5944 Commits

Author SHA1 Message Date
KOSAKI Motohiro
26e5438e4b profile: don't include <asm/ptrace.h> twice.
Currently, kernel/profile.c include <asm/ptrace.h> twice.  It can be
removed.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:14 -08:00
Paul Mackerras
e3d5a27d58 Allow times and time system calls to return small negative values
At the moment, the times() system call will appear to fail for a period
shortly after boot, while the value it want to return is between -4095 and
-1.  The same thing will also happen for the time() system call on 32-bit
platforms some time in 2106 or so.

On some platforms, such as x86, this is unavoidable because of the system
call ABI, but other platforms such as powerpc have a separate error
indication from the return value, so system calls can in fact return small
negative values without indicating an error.  On those platforms,
force_successful_syscall_return() provides a way to indicate that the
system call return value should not be treated as an error even if it is
in the range which would normally be taken as a negative error number.

This adds a force_successful_syscall_return() call to the time() and
times() system calls plus their 32-bit compat versions, so that they don't
erroneously indicate an error on those platforms whose system call ABI has
a separate error indication.  This will not affect anything on other
platforms.

Joakim Tjernlund added the fix for time() and the compat versions of
time() and times(), after I did the fix for times().

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:13 -08:00
Arjan van de Ven
d6624f996a oops: increment the oops UUID every time we oops
... because we do want repeated same-oops to be seen by automated
tools like kerneloops.org

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:12 -08:00
Zhaolei
60348802e9 fork.c: cleanup for copy_sighand()
Check CLONE_SIGHAND only is enough, because combination of CLONE_THREAD and
CLONE_SIGHAND is already done in copy_process().

Impact: cleanup, no functionality changed

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:11 -08:00
Alexey Dobriyan
f1883f86de Remove remaining unwinder code
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Gabor Gombas <gombasg@sztaki.hu>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:11 -08:00
Oleg Nesterov
901608d904 mm: introduce get_mm_hiwater_xxx(), fix taskstats->hiwater_xxx accounting
xacct_add_tsk() relies on do_exit()->update_hiwater_xxx() and uses
mm->hiwater_xxx directly, this leads to 2 problems:

- taskstats_user_cmd() can call fill_pid()->xacct_add_tsk() at any
  moment before the task exits, so we should check the current values of
  rss/vm anyway.

- do_exit()->update_hiwater_xxx() calls are racy.  An exiting thread can
  be preempted right before mm->hiwater_xxx = new_val, and another thread
  can use A_LOT of memory and exit in between.  When the first thread
  resumes it can be the last thread in the thread group, in that case we
  report the wrong hiwater_xxx values which do not take A_LOT into
  account.

Introduce get_mm_hiwater_rss() and get_mm_hiwater_vm() helpers and change
xacct_add_tsk() to use them.  The first helper will also be used by
rusage->ru_maxrss accounting.

Kill do_exit()->update_hiwater_xxx() calls.  Unless we are going to
decrease rss/vm there is no point to update mm->hiwater_xxx, and nobody
can look at this mm_struct when exit_mmap() actually unmaps the memory.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:09 -08:00
David Rientjes
2da02997e0 mm: add dirty_background_bytes and dirty_bytes sysctls
This change introduces two new sysctls to /proc/sys/vm:
dirty_background_bytes and dirty_bytes.

dirty_background_bytes is the counterpart to dirty_background_ratio and
dirty_bytes is the counterpart to dirty_ratio.

With growing memory capacities of individual machines, it's no longer
sufficient to specify dirty thresholds as a percentage of the amount of
dirtyable memory over the entire system.

dirty_background_bytes and dirty_bytes specify quantities of memory, in
bytes, that represent the dirty limits for the entire system.  If either
of these values is set, its value represents the amount of dirty memory
that is needed to commence either background or direct writeback.

When a `bytes' or `ratio' file is written, its counterpart becomes a
function of the written value.  For example, if dirty_bytes is written to
be 8096, 8K of memory is required to commence direct writeback.
dirty_ratio is then functionally equivalent to 8K / the amount of
dirtyable memory:

	dirtyable_memory = free pages + mapped pages + file cache

	dirty_background_bytes = dirty_background_ratio * dirtyable_memory
		-or-
	dirty_background_ratio = dirty_background_bytes / dirtyable_memory

		AND

	dirty_bytes = dirty_ratio * dirtyable_memory
		-or-
	dirty_ratio = dirty_bytes / dirtyable_memory

Only one of dirty_background_bytes and dirty_background_ratio may be
specified at a time, and only one of dirty_bytes and dirty_ratio may be
specified.  When one sysctl is written, the other appears as 0 when read.

