Commit Graph

157415 Commits

Author SHA1 Message Date
Masami Hiramatsu eca0d916f6 tracing/kprobes: Add argument name support
Add argument name assignment support and remove "alias" lines from format.
This allows user to assign unique name to each argument. For example,

$ echo p do_sys_open dfd=a0 filename=a1 flags=a2 mode=a3 > kprobe_events

This assigns dfd, filename, flags, and mode to 1st - 4th arguments
respectively. Trace buffer shows those names too.

	<...>-1439  [000] 1200885.933147: do_sys_open+0x0/0xdf: dfd=ffffff9c filename=bfa898ac flags=8000 mode=0

This helps users to know what each value means.

Users can filter each events by these names too. Note that you can not
filter by argN anymore.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235337.22412.77383.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 06:08:00 +02:00
Masami Hiramatsu e08d1c657f tracing/kprobes: Add event profiling support
Add *probe_profile_enable/disable to support kprobes raw events
sampling from perf counters, like other ftrace events, when
CONFIG_PROFILE_EVENT=y.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235329.22412.94731.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 05:33:03 +02:00
Masami Hiramatsu 4a846b443b tracing/kprobes: Cleanup kprobe tracer code.
Simplify trace_probe to remove a union, and remove some redundant
wrappers.
And also, cleanup create_trace_probe() function.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235322.22412.52525.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 05:31:21 +02:00
Masami Hiramatsu 2fba0c8867 tracing/kprobes: Fix probe offset to be unsigned
Prohibit user to specify negative offset from symbols.
Since kprobe.offset is unsigned int, the offset must be always positive
value.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235314.22412.64631.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 04:18:58 +02:00
Masami Hiramatsu ad5cafcdb0 x86/ptrace: Fix regs_get_argument_nth() to add correct offset
Fix regs_get_argument_nth() to add correct offset bytes. Because
offset_of() returns offset in byte, the offset should be added
to char * instead of unsigned long *.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235306.22412.31613.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 04:14:24 +02:00
Masami Hiramatsu a00e817f42 kprobes/x86-32: Move irq-exit functions to kprobes section
Move irq-exit functions to .kprobes.text section to protect against
kprobes recursion.

When I ran kprobe stress test on x86-32, I found below symbols
cause unrecoverable recursive probing:

	ret_from_exception
	ret_from_intr
	check_userspace
	restore_all
	restore_all_notrace
	restore_nocheck
	irq_return

And also, I found some interrupt/exception entry points that
cause similar problems.

This patch moves those symbols (including their container functions)
to .kprobes.text section to prevent any kprobes probing.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20090908164755.24050.81182.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 03:59:35 +02:00
Masami Hiramatsu f12b4f546b x86: Add MMX support for instruction decoder
Add MMX/SSE instructions to x86 opcode maps, since some of those
instructions are used in the kernel.

This also fixes failures in the x86 instruction decoder seftest.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20090908163246.23516.78835.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 01:12:34 +02:00
Frederic Weisbecker 8f8ffe2485 Merge commit 'tracing/core' into tracing/kprobes
Conflicts:
	kernel/trace/trace_export.c
	kernel/trace/trace_kprobe.c

Merge reason: This topic branch lacks an important
build fix in tracing/core:

	0dd7b74787eaf7858c6c573353a83c3e2766e674:
	tracing: Fix double CPP substitution in TRACE_EVENT_FN

that prevents from multiple tracepoint headers inclusion crashes.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11 01:09:23 +02:00
Ingo Molnar d28daf923a Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core 2009-09-06 06:27:40 +02:00
Ingo Molnar ed011b22ce Merge commit 'v2.6.31-rc9' into tracing/core
Merge reason: move from -rc5 to -rc9.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-06 06:11:42 +02:00
Linus Torvalds e07cccf404 Linux 2.6.31-rc9 2009-09-05 16:38:12 -07:00
Linus Torvalds f815c335d2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: sbp2: fix freeing of unallocated memory
  firewire: ohci: fix Ricoh R5C832, video reception
  firewire: ohci: fix Agere FW643 and multiple cameras
  firewire: core: fix crash in iso resource management
2009-09-05 14:59:00 -07:00
Roderick Colenbrander 74a01180db powerpc: Fix i8259 interrupt driver kernel crash on ML510
This patch fixes a null pointer exception caused by removal of
'ack()' for level interrupts in the Xilinx interrupt driver.  A recent
change to the xilinx interrupt controller removed the ack hook for
level irqs.

