Commit Graph

5592 Commits

Author SHA1 Message Date
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 3b11a1dece
	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 14eaddc967.

David has a better version to come.
2009-01-07 09:21:54 +11:00
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
Linus Torvalds 6a94cb7306 Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (184 commits)
  [XFS] Fix race in xfs_write() between direct and buffered I/O with DMAPI
  [XFS] handle unaligned data in xfs_bmbt_disk_get_all
  [XFS] avoid memory allocations in xfs_fs_vcmn_err
  [XFS] Fix speculative allocation beyond eof
  [XFS] Remove XFS_BUF_SHUT() and friends
  [XFS] Use the incore inode size in xfs_file_readdir()
  [XFS] set b_error from bio error in xfs_buf_bio_end_io
  [XFS] use inode_change_ok for setattr permission checking
  [XFS] add a FMODE flag to make XFS invisible I/O less hacky
  [XFS] resync headers with libxfs
  [XFS] simplify projid check in xfs_rename
  [XFS] replace b_fspriv with b_mount
  [XFS] Remove unused tracing code
  [XFS] Remove unnecessary assertion
  [XFS] Remove unused variable in ktrace_free()
  [XFS] Check return value of xfs_buf_get_noaddr()
  [XFS] Fix hang after disallowed rename across directory quota domains
  [XFS] Fix compile with CONFIG_COMPAT enabled
  move inode tracing out of xfs_vnode.
  move vn_iowait / vn_iowake into xfs_aops.c
  ...
2008-12-30 17:48:25 -08:00
Huang Weiyi 1af237a099 tracing: removed duplicated #include
Removed duplicated #include in kernel/trace/trace.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-30 17:35:40 -08:00
Linus Torvalds 526ea064f9 Merge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  oprofile: select RING_BUFFER
  ring_buffer: adding EXPORT_SYMBOLs
  oprofile: fix lost sample counter
  oprofile: remove nr_available_slots()
  oprofile: port to the new ring_buffer
  ring_buffer: add remaining cpu functions to ring_buffer.h
  oprofile: moving cpu_buffer_reset() to cpu_buffer.h
  oprofile: adding cpu_buffer_entries()
  oprofile: adding cpu_buffer_write_commit()
  oprofile: adding cpu buffer r/w access functions
  ftrace: remove unused function arg in trace_iterator_increment()
  ring_buffer: update description for ring_buffer_alloc()
  oprofile: set values to default when creating oprofilefs
  oprofile: implement switch/case in buffer_sync.c
  x86/oprofile: cleanup IBS init/exit functions in op_model_amd.c
  x86/oprofile: reordering IBS code in op_model_amd.c
  oprofile: fix typo
  oprofile: whitspace changes only
  oprofile: update comment for oprofile_add_sample()
  oprofile: comment cleanup
2008-12-30 17:31:25 -08:00
Linus Torvalds 6de71484cf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (98 commits)
  sparc: move select of ARCH_SUPPORTS_MSI
  sparc: drop SUN_IO
  sparc: unify sections.h
  sparc: use .data.init_task section for init_thread_union
  sparc: fix array overrun check in of_device_64.c
  sparc: unify module.c
  sparc64: prepare module_64.c for unification
  sparc64: use bit neutral Elf symbols
  sparc: unify module.h
  sparc: introduce CONFIG_BITS
  sparc: fix hardirq.h removal fallout
  sparc64: do not export pus_fs_struct
  sparc: use sparc64 version of scatterlist.h
  sparc: Commonize memcmp assembler.
  sparc: Unify strlen assembler.
  sparc: Add asm/asm.h
  sparc: Kill memcmp_32.S code which has been ifdef'd out for centuries.
  sparc: replace for_each_cpu_mask_nr with for_each_cpu
  sparc: fix sparse warnings in irq_32.c
  sparc: add include guards to kernel.h
  ...
2008-12-30 17:23:31 -08:00
Linus Torvalds 1dff81f20c Merge branch 'for-2.6.29' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.29' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  bio: get rid of bio_vec clearing
  bounce: don't rely on a zeroed bio_vec list
  cciss: simplify parameters to deregister_disk function
  cfq-iosched: fix race between exiting queue and exiting task
  loop: Do not call loop_unplug for not configured loop device.
  loop: Flush possible running bios when loop device is released.
  alpha: remove dead BIO_VMERGE_BOUNDARY
  Get rid of CONFIG_LSF
  block: make blk_softirq_init() static
  block: use min_not_zero in blk_queue_stack_limits
  block: add one-hit cache for disk partition lookup
  cfq-iosched: remove limit of dispatch depth of max 4 times quantum
  nbd: tell the block layer that it is not a rotational device
  block: get rid of elevator_t typedef
  aio: make the lookup_ioctx() lockless
  bio: add support for inlining a number of bio_vecs inside the bio
  bio: allow individual slabs in the bio_set
  bio: move the slab pointer inside the bio_set
  bio: only mempool back the largest bio_vec slab cache
  block: don't use plugging on SSD devices
  ...
2008-12-30 17:20:05 -08:00
Linus Torvalds 179475a3b4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, sparseirq: clean up Kconfig entry
  x86: turn CONFIG_SPARSE_IRQ off by default
  sparseirq: fix numa_migrate_irq_desc dependency and comments
  sparseirq: add kernel-doc notation for new member in irq_desc, -v2
  locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP
  sparseirq, xen: make sure irq_desc is allocated for interrupts
  sparseirq: fix !SMP building, #2
  x86, sparseirq: move irq_desc according to smp_affinity, v7
  proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ
  sparse irqs: add irqnr.h to the user headers list
  sparse irqs: handle !GENIRQ platforms
  sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build
  sparseirq: fix Alpha build failure
  sparseirq: fix typo in !CONFIG_IO_APIC case
  x86, MSI: pass irq_cfg and irq_desc
  x86: MSI start irq numbering from nr_irqs_gsi
  x86: use NR_IRQS_LEGACY
  sparse irq_desc[] array: core kernel and x86 changes
  genirq: record IRQ_LEVEL in irq_desc[]
  irq.h: remove padding from irq_desc on 64bits
2008-12-30 16:20:19 -08:00
Linus Torvalds bb758e9637 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: fix warning in kernel/hrtimer.c
  x86: make sure we really have an hpet mapping before using it
  x86: enable HPET on Fujitsu u9200
  linux/timex.h: cleanup for userspace
  posix-timers: simplify de_thread()->exit_itimers() path
  posix-timers: check ->it_signal instead of ->it_pid to validate the timer
  posix-timers: use "struct pid*" instead of "struct task_struct*"
  nohz: suppress needless timer reprogramming
  clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
  nohz: no softirq pending warnings for offline cpus
  hrtimer: removing all ur callback modes, fix
  hrtimer: removing all ur callback modes, fix hotplug
  hrtimer: removing all ur callback modes
  x86: correct link to HPET timer specification
  rtc-cmos: export second NVRAM bank