The `bytes' files operate on a page size granularity since dirty limits
are compared with ZVC values, which are in page units.

Prior to this change, the minimum dirty_ratio was 5 as implemented by
get_dirty_limits() although /proc/sys/vm/dirty_ratio would show any user
written value between 0 and 100.  This restriction is maintained, but
dirty_bytes has a lower limit of only one page.

Also prior to this change, the dirty_background_ratio could not equal or
exceed dirty_ratio.  This restriction is maintained in addition to
restricting dirty_background_bytes.  If either background threshold equals
or exceeds that of the dirty threshold, it is implicitly set to half the
dirty threshold.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:03 -08:00
Hugh Dickins
e5991371ee mm: remove cgroup_mm_owner_callbacks
cgroup_mm_owner_callbacks() was brought in to support the memrlimit
controller, but sneaked into mainline ahead of it.  That controller has
now been shelved, and the mm_owner_changed() args were inadequate for it
anyway (they needed an mm pointer instead of a task pointer).

Remove the dead code, and restore mm_update_next_owner() locking to how it
was before: taking mmap_sem there does nothing for memcontrol.c, now the
only user of mm->owner.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:01 -08:00
David Rientjes
75aa199410 oom: print triggering task's cpuset and mems allowed
When cpusets are enabled, it's necessary to print the triggering task's
set of allowable nodes so the subsequently printed meminfo can be
interpreted correctly.

We also print the task's cpuset name for informational purposes.

[rientjes@google.com: task lock current before dereferencing cpuset]
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:58:59 -08:00
James Morris
ac8cc0fa53 Merge branch 'next' into for-linus 2009-01-07 09:58:22 +11:00
David Howells
3699c53c48 CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #3]
Fix a regression in cap_capable() due to:

	commit 3b11a1decef07c19443d24ae926982bc8ec9f4c0
	Author: David Howells <dhowells@redhat.com>
	Date:   Fri Nov 14 10:39:26 2008 +1100

	    CRED: Differentiate objective and effective subjective credentials on a task

The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.

There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.

Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds.  However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.

One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.

The affected capability check is in generic_permission():

	if (!(mask & MAY_EXEC) || execute_ok(inode))
		if (capable(CAP_DAC_OVERRIDE))
			return 0;

This change passes the set of credentials to be tested down into the commoncap
and SELinux code.  The security functions called by capable() and
has_capability() select the appropriate set of credentials from the process
being checked.

This can be tested by compiling the following program from the XFS testsuite:

/*
 *  t_access_root.c - trivial test program to show permission bug.
 *
 *  Written by Michael Kerrisk - copyright ownership not pursued.
 *  Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
 */
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>

#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"

static void
errExit(char *msg)
{
    perror(msg);
    exit(EXIT_FAILURE);
} /* errExit */

static void
accessTest(char *file, int mask, char *mstr)
{
    printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */

int
main(int argc, char *argv[])
{
    int fd, perm, uid, gid;
    char *testpath;
    char cmd[PATH_MAX + 20];

    testpath = (argc > 1) ? argv[1] : TESTPATH;
    perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
    uid = (argc > 3) ? atoi(argv[3]) : UID;
    gid = (argc > 4) ? atoi(argv[4]) : GID;

    unlink(testpath);

    fd = open(testpath, O_RDWR | O_CREAT, 0);
    if (fd == -1) errExit("open");

    if (fchown(fd, uid, gid) == -1) errExit("fchown");
    if (fchmod(fd, perm) == -1) errExit("fchmod");
    close(fd);

    snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
    system(cmd);

    if (seteuid(uid) == -1) errExit("seteuid");

    accessTest(testpath, 0, "0");
    accessTest(testpath, R_OK, "R_OK");
    accessTest(testpath, W_OK, "W_OK");
    accessTest(testpath, X_OK, "X_OK");
    accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
    accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
    accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
    accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");

    exit(EXIT_SUCCESS);
} /* main */

This can be run against an Ext3 filesystem as well as against an XFS
filesystem.  If successful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns 0
	access(/tmp/xxx, W_OK) returns 0
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns 0
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

If unsuccessful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns -1
	access(/tmp/xxx, W_OK) returns -1
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns -1
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

I've also tested the fix with the SELinux and syscalls LTP testsuites.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-01-07 09:38:48 +11:00
James Morris
29881c4502 Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]"
This reverts commit 14eaddc967b16017d4a1a24d2be6c28ecbe06ed8.