Signed-off-by: Roderick Colenbrander <thunderbird2k@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 14:58:07 -07:00
Linus Torvalds 5136a6c0fd Merge git://git.infradead.org/~dwmw2/mtd-2.6.31
* git://git.infradead.org/~dwmw2/mtd-2.6.31:
  JFFS2: add missing verify buffer allocation/deallocation
  mtd: nftl: fix offset alignments
  mtd: nftl: write support is broken
  mtd: m25p80: fix null pointer dereference bug
2009-09-05 14:57:04 -07:00
Linus Torvalds e505a8d5f9 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: Allow changing max_sectors_kb above the default 512
2009-09-05 14:56:13 -07:00
Linus Torvalds b71b7dc09a Merge branch 'fix/oxygen' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'fix/oxygen' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  sound: oxygen: handle cards with missing EEPROM
  sound: oxygen: fix MCLK rate for 192 kHz playback
2009-09-05 14:55:30 -07:00
Linus Torvalds 59430c2f43 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  tc: Fix unitialized kernel memory leak
  pkt_sched: Revert tasklet_hrtimer changes.
  net: sk_free() should be allowed right after sk_alloc()
  gianfar: gfar_remove needs to call unregister_netdev()
  ipw2200: firmware DMA loading rework
2009-09-05 14:52:41 -07:00
Linus Torvalds e9ee3a54a1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: skcipher - Fix skcipher_dequeue_givcrypt NULL test
2009-09-05 14:51:45 -07:00
Linus Torvalds 3bb314f01c Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Re-enable cpufreq suspend and resume code
2009-09-05 14:51:24 -07:00
Linus Torvalds 535e0c1726 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] fix csum_ipv6_magic()
  [IA64] Fix warning in dma-mapping.c
2009-09-05 14:50:53 -07:00
Linus Torvalds 0edfa2b1b5 Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: actually enable the swapext compat handler
2009-09-05 14:25:14 -07:00
Linus Torvalds 5a09adf130 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix preempt count underflow in nilfs_btnode_prepare_change_key
2009-09-05 14:24:33 -07:00
Linus Torvalds 931f70350e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: don't assume existence of cpu0
2009-09-05 14:22:00 -07:00
Linus Torvalds e305fc5ecd Merge branch 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU
2009-09-05 13:57:53 -07:00
Linus Torvalds 154f807e55 Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm snapshot: fix on disk chunk size validation
  dm exception store: split set_chunk_size
  dm snapshot: fix header corruption race on invalidation
  dm snapshot: refactor zero_disk_area to use chunk_io
  dm log: userspace add luid to distinguish between concurrent log instances
  dm raid1: do not allow log_failure variable to unset after being set
  dm log: remove incorrect field from userspace table output
  dm log: fix userspace status output
  dm stripe: expose correct io hints
  dm table: add more context to terse warning messages
  dm table: fix queue_limit checking device iterator
  dm snapshot: implement iterate devices
  dm multipath: fix oops when request based io fails when no paths
2009-09-05 13:51:07 -07:00
Linus Torvalds 9b6a3df372 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI SR-IOV: correct broken resource alignment calculations
2009-09-05 13:50:46 -07:00
Linus Torvalds d3acd16cda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Fix bootup with mcount in some configs.
  sparc64: Kill spurious NMI watchdog triggers by increasing limit to 30 seconds.
2009-09-05 13:49:06 -07:00
Linus Torvalds 93697a3cab Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter/powerpc: Fix cache event codes for POWER7
  perf_counter: Fix /0 bug in swcounters
  perf_counters: Increase paranoia level
2009-09-05 13:48:37 -07:00
Linus Torvalds 6399534472 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: atkbd - add Compaq Presario R4000-series repeat quirk
  Input: i8042 - add Acer Aspire 5536 to the nomux list
2009-09-05 13:41:29 -07:00
Nicolas Pitre 9de6886ec6 ext2: fix unbalanced kmap()/kunmap()
In ext2_rename(), dir_page is acquired through ext2_dotdot().  It is
then released through ext2_set_link() but only if old_dir != new_dir.
Failing that, the pkmap reference count is never decremented and the
page remains pinned forever.  Repeat that a couple times with highmem
pages and all pkmap slots get exhausted, and every further kmap() calls
end up stalling on the pkmap_map_wait queue at which point the whole
system comes to a halt.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 13:41:08 -07:00
Linus Torvalds ac7ac9f2b9 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
  ocfs2: ocfs2_write_begin_nolock() should handle len=0
  ocfs2: invalidate dentry if its dentry_lock isn't initialized.
2009-09-05 13:38:37 -07:00
Linus Torvalds ac89a9174d pty: don't limit the writes to 'pty_space()' inside 'pty_write()'
The whole write-room thing is something that is up to the _caller_ to
worry about, not the pty layer itself.  The total buffer space will
still be limited by the buffering routines themselves, so there is no
advantage or need in having pty_write() artificially limit the size
somehow.

