and no longer use its debugfs knobs. The change slightly touches
kernel/trace directory, but it got the needed ack from Steven Rostedt:
http://lkml.org/lkml/2012/8/21/688
2. Added maintainers entry;
3. A bunch of fixes, nothing special.
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Merge tag 'for-v3.7' of git://git.infradead.org/users/cbou/linux-pstore
Pull pstore changes from Anton Vorontsov:
1) We no longer ad-hoc to the function tracer "high level"
infrastructure and no longer use its debugfs knobs. The change
slightly touches kernel/trace directory, but it got the needed ack
from Steven Rostedt:
http://lkml.org/lkml/2012/8/21/688
2) Added maintainers entry;
3) A bunch of fixes, nothing special.
* tag 'for-v3.7' of git://git.infradead.org/users/cbou/linux-pstore:
pstore: Avoid recursive spinlocks in the oops_in_progress case
pstore/ftrace: Convert to its own enable/disable debugfs knob
pstore/ram: Add missing platform_device_unregister
MAINTAINERS: Add pstore maintainers
pstore/ram: Mark ramoops_pstore_write_buf() as notrace
pstore/ram: Fix printk format warning
pstore/ram: Fix possible NULL dereference
Pull user namespace changes from Eric Biederman:
"This is a mostly modest set of changes to enable basic user namespace
support. This allows the code to code to compile with user namespaces
enabled and removes the assumption there is only the initial user
namespace. Everything is converted except for the most complex of the
filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
nfs, ocfs2 and xfs as those patches need a bit more review.
The strategy is to push kuid_t and kgid_t values are far down into
subsystems and filesystems as reasonable. Leaving the make_kuid and
from_kuid operations to happen at the edge of userspace, as the values
come off the disk, and as the values come in from the network.
Letting compile type incompatible compile errors (present when user
namespaces are enabled) guide me to find the issues.
The most tricky areas have been the places where we had an implicit
union of uid and gid values and were storing them in an unsigned int.
Those places were converted into explicit unions. I made certain to
handle those places with simple trivial patches.
Out of that work I discovered we have generic interfaces for storing
quota by projid. I had never heard of the project identifiers before.
Adding full user namespace support for project identifiers accounts
for most of the code size growth in my git tree.
Ultimately there will be work to relax privlige checks from
"capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
root in a user names to do those things that today we only forbid to
non-root users because it will confuse suid root applications.
While I was pushing kuid_t and kgid_t changes deep into the audit code
I made a few other cleanups. I capitalized on the fact we process
netlink messages in the context of the message sender. I removed
usage of NETLINK_CRED, and started directly using current->tty.
Some of these patches have also made it into maintainer trees, with no
problems from identical code from different trees showing up in
linux-next.
After reading through all of this code I feel like I might be able to
win a game of kernel trivial pursuit."
Fix up some fairly trivial conflicts in netfilter uid/git logging code.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
userns: Convert the ufs filesystem to use kuid/kgid where appropriate
userns: Convert the udf filesystem to use kuid/kgid where appropriate
userns: Convert ubifs to use kuid/kgid
userns: Convert squashfs to use kuid/kgid where appropriate
userns: Convert reiserfs to use kuid and kgid where appropriate
userns: Convert jfs to use kuid/kgid where appropriate
userns: Convert jffs2 to use kuid and kgid where appropriate
userns: Convert hpfs to use kuid and kgid where appropriate
userns: Convert btrfs to use kuid/kgid where appropriate
userns: Convert bfs to use kuid/kgid where appropriate
userns: Convert affs to use kuid/kgid wherwe appropriate
userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
userns: On ia64 deal with current_uid and current_gid being kuid and kgid
userns: On ppc convert current_uid from a kuid before printing.
userns: Convert s390 getting uid and gid system calls to use kuid and kgid
userns: Convert s390 hypfs to use kuid and kgid where appropriate
userns: Convert binder ipc to use kuids
userns: Teach security_path_chown to take kuids and kgids
userns: Add user namespace support to IMA
userns: Convert EVM to deal with kuids and kgids in it's hmac computation
...
This patch splits trace event initialization in two stages:
* ftrace enable
* sysfs event entry creation
This allows to capture trace events from an earlier point
by using 'trace_event' kernel parameter and is important
to trace boot-up allocations.
Note that, in order to enable events at core_initcall,
it's necessary to move init_ftrace_syscalls() from
core_initcall to early_initcall.
