Commit Graph

10240 Commits

Author SHA1 Message Date
Linus Torvalds 1ca72feb93 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Fix build on POSIX shells
  latencytop: Fix kconfig dependency warnings
  perf annotate tui: Fix exit and RIGHT keys handling
  tracing: Sanitize value returned from write(trace_marker, "...", len)
  tracing/events: Convert format output to seq_file
  tracing: Extend recordmcount to better support Blackfin mcount
  tracing: Fix ring_buffer_read_page reading out of page boundary
  tracing: Fix an unallocated memory access in function_graph
2010-08-18 09:32:13 -07:00
Nick Piggin 2a4419b5b2 fs: fs_struct rwlock to spinlock
fs: fs_struct rwlock to spinlock

struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.

Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:46 -04:00
Linus Torvalds 392abeea52 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  vt,console,kdb: preserve console_blanked while in kdb
  vt: fix regression warnings from KMS merge
  arm,kgdb: fix GDB_MAX_REGS no longer used
  kgdb: add missing __percpu markup in arch/x86/kernel/kgdb.c
  kdb: fix compile error without CONFIG_KALLSYMS
2010-08-17 18:36:19 -07:00
Daniel J Blueman f362b73244 Fix unprotected access to task credentials in waitid()
Using a program like the following:

	#include <stdlib.h>
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	int main() {
		id_t id;
		siginfo_t infop;
		pid_t res;

		id = fork();
		if (id == 0) { sleep(1); exit(0); }
		kill(id, SIGSTOP);
		alarm(1);
		waitid(P_PID, id, &infop, WCONTINUED);
		return 0;
	}

to call waitid() on a stopped process results in access to the child task's
credentials without the RCU read lock being held - which may be replaced in the
meantime - eliciting the following warning:

	===================================================
	[ INFO: suspicious rcu_dereference_check() usage. ]
	---------------------------------------------------
	kernel/exit.c:1460 invoked rcu_dereference_check() without protection!

	other info that might help us debug this:

	rcu_scheduler_active = 1, debug_locks = 1
	2 locks held by waitid02/22252:
	 #0:  (tasklist_lock){.?.?..}, at: [<ffffffff81061ce5>] do_wait+0xc5/0x310
	 #1:  (&(&sighand->siglock)->rlock){-.-...}, at: [<ffffffff810611da>]
	wait_consider_task+0x19a/0xbe0

	stack backtrace:
	Pid: 22252, comm: waitid02 Not tainted 2.6.35-323cd+ #3
	Call Trace:
	 [<ffffffff81095da4>] lockdep_rcu_dereference+0xa4/0xc0
	 [<ffffffff81061b31>] wait_consider_task+0xaf1/0xbe0
	 [<ffffffff81061d15>] do_wait+0xf5/0x310
	 [<ffffffff810620b6>] sys_waitid+0x86/0x1f0
	 [<ffffffff8105fce0>] ? child_wait_callback+0x0/0x70
	 [<ffffffff81003282>] system_call_fastpath+0x16/0x1b

This is fixed by holding the RCU read lock in wait_task_continued() to ensure
that the task's current credentials aren't destroyed between us reading the
cred pointer and us reading the UID from those credentials.

Furthermore, protect wait_task_stopped() in the same way.

We don't need to keep holding the RCU read lock once we've read the UID from
the credentials as holding the RCU read lock doesn't stop the target task from
changing its creds under us - so the credentials may be outdated immediately
after we've read the pointer, lock or no lock.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-17 18:07:43 -07:00
David Howells d7627467b7 Make do_execve() take a const filename pointer
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-17 18:07:43 -07:00
Jason Wessel b590cddfa6 kdb: fix compile error without CONFIG_KALLSYMS
If CONFIG_KGDB_KDB is set and CONFIG_KALLSYMS is not set the kernel
will fail to build with the error:

kernel/built-in.o: In function `kallsyms_symbol_next':
kernel/debug/kdb/kdb_support.c:237: undefined reference to `kdb_walk_kallsyms'
kernel/built-in.o: In function `kallsyms_symbol_complete':
kernel/debug/kdb/kdb_support.c:193: undefined reference to `kdb_walk_kallsyms'

The kdb_walk_kallsyms needs a #ifdef proper header to match the C
implementation.  This patch also fixes the compiler warnings in
kdb_support.c when compiling without CONFIG_KALLSYMS set.  The
compiler warnings are a result of the kallsyms_lookup() macro not
initializing the two of the pass by reference variables.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reported-by: Michal Simek <monstr@monstr.eu>
2010-08-16 15:58:29 -05:00
Steven Rostedt d244b6bd41 Merge branch 'tip/perf/urgent-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into trace/tip/perf/urgent-4
Conflicts:
	kernel/trace/trace_events.c

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-16 11:17:30 -04:00
Xiaotian Feng 8d9df9f084 workqueue: free rescuer on destroy_workqueue
wq->rescuer is not freed when wq is destroyed, leads a memory leak
then. This patch also remove a redundant line.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
2010-08-16 09:55:01 +02:00
Marcin Slusarz 1aa54bca6e tracing: Sanitize value returned from write(trace_marker, "...", len)
When userspace code writes non-new-line-terminated string to trace_marker
file, write handler appends new-line and returns number of bytes written
to trace buffer, so
write(fd, "abc", 3) will return 4

That's unexpected and unfortunately it confuses glibc's fprintf function.

Example:
int main() {
  fprintf(stderr, "abc");
  return 0;
}

$ gcc test.c -o test
$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
$ ./test 2>/sys/kernel/debug/tracing/trace_marker

results in infinite loop:
write(fd, "abc", 3) = 4
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
(...)

...and kernel trace buffer full of empty markers.

Fix it by sanitizing write return value.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
LKML-Reference: <20100727231801.GB2826@joi.lan>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-13 15:23:16 -04:00
John Stultz c7dcf87a68 time: Workaround gcc loop optimization that causes 64bit div errors
Early 4.3 versions of gcc apparently aggressively optimize the raw
time accumulation loop, replacing it with a divide.

On 32bit systems, this causes the following link errors:
	undefined reference to `__umoddi3'
	undefined reference to `__udivdi3'

The gcc issue has been fixed in 4.4 and greater.

This patch replaces the accumulation loop with a do_div, as suggested
by Linus.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
CC: Jason Wessel <jason.wessel@windriver.com>
CC: Larry Finger <Larry.Finger@lwfinger.net>
CC: Ingo Molnar <mingo@elte.hu>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-13 12:03:24 -07:00
Linus Torvalds 2069601b3f Revert "fsnotify: store struct file not struct path"
This reverts commit 3bcf3860a4 (and the
accompanying commit c1e5c95402 "vfs/fsnotify: fsnotify_close can delay
the final work in fput" that was a horribly ugly hack to make it work at
all).

The 'struct file' approach not only causes that disgusting hack, it
somehow breaks pulseaudio, probably due to some other subtlety with
f_count handling.

Fix up various conflicts due to later fsnotify work.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 14:23:04 -07:00
Steven Rostedt 2a37a3df57 tracing/events: Convert format output to seq_file
Two new events were added that broke the current format output.

Both from the SCSI system: scsi_dispatch_cmd_done and scsi_dispatch_cmd_timeout

The reason is that their print_fmt exceeded a page size. Since the output
of the format used simple_read_from_buffer and trace_seq, it was limited
to a page size in output.

This patch converts the printing of the format of an event into seq_file,
which allows greater than a page size to be shown.

