Add a helper function __ftrace_set_clr_event(), and replace some
ftrace_set_clr_event() calls with this helper, thus we don't need any
kstrdup() or kmalloc().
As a side effect, this patch fixes an issue in self tests code, which is
similar to the one fixed in commit d6bf81ef0f
("tracing: append ":*" to internal setting of system events")
It's a small issue and won't cause any bug in fact, but we should do things
right anyway.
[ Impact: prevent spurious event-enabling in tracing self-tests ]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A03998E.3020503@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch removes module_param oprofile.force_arch_perfmon and
introduces oprofile.cpu_type=archperfmon instead. This new parameter
can be reused for other models and architectures.
Currently only archperfmon is supported.
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
The registers are about the same as other Family 6 CPUs
so we only need to add detection.
I'm not completely happy with calling Nehalem Core i7 because
there will be undoubtedly other Nehalem based CPUs
in the future with different marketing names, but it's
the best we got for now.
Requires updated oprofile userland for the new event files.
If you don't want to update right now you can also use
oprofile.force_arch_perfmon=1 (added in the next patch) with 0.9.4
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
There are no new P4s and the oprofile code knows about all existing
ones, so we don't really need the p4force option anymore.
Remove it.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This re-adds the force_arch_perfmon option that was in the original
arch perfmon patchkit. Originally this was rejected in favour
of a generalized perfmon=name option, but it turned out implementing
the later in a reliable way is hard (and it would have been easy
to crash the kernel if a user gets it wrong)
But now Atom and Core i7 support being readded a user would
need to update their oprofile userland to beyond 0.9.4 to use oprofile again
on Atom or Core i7.
To avoid this problem readd the force_arch_perfmon option.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Lockdep reports the warning below when Li tries to offline one cpu:
[ 110.835487] =================================
[ 110.835616] [ INFO: inconsistent lock state ]
[ 110.835688] 2.6.30-rc4-00336-g8c9ed89 #52
[ 110.835757] ---------------------------------
[ 110.835828] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
[ 110.835908] swapper/0 [HC1[1]:SC0[0]:HE0:SE1] takes:
[ 110.835982] (cmci_discover_lock){?.+...}, at: [<ffffffff80236dc0>] cmci_clear+0x30/0x9b
cmci_clear() can be called via smp_call_function_single().
It is better to disable interrupt while holding cmci_discover_lock,
to turn it into an irq-safe lock - we can deadlock otherwise.
[ Impact: fix possible deadlock in the MCE code ]
Reported-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A03ED38.8000700@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Shaohua Li<shaohua.li@intel.com>
Use reserve_early rather than e820 reservations for Xen start info and mfn->pfn
table, so that the memory use is a bit more self-documenting.
[ Impact: cleanup ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EF1.6070708@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/frv/include/asm/pgtable.h
arch/x86/include/asm/required-features.h
arch/x86/xen/mmu.c
Merge reason: x86/xen was on a .29 base still, move it to a fresher
branch and pick up Xen fixes as well, plus resolve
conflicts
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The Xen pagetables are no longer implicitly reserved as part of the other
i386_start_kernel reservations, so make sure we explicitly reserve them.
This prevents them from being released into the general kernel free page
pool and reused.
[ Impact: fix Xen guest crash ]
Also-Bisected-by: Bryan Donlan <bdonlan@gmail.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EEC.30509@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
BIOS on Mac Mini Core2 Duo sets both INPUT and OUTPUT pinctl bits to
the line-in jack, and it confuses the driver as if it's a valid input.
This patch adds the check of OUTPUT bit so that the driver fixes the
invalid pin setup.
Tested-by: Tino Keitel <tino.keitel@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tim Starling reported that crashdump will panic with kernel compiled
with CONFIG_KEXEC_JUMP due to null pointer deference in
machine_kexec_32.c: machine_kexec(), when deferencing
kexec_image. Refering to:
http://bugzilla.kernel.org/show_bug.cgi?id=13265
This patch fixes the BUG via replacing global variable reference:
kexec_image in machine_kexec() with local variable reference: image,
which is more appropriate, and will not be null.