Link: http://lkml.kernel.org/r/1347461277-25302-1-git-send-email-elezegarcia@gmail.com
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In our application, we have trace markers spread through user-space.
We have markers in GL, X, etc. These are super handy for Chrome's
about:tracing feature (Chrome + system + kernel trace view), but
can be very distracting when you're trying to debug a kernel issue.
I normally, use "grep -v tracing_mark_write" but it would be nice
if I could just temporarily disable markers all together.
Link: http://lkml.kernel.org/r/1347066739-26285-1-git-send-email-msb@chromium.org
CC: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- When tracing capture the kuid.
- When displaying the data to user space convert the kuid into the
user namespace of the process that opened the report file.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Commit 56449f437 "tracing: make the trace clocks available generally",
in April 2009, made trace_clock available unconditionally, since
CONFIG_X86_DS used it too.
Commit faa4602e47 "x86, perf, bts, mm: Delete the never used BTS-ptrace code",
in March 2010, removed CONFIG_X86_DS, and now only CONFIG_RING_BUFFER (split
out from CONFIG_TRACING for general use) has a dependency on trace_clock. So,
only compile in trace_clock with CONFIG_RING_BUFFER or CONFIG_TRACING
enabled.
Link: http://lkml.kernel.org/r/20120903024513.GA19583@leaf
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.
It's a bit more code, but that is the only downside. On the bright side we
have:
- Ability to make persistent_ram module removable (when needed, we can
move ftrace_ops struct into a module). Note that persistent_ram is still
not removable for other reasons, but with this patch it's just one
thing less to worry about;
- Pstore part is more isolated from the generic function tracer. We tried
it already by registering our own tracer in available_tracers, but that
way we're loosing ability to see the traces while we record them to
pstore. This solution is somewhere in the middle: we only register
"internal ftracer" back-end, but not the "front-end";
- When there is only pstore tracing enabled, the kernel will only write
to the pstore buffer, omitting function tracer buffer (which, of course,
still can be enabled via 'echo function > current_tracer').
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
The function graph has a test to check if the frame pointer is
corrupted, which can happen with various options of gcc with mcount.
But this is not an issue with -mfentry as -mfentry does not need nor use
frame pointers for function graph tracing.
Link: http://lkml.kernel.org/r/20120807194059.773895870@goodmis.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Thanks to Andi Kleen, gcc 4.6.0 now supports -mfentry for x86
(and hopefully soon for other archs). What this does is to have
the function profiler start at the beginning of the function
instead of after the stack is set up. As plain -pg (mcount) is
called after the stack is set up, and in some cases can have issues
with the function graph tracer. It also requires frame pointers to
be enabled.
The -mfentry now calls __fentry__ at the beginning of the function.
This allows for compiling without frame pointers and even has the
ability to access parameters if needed.
If the architecture and the compiler both support -mfentry then
use that instead.
Link: http://lkml.kernel.org/r/20120807194059.392617243@goodmis.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
. Fix include order for bison/flex-generated C files, from Ben Hutchings
. Build fixes and documentation corrections from David Ahern
. Group parsing support, from Jiri Olsa
. UI/gtk refactorings and improvements from Namhyung Kim
. NULL deref fix for perf script, from Namhyung Kim
. Assorted cleanups from Robert Richter
. Let O= makes handle relative paths, from Steven Rostedt
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
* Fix include order for bison/flex-generated C files, from Ben Hutchings
* Build fixes and documentation corrections from David Ahern
* Group parsing support, from Jiri Olsa
* UI/gtk refactorings and improvements from Namhyung Kim
* NULL deref fix for perf script, from Namhyung Kim
* Assorted cleanups from Robert Richter
* Let O= makes handle relative paths, from Steven Rostedt
* perf script python fixes, from Feng Tang.
* Improve 'perf lock' error message when the needed tracepoints
are not present, from David Ahern.
* Initial bash completion support, from Frederic Weisbecker
* Allow building without libelf, from Namhyung Kim.
* Support DWARF CFI based unwind to have callchains when %bp
based unwinding is not possible, from Jiri Olsa.
* Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF
section was the end goal, several fixes for code that handles all
architectures and cleanups are included, from Cody Schafer.
* Add a description for the JIT interface, from Andi Kleen.
* Assorted fixes for Documentation and build in 32 bit, from Robert Richter
* Add support for non-tracepoint events in perf script python, from Feng Tang
* Cache the libtraceevent event_format associated to each evsel early, so that we
avoid relookups, i.e. calling pevent_find_event repeatedly when processing
tracepoint events.