I diffed all event formats comparing the output with and without this
patch. All matched except for the above two, which showed just:

  FORMAT TOO BIG

without this patch, but now properly displays the output with this patch.

v2: Remove updating *pos in seq start function.
   [ Thanks to Li Zefan for pointing that out ]

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-12 16:59:29 -04:00
Linus Torvalds 26df0766a7 Merge branch 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (22 commits)
  param: don't deref arg in __same_type() checks
  param: update drivers/acpi/debug.c to new scheme
  param: use module_param in drivers/message/fusion/mptbase.c
  ide: use module_param_named rather than module_param_call
  param: update drivers/char/ipmi/ipmi_watchdog.c to new scheme
  param: lock if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes.
  param: lock myri10ge_fw_name against sysfs changes.
  param: simple locking for sysfs-writable charp parameters
  param: remove unnecessary writable charp
  param: add kerneldoc to moduleparam.h
  param: locking for kernel parameters
  param: make param sections const.
  param: use free hook for charp (fix leak of charp parameters)
  param: add a free hook to kernel_param_ops.
  param: silence .init.text references from param ops
  Add param ops struct for hvc_iucv driver.
  nfs: update for module_param_named API change
  AppArmor: update for module_param_named API change
  param: use ops in struct kernel_param, rather than get and set fns directly
  param: move the EXPORT_SYMBOL to after the definitions.
  ...
2010-08-12 10:01:59 -07:00
Jason Wessel deda2e8196 timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archs
The tv_nsec is a long and when added to the shifted interval it can wrap
and become negative which later causes looping problems in the
getrawmonotonic().  The edge case occurs when the system has slept for
a short period of time of ~2 seconds.

A trace printk of the values in this patch illustrate the problem:

ftrace time stamp: log
43.716079: logarithmic_accumulation: raw: 3d0913 tv_nsec d687faa
43.718513: logarithmic_accumulation: raw: 3d0913 tv_nsec da588bd
43.722161: logarithmic_accumulation: raw: 3d0913 tv_nsec de291d0
46.349925: logarithmic_accumulation: raw: 7a122600 tv_nsec e1f9ae3
46.349930: logarithmic_accumulation: raw: 1e848980 tv_nsec 8831c0e3

The kernel starts looping at 46.349925 in the getrawmonotonic() due to
the negative value from adding the raw value to tv_nsec.

A simple solution is to accumulate into a u64, and then normalize it
to a timespec_t.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
 [ Reworked variable names and simplified some of the code. - John ]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 09:53:39 -07:00
David Howells 12fdff3fc2 Add a dummy printk function for the maintenance of unused printks
Add a dummy printk function for the maintenance of unused printks through gcc
format checking, and also so that side-effect checking is maintained too.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 09:51:35 -07:00
Adrian Hunter 8d57a98ccd block: add secure discard
Secure discard is the same as discard except that all copies of the
discarded sectors (perhaps created by garbage collection) must also be
erased.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 08:43:30 -07:00
Stefani Seibold d78a3eda69 kernel/kfifo.c: add handling of chained scatterlists
The current kfifo scatterlist implementation will not work with chained
scatterlists.  It assumes that struct scatterlist arrays are allocated
contiguously, which is not the case when chained scatterlists (struct
sg_table) are in use.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 08:43:29 -07:00
Linus Torvalds 5af568cbd5 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:
  isofs: Fix lseek() to position beyond 4 GB
  vfs: remove unused MNT_STRICTATIME
  vfs: show unreachable paths in getcwd and proc
  vfs: only add " (deleted)" where necessary
  vfs: add prepend_path() helper
  vfs: __d_path: dont prepend the name of the root dentry
  ia64: perfmon: add d_dname method
  vfs: add helpers to get root and pwd
  cachefiles: use path_get instead of lone dget
  fs/sysv/super.c: add support for non-PDP11 v7 filesystems
  V7: Adjust sanity checks for some volumes
  Add v7 alias
  v9fs: fixup for inode_setattr being removed

Manual merge to take Al's version of the fs/sysv/super.c file: it merged
cleanly, but Al had removed an unnecessary header include, so his side
was better.
2010-08-11 09:23:32 -07:00
Stefani Seibold 2e956fb320 kfifo: replace the old non generic API
Simply replace the whole kfifo.c and kfifo.h files with the new generic
version and fix the kerneldoc API template file.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:23 -07:00
Stefani Seibold 4201d9a8e8 kfifo: add the new generic kfifo API
Add the new version of the kfifo API files kfifo.c and kfifo.h.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:23 -07:00
Dan Carpenter f65a03f6ab kexec: return -EFAULT on copy_to_user() failures
copy_to/from_user() returns the number of bytes remaining to be copied.
It never returns a negative value.  The correct return code is -EFAULT and
not -EIO.

All the callers check for non-zero returns so that's Ok, but the return
code is passed to the user so we should fix this.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:22 -07:00
Anton Blanchard 863a604920 lib/bug.c: add oops end marker to WARN implementation
We are missing the oops end marker for the exception based WARN implementation
in lib/bug.c. This is useful for logfile analysis tools.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:22 -07:00
TAMUKI Shoichi c7ff0d9c92 panic: keep blinking in spite of long spin timer mode
To keep panic_timeout accuracy when running under a hypervisor, the
current implementation only spins on long time (1 second) calls to mdelay.
 That brings a good effect, but the problem is the keyboard LEDs don't
blink at all on that situation.

This patch changes to call to panic_blink_enter() between every mdelay and
keeps blinking in spite of long spin timer mode.

The time to call to mdelay is now 100ms.  Even this change will keep
panic_timeout accuracy enough when running under a hypervisor.

Signed-off-by: TAMUKI Shoichi <tamuki@linet.gr.jp>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:22 -07:00
Oleg Nesterov c52b0b91ba pids: alloc_pidmap: remove the unnecessary boundary checks
alloc_pidmap() calculates max_scan so that if the initial offset != 0 we
inspect the first map->page twice.  This is correct, we want to find the
unused bits < offset in this bitmap block.  Add the comment.

But it doesn't make any sense to stop the find_next_offset() loop when we
are looking into this map->page for the second time.  We have already
already checked the bits >= offset during the first attempt, it is fine to
do this again, no matter if we succeed this time or not.

Remove this hard-to-understand code.  It optimizes the very unlikely case
when we are going to fail, but slows down the more likely case.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Salman Qazi <sqazi@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:20 -07:00
Salman 5fdee8c4a5 pids: fix a race in pid generation that causes pids to be reused immediately
A program that repeatedly forks and waits is susceptible to having the
same pid repeated, especially when it competes with another instance of
the same program.  This is really bad for bash implementation.
Furthermore, many shell scripts assume that pid numbers will not be used
for some length of time.

Race Description:

A                                    B

// pid == offset == n                // pid == offset == n + 1
test_and_set_bit(offset, map->page)
                                     test_and_set_bit(offset, map->page);
                                     pid_ns->last_pid = pid;
pid_ns->last_pid = pid;
                                     // pid == n + 1 is freed (wait())

                                     // Next fork()...
                                     last = pid_ns->last_pid; // == n
                                     pid = last + 1;

Code to reproduce it (Running multiple instances is more effective):

#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

// The distance mod 32768 between two pids, where the first pid is expected
// to be smaller than the second.
int PidDistance(pid_t first, pid_t second) {
  return (second + 32768 - first) % 32768;
}

int main(int argc, char* argv[]) {
  int failed = 0;
  pid_t last_pid = 0;
  int i;
  printf("%d\n", sizeof(pid_t));
  for (i = 0; i < 10000000; ++i) {
    if (i % 32786 == 0)
      printf("Iter: %d\n", i/32768);
    int child_exit_code = i % 256;
    pid_t pid = fork();
    if (pid == -1) {
      fprintf(stderr, "fork failed, iteration %d, errno=%d", i, errno);
      exit(1);
    }
    if (pid == 0) {
      // Child
      exit(child_exit_code);
    } else {
      // Parent
      if (i > 0) {
        int distance = PidDistance(last_pid, pid);
        if (distance == 0 || distance > 30000) {
          fprintf(stderr,
                  "Unexpected pid sequence: previous fork: pid=%d, "
                  "current fork: pid=%d for iteration=%d.\n",
                  last_pid, pid, i);
          failed = 1;
        }
      }
      last_pid = pid;
      int status;
      int reaped = wait(&status);
      if (reaped != pid) {
        fprintf(stderr,
                "Wait return value: expected pid=%d, "
                "got %d, iteration %d\n",
                pid, reaped, i);
        failed = 1;
      } else if (WEXITSTATUS(status) != child_exit_code) {
        fprintf(stderr,
                "Unexpected exit status %x, iteration %d\n",
                WEXITSTATUS(status), i);
        failed = 1;
      }
    }
  }
  exit(failed);
}

Thanks to Ted Tso for the key ideas of this implementation.