And what happened was that the caller (the n_tty line discipline, in
this case) may have verified that there is room for 2 bytes to be
written (for NL -> CRNL expansion), and it used to then do those writes
as two single-byte writes.  And if the first byte written (CR) then
caused a new tty buffer to be allocated, pty_space() may have returned
zero when trying to write the second byte (LF), and then incorrectly
failed the write - leading to a lost newline character.

This should finally fix

	http://bugzilla.kernel.org/show_bug.cgi?id=14015

Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 13:27:10 -07:00
Linus Torvalds 37f81fa1f6 n_tty: do O_ONLCR translation as a single write
When translating CR to CRNL in the n_tty line discipline, we did it as
two tty_put_char() calls.  Which works, but is stupid, and has caused
problems before too with bad interactions with the write_room() logic.
The generic USB serial driver had that problem, for example.

Now the pty layer had similar issues after being moved to the generic
tty buffering code (in commit d945cb9cce20ac7143c2de8d88b187f62db99bdc:
"pty: Rework the pty layer to use the normal buffering logic").

So stop doing the silly separate two writes, and do it as a single write
instead.  That's what the n_tty layer already does for the space
expansion of tabs (XTABS), and it means that we'll now always have just
a single write for the CRNL to match the single 'tty_write_room()' test,
which hopefully means that the next time somebody screws up buffering,
it won't cause weeks of debugging.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 12:46:07 -07:00
Oleg Nesterov a2a8474c3f exec: do not sleep in TASK_TRACED under ->cred_guard_mutex
Tom Horsley reports that his debugger hangs when it tries to read
/proc/pid_of_tracee/maps, this happens since

	"mm_for_maps: take ->cred_guard_mutex to fix the race with exec"
	04b836cbf19e885f8366bccb2e4b0474346c02d

commit in 2.6.31.

But the root of the problem lies in the fact that do_execve() path calls
tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC.

The tracee must not sleep in TASK_TRACED holding this mutex.  Even if we
remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(),
another task doing PTRACE_ATTACH should not hang until it is killed or the
tracee resumes.

With this patch do_execve() does not use ->cred_guard_mutex directly and
we do not hold it throughout, instead:

	- introduce prepare_bprm_creds() helper, it locks the mutex
	  and calls prepare_exec_creds() to initialize bprm->cred.

	- install_exec_creds() drops the mutex after commit_creds(),
	  and thus before tracehook_report_exec()->ptrace_stop().

	  or, if exec fails,

	  free_bprm() drops this mutex when bprm->cred != NULL which
	  indicates install_exec_creds() was not called.

Reported-by: Tom Horsley <tom.horsley@att.net>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
Mel Gorman dd5d241ea9 page-allocator: always change pageblock ownership when anti-fragmentation is disabled
On low-memory systems, anti-fragmentation gets disabled as fragmentation
cannot be avoided on a sufficiently large boundary to be worthwhile.  Once
disabled, there is a period of time when all the pageblocks are marked
MOVABLE and the expectation is that they get marked UNMOVABLE at each call
to __rmqueue_fallback().

However, when MAX_ORDER is large the pageblocks do not change ownership
because the normal criteria are not met.  This has the effect of
prematurely breaking up too many large contiguous blocks.  This is most
serious on NOMMU systems which depend on high-order allocations to boot.
This patch causes pageblocks to change ownership on every fallback when
anti-fragmentation is disabled.  This prevents the large blocks being
prematurely broken up.