Same BUG is in machine_kexec_64.c too, so fixed too in the same way.
[ Impact: fix crash on kexec ]
Reported-by: Tim Starling <tstarling@wikimedia.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1241751101.6259.85.camel@yhuang-dev.sh.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.
[ Impact: avoids undesirable TLB aliases ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
If the first non-reserved (sub-)range doesn't fit the size requested,
an endless loop will be entered. If a range returned from
find_e820_area_size() turns out insufficient in size, the range must
be skipped before calling the function again.
[ Impact: fixes boot hang on some platforms ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The low-level mlx4 driver modified the page-list addresses for fast
register work requests post send to big-endian, and set a "present"
bit. This caused problems later when the consumer attempted to unmap
the pages using the page-list (using the list addresses which were
assumed to be still in CPU-endian order). Fix the mlx4 driver to
allocate two buffers and use a private buffer for the hardware-format
bus addresses.
This patch fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1571>,
an NFS/RDMA server crash. The cause of the crash was found by Vu Pham
of Mellanox. The fix is along the lines suggested by Steve Wise in
comment #21 in bug 1571.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
6328a57401
"Enable PNPACPI _PSx Support, v3"
added a call to acpi_bus_set_power(handle, ACPI_STATE_D3)
to pnpacpi_disable_resource() before the existing call
to evaluate _DIS on the device.
This caused suspend to fail on the system in
http://bugzilla.kernel.org/show_bug.cgi?id=13243
because the sanity check to verify we entered _PS3
failed on the serial port.
As a work-around, that sanity check can be disabled
system-wide with "acpi.power_nocheck=1"
Or perhaps we should just shrug off the _PS3 failure
and carry on with _DIS like we used to -- which is
what this patch does.
Signed-off-by: Len Brown <len.brown@intel.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (32 commits)
[CIFS] Fix double list addition in cifs posix open code
[CIFS] Allow raw ntlmssp code to be enabled with sec=ntlmssp
[CIFS] Fix SMB uid in NTLMSSP authenticate request
[CIFS] NTLMSSP reenabled after move from connect.c to sess.c
[CIFS] Remove sparse warning
[CIFS] remove checkpatch warning
[CIFS] Fix final user of old string conversion code
[CIFS] remove cifs_strfromUCS_le
[CIFS] NTLMSSP support moving into new file, old dead code removed
[CIFS] Fix endian conversion of vcnum field
[CIFS] Remove trailing whitespace
[CIFS] Remove sparse endian warnings
[CIFS] Add remaining ntlmssp flags and standardize field names
[CIFS] Fix build warning
cifs: fix length handling in cifs_get_name_from_search_buf
[CIFS] Remove unneeded QuerySymlink call and fix mapping for unmapped status
[CIFS] rename cifs_strndup to cifs_strndup_from_ucs
Added loop check when mounting DFS tree.
Enable dfs submounts to handle remote referrals.
[CIFS] Remove older session setup implementation
...
"Transitioning device [%s] to D%d" is not correct.
We print this line when we attempted to transition
the device, and it failed.
So instead, print
"Device [%s] failed to transition to D%d\n"
This can happen under two conditions:
1. acpi_power_transition() fails when trying to handle the
_ON/_OFF for associated power resource.
2. acpi_evaluate_object() on the explicit _PS0/_PS3
for that actual device could fail.
this change clarifies, but doesn't fix
http://bugzilla.kernel.org/show_bug.cgi?id=13243
Signed-off-by: Len Brown <len.brown@intel.com>
Remove adding open file entry twice to lists in the file
Do not fill file info twice in case of posix opens and creates
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When userspace sets effect->u.rumble.strong_magnitude to 0x8001 or
larger, ml_combine_effects() would always return strong_magnitude
0xffff.
Problem is that 'gain' is passed in as signed integer. Multiplying
magnitude (__u16) with gain (int) causes magnitude read as signed and
results negative value (with magnitude > 0x8000). This signed integer
is then divided and value, still negative, converted to 32bit unsigned
integer. Finally checking combine overflow min(new+old, 0xffff) gives
out 0xffff.