Signed-off-by: Salman Qazi <sqazi@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:20 -07:00
Oleg Nesterov c7e49c1488 ptrace: optimize exit_ptrace() for the likely case
exit_ptrace() takes tasklist_lock unconditionally.  We need this lock to
avoid the race with ptrace_traceme(), it acts as a barrier.

Change its caller, forget_original_parent(), to call exit_ptrace() under
tasklist_lock.  Change exit_ptrace() to drop and reacquire this lock if
needed.

This allows us to add the fastpath list_empty(ptraced) check.  In the
likely no-tracees case exit_ptrace() just returns and we avoid the lock()
+ unlock() sequence.

"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> suggested to add this
check, and he reports that this change adds about 11% improvement in some
tests.

Suggested-and-tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:19 -07:00
Dan Carpenter e400c28524 cgroups: save space for the terminator
The original code didn't leave enough space for a NULL terminator.  These
strings are copied with strcpy() into fixed length buffers in
cgroup_root_from_opts().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Reviewd-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ben Blum <bblum@andrew.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:18 -07:00
Rusty Russell 907b29eb41 param: locking for kernel parameters
There may be cases (most obviously, sysfs-writable charp parameters) where
a module needs to prevent sysfs access to parameters.

Rather than express this in terms of a big lock, the functions are
expressed in terms of what they protect against.  This is clearer, esp.
if the implementation changes to a module-level or even param-level lock.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:20 +09:30
Rusty Russell 914dcaa84c param: make param sections const.
Since this section can be read-only (they're in .rodata), they should
always have been const.  Minor flow-through various functions.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:19 +09:30
Rusty Russell a1054322af param: use free hook for charp (fix leak of charp parameters)
Instead of using a "I kmalloced this" flag, we keep track of the kmalloced
strings and use that list to check if we need to kfree (in practice, the
list is very short).

This means that kparams can be const again, and plugs a leak.  This
is important for drivers/usb/gadget/nokia.c which gets modprobe/rmmod'ed
frequently on the N9000.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:18 +09:30
Rusty Russell e6df34a442 param: add a free hook to kernel_param_ops.
This allows us to generalize the KPARAM_KMALLOCED flag, by calling a function
on every parameter when a module is unloaded.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:18 +09:30
Rusty Russell 9bbb9e5a33 param: use ops in struct kernel_param, rather than get and set fns directly
This is more kernel-ish, saves some space, and also allows us to
expand the ops without breaking all the callers who are happy for the
new members to be NULL.

The few places which defined their own param types are changed to the
new scheme (more which crept in recently fixed in following patches).

Since we're touching them anyway, we change get() and set() to take a
const struct kernel_param (which they really are).  This causes some
harmless warnings until we fix them (in following patches).

To reduce churn, module_param_call creates the ops struct so the callers
don't have to change (and casts the functions to reduce warnings).
The modern version which takes an ops struct is called module_param_cb.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Alessandro Rubini <rubini@ipvvis.unipv.it>
Cc: Michal Januszewski <spock@gentoo.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-fbdev-devel@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: netdev@vger.kernel.org
2010-08-11 23:04:13 +09:30
Rusty Russell a14fe249a8 param: move the EXPORT_SYMBOL to after the definitions.
This is modern style, and good to do before we start changing things.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:12 +09:30
Rusty Russell 2e9fb9953d params: don't hand NULL values to param.set callbacks.
An audit by Dongdong Deng revealed that most driver-author-written param
calls don't handle val == NULL (which happens when parameters are specified
with no =, eg "foo" instead of "foo=1").

The only real case to use this is boolean, so handle it specially for that
case and remove a source of bugs for everyone else.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dongdong Deng <dongdong.deng@windriver.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
2010-08-11 23:04:11 +09:30
Miklos Szeredi f7ad3c6be9 vfs: add helpers to get root and pwd
Add three helpers that retrieve a refcounted copy of the root and cwd
from the supplied fs_struct.

 get_fs_root()
 get_fs_pwd()
 get_fs_root_and_pwd()

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:28:20 -04:00
Randy Dunlap 0caa621065 kernel/timer.c: fix kernel-doc function parameter warning
Fix kernel-doc warning, add @timer description:

  Warning(kernel/timer.c:335): No description found for parameter 'timer'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10 15:33:09 -07:00
Linus Torvalds 2f9e825d3e Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
2010-08-10 15:22:42 -07:00
Linus Torvalds b34d8915c4 Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux
* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux:
  unistd: add __NR_prlimit64 syscall numbers
  rlimits: implement prlimit64 syscall
  rlimits: switch more rlimit syscalls to do_prlimit
  rlimits: redo do_setrlimit to more generic do_prlimit
  rlimits: add rlimit64 structure
  rlimits: do security check under task_lock
  rlimits: allow setrlimit to non-current tasks
  rlimits: split sys_setrlimit
  rlimits: selinux, do rlimits changes under task_lock
  rlimits: make sure ->rlim_max never grows in sys_setrlimit
  rlimits: add task_struct to update_rlimit_cpu
  rlimits: security, add task_struct to setrlimit

Fix up various system call number conflicts.  We not only added fanotify
system calls in the meantime, but asm-generic/unistd.h added a wait4
along with a range of reserved per-architecture system calls.
2010-08-10 12:07:51 -07:00
Linus Torvalds 8c8946f509 Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
  fanotify: use both marks when possible
  fsnotify: pass both the vfsmount mark and inode mark
  fsnotify: walk the inode and vfsmount lists simultaneously
  fsnotify: rework ignored mark flushing
  fsnotify: remove global fsnotify groups lists
  fsnotify: remove group->mask
  fsnotify: remove the global masks
  fsnotify: cleanup should_send_event
  fanotify: use the mark in handler functions
  audit: use the mark in handler functions
  dnotify: use the mark in handler functions
  inotify: use the mark in handler functions
  fsnotify: send fsnotify_mark to groups in event handling functions
  fsnotify: Exchange list heads instead of moving elements
  fsnotify: srcu to protect read side of inode and vfsmount locks
  fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
  fsnotify: use _rcu functions for mark list traversal
  fsnotify: place marks on object in order of group memory address
  vfs/fsnotify: fsnotify_close can delay the final work in fput
  fsnotify: store struct file not struct path
  ...

Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
2010-08-10 11:39:13 -07:00
Linus Torvalds 5f248c9c25 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: (96 commits)
  no need for list_for_each_entry_safe()/resetting with superblock list
  Fix sget() race with failing mount
  vfs: don't hold s_umount over close_bdev_exclusive() call
  sysv: do not mark superblock dirty on remount
  sysv: do not mark superblock dirty on mount
  btrfs: remove junk sb_dirt change
  BFS: clean up the superblock usage
  AFFS: wait for sb synchronization when needed
  AFFS: clean up dirty flag usage
  cifs: truncate fallout
  mbcache: fix shrinker function return value
  mbcache: Remove unused features
  add f_flags to struct statfs(64)
  pass a struct path to vfs_statfs
  update VFS documentation for method changes.
  All filesystems that need invalidate_inode_buffers() are doing that explicitly
  convert remaining ->clear_inode() to ->evict_inode()
  Make ->drop_inode() just return whether inode needs to be dropped
  fs/inode.c:clear_inode() is gone
  fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
  ...

