Commit graph

61644 commits

Author SHA1 Message Date
Johannes Berg
3b5ad0797c stacktrace: fix header file for !CONFIG_STACKTRACE
The print_stack_trace macro in stacktrace.h has a wrong number of
arguments, fix it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Johannes Berg
c71063c9c9 lockdep debugging: give stacktrace for init_error
When I started adding support for lockdep to 64-bit powerpc, I got a
lockdep_init_error and with this patch was able to pinpoint why and where
to put lockdep_init().  Let's support this generally for others adding
lockdep support to their architecture.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
d38e1d5aae lockstat: better class name representation
optionally add class->name_version and class->subclass to the class name

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
96645678cd lockstat: measure lock bouncing
__acquire
        |
       lock _____
        |        \
        |    __contended
        |         |
        |        wait
        | _______/
        |/
        |
   __acquired
        |
   __release
        |
     unlock

We measure acquisition and contention bouncing.

This is done by recording a cpu stamp in each lock instance.

Contention bouncing requires the cpu stamp to be set on acquisition. Hence we
move __acquired into the generic path.

__acquired is then used to measure acquisition bouncing by comparing the
current cpu with the old stamp before replacing it.

__contended is used to measure contention bouncing (only useful for preemptable
locks)

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
443aef0edd lockdep: fixup sk_callback_lock annotation
the two init sites resulted in inconsistend names for the lock class.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
4b32d0a4e9 lockdep: various fixes
- update the copyright notices
 - use the default hash function
 - fix a thinko in a BUILD_BUG_ON
 - add a WARN_ON to spot inconsitent naming
 - fix a termination issue in /proc/lock_stat

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
4fe87745a6 lockstat: hook into spinlock_t, rwlock_t, rwsem and mutex
Call the new lockstat tracking functions from the various lock primitives.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
c46261de0d lockstat: human readability tweaks
Present all this fancy new lock statistics information:

*warning, _wide_ output ahead*

(output edited for purpose of brevity)

 # cat /proc/lock_stat
lock_stat version 0.1
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
                              class name    contentions   waittime-min   waittime-max waittime-total   acquisitions   holdtime-min   holdtime-max holdtime-total
-----------------------------------------------------------------------------------------------------------------------------------------------------------------

                         &inode->i_mutex:         14458           6.57      398832.75     2469412.23        6768876           0.34    11398383.65   339410830.89
                         ---------------
                         &inode->i_mutex           4486          [<ffffffff802a08f9>] pipe_wait+0x86/0x8d
                         &inode->i_mutex              0          [<ffffffff802a01e8>] pipe_write_fasync+0x29/0x5d
                         &inode->i_mutex              0          [<ffffffff802a0e18>] pipe_read+0x74/0x3a5
                         &inode->i_mutex              0          [<ffffffff802a1a6a>] do_lookup+0x81/0x1ae

.................................................................................................................................................................

              &inode->i_data.tree_lock-W:           491           0.27          62.47         493.89        2477833           0.39         468.89     1146584.25
              &inode->i_data.tree_lock-R:            65           0.44           4.27          48.78       26288792           0.36         184.62    10197458.24
              --------------------------
                &inode->i_data.tree_lock             46          [<ffffffff80277095>] __do_page_cache_readahead+0x69/0x24f
                &inode->i_data.tree_lock             31          [<ffffffff8026f9fb>] add_to_page_cache+0x31/0xba
                &inode->i_data.tree_lock              0          [<ffffffff802770ee>] __do_page_cache_readahead+0xc2/0x24f
                &inode->i_data.tree_lock              0          [<ffffffff8026f6e4>] find_get_page+0x1a/0x58

.................................................................................................................................................................

                      proc_inum_idr.lock:             0           0.00           0.00           0.00             36           0.00          65.60         148.26
                        proc_subdir_lock:             0           0.00           0.00           0.00        3049859           0.00         106.81     1563212.42
                        shrinker_rwsem-W:             0           0.00           0.00           0.00              5           0.00           1.73           3.68
                        shrinker_rwsem-R:             0           0.00           0.00           0.00            633           2.57         246.57       10909.76

'contentions' and 'acquisitions' are the number of such events measured (since
the last reset). The waittime- and holdtime- (min, max, total) numbers are
presented in microseconds.

If there are any contention points, the lock class is presented in the block
format (as i_mutex and tree_lock above), otherwise a single line of output is
presented.

The output is sorted on absolute number of contentions (read + write), this
should get the worst offenders presented first, so that:

 # grep : /proc/lock_stat | head

will quickly show who's bad.

The stats can be reset using:

 # echo 0 > /proc/lock_stat

[bunk@stusta.de: make 2 functions static]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
f20786ff4d lockstat: core infrastructure
Introduce the core lock statistics code.

