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  1. 28 7月, 2010 13 次提交
  3. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  5. 04 3月, 2010 2 次提交
  7. 20 12月, 2009 2 次提交
    • A
      fix more leaks in audit_tree.c tag_chunk() · b4c30aad
      由 Al Viro 提交于 
      Several leaks in audit_tree didn't get caught by commit
318b6d3d, including the leak on normal
exit in case of multiple rules refering to the same chunk.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b4c30aad
    • A
      fix braindamage in audit_tree.c untag_chunk() · 6f5d5114
      由 Al Viro 提交于 
      ... aka "Al had badly fscked up when writing that thing and nobody
noticed until Eric had fixed leaks that used to mask the breakage".

The function essentially creates a copy of old array sans one element
and replaces the references to elements of original (they are on cyclic
lists) with those to corresponding elements of new one.  After that the
old one is fair game for freeing.

First of all, there's a dumb braino: when we get to list_replace_init we
use indices for wrong arrays - position in new one with the old array
and vice versa.

Another bug is more subtle - termination condition is wrong if the
element to be excluded happens to be the last one.  We shouldn't go
until we fill the new array, we should go until we'd finished the old
one.  Otherwise the element we are trying to kill will remain on the
cyclic lists...

That crap used to be masked by several leaks, so it was not quite
trivial to hit.  Eric had fixed some of those leaks a while ago and the
shit had hit the fan...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6f5d5114
  9. 24 6月, 2009 2 次提交
    • A
      Fix rule eviction order for AUDIT_DIR · 916d7576
      由 Al Viro 提交于 
      If syscall removes the root of subtree being watched, we
definitely do not want the rules refering that subtree
to be destroyed without the syscall in question having
a chance to match them.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      916d7576
    • E
      Audit: clean up all op= output to include string quoting · 9d960985
      由 Eric Paris 提交于 
      A number of places in the audit system we send an op= followed by a string
that includes spaces.  Somehow this works but it's just wrong.  This patch
moves all of those that I could find to be quoted.

Example:

Change From: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op=remove rule
key="number2" list=4 res=0

Change To: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op="remove rule"
key="number2" list=4 res=0
Signed-off-by: NEric Paris <eparis@redhat.com>
      9d960985
  11. 12 6月, 2009 1 次提交
  13. 21 4月, 2009 1 次提交
  15. 06 4月, 2009 1 次提交
  17. 05 1月, 2009 2 次提交
  19. 16 11月, 2008 1 次提交
    • A
      Fix inotify watch removal/umount races · 8f7b0ba1
      由 Al Viro 提交于 
      Inotify watch removals suck violently.

To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex.  That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount.  We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.

Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done.  Cleanup is just deactivate_super().

However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords.  That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.

We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable.  OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e.  that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().

So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong.  We had
to drop ih->mutex before we could grab ->s_umount.  So the watch
could've been gone already.

That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer.  If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address.  That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that.  Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.

So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check.  If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.

And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NGreg KH <greg@kroah.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8f7b0ba1
  21. 23 10月, 2008 1 次提交
  23. 17 5月, 2008 1 次提交
  25. 15 2月, 2008 2 次提交
  27. 21 10月, 2007 1 次提交
    • A
      [PATCH] audit: watching subtrees · 74c3cbe3
      由 Al Viro 提交于 
      New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is.  Limitations:
	* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
	* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
	* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there.  New command
tells audit to recalculate the trees, trimming such sources of false
positives.

Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      74c3cbe3