Fixed up conflicts in sound/drivers/pcsp/pcsp.c and sound/core/hrtimer.c
manually.
2008-12-30 16:16:21 -08:00
Linus Torvalds 5f34fe1cfc Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits)
  stacktrace: provide save_stack_trace_tsk() weak alias
  rcu: provide RCU options on non-preempt architectures too
  printk: fix discarding message when recursion_bug
  futex: clean up futex_(un)lock_pi fault handling
  "Tree RCU": scalable classic RCU implementation
  futex: rename field in futex_q to clarify single waiter semantics
  x86/swiotlb: add default swiotlb_arch_range_needs_mapping
  x86/swiotlb: add default phys<->bus conversion
  x86: unify pci iommu setup and allow swiotlb to compile for 32 bit
  x86: add swiotlb allocation functions
  swiotlb: consolidate swiotlb info message printing
  swiotlb: support bouncing of HighMem pages
  swiotlb: factor out copy to/from device
  swiotlb: add arch hook to force mapping
  swiotlb: allow architectures to override phys<->bus<->phys conversions
  swiotlb: add comment where we handle the overflow of a dma mask on 32 bit
  rcu: fix rcutorture behavior during reboot
  resources: skip sanity check of busy resources
  swiotlb: move some definitions to header
  swiotlb: allow architectures to override swiotlb pool allocation
  ...

