commit 87291347c49dc40aa339f587b209618201c2e527 upstream.
In event format strings, the array size is reported in two locations.
One in array subscript and then via the "size:" attribute. The values
reported there have a mismatch.
For e.g., in sched:sched_switch the prev_comm and next_comm character
arrays have subscript values as [32] where as the actual field size is
16.
name: sched_switch
ID: 301
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char prev_comm[32]; offset:8; size:16; signed:1;
field:pid_t prev_pid; offset:24; size:4; signed:1;
field:int prev_prio; offset:28; size:4; signed:1;
field:long prev_state; offset:32; size:8; signed:1;
field:char next_comm[32]; offset:40; size:16; signed:1;
field:pid_t next_pid; offset:56; size:4; signed:1;
field:int next_prio; offset:60; size:4; signed:1;
After bisection, the following commit was blamed:
92edca0 tracing: Use direct field, type and system names
This commit removes the duplication of strings for field->name and
field->type assuming that all the strings passed in
__trace_define_field() are immutable. This is not true for arrays, where
the type string is created in event_storage variable and field->type for
all array fields points to event_storage.
Use __stringify() to create a string constant for the type string.
Also, get rid of event_storage and event_storage_mutex that are not
needed anymore.
also, an added benefit is that this reduces the overhead of events a bit more:
text data bss dec hex filename
8424787 2036472 1302528 11763787 b3804b vmlinux
8420814 2036408 1302528 11759750 b37086 vmlinux.patched
Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0dc83bd30b0bf5410c0933cfbbf8853248eff0a9 upstream. This reverts commit c4a391b53a72d2df4ee97f96f78c1d5971b47489. Dave Chinner <david@fromorbit.com> has reported the commit may cause some inodes to be left out from sync(2). This is because we can call redirty_tail() for some inode (which sets i_dirtied_when to current time) after sync(2) has started or similarly requeue_inode() can set i_dirtied_when to current time if writeback had to skip some pages. The real problem is in the functions clobbering i_dirtied_when but fixing that isn't trivial so revert is a safer choice for now. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull perf fixes from Ingo Molnar: "Misc kernel and tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools lib traceevent: Fix conversion of pointer to integer of different size perf/trace: Properly use u64 to hold event_id perf: Remove fragile swevent hlist optimization ftrace, perf: Avoid infinite event generation loop tools lib traceevent: Fix use of multiple options in processing field perf header: Fix possible memory leaks in process_group_desc() perf header: Fix bogus group name perf tools: Tag thread comm as overriden
If an TRACE_EVENT() uses __assign_str() or __get_str on a NULL pointer
then the following oops will happen:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c127a17b>] strlen+0x10/0x1a
*pde = 00000000 ^M
Oops: 0000 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.13.0-rc1-test+ #2
Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006^M
task: f5cde9f0 ti: f5e5e000 task.ti: f5e5e000
EIP: 0060:[<c127a17b>] EFLAGS: 00210046 CPU: 1
EIP is at strlen+0x10/0x1a
EAX: 00000000 EBX: c2472da8 ECX: ffffffff EDX: c2472da8
ESI: c1c5e5fc EDI: 00000000 EBP: f5e5fe84 ESP: f5e5fe80
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: 00000000 CR3: 01f32000 CR4: 000007d0
Stack:
f5f18b90 f5e5feb8 c10687a8 0759004f 00000005 00000005 00000005 00200046
00000002 00000000 c1082a93 f56c7e28 c2472da8 c1082a93 f5e5fee4 c106bc61^M
00000000 c1082a93 00000000 00000000 00000001 00200046 00200082 00000000
Call Trace:
[<c10687a8>] ftrace_raw_event_lock+0x39/0xc0
[<c1082a93>] ? ktime_get+0x29/0x69
[<c1082a93>] ? ktime_get+0x29/0x69
[<c106bc61>] lock_release+0x57/0x1a5
[<c1082a93>] ? ktime_get+0x29/0x69
[<c10824dd>] read_seqcount_begin.constprop.7+0x4d/0x75
[<c1082a93>] ? ktime_get+0x29/0x69^M
[<c1082a93>] ktime_get+0x29/0x69
[<c108a46a>] __tick_nohz_idle_enter+0x1e/0x426
[<c10690e8>] ? lock_release_holdtime.part.19+0x48/0x4d
[<c10bc184>] ? time_hardirqs_off+0xe/0x28
[<c1068c82>] ? trace_hardirqs_off_caller+0x3f/0xaf
[<c108a8cb>] tick_nohz_idle_enter+0x59/0x62
[<c1079242>] cpu_startup_entry+0x64/0x192
[<c102299c>] start_secondary+0x277/0x27c
Code: 90 89 c6 89 d0 88 c4 ac 38 e0 74 09 84 c0 75 f7 be 01 00 00 00 89 f0 48 5e 5d c3 55 89 e5 57 66 66 66 66 90 83 c9 ff 89 c7 31 c0 <f2> ae f7 d1 8d 41 ff 5f 5d c3 55 89 e5 57 66 66 66 66 90 31 ff
EIP: [<c127a17b>] strlen+0x10/0x1a SS:ESP 0068:f5e5fe80
CR2: 0000000000000000
---[ end trace 01bc47bf519ec1b2 ]---
New tracepoints have been added that have allowed for NULL pointers
being assigned to strings. To fix this, change the TRACE_EVENT() code
to check for NULL and if it is, it will assign "(null)" to it instead
(similar to what glibc printf does).