[ This is to reduce the surface contact with libtraceevents and make clear what
is that the perf tools needs from that lib: so far parsing the common and per
event fields. ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
syscall_get_nr can return -1 in the case that the task is not executing
a system call.
This patch fixes perf_syscall_{enter,exit} to check that the syscall
number is valid before using it as an index into a bitmap.
Link: http://lkml.kernel.org/r/1345137254-7377-1-git-send-email-will.deacon@arm.com
Cc: Jason Baron <jbaron@redhat.com>
Cc: Wade Farnsworth <wade_farnsworth@mentor.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add missing initialization for ret variable. Its initialization
is based on the re_cnt variable, which is being set deep down
in the ftrace_function_filter_re function.
I'm not sure compilers would be smart enough to see this in near
future, so killing the warning this way.
Link: http://lkml.kernel.org/r/1340120894-9465-2-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The warkeup_rt self test used msleep() calls to wait for real time
tasks to wake up and run. On bare-metal hardware, this was enough as
the scheduler should let the RT task run way before the non-RT task
wakes up from the msleep(). If it did not, then that would mean the
scheduler was broken.
But when dealing with virtual machines, this is a different story.
If the RT task wakes up on a VCPU, it's up to the host to decide when
that task gets to schedule, which can be far behind the time that the
non-RT task wakes up. In this case, the test would fail incorrectly.
As we are not testing the scheduler, but instead the wake up tracing,
we can use completions to wait and not depend on scheduler timings
to see if events happen on time.
Link: http://lkml.kernel.org/r/1343663105.3847.7.camel@fedora
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull perf fixes from Ingo Molnar:
"Fix merge window fallout and fix sleep profiling (this was always
broken, so it's not a fix for the merge window - we can skip this one
from the head of the tree)."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/trace: Add ability to set a target task for events
perf/x86: Fix USER/KERNEL tagging of samples properly
perf/x86/intel/uncore: Make UNCORE_PMU_HRTIMER_INTERVAL 64-bit
A few events are interesting not only for a current task.
For example, sched_stat_* events are interesting for a task
which wakes up. For this reason, it will be good if such
events will be delivered to a target task too.
Now a target task can be set by using __perf_task().
The original idea and a draft patch belongs to Peter Zijlstra.
I need these events for profiling sleep times. sched_switch is used for
getting callchains and sched_stat_* is used for getting time periods.
These events are combined in user space, then it can be analyzed by
perf tools.
Inspired-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arun Sharma <asharma@fb.com>
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a new filter update interface ftrace_set_filter_ip()
to set ftrace filter by ip address, not only glob pattern.
Link: http://lkml.kernel.org/r/20120605102808.27845.67952.stgit@localhost.localdomain
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add selftests to test the save-regs functionality of ftrace.
If the arch supports saving regs, then it will make sure that regs is
at least not NULL in the callback.
If the arch does not support saving regs, it makes sure that the
registering of the ftrace_ops that requests saving regs fails.
It then tests the registering of the ftrace_ops succeeds if the
'IF_SUPPORTED' flag is set. Then it makes sure that the regs passed to
the function is NULL.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add selftests to test the function tracing recursion protection actually
does work. It also tests if a ftrace_ops states it will perform its own
protection. Although, even if the ftrace_ops states it will protect itself,
the ftrace infrastructure may still provide protection if the arch does
not support all features or another ftrace_ops is registered.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As more users of the function tracer utility are being added, they do
not always add the necessary recursion protection. To protect from
function recursion due to tracing, if the callback ftrace_ops does not
specifically specify that it protects against recursion (by setting
the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be
called by the mcount trampoline which adds recursion protection.
If the flag is set, then the function will be called directly with no
extra protection.
Note, the list operation is called if more than one function callback
is registered, or if the arch does not support all of the function
tracer features.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Here's the big staging tree merge for the 3.6-rc1 merge window.
There are some patches in here outside of drivers/staging/, notibly the iio
code (which is still stradeling the staging / not staging boundry), the pstore
code, and the tracing code. All of these have gotten ackes from the various
subsystem maintainers to be included in this tree. The pstore and tracing
patches are related, and are coming here as they replace one of the android
staging drivers.
Otherwise, the normal staging mess. Lots of cleanups and a few new drivers
(some iio drivers, and the large csr wireless driver abomination.)