Lock statistics provides lock wait-time and hold-time (as well as the count
of corresponding contention and acquisitions events). Also, the first few
call-sites that encounter contention are tracked.

Lock wait-time is the time spent waiting on the lock. This provides insight
into the locking scheme, that is, a heavily contended lock is indicative of
a too coarse locking scheme.

Lock hold-time is the duration the lock was held, this provides a reference for
the wait-time numbers, so they can be put into perspective.

  1)
    lock
  2)
    ... do stuff ..
    unlock
  3)

The time between 1 and 2 is the wait-time. The time between 2 and 3 is the
hold-time.

The lockdep held-lock tracking code is reused, because it already collects locks
into meaningful groups (classes), and because it is an existing infrastructure
for lock instrumentation.

Currently lockdep tracks lock acquisition with two hooks:

  lock()
    lock_acquire()
    _lock()

 ... code protected by lock ...

  unlock()
    lock_release()
    _unlock()

We need to extend this with two more hooks, in order to measure contention.

  lock_contended() - used to measure contention events
  lock_acquired()  - completion of the contention

These are then placed the following way:

  lock()
    lock_acquire()
    if (!_try_lock())
      lock_contended()
      _lock()
      lock_acquired()

 ... do locked stuff ...

  unlock()
    lock_release()
    _unlock()

(Note: the try_lock() 'trick' is used to avoid instrumenting all platform
       dependent lock primitive implementations.)

It is also possible to toggle the two lockdep features at runtime using:

  /proc/sys/kernel/prove_locking
  /proc/sys/kernel/lock_stat

(esp. turning off the O(n^2) prove_locking functionaliy can help)

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: nuke unneeded ifdefs]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
8e18257d29 lockdep: reduce the ifdeffery
Move code around to get fewer but larger #ifdef sections.  Break some
in-function #ifdefs out into their own functions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
ca58abcb4a lockdep: sanitise CONFIG_PROVE_LOCKING
Ensure that all of the lock dependency tracking code is under
CONFIG_PROVE_LOCKING.  This allows us to use the held lock tracking code for
other purposes.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Peter Zijlstra
21f8ca3bf6 fix raw_spinlock_t vs lockdep
Use the lockdep infrastructure to track lock contention and other lock
statistics.

It tracks lock contention events, and the first four unique call-sites that
encountered contention.

It also measures lock wait-time and hold-time in nanoseconds. The minimum and
maximum times are tracked, as well as a total (which together with the number
of event can give the avg).

All statistics are done per lock class, per write (exclusive state) and per read
(shared state).

The statistics are collected per-cpu, so that the collection overhead is
minimized via having no global cachemisses.

This new lock statistics feature is independent of the lock dependency checking
traditionally done by lockdep; it just shares the lock tracking code. It is
also possible to enable both and runtime disabled either component - thereby
avoiding the O(n^2) lock chain walks for instance.

This patch:

raw_spinlock_t should not use lockdep (and doesn't) since lockdep itself
relies on it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Jan Harkes
5b7f13bd26 coda: update module information
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Jan Harkes
3cf01f28c3 coda: remove statistics counters from /proc/fs/coda
Similar information can easily be obtained with strace -c.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
a1b0aa8764 coda: remove struct coda_sb_info
The sb_info structure only contains a single pointer to the character device,
there is no need for the added indirection.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
5fd31e9a67 coda: cleanup downcall handler
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
ed36f72367 coda: cleanup coda_lookup, use dsplice_alias
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
970648eb03 coda: ignore returned values when upcalls return errors
Venus returns an ENOENT error on open, so we shouldn't try to grab the
filehandle for the returned fd.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
37461e1957 coda: replace upc_alloc/upc_free with kmalloc/kfree
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
978752534e coda: avoid lockdep warning in coda_readdir
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
d9664c95af coda: block signals during upcall processing
We ignore signals for about 30 seconds to give userspace a chance to see the
upcall.  As we did not block signals we ended up in a busy loop for the
remainder of the period when a signal is received.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
fe71b5f387 coda: cleanup for upcall handling path
Make the code that processes upcall responses more straightforward, uncovered
at least one bad assumption.  We trusted that vc_inuse would be 0 when upcalls
are aborted, however the device may have been reopened.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
8706551963 coda: cleanup /dev/cfs open and close handling
- Make sure device index is not a negative number.
- Unlink queued requests when the device is closed to avoid passing them
  to the next opener.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
ed31a7dd63 coda: use ilookup5
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
fac1f0e340 coda: coda doesn't track atime
Set MS_NOATIME flag to avoid unnecessary calls when the coda inode is
accessed.