Fix is to simply change 'gain' to unsigned int.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
BTN_TOUCH is not set by the wacom driver which causes it to be handled by the
joydev driver while the resulting device is broken. This causes problems with
applications that try to use a joystick device.
Ubuntu BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/300143
Signed-off-by: Tim Cole <tim.cole@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Amit Kucheria <amit.kucheria@canonical.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
There's a WARN_ON in the ring buffer code that makes sure preemption
is disabled. It checks "!preempt_count()". But when CONFIG_PREEMPT is not
enabled, preempt_count() is always zero, and this will trigger the warning.
[ Impact: prevent false warning on non preemptible kernels ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It is nice to see the overhead of the benchmark test when tracing is
disabled. That is, we turn off the ring buffer just to see what the
cost of running the loop that calls into the ring buffer is.
Currently, if no entries wer made, we get 0. This is not informative.
This patch changes it to check if we had any "missed" (non recorded)
events. If so, a total count is also reported.
[ Impact: evaluate the over head of the ring buffer benchmark test ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ashish Karkare <akarkare@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add acpi/acpica/*.c to the acpi.* modparam namespace
so that any modparams we stick into ACPICA do not
expose ACPICA filenames to users.
There are currently only two modparams in ACPICA,
just recently added for
http://bugzilla.kernel.org/show_bug.cgi?id=13041
With this change, they become
acpi.gts=1
acpi.bfs=1
rather than
hwsleep.gts=1
hwsleep.bfs=1
Signed-off-by: Len Brown <len.brown@intel.com>
Don't check vm_region::vm_start is page aligned in add_nommu_region() because
the region may reflect some non-page-aligned mapped file, such as could be
obtained from RomFS XIP.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://neil.brown.name/md:
md: remove rd%d links immediately after stopping an array.
md: remove ability to explicit set an inactive array to 'clean'.
md: constify VFTs
md: tidy up status_resync to handle large arrays.
md: fix some (more) errors with bitmaps on devices larger than 2TB.
md/raid10: don't clear bitmap during recovery if array will still be degraded.
md: fix loading of out-of-date bitmap.
It's a really simple patch that basically just open-codes the current
"secure_ip_id()" call, but when open-coding it we now use a _static_
hashing area, so that it gets updated every time.
And to make sure somebody can't just start from the same original seed of
all-zeroes, and then do the "half_md4_transform()" over and over until
they get the same sequence as the kernel has, each iteration also mixes in
the same old "current->pid + jiffies" we used - so we should now have a
regular strong pseudo-number generator, but we also have one that doesn't
have a single seed.
Note: the "pid + jiffies" is just meant to be a tiny tiny bit of noise. It
has no real meaning. It could be anything. I just picked the previous
seed, it's just that now we keep the state in between calls and that will
feed into the next result, and that should make all the difference.
I made that hash be a per-cpu data just to avoid cache-line ping-pong:
having multiple CPU's write to the same data would be fine for randomness,
and add yet another layer of chaos to it, but since get_random_int() is
supposed to be a fast interface I did it that way instead. I considered
using "__raw_get_cpu_var()" to avoid any preemption overhead while still
getting the hash be _mostly_ ping-pong free, but in the end good taste won
out.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calling cond_resched at every iteration of the loop adds a bit of
overhead to the benchmark.
This patch does two things.
1) only calls cond-resched when CONFIG_PREEMPT is not enabled
2) only calls cond-resched after so many traces has been performed.
[ Impact: less overhead to the ring-buffer-benchmark ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Tracing can be very helpful to debug the kernel. When DEBUG_KERNEL is
enabled it is nice to enable the trace menu as well.
This patch only make the tracing menu enabled by default, it does not
make any of the tracers enabled. And the menu is only enabled by
default if DEBUG_KERNEL is enabled.
[ Impact: show tracing options to those debugging the kernel ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
From: Bruce Ashfield <bruce.ashfield@windriver.com>
To fully support the armv7-a instruction set/optimizations, support
for the R_ARM_MOVW_ABS_NC and R_ARM_MOVT_ABS relocation types is
required.
The MOVW and MOVT are both load-immediate instructions, MOVW loads 16
bits into the bottom half of a register, and MOVT loads 16 bits into the
top half of a register.