David has a better version to come.
2009-01-07 09:21:54 +11:00
Kay Sievers
81ff86a11f pm: struct device - replace bus_id with dev_name(), dev_set_name()
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06 10:44:39 -08:00
Ming Lei
cd3772e689 kernel/ksysfs.c:fix dependence on CONFIG_NET
Access to uevent_seqnum and uevent_helper does not need to
depend on CONFIG_NET, so remove it.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06 10:44:31 -08:00
Frederik Schwarzer
025dfdafe7 trivial: fix then -> than typos in comments and documentation
- (better, more, bigger ...) then -> (...) than

Signed-off-by: Frederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-06 11:28:06 +01:00
Jiri Kosina
edb123e16c trivial: printk: fix indentation of new_text_line declaration
Remove bogus indentation of new_text_line declaration introduced in
commit ac60ad741.

Acked-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-06 11:28:06 +01:00
Li Zefan
db2f59c8c9 sched: fix section mismatch
init_rootdomain() calls alloc_bootmem_cpumask_var() at system boot,
so does cpupri_init().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06 11:07:15 +01:00
Li Zefan
0c910d2895 sched: fix double kfree in failure path
It's not the responsibility of init_rootdomain() to free root_domain
allocated by alloc_rootdomain().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06 11:07:04 +01:00
Ingo Molnar
d9be28ea91 Merge branches 'sched/clock', 'sched/cleanups' and 'linus' into sched/urgent 2009-01-06 09:33:57 +01:00
Ingo Molnar
fdbc0450df Merge branches 'core/futexes', 'core/locking', 'core/rcu' and 'linus' into core/urgent 2009-01-06 09:32:11 +01:00
Linus Torvalds
0bbb275358 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: convert to stop_machine_create/destroy.
  stop_machine: introduce stop_machine_create/destroy.
  parisc: fix module loading failure of large kernel modules
  module: fix module loading failure of large kernel modules for parisc
  module: fix warning of unused function when !CONFIG_PROC_FS
  kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms.
  remove CONFIG_KMOD
2009-01-05 19:03:39 -08:00
Linus Torvalds
520c853466 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  inotify: fix type errors in interfaces
  fix breakage in reiserfs_new_inode()
  fix the treatment of jfs special inodes
  vfs: remove duplicate code in get_fs_type()
  add a vfs_fsync helper
  sys_execve and sys_uselib do not call into fsnotify
  zero i_uid/i_gid on inode allocation
  inode->i_op is never NULL
  ntfs: don't NULL i_op
  isofs check for NULL ->i_op in root directory is dead code
  affs: do not zero ->i_op
  kill suid bit only for regular files
  vfs: lseek(fd, 0, SEEK_CUR) race condition
2009-01-05 18:32:06 -08:00
Al Viro
56ff5efad9 zero i_uid/i_gid on inode allocation
... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Ingo Molnar
82c5b7b527 hrtimer: splitout peek ahead functionality, fix
Impact: build fix on !CONFIG_HIGH_RES_TIMERS

Fix:

  kernel/hrtimer.c:1586: error: implicit declaration of function '__hrtimer_peek_ahead_timers'

Signen-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 14:11:10 +01:00
Li Zefan
c70f22d203 sched: clean up arch_reinit_sched_domains()
- Make arch_reinit_sched_domains() static. It was exported to be used in
  s390, but now rebuild_sched_domains() is used instead.