Note, you will get a merge issue with the following files:
drivers/staging/comedi/drivers/s626.h
drivers/staging/gdm72xx/netlink_k.c
both of which should be trivial for you to handle.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging tree patches from Greg Kroah-Hartman:
"Here's the big staging tree merge for the 3.6-rc1 merge window.
There are some patches in here outside of drivers/staging/, notibly
the iio code (which is still stradeling the staging / not staging
boundry), the pstore code, and the tracing code. All of these have
gotten acks from the various subsystem maintainers to be included in
this tree. The pstore and tracing patches are related, and are coming
here as they replace one of the android staging drivers.
Otherwise, the normal staging mess. Lots of cleanups and a few new
drivers (some iio drivers, and the large csr wireless driver
abomination.)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fixed up trivial conflicts in drivers/staging/comedi/drivers/s626.h and
drivers/staging/gdm72xx/netlink_k.c
* tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1108 commits)
staging: csr: delete a bunch of unused library functions
staging: csr: remove csr_utf16.c
staging: csr: remove csr_pmem.h
staging: csr: remove CsrPmemAlloc
staging: csr: remove CsrPmemFree()
staging: csr: remove CsrMemAllocDma()
staging: csr: remove CsrMemCalloc()
staging: csr: remove CsrMemAlloc()
staging: csr: remove CsrMemFree() and CsrMemFreeDma()
staging: csr: remove csr_util.h
staging: csr: remove CsrOffSetOf()
stating: csr: remove unneeded #includes in csr_util.c
staging: csr: make CsrUInt16ToHex static
staging: csr: remove CsrMemCpy()
staging: csr: remove CsrStrLen()
staging: csr: remove CsrVsnprintf()
staging: csr: remove CsrStrDup
staging: csr: remove CsrStrChr()
staging: csr: remove CsrStrNCmp
staging: csr: remove CsrStrCmp
...
Add a way to have different functions calling different trampolines.
If a ftrace_ops wants regs saved on the return, then have only the
functions with ops registered to save regs. Functions registered by
other ops would not be affected, unless the functions overlap.
If one ftrace_ops registered functions A, B and C and another ops
registered fucntions to save regs on A, and D, then only functions
A and D would be saving regs. Function B and C would work as normal.
Although A is registered by both ops: normal and saves regs; this is fine
as saving the regs is needed to satisfy one of the ops that calls it
but the regs are ignored by the other ops function.
x86_64 implements the full regs saving, and i386 just passes a NULL
for regs to satisfy the ftrace_ops passing. Where an arch must supply
both regs and ftrace_ops parameters, even if regs is just NULL.
It is OK for an arch to pass NULL regs. All function trace users that
require regs passing must add the flag FTRACE_OPS_FL_SAVE_REGS when
registering the ftrace_ops. If the arch does not support saving regs
then the ftrace_ops will fail to register. The flag
FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED may be set that will prevent the
ftrace_ops from failing to register. In this case, the handler may
either check if regs is not NULL or check if ARCH_SUPPORTS_FTRACE_SAVE_REGS.
If the arch supports passing regs it will set this macro and pass regs
for ops that request them. All other archs will just pass NULL.
Link: Link: http://lkml.kernel.org/r/20120711195745.107705970@goodmis.org
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Return as the 4th paramater to the function tracer callback the pt_regs.
Later patches that implement regs passing for the architectures will require
having the ftrace_ops set the SAVE_REGS flag, which will tell the arch
to take the time to pass a full set of pt_regs to the ftrace_ops callback
function. If the arch does not support it then it should pass NULL.
If an arch can pass full regs, then it should define:
ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1
Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As the function tracer starts to get more features, the support for
theses features will spread out throughout the different architectures
over time. These features boil down to what each arch does in the
mcount trampoline (the ftrace_caller).
Currently there's two features that are not the same throughout the
archs.
1) Support to stop function tracing before the callback
2) passing of the ftrace ops
Both of these require placing an indirect function to support the
features if the mcount trampoline does not.
On a side note, for all architectures, when more than one callback
is registered to the function tracer, an intermediate 'list' function
is called by the mcount trampoline to iterate through the callbacks
that are registered.
Instead of making a separate function for each of these features,
and requiring several indirect calls, just use the single 'list' function
as the intermediate, to handle all cases. If an arch does not support
the 'stop function tracing' or the passing of ftrace ops, just force
it to use the list function that will handle the features required.
This makes the code cleaner and simpler and removes a lot of
#ifdefs in the code.