Fix up trivial conflicts in
  arch/x86/kernel/Makefile
  arch/x86/mm/init_32.c
  include/linux/hardirq.h
as per Ingo's suggestions.
2008-12-30 16:10:19 -08:00
Jens Axboe abf137dd77 aio: make the lookup_ioctx() lockless
The mm->ioctx_list is currently protected by a reader-writer lock,
so we always grab that lock on the read side for doing ioctx
lookups. As the workload is extremely reader biased, turn this into
an rcu hlist so we can make lookup_ioctx() lockless. Get rid of
the rwlock and use a spinlock for providing update side exclusion.

There's usually only 1 entry on this list, so it doesn't make sense
to look into fancier data structures.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29 08:29:50 +01:00
Nikanth Karthikesan 7c0990c7ee Do not free io context when taking recursive faults in do_exit
When taking recursive faults in do_exit, if the io_context is not null,
exit_io_context() is being called. But it might decrement the refcount
more than once. It is better to leave this task alone.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29 08:28:43 +01:00
Lachlan McIlroy 0a8c5395f9 [XFS] Fix merge failures
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Conflicts:

	fs/xfs/linux-2.6/xfs_cred.h
	fs/xfs/linux-2.6/xfs_globals.h
	fs/xfs/linux-2.6/xfs_ioctl.c
	fs/xfs/xfs_vnodeops.h

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-12-29 16:47:18 +11:00
David S. Miller e3c6d4ee54 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
	arch/sparc64/kernel/idprom.c
2008-12-28 20:19:47 -08:00
Linus Torvalds 96faec945f Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (25 commits)
  allow stripping of generated symbols under CONFIG_KALLSYMS_ALL
  kbuild: strip generated symbols from *.ko
  kbuild: simplify use of genksyms
  kernel-doc: check for extra kernel-doc notations
  kbuild: add headerdep used to detect inclusion cycles in header files
  kbuild: fix string equality testing in tags.sh
  kbuild: fix make tags/cscope
  kbuild: fix make incompatibility
  kbuild: remove TAR_IGNORE
  setlocalversion: add git-svn support
  setlocalversion: print correct subversion revision
  scripts: improve the decodecode script
  scripts/package: allow custom options to rpm
  genksyms: allow to ignore symbol checksum changes
  genksyms: track symbol checksum changes
  tags and cscope support really belongs in a shell script
  kconfig: fix options to check-lxdialog.sh
  kbuild: gen_init_cpio expands shell variables in file names
  remove bashisms from scripts/extract-ikconfig
  kbuild: teach mkmakfile to be silent
  ...
2008-12-28 15:13:48 -08:00
Linus Torvalds a39b863342 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  sched: fix warning in fs/proc/base.c
  schedstat: consolidate per-task cpu runtime stats
  sched: use RCU variant of list traversal in for_each_leaf_rt_rq()
  sched, cpuacct: export percpu cpuacct cgroup stats
  sched, cpuacct: refactoring cpuusage_read / cpuusage_write
  sched: optimize update_curr()
  sched: fix wakeup preemption clock
  sched: add missing arch_update_cpu_topology() call
  sched: let arch_update_cpu_topology indicate if topology changed
  sched: idle_balance() does not call load_balance_newidle()
  sched: fix sd_parent_degenerate on non-numa smp machine
  sched: add uid information to sched_debug for CONFIG_USER_SCHED
  sched: move double_unlock_balance() higher
  sched: update comment for move_task_off_dead_cpu
  sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares
  sched/rt: removed unneeded defintion
  sched: add hierarchical accounting to cpu accounting controller
  sched: include group statistics in /proc/sched_debug
  sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER
  sched: clean up SCHED_CPUMASK_ALLOC
  ...
2008-12-28 12:27:58 -08:00
Linus Torvalds b0f4b285d7 Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
  sched, trace: update trace_sched_wakeup()
  tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
  Revert "x86: disable X86_PTRACE_BTS"
  ring-buffer: prevent false positive warning
  ring-buffer: fix dangling commit race
  ftrace: enable format arguments checking
  x86, bts: memory accounting
  x86, bts: add fork and exit handling
  ftrace: introduce tracing_reset_online_cpus() helper
  tracing: fix warnings in kernel/trace/trace_sched_switch.c
  tracing: fix warning in kernel/trace/trace.c
  tracing/ring-buffer: remove unused ring_buffer size
  trace: fix task state printout
  ftrace: add not to regex on filtering functions
  trace: better use of stack_trace_enabled for boot up code
  trace: add a way to enable or disable the stack tracer
  x86: entry_64 - introduce FTRACE_ frame macro v2
  tracing/ftrace: add the printk-msg-only option
  tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
  x86, bts: correctly report invalid bts records
  ...

Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
2008-12-28 12:21:10 -08:00
Ingo Molnar 32e8d18683 Merge branches 'timers/clocksource', 'timers/hpet', 'timers/hrtimers', 'timers/nohz', 'timers/ntp', 'timers/posixtimers' and 'timers/rtc' into timers/core 2008-12-25 18:02:25 +01:00
Ingo Molnar 860cf8894b Merge branches 'irq/sparseirq', 'irq/genirq' and 'irq/urgent'; commit 'v2.6.28' into irq/core 2008-12-25 16:27:54 +01:00
Ingo Molnar 6638101c11 Merge branches 'core/debugobjects', 'core/iommu', 'core/locking', 'core/printk', 'core/rcu', 'core/resources', 'core/softirq' and 'core/stacktrace' into core/core 2008-12-25 14:06:29 +01:00
Ingo Molnar cc37d3d206 Merge branch 'core/futexes' into core/core 2008-12-25 13:54:14 +01:00
Ingo Molnar b594deb0cc Merge branch 'core/debug' into core/core 2008-12-25 13:53:11 +01:00
Ingo Molnar 0b271ef452 Merge commit 'v2.6.28' into core/core 2008-12-25 13:51:46 +01:00
Ingo Molnar 4e202284e6 Merge branch 'sched/urgent'; commit 'v2.6.28' into sched/core 2008-12-25 13:42:23 +01:00
Ingo Molnar 5250d329e3 Merge branches 'tracing/ftrace', 'tracing/hw-branch-tracing' and 'tracing/ring-buffer'; commit 'v2.6.28' into tracing/core 2008-12-25 13:11:00 +01:00
Peter Zijlstra 468a15bb4c sched, trace: update trace_sched_wakeup()
Impact: extend the wakeup tracepoint with the info whether the wakeup was real

Add the information needed to distinguish 'real' wakeups from 'false'
wakeups.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 13:10:21 +01:00
Ingo Molnar 9212ddb5ea stacktrace: provide save_stack_trace_tsk() weak alias
Impact: build fix

Some architectures have not implemented save_stack_trace_tsk() yet:

  fs/built-in.o: In function `proc_pid_stack':
  base.c:(.text+0x3f140): undefined reference to `save_stack_trace_tsk'

So warn about that if the facility is used.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 11:44:43 +01:00
Ingo Molnar 12d79bafb7 rcu: provide RCU options on non-preempt architectures too
Impact: build fix

Some old architectures still do not use kernel/Kconfig.preempt, so the
moving of the RCU options there broke their build:

 In file included from /home/mingo/tip/include/linux/sem.h:81,
                 from /home/mingo/tip/include/linux/sched.h:69,
                 from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9:
 /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration"

Move these options back to init/Kconfig, which every architecture
includes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 09:31:28 +01:00
James Morris cbacc2c7f0 Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
Ingo Molnar db8862eafe Merge branch 'linus' into tracing/hw-branch-tracing 2008-12-24 21:08:26 +01:00
Li Zefan 20ca9b3f4c cgroups: avoid accessing uninitialized data in failure path
If cgroup_get_rootdir() failed, free_cg_links() will be called in the
failure path, but tmp_cg_links hasn't been initialized at that time.