Fix up trivial conflicts in fs/nilfs2/super.c
2010-08-10 11:26:52 -07:00
Andi Kleen 8c4af38e9b gcc-4.6: printk: use stable variable to dump kmsg buffer
kmsg_dump takes care to sample the global variables
inside a spinlock, but then goes on to use the same
variables outside the spinlock region too.

Use the correct variable. This will make the race
window smaller.

Found by gcc 4.6's new warnings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:06 -07:00
Richard Kennedy 878ae12749 stop_machine: struct cpu_stopper, remove alignment padding on 64 bits
Reorder elements in structure cpu_stopper to remove alignment padding on
64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes
per cpu.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:06 -07:00
Geert Uytterhoeven 459b37d423 kernel/range: remove unused definition of ARRAY_SIZE()
Remove duplicate definition of ARRAY_SIZE(), which was never used anyway.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:06 -07:00
Oleg Nesterov 2ee7c922f2 sys_personality: remove the bogus checks in sys_personality()->__set_personality() path
Cleanup, no functional changes.

- __set_personality() always changes ->exec_domain/personality, the
  special case when ->exec_domain remains the same buys nothing but
  complicates the code. Unify both cases to simplify the code.

- The -EINVAL check in sys_personality() was never right. If we assume
  that set_personality() can fail we should check the value it returns
  instead of verifying that task->personality was actually changed.

  Remove it. Before the previous patch it was possible to hit this case
  due to overflow problems, but this -EINVAL just indicated the kernel
  bug.

OTOH, probably it makes sense to change lookup_exec_domain() to return
ERR_PTR() instead of default_exec_domain if the search in exec_domains
list fails, and report this error to the user-space.  But this means
another user-space change, and we have in-kernel users which need fixes.
For example, PER_OSF4 falls into PER_MASK for unkown reason and nobody
cares to register this domain.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Wenming Zhang <wezhang@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:05 -07:00
KAMEZAWA Hiroyuki d2997b1042 hibernation: freeze swap at hibernation
When taking a memory snapshot in hibernate_snapshot(), all (directly
called) memory allocations use GFP_ATOMIC.  Hence swap misusage during
hibernation never occurs.

But from a pessimistic point of view, there is no guarantee that no page
allcation has __GFP_WAIT.  It is better to have a global indication "we
enter hibernation, don't use swap!".

This patch tries to freeze new-swap-allocation during hibernation.  (All
user processes are frozenm so swapin is not a concern).

This way, no updates will happen to swap_map[] between
hibernate_snapshot() and save_image().  Swap is thawed when swsusp_free()
is called.  We can be assured that swap corruption will not occur.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ondrej Zary <linux@rainbow-software.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:04 -07:00
David Rientjes a63d83f427 oom: badness heuristic rewrite
This a complete rewrite of the oom killer's badness() heuristic which is
used to determine which task to kill in oom conditions.  The goal is to
make it as simple and predictable as possible so the results are better
understood and we end up killing the task which will lead to the most
memory freeing while still respecting the fine-tuning from userspace.

Instead of basing the heuristic on mm->total_vm for each task, the task's
rss and swap space is used instead.  This is a better indication of the
amount of memory that will be freeable if the oom killed task is chosen
and subsequently exits.  This helps specifically in cases where KDE or
GNOME is chosen for oom kill on desktop systems instead of a memory
hogging task.

The baseline for the heuristic is a proportion of memory that each task is
currently using in memory plus swap compared to the amount of "allowable"
memory.  "Allowable," in this sense, means the system-wide resources for
unconstrained oom conditions, the set of mempolicy nodes, the mems
attached to current's cpuset, or a memory controller's limit.  The
proportion is given on a scale of 0 (never kill) to 1000 (always kill),
roughly meaning that if a task has a badness() score of 500 that the task
consumes approximately 50% of allowable memory resident in RAM or in swap
space.

The proportion is always relative to the amount of "allowable" memory and
not the total amount of RAM systemwide so that mempolicies and cpusets may
operate in isolation; they shall not need to know the true size of the
machine on which they are running if they are bound to a specific set of
nodes or mems, respectively.

Root tasks are given 3% extra memory just like __vm_enough_memory()
provides in LSMs.  In the event of two tasks consuming similar amounts of
memory, it is generally better to save root's task.

Because of the change in the badness() heuristic's baseline, it is also
necessary to introduce a new user interface to tune it.  It's not possible
to redefine the meaning of /proc/pid/oom_adj with a new scale since the
ABI cannot be changed for backward compatability.  Instead, a new tunable,
/proc/pid/oom_score_adj, is added that ranges from -1000 to +1000.  It may
be used to polarize the heuristic such that certain tasks are never
considered for oom kill while others may always be considered.  The value
is added directly into the badness() score so a value of -500, for
example, means to discount 50% of its memory consumption in comparison to
other tasks either on the system, bound to the mempolicy, in the cpuset,
or sharing the same memory controller.

/proc/pid/oom_adj is changed so that its meaning is rescaled into the
units used by /proc/pid/oom_score_adj, and vice versa.  Changing one of
these per-task tunables will rescale the value of the other to an
equivalent meaning.  Although /proc/pid/oom_adj was originally defined as
a bitshift on the badness score, it now shares the same linear growth as
/proc/pid/oom_score_adj but with different granularity.  This is required
so the ABI is not broken with userspace applications and allows oom_adj to
be deprecated for future removal.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.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>
2010-08-09 20:45:02 -07:00
David Rientjes 8e4228e1ed oom: move sysctl declarations to oom.h
The three oom killer sysctl variables (sysctl_oom_dump_tasks,
sysctl_oom_kill_allocating_task, and sysctl_panic_on_oom) are better
declared in include/linux/oom.h rather than kernel/sysctl.c.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:44:57 -07:00
Christoph Hellwig ebabe9a900 pass a struct path to vfs_statfs
We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:

 - ecryptfs_statfs.  This one doesn't actually need vfs_statfs but just
   needs to do a caller to the lower filesystem statfs method.
 - sys_ustat.  Add a non-exported statfs_by_dentry helper for it which
   doesn't won't be able to fill out the flags field later on.

In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:42 -04:00
Tejun Heo f6500947a9 workqueue: workqueue_cpu_callback() should be cpu_notifier instead of hotcpu_notifier
Commit 6ee0578b (workqueue: mark init_workqueues as early_initcall)
made workqueue SMP initialization depend on workqueue_cpu_callback(),
which however was registered as hotcpu_notifier() and didn't get
called if CONFIG_HOTPLUG_CPU is not set.  This made gcwqs on non-boot
CPUs not create their initial workers leading to boot failures.  Fix
it by making it a cpu_notifier.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-bisected-by: walt <w41ter@gmail.com>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
2010-08-09 11:50:34 +02:00
Namhyung Kim 38f5156800 workqueue: add missing __percpu markup in kernel/workqueue.c
works in schecule_on_each_cpu() is a percpu pointer but was missing
__percpu markup.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-08-08 14:24:09 +02:00
Linus Torvalds 78417334b5 Merge branch 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing
* 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  do_coredump: Do not take BKL
  init: Remove the BKL from startup code
2010-08-07 17:06:54 -07:00
Linus Torvalds 3b7433b8a8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
  workqueue: mark init_workqueues() as early_initcall()
  workqueue: explain for_each_*cwq_cpu() iterators
  fscache: fix build on !CONFIG_SYSCTL
  slow-work: kill it
  gfs2: use workqueue instead of slow-work
  drm: use workqueue instead of slow-work
  cifs: use workqueue instead of slow-work
  fscache: drop references to slow-work
  fscache: convert operation to use workqueue instead of slow-work
  fscache: convert object to use workqueue instead of slow-work
  workqueue: fix how cpu number is stored in work->data
  workqueue: fix mayday_mask handling on UP
  workqueue: fix build problem on !CONFIG_SMP
  workqueue: fix locking in retry path of maybe_create_worker()
  async: use workqueue for worker pool
  workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
  workqueue: implement unbound workqueue
  workqueue: prepare for WQ_UNBOUND implementation
  libata: take advantage of cmwq and remove concurrency limitations
  workqueue: fix worker management invocation without pending works
  ...

Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
2010-08-07 12:42:58 -07:00
Arnd Bergmann 62c2a7d969 block: push BKL into blktrace ioctls
The blktrace driver currently needs the BKL, but
we should not need to take that in the block layer,
so just push it down into the driver itself.

It is quite likely that the BKL is not actually
required in blktrace code and could be removed
in a follow-on patch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:26:08 +02:00
Christoph Hellwig 7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00
Christoph Hellwig 33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
Linus Torvalds 1787985782 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:
  xen: Do not suspend IPI IRQs.
  powerpc: Use IRQF_NO_SUSPEND not IRQF_TIMER for non-timer interrupts
  ixp4xx-beeper: Use IRQF_NO_SUSPEND not IRQF_TIMER for non-timer interrupt
  irq: Add new IRQ flag IRQF_NO_SUSPEND
2010-08-06 13:25:43 -07:00
Linus Torvalds b62ad9ab18 Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  um: Fix read_persistent_clock fallout
  kgdb: Do not access xtime directly
  powerpc: Clean up obsolete code relating to decrementer and timebase
  powerpc: Rework VDSO gettimeofday to prevent time going backwards
  clocksource: Add __clocksource_updatefreq_hz/khz methods
  x86: Convert common clocksources to use clocksource_register_hz/khz
  timekeeping: Make xtime and wall_to_monotonic static
  hrtimer: Cleanup direct access to wall_to_monotonic
  um: Convert to use read_persistent_clock
  timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset
  powerpc: Cleanup xtime usage
  powerpc: Simplify update_vsyscall
  time: Kill off CONFIG_GENERIC_TIME
  time: Implement timespec_add
  x86: Fix vtime/file timestamp inconsistencies

Trivial conflicts in Documentation/feature-removal-schedule.txt

Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as
per Thomas' earlier merge commit 47916be4e2 ("Merge branch
'powerpc.cherry-picks' into timers/clocksource")
2010-08-06 13:18:29 -07:00
Linus Torvalds af39008435 Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  Documentation: Add timers/timers-howto.txt
  timer: Added usleep_range timer
  Revert "timer: Added usleep[_range] timer"
  clockevents: Remove the per cpu tick skew
  posix_timer: Move copy_to_user(created_timer_id) down in timer_create()
  timer: Added usleep[_range] timer
  timers: Document meaning of deferrable timer
2010-08-06 13:12:36 -07:00
Linus Torvalds ab69bcd66f Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (28 commits)
  driver core: device_rename's new_name can be const
  sysfs: Remove owner field from sysfs struct attribute
  powerpc/pci: Remove owner field from attribute initialization in PCI bridge init
  regulator: Remove owner field from attribute initialization in regulator core driver
  leds: Remove owner field from attribute initialization in bd2802 driver
  scsi: Remove owner field from attribute initialization in ARCMSR driver
  scsi: Remove owner field from attribute initialization in LPFC driver
  cgroupfs: create /sys/fs/cgroup to mount cgroupfs on
  Driver core: Add BUS_NOTIFY_BIND_DRIVER
  driver core: fix memory leak on one error path in bus_register()
  debugfs: no longer needs to depend on SYSFS
  sysfs: Fix one more signature discrepancy between sysfs implementation and docs.
  sysfs: fix discrepancies between implementation and documentation
  dcdbas: remove a redundant smi_data_buf_free in dcdbas_exit
  dmi-id: fix a memory leak in dmi_id_init error path
  sysfs: sysfs_chmod_file's attr can be const
  firmware: Update hotplug script
  Driver core: move platform device creation helpers to .init.text (if MODULE=n)
  Driver core: reduce duplicated code for platform_device creation
  Driver core: use kmemdup in platform_device_add_resources
  ...
2010-08-06 11:36:30 -07:00
Huang Ying 18fab912d4 tracing: Fix ring_buffer_read_page reading out of page boundary
With the configuration: CONFIG_DEBUG_PAGEALLOC=y and Shaohua's patch:

[PATCH]x86: make spurious_fault check correct pte bit

Function call graph trace with the following will trigger a page fault.

# cd /sys/kernel/debug/tracing/
# echo function_graph > current_tracer
# cat per_cpu/cpu1/trace_pipe_raw > /dev/null

BUG: unable to handle kernel paging request at ffff880006e99000
IP: [<ffffffff81085572>] rb_event_length+0x1/0x3f
PGD 1b19063 PUD 1b1d063 PMD 3f067 PTE 6e99160
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
last sysfs file: /sys/devices/virtual/net/lo/operstate
CPU 1
Modules linked in:

Pid: 1982, comm: cat Not tainted 2.6.35-rc6-aes+ #300 /Bochs
RIP: 0010:[<ffffffff81085572>]  [<ffffffff81085572>] rb_event_length+0x1/0x3f
RSP: 0018:ffff880006475e38  EFLAGS: 00010006
RAX: 0000000000000ff0 RBX: ffff88000786c630 RCX: 000000000000001d
RDX: ffff880006e98000 RSI: 0000000000000ff0 RDI: ffff880006e99000
RBP: ffff880006475eb8 R08: 000000145d7008bd R09: 0000000000000000
R10: 0000000000008000 R11: ffffffff815d9336 R12: ffff880006d08000
R13: ffff880006e605d8 R14: 0000000000000000 R15: 0000000000000018
FS:  00007f2b83e456f0(0000) GS:ffff880002100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff880006e99000 CR3: 00000000064a8000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process cat (pid: 1982, threadinfo ffff880006474000, task ffff880006e40770)
Stack:
 ffff880006475eb8 ffffffff8108730f 0000000000000ff0 000000145d7008bd
<0> ffff880006e98010 ffff880006d08010 0000000000000296 ffff88000786c640
<0> ffffffff81002956 0000000000000000 ffff8800071f4680 ffff8800071f4680
Call Trace:
 [<ffffffff8108730f>] ? ring_buffer_read_page+0x15a/0x24a
 [<ffffffff81002956>] ? return_to_handler+0x15/0x2f
 [<ffffffff8108a575>] tracing_buffers_read+0xb9/0x164
 [<ffffffff810debfe>] vfs_read+0xaf/0x150
 [<ffffffff81002941>] return_to_handler+0x0/0x2f
 [<ffffffff810248b0>] __bad_area_nosemaphore+0x17e/0x1a1
 [<ffffffff81002941>] return_to_handler+0x0/0x2f
 [<ffffffff810248e6>] bad_area_nosemaphore+0x13/0x15
Code: 80 25 b2 16 b3 00 fe c9 c3 55 48 89 e5 f0 80 0d a4 16 b3 00 02 c9 c3 55 31 c0 48 89 e5 48 83 3d 94 16 b3 00 01 c9 0f 94 c0 c3 55 <8a> 0f 48 89 e5 83 e1 1f b8 08 00 00 00 0f b6 d1 83 fa 1e 74 27
RIP  [<ffffffff81085572>] rb_event_length+0x1/0x3f
 RSP <ffff880006475e38>
CR2: ffff880006e99000
---[ end trace a6877bb92ccb36bb ]---

The root cause is that ring_buffer_read_page() may read out of page
boundary, because the boundary checking is done after reading. This is
fixed via doing boundary checking before reading.