- Make it return void.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:54:16 +01:00
Li Zefan
39aac64812 sched: mark sched_create_sysfs_power_savings_entries() as __init
Impact: cleanup

The only caller is cpu_dev_init() which is marked as __init.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:54:16 +01:00
Ingo Molnar
5359c32eb7 Merge branch 'linus' into sched/urgent 2009-01-05 13:53:39 +01:00
Thomas Gleixner
e3f1d88374 hrtimer: fixup comments
Clean up the comments

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:14:34 +01:00
Peter Zijlstra
a6037b61c2 hrtimer: fix recursion deadlock by re-introducing the softirq
Impact: fix rare runtime deadlock

There are a few sites that do:

  spin_lock_irq(&foo)
  hrtimer_start(&bar)
    __run_hrtimer(&bar)
      func()
        spin_lock(&foo)

which obviously deadlocks. In order to avoid this, never call __run_hrtimer()
from hrtimer_start*() context, but instead defer this to softirq context.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:14:33 +01:00
Thomas Gleixner
731a55ba0f hrtimer: simplify hotplug migration
Impact: cleanup

No need for a smp function call, which is likely to run on the same
CPU anyway. We can just call hrtimers_peek_ahead() in the interrupts
disabled section of migrate_hrtimers().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:14:33 +01:00
Thomas Gleixner
d5fd43c4ae hrtimer: fix HOTPLUG_CPU=n compile warning
Impact: cleanup

 kernel/hrtimer.c: In function 'hrtimer_cpu_notify':
 kernel/hrtimer.c:1574: warning: unused variable 'dcpu'

Introduced by commit 37810659ea7d9572c5ac284ade272f806ef8f788
("hrtimer: removing all ur callback modes, fix hotplug") from the
timers.  dcpu is only used if CONFIG_HOTPLUG_CPU is set.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:14:32 +01:00
Thomas Gleixner
8bdec955b0 hrtimer: splitout peek ahead functionality
Impact: cleanup

Provide a peek ahead function that assumes irqs disabled, allows for micro
optimizations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:14:32 +01:00
Paul E. McKenney
c59ab97e9e rcu: fix rcutorture bug
Fix an rcutorture bug that prevents the shutdown notifier from ever
actually having any effect, due to the fact that kthreads ignore all
signals.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 13:09:49 +01:00
Paul E. McKenney
ea7d3fef42 rcu: eliminate synchronize_rcu_xxx macro
Impact: cleanup

Expand macro into two files.

The synchronize_rcu_xxx macro is quite ugly and it's only used by two
callers, so expand it instead.  This makes this code easier to change.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 10:18:08 +01:00
Paul E. McKenney
90a4d2c010 rcu: make treercu safe for suspend and resume
Impact: fix kernel warnings [and potential crash] during suspend+resume

Kudos to both Dhaval Giani and Jens Axboe for finding a bug in treercu
that causes warnings after suspend-resume cycles in Dhaval's case and
during stress tests in Jens's case.  It would also probably cause failures
if heavily stressed.  The solution, ironically enough, is to revert to
rcupreempt's code for initializing the dynticks state.  And the patch
even results in smaller code -- so what was I thinking???

This is 2.6.29 material, given that people really do suspend and resume
Linux these days.  ;-)

Reported-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 10:12:33 +01:00
Paul E. McKenney
c12172c025 rcu: fix rcutree grace-period-latency bug on small systems
Impact: fix delays during bootup

Kudos to Andi Kleen for finding a grace-period-latency problem!  The
problem was that the special-case code for small machines never updated
the ->signaled field to indicate that grace-period initialization had
completed, which prevented force_quiescent_state() from ever expediting
grace periods.  This problem resulted in grace periods extending for more
than 20 seconds.  Not subtle.  I introduced this bug during my inspection
process when I fixed a race between grace-period initialization and
force_quiescent_state() execution.

The following patch properly updates the ->signaled field for the
"small"-system case (no more than 32 CPUs for 32-bit kernels and no more
than 64 CPUs for 64-bit kernels).

Reported-by: Andi Kleen <andi@firstfloor.org>
Tested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 10:10:28 +01:00
Linus Torvalds
fe0bdec68b Merge branch 'audit.b61' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b61' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  audit: validate comparison operations, store them in sane form
  clean up audit_rule_{add,del} a bit
  make sure that filterkey of task,always rules is reported
  audit rules ordering, part 2
  fixing audit rule ordering mess, part 1
  audit_update_lsm_rules() misses the audit_inode_hash[] ones
  sanitize audit_log_capset()
  sanitize audit_fd_pair()
  sanitize audit_mq_open()
  sanitize AUDIT_MQ_SENDRECV
  sanitize audit_mq_notify()
  sanitize audit_mq_getsetattr()
  sanitize audit_ipc_set_perm()
  sanitize audit_ipc_obj()
  sanitize audit_socketcall
  don't reallocate buffer in every audit_sockaddr()
2009-01-04 16:32:11 -08:00
David Howells
14eaddc967 CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]
Fix a regression in cap_capable() due to:

	commit 5ff7711e635b32f0a1e558227d030c7e45b4a465
	Author: David Howells <dhowells@redhat.com>
	Date:   Wed Dec 31 02:52:28 2008 +0000

	    CRED: Differentiate objective and effective subjective credentials on a task

The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.