I introduced this bug in the 2.6.27 merge window.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-23 15:58:21 -08:00
Sharyathi Nagesh e368d3a836 cgroups: suppress bogus warning messages
Remove spurious warning messages that are thrown onto the console during
cgroup operations.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Sharyathi Nagesh <sharyathi@in.ibm.com>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-23 15:58:21 -08:00
Steven Rostedt 98db8df777 ring-buffer: prevent false positive warning
Impact: eliminate false WARN_ON message

If an interrupt goes off after the setting of the local variable
tail_page and before incrementing the write index of that page,
the interrupt could push the commit forward to the next page.

Later a check is made to see if interrupts pushed the buffer around
the entire ring buffer by comparing the next page to the last commited
page. This can produce a false positive if the interrupt had pushed
the commit page forward as stated above.

Thanks to Jiaying Zhang for finding this race.

Reported-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 18:45:26 +01:00
Steven Rostedt a8ccf1d6f6 ring-buffer: fix dangling commit race
Impact: fix stuck trace-buffers

If an interrupt comes in during the rb_set_commit_to_write and
pushes the tail page forward just at the right time, the commit
updates will miss the adding of the interrupt data. This will
cause the commit pointer to cease from moving forward.

Thanks to Jiaying Zhang for finding this race.

Reported-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 18:45:25 +01:00
Lachlan McIlroy 27a0464a6c [XFS] Fix merge conflict in fs/xfs/xfs_rename.c
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Conflicts:

	fs/xfs/xfs_rename.c

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-12-22 17:34:26 +11:00
Thomas Gleixner 3d44cc3e01 Null pointer deref with hrtimer_try_to_cancel()
Impact: Prevent kernel crash with posix timer clockid CLOCK_MONOTONIC_RAW

commit 2d42244ae7 (clocksource:
introduce CLOCK_MONOTONIC_RAW) introduced a new clockid, which is only
available to read out the raw not NTP adjusted system time.

The above commit did not prevent that a posix timer can be created
with that clockid. The timer_create() syscall succeeds and initializes
the timer to a non existing hrtimer base. When the timer is deleted
either by timer_delete() or by the exit() cleanup the kernel crashes.

Prevent the creation of timers for CLOCK_MONOTONIC_RAW by setting the
posix clock function to no_timer_create which returns an error code.

Reported-and-tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-20 14:13:45 -08:00
Markus Metzger bf53de907d x86, bts: add fork and exit handling
Impact: introduce new ptrace facility

Add arch_ptrace_untrace() function that is called when the tracer
detaches (either voluntarily or when the tracing task dies);
ptrace_disable() is only called on a voluntary detach.

Add ptrace_fork() and arch_ptrace_fork(). They are called when a
traced task is forked.

Clear DS and BTS related fields on fork.

Release DS resources and reclaim memory in ptrace_untrace(). This
releases resources already when the tracing task dies. We used to do
that when the traced task dies.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-20 09:15:46 +01:00
Yinghai Lu b909895739 sparseirq: fix numa_migrate_irq_desc dependency and comments
Impact: reduce kconfig variable scope and clean up

Bartlomiej pointed out that the config dependencies and comments are not right.

update it depend to NUMA, and fix some comments

Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 22:56:02 +01:00
Hiroshi Shimamoto 26cc271db7 printk: fix discarding message when recursion_bug
Impact: fix truncated recursion bug message printout

When recursion_bug is true, kernel discards original message because printk_buf
contains recursion_bug_msg with NULL terminator. The sizeof(recursion_bug_msg)
makes this, use strlen() to get correct length without NULL terminator.

Reported-by: Toshikazu Nakayama <nakayama.ts@ncos.nec.co.jp>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 22:52:47 +01:00
Jan Beulich 9bb482476c allow stripping of generated symbols under CONFIG_KALLSYMS_ALL
Building upon parts of the module stripping patch, this patch
introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
kernels I tested with.