Link: http://lkml.kernel.org/r/20120612225424.495625483@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the function trace callback receives only the ip and parent_ip
of the function that it traced. It would be more powerful to also return
the ops that registered the function as well. This allows the same function
to act differently depending on what ftrace_ops registered it.
Link: http://lkml.kernel.org/r/20120612225424.267254552@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since the function accepts just one bit, we can use the switch
construction instead of if/else if/...
Just a cosmetic change, there should be no functional changes.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces 'func_ptrace' option, now available in
/sys/kernel/debug/tracing/options when function tracer
is selected.
The patch also adds some tiny code that calls back to pstore
to record the trace. The callback is no-op when PSTORE=n.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If tracer->init() fails, current code will leave current_tracer pointing
to an unusable tracer, which at best makes 'current_tracer' report
inaccurate value.
Fix the issue by pointing current_tracer to nop tracer, and only update
current_tracer with the new one after all the initialization succeeds.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull RCU, perf, and scheduler fixes from Ingo Molnar.
The RCU fix is a revert for an optimization that could cause deadlocks.
One of the scheduler commits (164c33c6ad "sched: Fix fork() error path
to not crash") is correct but not complete (some architectures like Tile
are not covered yet) - the resulting additional fixes are still WIP and
Ingo did not want to delay these pending fixes. See this thread on
lkml:
[PATCH] fork: fix error handling in dup_task()
The perf fixes are just trivial oneliners.
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf kvm: Fix segfault with report and mixed guestmount use
perf kvm: Fix regression with guest machine creation
perf script: Fix format regression due to libtraceevent merge
ring-buffer: Fix accounting of entries when removing pages
ring-buffer: Fix crash due to uninitialized new_pages list head
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
MAINTAINERS/sched: Update scheduler file pattern
sched/nohz: Rewrite and fix load-avg computation -- again
sched: Fix fork() error path to not crash
Clean up and return -ENOMEM on if the kzalloc() fails.
This also prevents a potential crash, as the pointer that failed to
allocate would be later used.
Link: http://lkml.kernel.org/r/20120711063507.GF11812@elgon.mountain
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull block bits from Jens Axboe:
"As vacation is coming up, thought I'd better get rid of my pending
changes in my for-linus branch for this iteration. It contains:
- Two patches for mtip32xx. Killing a non-compliant sysfs interface
and moving it to debugfs, where it belongs.
- A few patches from Asias. Two legit bug fixes, and one killing an
interface that is no longer in use.
- A patch from Jan, making the annoying partition ioctl warning a bit
less annoying, by restricting it to !CAP_SYS_RAWIO only.
- Three bug fixes for drbd from Lars Ellenberg.
- A fix for an old regression for umem, it hasn't really worked since
the plugging scheme was changed in 3.0.
- A few fixes from Tejun.
- A splice fix from Eric Dumazet, fixing an issue with pipe
resizing."
* 'for-linus' of git://git.kernel.dk/linux-block:
scsi: Silence unnecessary warnings about ioctl to partition
block: Drop dead function blk_abort_queue()
block: Mitigate lock unbalance caused by lock switching
block: Avoid missed wakeup in request waitqueue
umem: fix up unplugging
splice: fix racy pipe->buffers uses
drbd: fix null pointer dereference with on-congestion policy when diskless
drbd: fix list corruption by failing but already aborted reads
drbd: fix access of unallocated pages and kernel panic
xen/blkfront: Add WARN to deal with misbehaving backends.
blkcg: drop local variable @q from blkg_destroy()
mtip32xx: Create debugfs entries for troubleshooting
mtip32xx: Remove 'registers' and 'flags' from sysfs
blkcg: fix blkg_alloc() failure path
block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED
block: fix return value on cfq_init() failure
mtip32xx: Remove version.h header file inclusion
xen/blkback: Copy id field when doing BLKIF_DISCARD.
When removing pages from the ring buffer, its state is not reset. This
means that the counters need to be correctly updated to account for the
pages removed.
Update the overrun counter to reflect the removed events from the pages.
Link: http://lkml.kernel.org/r/1340998301-1715-1-git-send-email-vnagarnaik@google.com
Cc: Justin Teravest <teravest@google.com>
Cc: David Sharp <dhsharp@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The new_pages list head in the cpu_buffer is not initialized. When
adding pages to the ring buffer, if the memory allocation fails in
ring_buffer_resize, the clean up handler tries to free up the allocated
pages from all the cpu buffers. The panic is caused by referencing the
uninitialized new_pages list head.