Reported-by: Shaohua Li <shaohua.li@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1280297641.2771.307.camel@yhuang-dev>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-06 14:34:45 -04:00
Linus Torvalds c4efd6b569 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: (27 commits)
  sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug
  sched: No need for bootmem special cases
  sched: Revert nohz_ratelimit() for now
  sched: Reduce update_group_power() calls
  sched: Update rq->clock for nohz balanced cpus
  sched: Fix spelling of sibling
  sched, cpuset: Drop __cpuexit from cpu hotplug callbacks
  sched: Fix the racy usage of thread_group_cputimer() in fastpath_timer_check()
  sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()
  sched: thread_group_cputime: Simplify, document the "alive" check
  sched: Remove the obsolete exit_state/signal hacks
  sched: task_tick_rt: Remove the obsolete ->signal != NULL check
  sched: __sched_setscheduler: Read the RLIMIT_RTPRIO value lockless
  sched: Fix comments to make them DocBook happy
  sched: Fix fix_small_capacity
  powerpc: Exclude arch_sd_sibiling_asym_packing() on UP
  powerpc: Enable asymmetric SMT scheduling on POWER7
  sched: Add asymmetric group packing option for sibling domain
  sched: Fix capacity calculations for SMT4
  sched: Change nohz idle load balancing logic to push model
  ...
2010-08-06 09:39:22 -07:00
Linus Torvalds 4aed2fd8e3 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits)
  tracing/kprobes: unregister_trace_probe needs to be called under mutex
  perf: expose event__process function
  perf events: Fix mmap offset determination
  perf, powerpc: fsl_emb: Restore setting perf_sample_data.period
  perf, powerpc: Convert the FSL driver to use local64_t
  perf tools: Don't keep unreferenced maps when unmaps are detected
  perf session: Invalidate last_match when removing threads from rb_tree
  perf session: Free the ref_reloc_sym memory at the right place
  x86,mmiotrace: Add support for tracing STOS instruction
  perf, sched migration: Librarize task states and event headers helpers
  perf, sched migration: Librarize the GUI class
  perf, sched migration: Make the GUI class client agnostic
  perf, sched migration: Make it vertically scrollable
  perf, sched migration: Parameterize cpu height and spacing
  perf, sched migration: Fix key bindings
  perf, sched migration: Ignore unhandled task states
  perf, sched migration: Handle ignored migrate out events
  perf: New migration tool overview
  tracing: Drop cpparg() macro
  perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call
  ...

Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
2010-08-06 09:30:52 -07:00
Linus Torvalds 3a3527b646 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  Revert "net: Make accesses to ->br_port safe for sparse RCU"
  mce: convert to rcu_dereference_index_check()
  net: Make accesses to ->br_port safe for sparse RCU
  vfs: add fs.h to define struct file
  lockdep: Add an in_workqueue_context() lockdep-based test function
  rcu: add __rcu API for later sparse checking
  rcu: add an rcu_dereference_index_check()
  tree/tiny rcu: Add debug RCU head objects
  mm: remove all rcu head initializations
  fs: remove all rcu head initializations, except on_stack initializations
  powerpc: remove all rcu head initializations
2010-08-06 09:23:07 -07:00
Shaohua Li 575570f027 tracing: Fix an unallocated memory access in function_graph
With CONFIG_DEBUG_PAGEALLOC, I observed an unallocated memory access in
function_graph trace. It appears we find a small size entry in ring buffer,
but we access it as a big size entry. The access overflows the page size
and touches an unallocated page.

Cc: <stable@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <1280217994.32400.76.camel@sli10-desk.sh.intel.com>
[ Added a comment to explain the problem - SDR ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-06 12:19:15 -04:00
Linus Torvalds 9779714c8a Merge branch 'kms-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'kms-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb,docs: Update the kgdb docs to include kms
  drm_fb_helper: Preserve capability to use atomic kms
  i915: when kgdb is active display compression should be off
  drm/i915: use new fb debug hooks
  drm: add KGDB/KDB support
  fb: add hooks to handle KDB enter/exit
  kgdboc: Add call backs to allow kernel mode switching
  vt,console,kdb: automatically set kdb LINES variable
  vt,console,kdb: implement atomic console enter/leave functions
2010-08-05 16:00:44 -07:00
Linus Torvalds 89a6c8cb9e Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  debug_core,kdb: fix crash when arch does not have single step
  kgdb,x86: use macro HBP_NUM to replace magic number 4
  kgdb,mips: remove unused kgdb_cpu_doing_single_step operations
  mm,kdb,kgdb: Add a debug reference for the kdb kmap usage
  KGDB: Remove set but unused newPC
  ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
  ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
  kgdb,powerpc: Replace hardcoded offset by BREAK_INSTR_SIZE
  arm,kgdb: Add ability to trap into debugger on notify_die
  gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set()
  gdbstub: Implement gdbserial 'p' and 'P' packets
  kgdb,arm: Individual register get/set for arm
  kgdb,mips: Individual register get/set for mips
  kgdb,x86: Individual register get/set for x86
  kgdb,kdb: individual register set and and get API
  gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol
  kgdb: remove custom hex_to_bin()implementation
2010-08-05 15:59:48 -07:00
Greg KH 676db4af04 cgroupfs: create /sys/fs/cgroup to mount cgroupfs on
We really shouldn't be asking userspace to create new root filesystems.
So follow along with all of the other in-kernel filesystems, and provide
a mount point in sysfs.

For cgroupfs, this should be in /sys/fs/cgroup/  This change provides
that mount point when the cgroup filesystem is registered in the kernel.

Acked-by: Paul Menage <menage@google.com>
Acked-by: Dhaval Giani <dhaval.giani@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05 13:53:35 -07:00
Ian Abbott 94f17cd788 hotplug: Support kernel/hotplug sysctl variable when !CONFIG_NET
The kernel/hotplug sysctl variable (/proc/sys/kernel/hotplug file) was
made conditional on CONFIG_NET by commit
f743ca5e10 (applied in 2.6.18) to fix
problems with undefined references in 2.6.16 when CONFIG_HOTPLUG=y &&
!CONFIG_NET, but this restriction is no longer needed.