The patch also does away with the need to special case the kallsyms-
internal symbols by making them available even in the first linking
stage.

While it is a generated file, the patch includes the changes to
scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
here is.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-19 22:47:10 +01:00
Pekka J Enberg 213cc06079 ftrace: introduce tracing_reset_online_cpus() helper
Impact: cleanup

This patch factors out common code from multiple tracers into a
tracing_reset_online_cpus() function and converts the tracers to use it.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 16:29:34 +01:00
Ingo Molnar 30cd324e97 Merge branches 'tracing/ftrace', 'tracing/ring-buffer' and 'tracing/urgent' into tracing/core
Conflicts:
	include/linux/ftrace.h
2008-12-19 09:42:40 +01:00
Darren Hart b56863630d futex: clean up futex_(un)lock_pi fault handling
Impact: cleanup

Some apparently left over cruft code was complicating the fault logic:

Testing if uval != -EFAULT doesn't have any meaning, get_user() sets ret
to either 0 or -EFAULT, there's no need to compare uval, especially not
against EFAULT which it will never be.  This patch removes the superfluous
test and clarifies the comment blocks.

Build and boot tested on an 8way x86_64 system.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 09:20:21 +01:00
Ingo Molnar c71dd42db2 tracing: fix warnings in kernel/trace/trace_sched_switch.c
these warnings:

  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_register’:
  kernel/trace/trace_sched_switch.c:96: warning: passing argument 1 of ‘register_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c:112: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_unregister’:
  kernel/trace/trace_sched_switch.c:121: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type

Trigger because sched_wakeup_new tracepoints need the same trace
signature as sched_wakeup - which was changed recently.

Fix it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 01:05:38 +01:00
Ingo Molnar 3bddb9a324 tracing: fix warning in kernel/trace/trace.c
this warning:

  kernel/trace/trace.c: In function ‘print_lat_fmt’:
  kernel/trace/trace.c:1826: warning: unused variable ‘state’

Triggers because 'state' has become unused - remove it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 01:01:25 +01:00
Ingo Molnar b2e3c0adec hrtimers: fix warning in kernel/hrtimer.c
this warning:

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

is caused because 'dcpu' is only used in the CONFIG_HOTPLUG_CPU case.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 00:45:32 +01:00
Paul E. McKenney 64db4cfff9 "Tree RCU": scalable classic RCU implementation
This patch fixes a long-standing performance bug in classic RCU that
results in massive internal-to-RCU lock contention on systems with
more than a few hundred CPUs.  Although this patch creates a separate
flavor of RCU for ease of review and patch maintenance, it is intended
to replace classic RCU.

This patch still handles stress better than does mainline, so I am still
calling it ready for inclusion.  This patch is against the -tip tree.
Nevertheless, experience on an actual 1000+ CPU machine would still be
most welcome.

Most of the changes noted below were found while creating an rcutiny
(which should permit ejecting the current rcuclassic) and while doing
detailed line-by-line documentation.

Updates from v9 (http://lkml.org/lkml/2008/12/2/334):

o	Fixes from remainder of line-by-line code walkthrough,
	including comment spelling, initialization, undesirable
	narrowing due to type conversion, removing redundant memory
	barriers, removing redundant local-variable initialization,
	and removing redundant local variables.

	I do not believe that any of these fixes address the CPU-hotplug
	issues that Andi Kleen was seeing, but please do give it a whirl
	in case the machine is smarter than I am.

	A writeup from the walkthrough may be found at the following
	URL, in case you are suffering from terminal insomnia or
	masochism:

	http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf

o	Made rcutree tracing use seq_file, as suggested some time
	ago by Lai Jiangshan.

o	Added a .csv variant of the rcudata debugfs trace file, to allow
	people having thousands of CPUs to drop the data into
	a spreadsheet.	Tested with oocalc and gnumeric.  Updated
	documentation to suit.

