linux/kernel/trace/trace.c, branch v3.13

Merge tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-11-16T20:23:18Z

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

ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED

2013-11-11T11:43:39Z

Since the introduction of PREEMPT_NEED_RESCHED in: f27dde8deef3 ("sched: Add NEED_RESCHED to the preempt_count") we need to be able to look at both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED to understand the full preemption behaviour. Add it to the trace output. Signed-off-by: Peter Zijlstra Acked-by: Steven Rostedt Cc: Fengguang Wu Cc: Huang Ying Cc: Yuanhan Liu Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

tracing: Remove unused function ftrace_off_permanent()

2013-11-06T20:26:55Z

In the past, ftrace_off_permanent() was called if something strange was detected. But the ftrace_bug() now handles all the anomolies that can happen with ftrace (function tracing), and there are no uses of ftrace_off_permanent(). Get rid of it. Signed-off-by: Steven Rostedt

tracing: Add helper function tracing_is_disabled()

2013-11-06T16:06:00Z

This patch creates the function 'tracing_is_disabled', which can be used outside of trace.c. Link: http://lkml.kernel.org/r/1382141754-12155-1-git-send-email-geyslan@gmail.com Signed-off-by: Geyslan G. Bem Signed-off-by: Steven Rostedt

tracing: Open tracer when ftrace_dump_on_oops is used

2013-11-06T15:03:11Z

With ftrace_dump_on_oops, we previously did not open the tracer in question, sometimes causing the trace output to be useless. For example, the function_graph tracer with tracing_thresh set dumped via ftrace_dump_on_oops would show a series of '}' indented at different levels, but no function names. call trace->open() (and do a few other fixups copied from the normal dump path) to make the output more intelligible. Link: http://lkml.kernel.org/r/1382554197-16961-1-git-send-email-cody@linux.vnet.ibm.com Signed-off-by: Cody P Schafer Signed-off-by: Steven Rostedt

tracing: Make register/unregister_ftrace_command __init

2013-11-05T22:43:40Z

register/unregister_ftrace_command() are only ever called from __init functions, so can themselves be made __init. Also make register_snapshot_cmd() __init for the same reason. Link: http://lkml.kernel.org/r/d4042c8cadb7ae6f843ac9a89a24e1c6a3099727.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt

tracing: Update event filters for multibuffer

2013-11-05T21:50:20Z

The trace event filters are still tied to event calls rather than event files, which means you don't get what you'd expect when using filters in the multibuffer case: Before: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 2048 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 Setting the filter in tracing/instances/test1/events shouldn't affect the same event in tracing/events as it does above. After: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 We'd like to just move the filter directly from ftrace_event_call to ftrace_event_file, but there are a couple cases that don't yet have multibuffer support and therefore have to continue using the current event_call-based filters. For those cases, a new USE_CALL_FILTER bit is added to the event_call flags, whose main purpose is to keep the old behavior for those cases until they can be updated with multibuffer support; at that point, the USE_CALL_FILTER flag (and the new associated call_filter_check_discard() function) can go away. The multibuffer support also made filter_current_check_discard() redundant, so this change removes that function as well and replaces it with filter_check_discard() (or call_filter_check_discard() as appropriate). Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt

tracing: Fix potential out-of-bounds in trace_get_user()

2013-10-19T01:02:56Z

Andrey reported the following report: ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3 ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3) Accessed by thread T13003: #0 ffffffff810dd2da (asan_report_error+0x32a/0x440) #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40) #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20) #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260) #4 ffffffff812a1065 (__fput+0x155/0x360) #5 ffffffff812a12de (____fput+0x1e/0x30) #6 ffffffff8111708d (task_work_run+0x10d/0x140) #7 ffffffff810ea043 (do_exit+0x433/0x11f0) #8 ffffffff810eaee4 (do_group_exit+0x84/0x130) #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30) #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Allocated by thread T5167: #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0) #1 ffffffff8128337c (__kmalloc+0xbc/0x500) #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90) #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0) #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40) #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430) #6 ffffffff8129b668 (finish_open+0x68/0xa0) #7 ffffffff812b66ac (do_last+0xb8c/0x1710) #8 ffffffff812b7350 (path_openat+0x120/0xb50) #9 ffffffff812b8884 (do_filp_open+0x54/0xb0) #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0) #11 ffffffff8129d4b7 (SyS_open+0x37/0x50) #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Shadow bytes around the buggy address: ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap redzone: fa Heap kmalloc redzone: fb Freed heap region: fd Shadow gap: fe The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;' Although the crash happened in ftrace_regex_open() the real bug occurred in trace_get_user() where there's an incrementation to parser->idx without a check against the size. The way it is triggered is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop that reads the last character stores it and then breaks out because there is no more characters. Then the last character is read to determine what to do next, and the index is incremented without checking size. Then the caller of trace_get_user() usually nulls out the last character with a zero, but since the index is equal to the size, it writes a nul character after the allocated space, which can corrupt memory. Luckily, only root user has write access to this file. Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home Reported-by: Andrey Konovalov Signed-off-by: Steven Rostedt

tracing: Show more exact help information about snapshot

2013-10-10T01:38:22Z

The current "help" that comes out of the snapshot file when it is not allocated looks like this: # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') Echo 2 says that it does not allocate the buffer, which is correct, but to be more consistent with "echo 0" it should also state that it does not free. Link: http://lkml.kernel.org/r/20130914045916.GA4243@udknight Signed-off-by: Wang YanQing Signed-off-by: Steven Rostedt

tracing: Make tracing_cpumask available for all instances

2013-08-22T16:45:24Z

Allow tracer instances to disable tracing by cpu by moving the static global tracing_cpumask into trace_array. Link: http://lkml.kernel.org/r/921622317f239bfc2283cac2242647801ef584f2.1375980149.git.azl@google.com Cc: Vaibhav Nagarnaik Cc: David Sharp Cc: Alexander Z Lam Signed-off-by: Alexander Z Lam Signed-off-by: Steven Rostedt