Reported-by: Shuah Khan <shuah.kh@samsung.com>
Reported-by: Jovi Zhangwei <jovi.zhangwei@gmail.com>
Link: http://lkml.kernel.org/r/CAGdX0WFeEuy+DtpsJzyzn0343qEEjLX97+o1VREFkUEhndC+5Q@mail.gmail.com
Link: http://lkml.kernel.org/r/528D6972.9010702@samsung.com
Fixes: 9cbf117662e2 ("tracing/events: provide string with undefined size support")
Cc: stable@vger.kernel.org # 2.6.31+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull btrfs fixes from Chris Mason: "Almost all of these are bug fixes. Dave Sterba's documentation update is the big exception because he removed our promises to set any machine running Btrfs on fire" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Documentation: filesystems: update btrfs tools section Documentation: filesystems: add new btrfs mount options btrfs: update kconfig help text btrfs: fix bio_size_ok() for max_sectors > 0xffff btrfs: Use trace condition for get_extent tracepoint btrfs: fix typo in the log message Btrfs: fix list delete warning when removing ordered root from the list Btrfs: print bytenr instead of page pointer in check-int Btrfs: remove dead codes from ctree.h Btrfs: don't wait for ordered data outside desired range Btrfs: fix lockdep error in async commit Btrfs: avoid heavy operations in btrfs_commit_super Btrfs: fix __btrfs_start_workers retval Btrfs: disable online raid-repair on ro mounts Btrfs: do not inc uncorrectable_errors counter on ro scrubs Btrfs: only drop modified extents if we logged the whole inode Btrfs: make sure to copy everything if we rename Btrfs: don't BUG_ON() if we get an error walking backrefs
Doing an if statement to test some condition to know if we should
trigger a tracepoint is pointless when tracing is disabled. This just
adds overhead and wastes a branch prediction. This is why the
TRACE_EVENT_CONDITION() was created. It places the check inside the jump
label so that the branch does not happen unless tracing is enabled.
That is, instead of doing:
if (em)
trace_btrfs_get_extent(root, em);
Which is basically this:
if (em)
if (static_key(trace_btrfs_get_extent)) {
Using a TRACE_EVENT_CONDITION() we can just do:
trace_btrfs_get_extent(root, em);
And the condition trace event will do:
if (static_key(trace_btrfs_get_extent)) {
if (em) {
...