Updates from v8 (http://lkml.org/lkml/2008/11/15/139):

o	Fix a theoretical race between grace-period initialization and
	force_quiescent_state() that could occur if more than three
	jiffies were required to carry out the grace-period
	initialization.  Which it might, if you had enough CPUs.

o	Apply Ingo's printk-standardization patch.

o	Substitute local variables for repeated accesses to global
	variables.

o	Fix comment misspellings and redundant (but harmless) increments
	of ->n_rcu_pending (this latter after having explicitly added it).

o	Apply checkpatch fixes.

Updates from v7 (http://lkml.org/lkml/2008/10/10/291):

o	Fixed a number of problems noted by Gautham Shenoy, including
	the cpu-stall-detection bug that he was having difficulty
	convincing me was real.  ;-)

o	Changed cpu-stall detection to wait for ten seconds rather than
	three in order to reduce false positive, as suggested by Ingo
	Molnar.

o	Produced a design document (http://lwn.net/Articles/305782/).
	The act of writing this document uncovered a number of both
	theoretical and "here and now" bugs as noted below.

o	Fix dynticks_nesting accounting confusion, simplify WARN_ON()
	condition, fix kerneldoc comments, and add memory barriers
	in dynticks interface functions.

o	Add more data to tracing.

o	Remove unused "rcu_barrier" field from rcu_data structure.

o	Count calls to rcu_pending() from scheduling-clock interrupt
	to use as a surrogate timebase should jiffies stop counting.

o	Fix a theoretical race between force_quiescent_state() and
	grace-period initialization.  Yes, initialization does have to
	go on for some jiffies for this race to occur, but given enough
	CPUs...

Updates from v6 (http://lkml.org/lkml/2008/9/23/448):

o	Fix a number of checkpatch.pl complaints.

o	Apply review comments from Ingo Molnar and Lai Jiangshan
	on the stall-detection code.

o	Fix several bugs in !CONFIG_SMP builds.

o	Fix a misspelled config-parameter name so that RCU now announces
	at boot time if stall detection is configured.

o	Run tests on numerous combinations of configurations parameters,
	which after the fixes above, now build and run correctly.

Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):

o	Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
	changeset some time ago, and finally got around to retesting
	this option).

o	Fix some tracing bugs in rcupreempt that caused incorrect
	totals to be printed.

o	I now test with a more brutal random-selection online/offline
	script (attached).  Probably more brutal than it needs to be
	on the people reading it as well, but so it goes.

o	A number of optimizations and usability improvements:

	o	Make rcu_pending() ignore the grace-period timeout when
		there is no grace period in progress.

	o	Make force_quiescent_state() avoid going for a global
		lock in the case where there is no grace period in
		progress.

	o	Rearrange struct fields to improve struct layout.

	o	Make call_rcu() initiate a grace period if RCU was
		idle, rather than waiting for the next scheduling
		clock interrupt.

	o	Invoke rcu_irq_enter() and rcu_irq_exit() only when
		idle, as suggested by Andi Kleen.  I still don't
		completely trust this change, and might back it out.

	o	Make CONFIG_RCU_TRACE be the single config variable
		manipulated for all forms of RCU, instead of the prior
		confusion.

	o	Document tracing files and formats for both rcupreempt
		and rcutree.

Updates from v4 for those missing v5 given its bad subject line:

o	Separated dynticks interface so that NMIs and irqs call separate
	functions, greatly simplifying it.  In particular, this code
	no longer requires a proof of correctness.  ;-)

o	Separated dynticks state out into its own per-CPU structure,
	avoiding the duplicated accounting.

o	The case where a dynticks-idle CPU runs an irq handler that
	invokes call_rcu() is now correctly handled, forcing that CPU
	out of dynticks-idle mode.

o	Review comments have been applied (thank you all!!!).
	For but one example, fixed the dynticks-ordering issue that
	Manfred pointed out, saving me much debugging.  ;-)

o	Adjusted rcuclassic and rcupreempt to handle dynticks changes.

