

- Full-featured syslog facility value support. Different facilities
  can tag their messages. All userspace-injected messages enforce a
  facility value > 0 now, to be able to reliably distinguish them from
  the kernel-generated messages. Independent subsystems like a
  baseband processor running its own firmware, or a kernel-related
  userspace process can use their own unique facility values. Multiple
  independent log streams can co-exist that way in the same
  buffer. All share the same global sequence number counter to ensure
  proper ordering (and interleaving) and to allow the consumers of the
  log to reliably correlate the events from different facilities.
Tested-by: default avatarWilliam Douglas <william.douglas@intel.com>
Signed-off-by: default avatarKay Sievers <kay@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7ff9554b
    • Paul Gortmaker's avatar
      powerpc: fix compile fail in hugetlb cmdline parsing · 89528127
      Paul Gortmaker authored 
      Commit 9fb48c74

    "params: add 3rd arg to option handler callback signature"

added an extra arg to the function, but didn't catch all the use
cases needing it, causing this compile fail in mpc85xx_defconfig:

 arch/powerpc/mm/hugetlbpage.c:316:4: error: passing argument 7 of
 'parse_args' from incompatible pointer type [-Werror]

 include/linux/moduleparam.h:317:12: note: expected
	 'int (*)(char *, char *, const char *)' but argument is of type
	 'int (*)(char *, char *)'

This function has no need to printk out the "doing" value, so
just add the arg as an "unused".

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      89528127
    • Zhi Yong Wu's avatar
      kobject: fix the uncorrect comment · 9ff1f838
      Zhi Yong Wu authored 
      Signed-off-by: default avatarZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9ff1f838
    • Greg Kroah-Hartman's avatar
      Revert "dynamic_debug: remove unneeded includes" · fef15d2f
      Greg Kroah-Hartman authored 
      This reverts commit 04db6e5f.

Odds are, we really don't want to revert all of these, and need to be
more careful in the future to make sure we don't break the build of
other arches.
Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fef15d2f
  15. 05 May, 2012 3 commits
  17. 04 May, 2012 2 commits
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