The static key is a non conditional jump (or nop) that is faster than
having to check if em is NULL or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Vince's perf-trinity fuzzer found yet another 'interesting' problem. When we sample the irq_work_exit tracepoint with period==1 (or PERF_SAMPLE_PERIOD) and we add an fasync SIGNAL handler we create an infinite event generation loop: ,-> <IPI> | irq_work_exit() -> | trace_irq_work_exit() -> | ... | __perf_event_overflow() -> (due to fasync) | irq_work_queue() -> (irq_work_list must be empty) '--------- arch_irq_work_raise() Similar things can happen due to regular poll() wakeups if we exceed the ring-buffer wakeup watermark, or have an event_limit. To avoid this, dis-allow sampling this particular tracepoint. In order to achieve this, create a special perf_perm function pointer for each event and call this (when set) on trying to create a tracepoint perf event. [ roasted: use expr... to allow for ',' in your expression ] Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Jones <davej@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20131114152304.GC5364@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull tracing update from Steven Rostedt: "This batch of changes is mostly clean ups and small bug fixes. The only real feature that was added this release is from Namhyung Kim, who introduced "set_graph_notrace" filter that lets you run the function graph tracer and not trace particular functions and their call chain. Tom Zanussi added some updates to the ftrace multibuffer tracing that made it more consistent with the top level tracing. One of the fixes for perf function tracing required an API change in RCU; the addition of "rcu_is_watching()". As Paul McKenney is pushing that change in this release too, he gave me a branch that included all the changes to get that working, and I pulled that into my tree in order to complete the perf function tracing fix" * tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add rcu annotation for syscall trace descriptors tracing: Do not use signed enums with unsigned long long in fgragh output tracing: Remove unused function ftrace_off_permanent() tracing: Do not assign filp->private_data to freed memory tracing: Add helper function tracing_is_disabled() tracing: Open tracer when ftrace_dump_on_oops is used tracing: Add support for SOFT_DISABLE to syscall events tracing: Make register/unregister_ftrace_command __init tracing: Update event filters for multibuffer recordmcount.pl: Add support for __fentry__ ftrace: Have control op function callback only trace when RCU is watching rcu: Do not trace rcu_is_watching() functions ftrace/x86: skip over the breakpoint for ftrace caller trace/trace_stat: use rbtree postorder iteration helper instead of opencoding ftrace: Add set_graph_notrace filter ftrace: Narrow down the protected area of graph_lock ftrace: Introduce struct ftrace_graph_data ftrace: Get rid of ftrace_graph_filter_enabled tracing: Fix potential out-of-bounds in trace_get_user() tracing: Show more exact help information about snapshot
Pull /dev/random changes from Ted Ts'o: "The /dev/random changes for 3.13 including a number of improvements in the following areas: performance, avoiding waste of entropy, better tracking of entropy estimates, support for non-x86 platforms that have a register which can't be used for fine-grained timekeeping, but which might be good enough for the random driver. Also add some printk's so that we can see how quickly /dev/urandom can get initialized, and when programs try to use /dev/urandom before it is fully initialized (since this could be a security issue). This shouldn't be an issue on x86 desktop/laptops --- a test on my Lenovo T430s laptop shows that /dev/urandom is getting fully initialized approximately two seconds before the root file system is mounted read/write --- this may be an issue with ARM and MIPS embedded/mobile systems, though. These printk's will be a useful canary before potentially adding a future change to start blocking processes which try to read from /dev/urandom before it is initialized, which is something FreeBSD does already for security reasons, and which security folks have been agitating for Linux to also adopt" * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: add debugging code to detect early use of get_random_bytes() random: initialize the last_time field in struct timer_rand_state random: don't zap entropy count in rand_initialize() random: printk notifications for urandom pool initialization random: make add_timer_randomness() fill the nonblocking pool first random: convert DEBUG_ENT to tracepoints random: push extra entropy to the output pools random: drop trickle mode random: adjust the generator polynomials in the mixing function slightly random: speed up the fast_mix function by a factor of four random: cap the rate which the /dev/urandom pool gets reseeded random: optimize the entropy_store structure random: optimize spinlock use in add_device_randomness() random: fix the tracepoint for get_random_bytes(_arch) random: account for entropy loss due to overwrites random: allow fractional bits to be tracked random: statically compute poolbitshift, poolbytes, poolbits random: mix in architectural randomness earlier in extract_buf()
Pull second round of block driver updates from Jens Axboe: "As mentioned in the original pull request, the bcache bits were pulled because of their dependency on the immutable bio vecs. Kent re-did this part and resubmitted it, so here's the 2nd round of (mostly) driver updates for 3.13. It contains: - The bcache work from Kent. - Conversion of virtio-blk to blk-mq. This removes the bio and request path, and substitutes with the blk-mq path instead. The end result almost 200 deleted lines. Patch is acked by Asias and Christoph, who both did a bunch of testing. - A removal of bootmem.h include from Grygorii Strashko, part of a larger series of his killing the dependency on that header file. - Removal of __cpuinit from blk-mq from Paul Gortmaker" * 'for-linus' of git://git.kernel.dk/linux-block: (56 commits) virtio_blk: blk-mq support blk-mq: remove newly added instances of __cpuinit bcache: defensively handle format strings bcache: Bypass torture test bcache: Delete some slower inline asm bcache: Use ida for bcache block dev minor bcache: Fix sysfs splat on shutdown with flash only devs bcache: Better full stripe scanning bcache: Have btree_split() insert into parent directly bcache: Move spinlock into struct time_stats bcache: Kill sequential_merge option bcache: Kill bch_next_recurse_key() bcache: Avoid deadlocking in garbage collection bcache: Incremental gc bcache: Add make_btree_freeing_key() bcache: Add btree_node_write_sync() bcache: PRECEDING_KEY() bcache: bch_(btree|extent)_ptr_invalid() bcache: Don't bother with bucket refcount for btree node allocations bcache: Debug code improvements ...