This patch makes the kernel/hotplug sysctl variable depend only on
CONFIG_HOTPLUG.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Randy Dunlap <randy.dunlap@oracle.COM>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05 13:53:33 -07:00
Linus Torvalds 90d3417a3a Merge branch 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: cleanup comments, remove noinline
  module: group post-relocation functions into post_relocation()
  module: move module args strndup_user to just before use
  module: pass load_info into other functions
  module: fix sysfs cleanup for !CONFIG_SYSFS
  module: sysfs cleanup
  module: layout_and_allocate
  module: fix crash in get_ksymbol() when oopsing in module init
  module: kallsyms functions take struct load_info
  module: refactor out section header rewriting: FIX modversions
  module: refactor out section header rewriting
  module: add load_info
  module: reduce stack usage for each_symbol()
  module: refactor load_module part 5
  module: refactor load_module part 4
  module: refactor load_module part 3
  module: refactor load_module part 2
  module: refactor load_module
  module: module_unload_init() cleanup
2010-08-05 13:49:55 -07:00
Linus Torvalds cdd854bc42 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (79 commits)
  powerpc/8xx: Add support for the MPC8xx based boards from TQC
  powerpc/85xx: Introduce support for the Freescale P1022DS reference board
  powerpc/85xx: Adding DTS for the STx GP3-SSA MPC8555 board
  powerpc/85xx: Change deprecated binding for 85xx-based boards
  powerpc/tqm85xx: add a quirk for ti1520 PCMCIA bridge
  powerpc/tqm85xx: update PCI interrupt-map attribute
  powerpc/mpc8308rdb: support for MPC8308RDB board from Freescale
  powerpc/fsl_pci: add quirk for mpc8308 pcie bridge
  powerpc/85xx: Cleanup QE initialization for MPC85xxMDS boards
  powerpc/85xx: Fix booting for P1021MDS boards
  powerpc/85xx: Fix SWIOTLB initalization for MPC85xxMDS boards
  powerpc/85xx: kexec for SMP 85xx BookE systems
  powerpc/5200/i2c: improve i2c bus error recovery
  of/xilinxfb: update tft compatible versions
  powerpc/fsl-diu-fb: Support setting display mode using EDID
  powerpc/5121: doc/dts-bindings: update doc of FSL DIU bindings
  powerpc/5121: shared DIU framebuffer support
  powerpc/5121: move fsl-diu-fb.h to include/linux
  powerpc/5121: fsl-diu-fb: fix issue with re-enabling DIU area descriptor
  powerpc/512x: add clock structure for Video-IN (VIU) unit
  ...
2010-08-05 09:03:46 -07:00
Linus Torvalds c3d1f1746b Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (150 commits)
  MIPS: PowerTV: Separate PowerTV USB support from non-USB code
  MIPS: strip the un-needed sections of vmlinuz
  MIPS: Clean up the calculation of VMLINUZ_LOAD_ADDRESS
  MIPS: Clean up arch/mips/boot/compressed/decompress.c
  MIPS: Clean up arch/mips/boot/compressed/ld.script
  MIPS: Unify the suffix of compressed vmlinux.bin
  MIPS: PowerTV: Add Gaia platform definitions.
  MIPS: BCM47xx: Fix nvram_getenv return value.
  MIPS: Octeon: Allow more than 3.75GB of memory with PCIe
  MIPS: Clean up notify_die() usage.
  MIPS: Remove unused task_struct.trap_no field.
  Documentation: Mention that KProbes is supported on MIPS
  SAMPLES: kprobe_example: Make it print something on MIPS.
  MIPS: kprobe: Add support.
  MIPS: Add instrunction format for BREAK and SYSCALL
  MIPS: kprobes: Define regs_return_value()
  MIPS: Ritually kill stupid printk.
  MIPS: Octeon: Disallow MSI-X interrupt and fall back to MSI interrupts.
  MIPS: Octeon: Support 256 MSI on PCIe
  MIPS: Decode core number for R2 CPUs.
  ...
2010-08-05 08:53:20 -07:00
Jason Wessel 81d4450732 vt,console,kdb: automatically set kdb LINES variable
The kernel console interface stores the number of lines it is
configured to use. The kdb debugger can greatly benefit by knowing how
many lines there are on the console for the pager functionality
without having the end user compile in the setting or have to
repeatedly change it at run time.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>
2010-08-05 09:22:30 -05:00
Jason Wessel 3fa43aba08 debug_core,kdb: fix crash when arch does not have single step
When an arch such as mips and microblaze does not implement either HW
or software single stepping the debug core should re-enter kdb.  The
kdb code will properly ignore the single step operation.  Attempting
to single step the kernel without software or hardware support causes
unpredictable kernel crashes.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:25 -05:00
Jason Wessel 19063c776f ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
In systems with more than one processor it is desirable to look at the
per cpu trace buffers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-05 09:22:23 -05:00
Jason Wessel 955b61e597 ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
Add in a helper function to allow the kdb shell to dump the ftrace
buffer.

Modify trace.c to expose the capability to iterate over the ftrace
buffer in a read only capacity.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-05 09:22:23 -05:00
Jason Wessel 6d855b1d83 gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set()
Presently the usable registers definitions on x86 are not contiguous
for kgdb.  The x86 kgdb uses a case statement for the sparse register
accesses.  The array which defines the registers (dbg_reg_def) should
not be used directly in order to safely work with sparse register
definitions.

Specifically there was a problem when gdb accesses ORIG_AX, which is
accessed only through the case statement.

This patch encodes register memory using the size information provided
from the debugger which avoids the need to look up the size of the
register.  The dbg_set_reg() function always further validates the
inputs from the debugger.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
2010-08-05 09:22:22 -05:00
Jason Wessel 55751145dc gdbstub: Implement gdbserial 'p' and 'P' packets
The gdbserial 'p' and 'P' packets allow gdb to individually get and
set registers instead of querying for all the available registers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:21 -05:00
Jason Wessel 534af10823 kgdb,kdb: individual register set and and get API
The kdb shell specification includes the ability to get and set
architecture specific registers by name.

For the time being individual register get and set will be implemented
on a per architecture basis.  If an architecture defines
DBG_MAX_REG_NUM > 0 then kdb and the gdbstub will use the capability
for individually getting and setting architecture specific registers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:20 -05:00
Jason Wessel 84a0bd5b28 gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol
The gdb debugger understands how to parse short versions of the thread
reference string as long as the bytes are paired in sets of two
characters.  The kgdb implementation was always sending 8 leading
zeros which could be omitted, and further optimized in the case of
non-negative thread numbers.  The negative numbers are used to
reference a specific cpu in the case of kgdb.

An example of the previous i386 stop packet looks like:
    T05thread:00000000000003bb;

New stop packet response:
    T05thread:03bb;

The previous ThreadInfo response looks like:
    m00000000fffffffe,0000000000000001,0000000000000002,0000000000000003,0000000000000004,0000000000000005,0000000000000006,0000000000000007,000000000000000c,0000000000000088,000000000000008a,000000000000008b,000000000000008c,000000000000008d,000000000000008e,00000000000000d4,00000000000000d5,00000000000000dd

New ThreadInfo response:
    mfffffffe,01,02,03,04,05,06,07,0c,88,8a,8b,8c,8d,8e,d4,d5,dd

A few bytes saved means better response time when using kgdb over a
serial line.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:19 -05:00
Andy Shevchenko a9fa20a7af kgdb: remove custom hex_to_bin()implementation
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:19 -05:00
Kevin Cernekee 034260d677 printk: fix delayed messages from CPU hotplug events
When a secondary CPU is being brought up, it is not uncommon for
printk() to be invoked when cpu_online(smp_processor_id()) == 0.  The
case that I witnessed personally was on MIPS:

http://lkml.org/lkml/2010/5/30/4

If (can_use_console() == 0), printk() will spool its output to log_buf
and it will be visible in "dmesg", but that output will NOT be echoed to
the console until somebody calls release_console_sem() from a CPU that
is online.  Therefore, the boot time messages from the new CPU can get
stuck in "limbo" for a long time, and might suddenly appear on the
screen when a completely unrelated event (e.g. "eth0: link is down")
occurs.

This patch modifies the console code so that any pending messages are
automatically flushed out to the console whenever a CPU hotplug
operation completes successfully or aborts.

The issue was seen on 2.6.34.

Original patch by Kevin Cernekee with cleanups by akpm and additional fixes
by Santosh Shilimkar.  This patch superseeds
https://patchwork.linux-mips.org/patch/1357/.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
To: <mingo@elte.hu>
To: <akpm@linux-foundation.org>
To: <simon.kagstrom@netinsight.net>
To: <David.Woodhouse@intel.com>
To: <lethal@linux-sh.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <linux-mips@linux-mips.org>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1534/
LKML-Reference: <ede63b5a20af951c755736f035d1e787772d7c28@localhost>
LKML-Reference: <EAF47CD23C76F840A9E7FCE10091EFAB02C5DB6D1F@dbde02.ent.ti.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:25:59 +01:00
Ingo Molnar 0bcfe75807 Merge branch 'sched/urgent' into sched/core
Conflicts:
	include/linux/sched.h

Merge reason: Add the leftover .35 urgent bits, fix the conflict.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-05 09:46:29 +02:00
Ingo Molnar fc9ea5a1e5 Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/core 2010-08-05 08:46:15 +02:00
Ingo Molnar 61be7fdec2 Merge branch 'perf/nmi' into perf/core
Conflicts:
	kernel/Makefile

Merge reason: Add the now complete topic, fix the conflict.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-05 08:45:05 +02:00
Rusty Russell 51f3d0f474 module: cleanup comments, remove noinline
On my (32-bit x86) machine, sys_init_module() uses 124 bytes of stack
once load_module() is inlined.