This is a fix to commit 49255c619f [page
allocator: move check for disabled anti-fragmentation out of fastpath] and
the problem affects 2.6.31-rc8.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
David Howells a190887b58 nommu: fix error handling in do_mmap_pgoff()
Fix the error handling in do_mmap_pgoff().  If do_mmap_shared_file() or
do_mmap_private() fail, we jump to the error_put_region label at which
point we cann __put_nommu_region() on the region - but we haven't yet
added the region to the tree, and so __put_nommu_region() may BUG
because the region tree is empty or it may corrupt the region tree.

To get around this, we can afford to add the region to the region tree
before calling do_mmap_shared_file() or do_mmap_private() as we keep
nommu_region_sem write-locked, so no-one can race with us by seeing a
transient region.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
Oleg Nesterov 4e49627b9b workqueues: introduce __cancel_delayed_work()
cancel_delayed_work() has to use del_timer_sync() to guarantee the timer
function is not running after return.  But most users doesn't actually
need this, and del_timer_sync() has problems: it is not useable from
interrupt, and it depends on every lock which could be taken from irq.

Introduce __cancel_delayed_work() which calls del_timer() instead.

The immediate reason for this patch is
http://bugzilla.kernel.org/show_bug.cgi?id=13757
but hopefully this helper makes sense anyway.

As for 13757 bug, actually we need requeue_delayed_work(), but its
semantics are not yet clear.

Merge this patch early to resolves cross-tree interdependencies between
input and infiniband.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
Stefan Richter baed6b82d9 firewire: sbp2: fix freeing of unallocated memory
If a target writes invalid status (typically status of a command that
already timed out), firewire-sbp2 attempts to put away an ORB that
doesn't exist.  https://bugzilla.redhat.com/show_bug.cgi?id=519772

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-09-05 15:59:34 +02:00
Stefan Richter 4fe0badd58 firewire: ohci: fix Ricoh R5C832, video reception
In dual-buffer DMA mode, no video frames are ever received from R5C832
by libdc1394.  Fallback to packet-per-buffer DMA works reliably.
http://thread.gmane.org/gmane.linux.kernel.firewire.devel/13393/focus=13476

Reported-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-09-05 15:59:34 +02:00
Stefan Richter fc383796a8 firewire: ohci: fix Agere FW643 and multiple cameras
An Agere FW643 OHCI 1.1 card works fine for video reception from one
camera but fails early if receiving from two cameras.  After a short
while, no IR IRQ events occur and the context control register does not
react anymore.  This happens regardless whether both IR DMA contexts are
dual-buffer or one is dual-buffer and the other packet-per-buffer.

This can be worked around by disabling dual buffer DMA mode entirely.
http://sourceforge.net/mailarchive/message.php?msg_name=4A7C0594.2020208%40gmail.com
(Reported by Samuel Audet.)

In another report (by Jonathan Cameron), an FW643 works OK with two
cameras in dual buffer mode.  Whether this is due to different chip
revisions or different usage patterns (different video formats) is not
yet clear.  However, as far as the current capabilities of
firewire-core's isochronous I/O interface are concerned, simply
switching off dual-buffer on non-working and working FW643s alike is not
a problem in practice.  We only need to revisit this issue if we are
going to enhance the interface, e.g. so that applications can explicitly
choose modes.

Reported-by: Samuel Audet <samuel.audet@gmail.com>
Reported-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-09-05 15:59:34 +02:00
Stefan Richter 1821bc19d5 firewire: core: fix crash in iso resource management
This fixes a regression due to post 2.6.30 commit "firewire: core: do
not DMA-map stack addresses" 6fdc037094.

As David Moore noted, a previously correct sizeof() expression became
wrong since the commit changed its argument from an array to a pointer.
This resulted in an oops in ohci_cancel_packet in the shared workqueue
thread's context when an isochronous resource was to be freed.

Reported-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-09-05 15:59:34 +02:00
Steven Rostedt 85bac32c4a ring-buffer: only enable ring_buffer_swap_cpu when needed
Since the ability to swap the cpu buffers adds a small overhead to
the recording of a trace, we only want to add it when needed.