The relocation information for these instructions has a full 32 bit
value, plus an addend which is stored in the 16 immediate bits in the
instruction itself. The immediate bits in the instruction are not
contiguous (the register # splits it into a 4 bit and 12 bit value),
so the addend has to be extracted accordingly and added to the value.
The value is then split and put into the instruction; a MOVW uses the
bottom 16 bits of the value, and a MOVT uses the top 16 bits.
Signed-off-by: David Borman <david.borman@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The system enabling of events uses the same code as the set_event file.
It passes in the name of the system to the parser and that will enable
all the events that has that system as a name.
The problem is that it will also enable events with the same name as the
system.
If you have system name foo, and system name bar, but within the system
bar, there exists an event called foo. By setting the system name foo,
you will also be enabling the event foo in the system bar. This is not
an expected result.
The solution is to pass in "foo:*", which will only enable the system
foo and not events called foo.
[ Impact: prevent accidental enabling of events with same name as a system ]
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The unit of oprofile_cpu_buffer_size is in samples, but was allocated
in bytes. This led to the allocation of too small cpu buffers. This
patch recalculates the buffer size in bytes taking also the
ring_buffer_event header size into account.
Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Ingo Molnar thought that the code to calculate the time in cond_resched
is a bit too ugly and is not needed. This patch removes it and replaces
it with a simple call to cond_resched. I kept the comment that explains
the reason for the cond_resched.
[ Impact: remove ugly code ]
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As per commit 284901a90a, use
DMA_BIT_MASK(n)
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge reason: this topic is ready for upstream now. It passed
Oleg's review and Andrew had no further mm/*
objections/observations either.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
on a handful of tracing fixes present in .30-rc5-almost.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In filter_add_subsystem_pred() we should release event_mutex before
calling filter_free_subsystem_preds(), since both functions hold
event_mutex.
[ Impact: fix deadlock when writing invalid pred into subsystem filter ]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: tzanussi@gmail.com
Cc: a.p.zijlstra@chello.nl
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <4A028993.7020509@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we set a filter for an event, such as:
echo "name == my_lock_name" > \
/debug/tracing/events/lockdep/lock_acquired/filter
then the following order of token type is parsed:
- space
- operator
- parentheses
- operand
Because the operators and parentheses have a higher precedence
than the operand characters, which is normal, then we can't
use any string containing such special characters:
()=<>!&|
To get this support and also avoid ambiguous intepretation from
the parser or the human, we can do it using double quotes so that
we keep the usual languages habits.
Then after this patch you can still declare string condition like
before:
echo name == myname
But if you want to compare against a string containing an operator
character, you can use double quotes:
echo 'name == "&myname"'
Don't forget to include the whole expression into single quotes or
the double ones will be eaten by echo.
[ Impact: support strings with special characters for tracing filters ]
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Currently the filtering infrastructure supports well the
numeric types and fixed sized array types.
But the recently added __string() field uses a specific
indirect offset mechanism which requires a specific
predicate. Until now it wasn't supported.
This patch adds this support and implies very few changes,
only a new predicate is needed, the management of this specific
field can be done through the usual string helpers in the
filtering infrastructure.
[ Impact: support all kinds of strings in the tracing filters ]
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
When a thread is oom killed and fails to exit, it's helpful to know which
threads have access to memory reserves if the machine livelocks. This is
done by testing for the TIF_MEMDIE thread info flag and should be
displayed alongside stack traces to identify tasks that have access to
such reserves but are still stuck allocating pages, for instance.
It would probably be helpful in other cases as well, so all thread info
flags are emitted when showing a task.
( v2: fix warning reported by Stephen Rothwell )
[ Impact: extend debug printout info ]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <alpine.DEB.2.00.0905040136390.15831@chino.kir.corp.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- remove unused define
- make the lock variable definition stand out some more
- convert KERN_* to pr_info() / pr_warning()
[ Impact: cleanup ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This code has apparently used "0" and not VM86_SIGNAL since Linux
1.1.9, when Linus added VM86_SIGNAL to vm86.h. This patch changes the
code to use the symbolic name.