Also, set statfs.f_bsize to 4k.  1k is obviously too small for the suggested
IO size.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
8c6d215284 coda: allow removal of busy directories
A directory without children may still be busy when it is the cwd for some
process.  We can safely remove such a directory because the VFS prevents
further operations.  Also we don't need to call d_delete as it is already
called in vfs_rmdir.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
d728900cd5 coda: fix nlink updates for directories
The Coda client sets the directory link count to 1 when it isn't sure how many
subdirectories we have.  In this case we shouldn't change the link count in
the kernel when a subdirectory is created or removed.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
56ee354794 coda: correctly invalidate cached access rights
Change the epoch value to forces a refresh instead of clearing the cached
rights mask and block all further accesses to the object.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Jan Harkes
38c2e4370d coda: do not grab an uninitialized fd when the open upcall returns an error
When open fails the fd in the response is uninitialized and we ended up taking
a reference on the file struct and never released it.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Roland McGrath
18991197b4 Use --build-id ld option
This change passes the --build-id when linking the kernel and when linking
modules, if ld supports it.  This is a new GNU ld option that synthesizes an
ELF note section inside the read-only data.  The note in this section contains
unique identifying bits called the "build ID", which are generated so as to be
different for any two linked ELF files that aren't identical.  The build ID
can be recovered from stripped files, memory dumps, etc.  and used to look up
the original program built, locate debuginfo or other details or history
associated with it.  For normal program linking, the compiler passes
--build-id to ld by default, but the option is needed when using ld directly
as we do.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:48 -07:00
Roland McGrath
da1a679cde Add /sys/kernel/notes
This patch adds the /sys/kernel/notes magic file.  Reading this delivers the
contents of the kernel's .notes section.  This lets userland easily glean any
detailed information about the running kernel's build that was stored there at
compile time.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Roland McGrath
86ead9caf9 s390: Put allocated ELF notes in read-only data segment
This changes the s390 linker script to use the asm-generic NOTES macro so that
ELF note sections with SHF_ALLOC set are linked into the kernel image along
with other read-only data.  The PT_NOTE also points to their location.

This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Roland McGrath
8fb775ee58 powerpc: Put allocated ELF notes in read-only data segment
This changes the powerpc linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data.  The PT_NOTE also points to their location.

This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Roland McGrath
caf45dd926 alpha: Put allocated ELF notes in read-only data segment
This changes the alpha linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data.  The PT_NOTE also points to their location.

This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Roland McGrath
2e1d5b8f24 x86_64: Put allocated ELF notes in read-only data segment
This changes the x86_64 linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data.  The PT_NOTE also points to their location.

This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Roland McGrath
cbe87121f1 i386: Put allocated ELF notes in read-only data segment
This changes the i386 linker script and the asm-generic macro it uses so that
ELF note sections with SHF_ALLOC set are linked into the kernel image along
with other read-only data.  The PT_NOTE also points to their location.

This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Mingming Cao
b38bd33a6b fix ext4/JBD2 build warnings
Looking at the current linus-git tree jbd_debug() define in
include/linux/jbd2.h

extern u8 journal_enable_debug;

#define jbd_debug(n, f, a...)                                           \
        do {                                                            \
                if ((n) <= journal_enable_debug) {                      \
                        printk (KERN_DEBUG "(%s, %d): %s: ",            \
                                __FILE__, __LINE__, __FUNCTION__);      \
                        printk (f, ## a);                               \
                }                                                       \
        } while (0)
> fs/ext4/inode.c: In function ‘ext4_write_inode’:
> fs/ext4/inode.c:2906: warning: comparison is always true due to limited
> range of data type
>
> fs/jbd2/recovery.c: In function ‘jbd2_journal_recover’:
> fs/jbd2/recovery.c:254: warning: comparison is always true due to
> limited range of data type
> fs/jbd2/recovery.c:257: warning: comparison is always true due to
> limited range of data type
>
> fs/jbd2/recovery.c: In function ‘jbd2_journal_skip_recovery’:
> fs/jbd2/recovery.c:301: warning: comparison is always true due to
> limited range of data type
>
Noticed all warnings are occurs when the debug level is 0. Then found
the "jbd2: Move jbd2-debug file to debugfs" patch
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0f49d5d019afa4e94253bfc92f0daca3badb990b

changed the jbd2_journal_enable_debug from int type to u8, makes the
jbd_debug comparision is always true when the debugging level is 0. Thus
the compile warning occurs.

Thought about changing the jbd2_journal_enable_debug data type back to
int, but can't, because the jbd2-debug is moved to debug fs, where
calling debugfs_create_u8() to create the debugfs entry needs the value
to be u8 type.

Even if we changed the data type back to int, the code is still buggy,
kernel should not print jbd2 debug message if the
jbd2_journal_enable_debug is set to 0. But this is not the case.