Only the irqsoff and preemptoff tracers use this feature, and both are
not recommended for production kernels. This patch disables its use
when neither irqsoff nor preemptoff is configured.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 19:42:22 -04:00
Steven Rostedt 62f0b3eb5c ring-buffer: check for swapped buffers in start of committing
Because the irqsoff tracer can swap an internal CPU buffer, it is possible
that a swap happens between the start of the write and before the committing
bit is set (the committing bit will disable swapping).

This patch adds a check for this and will fail the write if it detects it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 19:38:42 -04:00
Steven Rostedt e8165dbb03 tracing: report error in trace if we fail to swap latency buffer
The irqsoff tracer will fail to swap the cpu buffer with the max
buffer if it preempts a commit. Instead of ignoring this, this patch
makes the tracer report it if the last max latency failed due to preempting
a current commit.

The output of the latency tracer will look like this:

 # tracer: irqsoff
 #
 # irqsoff latency trace v1.1.5 on 2.6.31-rc5
 # --------------------------------------------------------------------
 # latency: 112 us, #1/1, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
 #    -----------------
 #    | task: -4281 (uid:0 nice:0 policy:0 rt_prio:0)
 #    -----------------
 #  => started at: save_args
 #  => ended at:   __do_softirq
 #
 #
 #                  _------=> CPU#
 #                 / _-----=> irqs-off
 #                | / _----=> need-resched
 #                || / _---=> hardirq/softirq
 #                ||| / _--=> preempt-depth
 #                |||| /
 #                |||||     delay
 #  cmd     pid   ||||| time  |   caller
 #     \   /      |||||   \   |   /
    bash-4281    1d.s6  265us : update_max_tr_single: Failed to swap buffers due to commit in progress

Note the latency time and the functions that disabled the irqs or preemption
will still be listed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 19:22:41 -04:00
Steven Rostedt 659372d3e4 tracing: add trace_array_printk for internal tracers to use
This patch adds a trace_array_printk to allow a tracer to use the
trace_printk on its own trace array.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 19:13:53 -04:00
Steven Rostedt e77405ad80 tracing: pass around ring buffer instead of tracer
The latency tracers (irqsoff and wakeup) can swap trace buffers
on the fly. If an event is happening and has reserved data on one of
the buffers, and the latency tracer swaps the global buffer with the
max buffer, the result is that the event may commit the data to the
wrong buffer.

This patch changes the API to the trace recording to be recieve the
buffer that was used to reserve a commit. Then this buffer can be passed
in to the commit.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 18:59:39 -04:00
Steven Rostedt f633903af2 tracing: make tracing_reset safe for external use
Reseting the trace buffer without first disabling the buffer and
waiting for any writers to complete, can corrupt the ring buffer.

This patch makes the external version of tracing_reset safe from
corruption by disabling the ring buffer and calling synchronize_sched.

This version can no longer be called from interrupt context. But all those
callers have been removed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 18:46:51 -04:00
Steven Rostedt 2f26ebd549 tracing: use timestamp to determine start of latency traces
Currently the latency tracers reset the ring buffer. Unfortunately
if a commit is in process (due to a trace event), this can corrupt
the ring buffer. When this happens, the ring buffer will detect
the corruption and then permanently disable the ring buffer.

The bug does not crash the system, but it does prevent further tracing
after the bug is hit.

Instead of reseting the trace buffers, the timestamp of the start of
the trace is used instead. The buffers will still contain the previous
data, but the output will not count any data that is before the
timestamp of the trace.

Note, this only affects the static trace output (trace) and not the
runtime trace output (trace_pipe). The runtime trace output does not
make sense for the latency tracers anyway.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 18:44:22 -04:00
Albin Tonnerre 4a88d44ab1 tracing: Remove mentioning of legacy latency_trace file from documentation
The latency_trace file got removed a while back by commit
886b5b73d7 and has been replaced
by the latency-format option.

This patch fixes the documentation by reflecting this change.

Changes since v1:
 - mention that the trace format is configurable through the
   latency-format option
 - Fix a couple mistakes related to the timestamps

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090831204007.GE4237@pc-ras4041.res.insa>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-04 23:30:38 +02:00
Sunil Mushran 8379e7c46c ocfs2: ocfs2_write_begin_nolock() should handle len=0
Bug introduced by mainline commit e7432675f8
The bug causes ocfs2_write_begin_nolock() to oops when len=0.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-09-04 14:28:31 -07:00