Attached is an updated patch to Classic RCU that applies a hierarchy,
greatly reducing the contention on the top-level lock for large machines.
This passes 10-hour concurrent rcutorture and online-offline testing on
128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
bugs in presence of dynticks (exciting working on a system where
"sleep 1" hangs until interrupted...), which were fixed in the
2.6.27 kernel.  It is getting more reliable than mainline by some
measures, so the next version will be against -tip for inclusion.
See also Manfred Spraul's recent patches (or his earlier work from
2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
We will converge onto a common patch in the fullness of time, but are
currently exploring different regions of the design space.  That said,
I have already gratefully stolen quite a few of Manfred's ideas.

This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
of the RCU hierarchy.  Defaults to 32 on 32-bit machines and 64 on
64-bit machines.  If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
there is no hierarchy.  By default, the RCU initialization code will
adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
this balancing, allowing the hierarchy to be exactly aligned to the
underlying hardware.  Up to two levels of hierarchy are permitted
(in addition to the root node), allowing up to 16,384 CPUs on 32-bit
systems and up to 262,144 CPUs on 64-bit systems.  I just know that I
am going to regret saying this, but this seems more than sufficient
for the foreseeable future.  (Some architectures might wish to set
CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
If this becomes a real problem, additional levels can be added, but I
doubt that it will make a significant difference on real hardware.)

In the common case, a given CPU will manipulate its private rcu_data
structure and the rcu_node structure that it shares with its immediate
neighbors.  This can reduce both lock and memory contention by multiple
orders of magnitude, which should eliminate the need for the strange
manipulations that are reported to be required when running Linux on
very large systems.

Some shortcomings:

o	More bugs will probably surface as a result of an ongoing
	line-by-line code inspection.

	Patches will be provided as required.

o	There are probably hangs, rcutorture failures, &c.  Seems
	quite stable on a 128-CPU machine, but that is kind of small
	compared to 4096 CPUs.  However, seems to do better than
	mainline.

	Patches will be provided as required.

o	The memory footprint of this version is several KB larger
	than rcuclassic.

	A separate UP-only rcutiny patch will be provided, which will
	reduce the memory footprint significantly, even compared
	to the old rcuclassic.  One such patch passes light testing,
	and has a memory footprint smaller even than rcuclassic.
	Initial reaction from various embedded guys was "it is not
	worth it", so am putting it aside.

Credits:

o	Manfred Spraul for ideas, review comments, and bugs spotted,
	as well as some good friendly competition.  ;-)

o	Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
	Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
	for reviews and comments.

o	Thomas Gleixner for much-needed help with some timer issues
	(see patches below).

o	Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
	Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
	Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
	alive despite my heavy abuse^Wtesting.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 21:56:04 +01:00
Ingo Molnar d110ec3a1e Merge branch 'linus' into core/rcu 2008-12-18 21:54:49 +01:00
KOSAKI Motohiro 74c8a61304 locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP
Impact: simplify code

commit "08678b0: generic: sparse irqs: use irq_desc() [...]" introduced
the irq_desc_lock_class variable.

But it is used only if CONFIG_SPARSE_IRQ=Y or CONFIG_TRACE_IRQFLAGS=Y.
Otherwise, following warnings happen:

	CC      kernel/irq/handle.o
	kernel/irq/handle.c:26: warning: 'irq_desc_lock_class' defined but not used

Actually, current early_init_irq_lock_class has a bit strange and messy ifdef.
In addition, it is not valueable.

1. this function is protected by !CONFIG_SPARSE_IRQ, but that is not necessary.
   if CONFIG_SPARSE_IRQ=Y, desc of all irq number are initialized by NULL
   at first - then this function calling is safe.

2. this function protected by CONFIG_TRACE_IRQFLAGS too. but it is not
   necessary either, because lockdep_set_class() doesn't have bad side
   effect even if CONFIG_TRACE_IRQFLAGS=n.

This patch bloat kernel size a bit on CONFIG_TRACE_IRQFLAGS=n and
CONFIG_SPARSE_IRQ=Y - but that's ok. early_init_irq_lock_class() is not
a fastpatch at all.

To avoid messy ifdefs is more important than a few bytes diet.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 14:35:53 +01:00