The fix is change the level of debugging to 1. The same should fixed in
ext3/JBD, but currently ext3 jbd-debug via /proc fs is broken, so we
probably should fix it all together.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Theodore Tso <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Andy Whitcroft
f0a594c1c7 update checkpatch.pl to version 0.08
This version brings a number of new checks, and a number of bug
fixes.  Of note:

  - warnings for multiple assignments per line
  - warnings for multiple declarations per line
  - checks for single statement blocks with braces

This patch includes an update for feature-removal-schedule.txt to
better target checks.

Andy Whitcroft (12):
      Version: 0.08
      only apply printk checks where there is a string literal
      allow suppression of errors for when no patch is found
      warn about multiple assignments
      warn on declaration of multiple variables
      check for kfree() with needless null check
      check for single statement braced blocks
      check for aggregate initialisation on the next line
      handle the => operator
      check for spaces between function name and open parenthesis
      move to explicit Check: entries in feature-removal-schedule.txt
      handle pointer attributes

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Rolf Eike Beer
4b8a8b812e Typo: fro -> from
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Ingo Molnar
aa781aeb49 add POSIX clocks and timers maintainer
Update the MAINTAINERS file: Thomas Gleixner has been the de-facto
maintainer of POSIX timers and clocks for quite some time.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Adrian Bunk
01c55ed326 kernel/relay.c: make functions static
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
bb90110dcb coredump masking: documentation for /proc/pid/coredump_filter
This patch adds the documentation for /proc/<pid>/coredump_filter.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
ee78b0a61f coredump masking: ELF-FDPIC: enable core dump filtering
This patch enables core dump filtering for ELF-FDPIC-formatted core file.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
e2e00906a0 coredump masking: ELF-FDPIC: remove an unused argument
This patch removes an unused argument from elf_fdpic_dump_segments().

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
a1b59e802f coredump masking: ELF: enable core dump filtering
This patch enables core dump filtering for ELF-formatted core file.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
3cb4a0bb1e coredump masking: add an interface for core dump filter
This patch adds an interface to set/reset flags which determines each memory
segment should be dumped or not when a core file is generated.

/proc/<pid>/coredump_filter file is provided to access the flags.  You can
change the flag status for a particular process by writing to or reading from
the file.

The flag status is inherited to the child process when it is created.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:47 -07:00
Kawai, Hidehiro
6c5d523826 coredump masking: reimplementation of dumpable using two flags
This patch changes mm_struct.dumpable to a pair of bit flags.

set_dumpable() converts three-value dumpable to two flags and stores it into
lower two bits of mm_struct.flags instead of mm_struct.dumpable.
get_dumpable() behaves in the opposite way.

[akpm@linux-foundation.org: export set_dumpable]
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:46 -07:00
Kawai, Hidehiro
76fdbb25f9 coredump masking: bound suid_dumpable sysctl
This patch series is version 5 of the core dump masking feature, which
controls which VMAs should be dumped based on their memory types and
per-process flags.

I adopted most of Andrew's suggestion at the previous version.  He also
suggested using system call instead of /proc/<pid>/ interface, I decided to
use the latter continuously because adding new system call with pid argument
will give a big impact on the kernel.

You can access the per-process flags via /proc/<pid>/coredump_filter
interface.  coredump_filter represents a bitmask of memory types, and if a bit
is set, VMAs of corresponding memory type are written into a core file when
the process is dumped.  The bitmask is inherited from the parent process when
a process is created.

The original purpose is to avoid longtime system slowdown when a number of
processes which share a huge shared memory are dumped at the same time.  To
achieve this purpose, this patch series adds an ability to suppress dumping
anonymous shared memory for specified processes.  In this version, three other
memory types are also supported.

Here are the coredump_filter bits:
  bit 0: anonymous private memory
  bit 1: anonymous shared memory
  bit 2: file-backed private memory
  bit 3: file-backed shared memory

The default value of coredump_filter is 0x3.  This means the new core dump
routine has the same behavior as conventional behavior by default.

In this version, coredump_filter bits and mm.dumpable are merged into
mm.flags, and it is accessed by atomic bitops.

The supported core file formats are ELF and ELF-FDPIC.  ELF has been tested,
but ELF-FDPIC has not been built and tested because I don't have the test
environment.

This patch limits a value of suid_dumpable sysctl to the range of 0 to 2.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:46 -07:00
Randy Dunlap
86fd6dfc09 docbook: don't reference file without kernel-doc
Remove include/linux/rmap.h from kernel-api.tmpl since it no longer
contains kernel-doc.  Fixes this warning:

Warning(linux-2.6.22//include/linux/rmap.h): no structured comments found

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:45 -07:00
Randy Dunlap
cdccb316c0 kernel-doc: fix leading dot in man-mode output
If a parameter description begins with a '.', this indicates a "request"
for "man" mode output (*roff), so it needs special handling.

Problem case is in include/asm-i386/atomic.h for function
atomic_add_unless():
 * @u: ...unless v is equal to u.
This parameter description is currently not printed in man mode output.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:45 -07:00