The magic 0 tripped me up in trying to extend the vm86(2) manpage to
actually explain vm86()'s interface -- my greps for VM86_SIGNAL came up
fruitless.
[ Impact: cleanup; no object code change ]
Signed-off-by: Samuel Bronson <naesten@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
With the current event directory, you can only enable individual events.
The file debugfs/tracing/set_event is used to be able to enable or
disable several events at once. But that can still be awkward.
This patch adds hierarchical enabling of events. That is, each directory
in debugfs/tracing/events has an "enable" file. This file can enable
or disable all events within the directory and below.
# echo 1 > /debugfs/tracing/events/enable
will enable all events.
# echo 1 > /debugfs/tracing/events/sched/enable
will enable all events in the sched subsystem.
# echo 1 > /debugfs/tracing/events/enable
# echo 0 > /debugfs/tracing/events/irq/enable
will enable all events, but then disable just the irq subsystem events.
When reading one of these enable files, there are four results:
0 - all events this file affects are disabled
1 - all events this file affects are enabled
X - there is a mixture of events enabled and disabled
? - this file does not affect any event
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Li Zefan found that there's a race using the event ids of events and
modules. When a module is loaded, an event id is incremented. We only
have 16 bits for event ids (65536) and there is a possible (but highly
unlikely) race that we could load and unload a module that registers
events so many times that the event id counter overflows.
When it overflows, it then restarts and goes looking for available
ids. An id is available if it was added by a module and released.
The race is if you have one module add an id, and then is removed.
Another module loaded can use that same event id. But if the old module
still had events in the ring buffer, the new module's call back would
get bogus data. At best (and most likely) the output would just be
garbage. But if the module for some reason used pointers (not recommended)
then this could potentially crash.
The safest thing to do is just reset the ring buffer if a module that
registered events is removed.
[ Impact: prevent unpredictable results of event id overflows ]
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <49FEAFD0.30106@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When creating trace events for ftrace, the header file with the TRACE_EVENT
macros must also have a macro called TRACE_SYSTEM. This macro describes
the name of the system the TRACE_EVENTS are defined for. It also doubles
as a way for the define_trace.h file to include the file that included
it.
For example:
in irq.h
#define TRACE_SYSTEM irq
[...]
#include <trace/define_trace.h>
The define_trace will use TRACE_SYSTEM to include irq.h. But if the name
of the trace system does not match the name of the trace header file,
one can override it with:
Which will change define_trace.h to inclued foo_trace.h instead of foo.h
The sample comments this, but people that use the sample code will more
likely use the code and not read the comments. This patch changes the
sample code to use the TRACE_INCLUDE_FILE to better show developers how to
use it.
[ Impact: make sample less confusing to developers ]
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
md maintains link in sys/mdXX/md/ to identify which device has
which role in the array. e.g.
rd2 -> dev-sda
indicates that the device with role '2' in the array is sda.
These links are only present when the array is active. They are
created immediately after ->run is called, and so should be removed
immediately after ->stop is called.
However they are currently removed a little bit later, and it is
possible for ->run to be called again, thus adding these links, before
they are removed.
So move the removal earlier so they are consistently only present when
the array is active.
Signed-off-by: NeilBrown <neilb@suse.de>
Being able to write 'clean' to an 'array_state' of an inactive array
to activate it in 'clean' mode is both unnecessary and inconvenient.
It is unnecessary because the same can be achieved by writing
'active'. This activates and array, but it still remains 'clean'
until the first write.
It is inconvenient because writing 'clean' is more often used to
cause an 'active' array to revert to 'clean' mode (thus blocking
any writes until a 'write-pending' is promoted to 'active').
Allowing 'clean' to both activate an array and mark an active array as
clean can lead to races: One program writes 'clean' to mark the
active array as clean at the same time as another program writes
'inactive' to deactivate (stop) and active array. Depending on which
writes first, the array could be deactivated and immediately
reactivated which isn't what was desired.
So just disable the use of 'clean' to activate an array.
This avoids a race that can be triggered with mdadm-3.0 and external
metadata, so it suitable for -stable.
Reported-by: Rafal Marszewski <rafal.marszewski@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