There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.

Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds.  However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.

One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.

The affected capability check is in generic_permission():

	if (!(mask & MAY_EXEC) || execute_ok(inode))
		if (capable(CAP_DAC_OVERRIDE))
			return 0;

This change splits capable() from has_capability() down into the commoncap and
SELinux code.  The capable() security op now only deals with the current
process, and uses the current process's subjective creds.  A new security op -
task_capable() - is introduced that can check any task's objective creds.

strictly the capable() security op is superfluous with the presence of the
task_capable() op, however it should be faster to call the capable() op since
two fewer arguments need be passed down through the various layers.

This can be tested by compiling the following program from the XFS testsuite:

/*
 *  t_access_root.c - trivial test program to show permission bug.
 *
 *  Written by Michael Kerrisk - copyright ownership not pursued.
 *  Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
 */
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>

#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"

static void
errExit(char *msg)
{
    perror(msg);
    exit(EXIT_FAILURE);
} /* errExit */

static void
accessTest(char *file, int mask, char *mstr)
{
    printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */

int
main(int argc, char *argv[])
{
    int fd, perm, uid, gid;
    char *testpath;
    char cmd[PATH_MAX + 20];

    testpath = (argc > 1) ? argv[1] : TESTPATH;
    perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
    uid = (argc > 3) ? atoi(argv[3]) : UID;
    gid = (argc > 4) ? atoi(argv[4]) : GID;

    unlink(testpath);

    fd = open(testpath, O_RDWR | O_CREAT, 0);
    if (fd == -1) errExit("open");

    if (fchown(fd, uid, gid) == -1) errExit("fchown");
    if (fchmod(fd, perm) == -1) errExit("fchmod");
    close(fd);

    snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
    system(cmd);

    if (seteuid(uid) == -1) errExit("seteuid");

    accessTest(testpath, 0, "0");
    accessTest(testpath, R_OK, "R_OK");
    accessTest(testpath, W_OK, "W_OK");
    accessTest(testpath, X_OK, "X_OK");
    accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
    accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
    accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
    accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");

    exit(EXIT_SUCCESS);
} /* main */

This can be run against an Ext3 filesystem as well as against an XFS
filesystem.  If successful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns 0
	access(/tmp/xxx, W_OK) returns 0
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns 0
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

If unsuccessful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns -1
	access(/tmp/xxx, W_OK) returns -1
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns -1
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

I've also tested the fix with the SELinux and syscalls LTP testsuites.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-01-05 11:17:04 +11:00
Heiko Carstens
9e01892c42 module: convert to stop_machine_create/destroy.
The module code relies on a non-failing stop_machine call. So we create
the kstop threads in advance and with that make sure the call won't fail.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-05 08:40:15 +10:30
Heiko Carstens
9ea09af3bd stop_machine: introduce stop_machine_create/destroy.
Introduce stop_machine_create/destroy. With this interface subsystems
that need a non-failing stop_machine environment can create the
stop_machine machine threads before actually calling stop_machine.
When the threads aren't needed anymore they can be killed with
stop_machine_destroy again.

When stop_machine gets called and the threads aren't present they
will be created and destroyed automatically. This restores the old
behaviour of stop_machine.

This patch also converts cpu hotplug to the new interface since it
is special: cpu_down calls __stop_machine instead of stop_machine.
However the kstop threads will only be created when stop_machine
gets called.