Initializing the new_pages list head in rb_allocate_cpu_buffer fixes
this.
Link: http://lkml.kernel.org/r/1340391005-10880-1-git-send-email-vnagarnaik@google.com
Cc: Justin Teravest <teravest@google.com>
Cc: David Sharp <dhsharp@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ring buffer reader page is used to swap a page from the writable
ring buffer. If the writer happens to be on that page, it ends up on the
reader page, but will simply move off of it, back into the writable ring
buffer as writes are added.
The time stamp passed back to the readers is stored in the cpu_buffer per
CPU descriptor. This stamp is updated when a swap of the reader page takes
place, and it reads the current stamp from the page taken from the writable
ring buffer. Everytime a writer goes to a new page, it updates the time stamp
of that page.
The problem happens if a reader reads a page from an empty per CPU ring buffer.
If the buffer is empty, the swap still takes place, placing the writer at the
start of the reader page. If at a later time, a write happens, it updates the
page's time stamp and continues. But the problem is that the read_stamp does
not get updated, because the page was already swapped.
The solution to this was to not swap the page if the ring buffer happens to
be empty. This also removes the side effect that the writes on the reader
page will not get updated because the writer never gets back on the reader
page without a swap. That is, if a read happens on an empty buffer, but then
no reads happen for a while. If a swap took place, and the writer were to start
writing a lot of data (function tracer), it will start overflowing the ring buffer
and overwrite the older data. But because the writer never goes back onto the
reader page, the data left on the reader page never gets overwritten. This
causes the reader to see really old data, followed by a jump to newer data.
Link: http://lkml.kernel.org/r/1340060577-9112-1-git-send-email-dhsharp@google.com
Google-Bug-Id: 6410455
Reported-by: David Sharp <dhsharp@google.com>
tested-by: David Sharp <dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Replace the NR_CPUS array of buffer_iter from the trace_iterator
with an allocated array. This will just create an array of
possible CPUS instead of the max number specified.
The use of NR_CPUS in that array caused allocation failures for
machines that were tight on memory. This did not cause any failures
to the system itself (no crashes), but caused unnecessary failures
for reading the trace files.
Added a helper function called 'trace_buffer_iter()' that returns
the buffer_iter item or NULL if it is not defined or the array was
not allocated. Some routines do not require the array
(tracing_open_pipe() for one).
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a WARN_ON() output on test failures so that they are easier to detect
in automated tests. Although, the WARN_ON() will not print if the test
causes the system to crash, obviously.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
All trace events including ftrace internel events (like trace_printk
and function tracing), register functions that describe how to print
their output. The events may be recorded as soon as the ring buffer
is allocated, but they are just raw binary in the buffer. The mapping
of event ids to how to print them are held within a structure that
is registered on system boot.
If a crash happens in boot up before these functions are registered
then their output (via ftrace_dump_on_oops) will be useless:
Dumping ftrace buffer:
---------------------------------
<...>-1 0.... 319705us : Unknown type 6
---------------------------------
This can be quite frustrating for a kernel developer trying to see
what is going wrong.
There's no reason to register them so late in the boot up process.
They can be registered by early_initcall().
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
register_ftrace_function() checks ftrace_disabled and calls
__register_ftrace_function which does it again.
Drop the first check and add the unlikely hint to the second one. Also,
drop the label as John correctly notices.
No functional change.
Link: http://lkml.kernel.org/r/20120329171140.GE6409@aftab
Cc: Borislav Petkov <bp@amd64.org>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()
commit 35f3d14dbb (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe->buffers.
Problem is some paths don't hold pipe mutex and assume pipe->buffers
doesn't change for their duration.
Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe->buffers where appropriate.
splice_shrink_spd() loses its struct pipe_inode_info argument.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Tom Herbert <therbert@google.com>
Cc: stable <stable@vger.kernel.org> # 2.6.35
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A recent update to have tracing_on/off() only affect the ftrace ring
buffers instead of all ring buffers had a cut and paste error.
The tracing_off() did the exact same thing as tracing_on() and
would not actually turn off tracing. Unfortunately, tracing_off()
is more important to be working than tracing_on() as this is a key
development tool, as it lets the developer turn off tracing as soon
as a problem is discovered. It is also used by panic and oops code.
This bug also breaks the 'echo func:traceoff > set_ftrace_filter'
Cc: <stable@vger.kernel.org> # 3.4
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