This effectively reverts ffb4ba76 which inlined it due to stack
pressure.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:13 +09:30
Rusty Russell 811d66a0e1 module: group post-relocation functions into post_relocation()
This simply hoists more code out of load_module; we also put the
identification of the extable and dynamic debug table in with the
others in find_module_sections().

We move the taint check to the actual add/remove of the dynamic debug
info: this is certain (find_module_sections is too early).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yehuda Sadeh <yehuda@hq.newdream.net>
2010-08-05 12:59:13 +09:30
Rusty Russell 6526c534b2 module: move module args strndup_user to just before use
Instead of copying and allocating the args and storing it in
load_info, we can just allocate them right before we need them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:12 +09:30
Rusty Russell 49668688dd module: pass load_info into other functions
Pass the struct load_info into all the other functions in module
loading.  This neatens things and makes them more consistent.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:10 +09:30
Rusty Russell 36b0360d17 module: fix sysfs cleanup for !CONFIG_SYSFS
Restore the stub module_remove_modinfo_attrs, remove the now-unused
!CONFIG_SYSFS module_sysfs_init.

Also, rename mod_kobject_remove() to mod_sysfs_teardown() as
it is the logical counterpart to mod_sysfs_setup now.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:10 +09:30
Rusty Russell 8f6d037815 module: sysfs cleanup
We change the sysfs functions to take struct load_info, and call
them all in mod_sysfs_setup().

We also clean up the #ifdefs a little.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:09 +09:30
Rusty Russell d913188c75 module: layout_and_allocate
layout_and_allocate() does everything up to and including the final
struct module placement inside the allocated module memory.  We have
to store the symbol layout information in our struct load_info though.

This avoids the nasty code we had before where 'mod' pointed first
to the version inside the temporary allocation containing the entire
file, then later was moved to point to the real struct module: now
the main code only ever sees the final module address.

(Includes fix for the Tony Luck-found Linus-diagnosed failure path
 error).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:09 +09:30
Rusty Russell 511ca6ae43 module: fix crash in get_ksymbol() when oopsing in module init
Andrew had the sole pleasure of tickling this bug in linux-next; when we set
up "info->strtab" it's pointing into the temporary copy of the module.  For
most uses that is fine, but kallsyms keeps a pointer around during module
load (inside mod->strtab).

If we oops for some reason inside a module's init function, kallsyms will use
the mod->strtab pointer into the now-freed temporary module copy.

(Later oopses work fine: after init we overwrite mod->strtab to point to a
 compacted core-only strtab).

Reported-by: Andrew "Grumpy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty "Buggy" Russell <rusty@rustcorp.com.au>
Tested-by: Andrew "Happy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:08 +09:30
Rusty Russell eded41c1c6 module: kallsyms functions take struct load_info
Simple refactor causes us to lift struct definition to top of file.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:08 +09:30
Rusty Russell d6df72a06e module: refactor out section header rewriting: FIX modversions
We can't do the find_sec after removing the SHF_ALLOC flags; it won't
find the sections.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:07 +09:30
Rusty Russell 8b5f61a795 module: refactor out section header rewriting
Put all the "rewrite and check section headers" in one place.  This
adds another iteration over the sections, but it's far clearer.  We
iterate once for every find_section() so we already iterate over many
times.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:06 +09:30
Linus Torvalds 3264d3f9dd module: add load_info
Btw, here's a patch that _looks_ large, but it really pretty trivial, and
sets things up so that it would be way easier to split off pieces of the
module loading.

The reason it looks large is that it creates a "module_info" structure
that contains all the module state that we're building up while loading,
instead of having individual variables for all the indices etc.

So the patch ends up being large, because every "symindex" access instead
becomes "info.index.sym" etc. That may be a few characters longer, but it
then means that we can just pass a pointer to that "info" structure
around. and let all the pieces fill it in very naturally.

As an example of that, the patch also moves the initialization of all
those convenience variables into a "setup_module_info()" function. And at
this point it really does become very natural to start to peel off some of
the error labels and move them into the helper functions - now the
"truncated" case is gone, and is handled inside that setup function
instead.

So maybe you don't like this approach, and it does make the variable
accesses a bit longer, but I don't think unreadably so. And the patch
really does look big and scary, but there really should be absolutely no
semantic changes - most of it was a trivial and mindless rename.

In fact, it was so mindless that I on purpose kept the existing helper
functions looking like this:

-       err = check_modinfo(mod, sechdrs, infoindex, versindex);
+       err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers);

rather than changing them to just take the "info" pointer. IOW, a second
phase (if you think the approach is ok) would change that calling
convention to just do

	err = check_modinfo(mod, &info);

(and same for "layout_sections()", "layout_symtabs()" etc.) Similarly,
while right now it makes things _look_ bigger, with things like this:

	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");

becoming

	info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions");

in the new "setup_module_info()" function, that's again just a result of
it being a search-and-replace patch. By using the 'info' pointer, we could
just change the 'find_sec()' interface so that it ends up being

	info->index.vers = find_sec(info, "__versions");

instead, and then we'd actually have a shorter and more readable line. So
for a lot of those mindless variable name expansions there's would be room
for separate cleanups.

I didn't move quite everything in there - if we do this to layout_symtabs,
for example, we'd want to move the percpu, symoffs, stroffs, *strmap
variables to be fields in that module_info structure too. But that's a
much smaller patch, I moved just the really core stuff that is currently
being set up and used in various parts.

But even in this rough form, it removes close to 70 lines from that
function (but adds 22 lines overall, of course - the structure definition,
the helper function declarations and call-sites etc etc).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:06 +09:30
Linus Torvalds 44032e6316 module: reduce stack usage for each_symbol()
And now that I'm looking at that call-chain (to see if it would make sense
to use some other more specific lock - doesn't look like it: all the
readers are using RCU and this is the only writer), I also give you this
trivial one-liner. It changes each_symbol() to not put that constant array
on the stack, resulting in changing

        movq    $C.388.31095, %rsi      #, tmp85
        subq    $376, %rsp      #,
        movq    %rdi, %rbx      # fn, fn
        leaq    -208(%rbp), %rdi        #, tmp84
        movq    %rbx, %rdx      # fn,
        rep movsl
        xorl    %esi, %esi      #
        leaq    -208(%rbp), %rdi        #, tmp87
        movq    %r12, %rcx      # data,
        call    each_symbol_in_section.clone.0  #

into

        xorl    %esi, %esi      #
        subq    $216, %rsp      #,
        movq    %rdi, %rbx      # fn, fn
        movq    $arr.31078, %rdi        #,
        call    each_symbol_in_section.clone.0  #

which is not so much about being obviously shorter and simpler because we
don't unnecessarily copy that constant array around onto the stack, but
also about having a much smaller stack footprint (376 vs 216 bytes - see
the update of 'rsp').

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:06 +09:30
Rusty Russell 22e268ebec module: refactor load_module part 5
1) Extract out the relocation loop into apply_relocations
2) Extract license and version checks into check_module_license_and_versions
3) Extract icache flushing into flush_module_icache
4) Move __obsparm warning into find_module_sections
5) Move license setting into check_modinfo.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:05 +09:30
Rusty Russell 9f85a4bbb1 module: refactor load_module part 4
Allocate references inside module_unload_init(), clean up inside
module_unload_free().

This version fixed to do allocation before __this_cpu_write, thanks to
bug reports from linux-next from Dave Young <hidave.darkstar@gmail.com>
and Stephen Rothwell <sfr@canb.auug.org.au>.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:05 +09:30
Rusty Russell 40dd2560ec module: refactor load_module part 3
Extract out the allocation and copying in from userspace, and the
first set of modinfo checks.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 12:59:04 +09:30