Changing the code so that the threads would be created automatically
on __stop_machine is currently not possible: when __stop_machine gets
called we hold cpu_add_remove_lock, which is the same lock that
create_rt_workqueue would take. So the workqueue needs to be created
before the cpu hotplug code locks cpu_add_remove_lock.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-05 08:40:14 +10:30
Helge Deller
088af9a6e0 module: fix module loading failure of large kernel modules for parisc
When creating the final layout of a kernel module in memory, allow the
module loader to reserve some additional memory in front of a given section.
This is currently only needed for the parisc port which needs to put the
stub entries there to fulfill the 17/22bit PCREL relocations with large
kernel modules like xfs.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (renamed fn)
2009-01-05 08:40:13 +10:30
Jianjun Kong
d1e99d7ae4 module: fix warning of unused function when !CONFIG_PROC_FS
Fix this warning:
kernel/module.c:824: warning: ‘print_unload_info’ defined but not used
print_unload_info() just was used when CONFIG_PROC_FS was defined.
This patch mark print_unload_info() inline to solve the problem.

Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Ingo Molnar <mingo@elte.hu>
CC: Américo Wang <xiyou.wangcong@gmail.com>
2009-01-05 08:40:11 +10:30
Tim Abbott
ca4787b779 kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms.
When there are two symbols in a module with the same name, one of which is
exported, both will be marked as exported in /proc/kallsyms.  There aren't
any instances of this in the current kernel, but it is easy to construct a
simple module with two compilation units that exhibits the problem.

$ objdump -j .text -t testmod.ko | grep foo
00000000 l     F .text	00000032 foo
00000080 g     F .text	00000001 foo
$ sudo insmod testmod.ko
$ grep "T foo" /proc/kallsyms
c28e8000 T foo	[testmod]
c28e8080 T foo	[testmod]

Fix this by comparing the symbol values once we've found the exported
symbol table entry matching the symbol name.  Tested using Ksplice:

$ ksplice-create --patch=this_commit.patch --id=bar .
$ sudo ksplice-apply ksplice-bar.tar.gz
Done!
$ grep "T foo" /proc/kallsyms
c28e8080 T foo	[testmod]

Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-05 08:40:11 +10:30
Li Zefan
7b574b7b01 cgroups: fix a race between cgroup_clone and umount
The race is calling cgroup_clone() while umounting the ns cgroup subsys,
and thus cgroup_clone() might access invalid cgroup_fs, or kill_sb() is
called after cgroup_clone() created a new dir in it.

The BUG I triggered is BUG_ON(root->number_of_cgroups != 1);

  ------------[ cut here ]------------
  kernel BUG at kernel/cgroup.c:1093!
  invalid opcode: 0000 [#1] SMP
  ...
  Process umount (pid: 5177, ti=e411e000 task=e40c4670 task.ti=e411e000)
  ...
  Call Trace:
   [<c0493df7>] ? deactivate_super+0x3f/0x51
   [<c04a3600>] ? mntput_no_expire+0xb3/0xdd
   [<c04a3ab2>] ? sys_umount+0x265/0x2ac
   [<c04a3b06>] ? sys_oldumount+0xd/0xf
   [<c0403911>] ? sysenter_do_call+0x12/0x31
  ...
  EIP: [<c0456e76>] cgroup_kill_sb+0x23/0xe0 SS:ESP 0068:e411ef2c
  ---[ end trace c766c1be3bf944ac ]---

Cc: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-04 13:33:19 -08:00
Al Viro
5af75d8d58 audit: validate comparison operations, store them in sane form
Don't store the field->op in the messy (and very inconvenient for e.g.
audit_comparator()) form; translate to dense set of values and do full
validation of userland-submitted value while we are at it.

->audit_init_rule() and ->audit_match_rule() get new values now; in-tree
instances updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:42 -05:00
Al Viro
36c4f1b18c clean up audit_rule_{add,del} a bit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:42 -05:00
Al Viro
e048e02c89 make sure that filterkey of task,always rules is reported
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:42 -05:00
Al Viro
e45aa212ea audit rules ordering, part 2
Fix the actual rule listing; add per-type lists _not_ used for matching,
with all exit,... sitting on one such list.  Simplifies "do something
for all rules" logics, while we are at it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:42 -05:00
Al Viro
0590b9335a fixing audit rule ordering mess, part 1
Problem: ordering between the rules on exit chain is currently lost;
all watch and inode rules are listed after everything else _and_
exit,never on one kind doesn't stop exit,always on another from
being matched.

Solution: assign priorities to rules, keep track of the current
highest-priority matching rule and its result (always/never).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:41 -05:00
Al Viro
1a9d0797b8 audit_update_lsm_rules() misses the audit_inode_hash[] ones
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-04 15:14:41 -05:00