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2018-09-09tracing: Do not call start/stop() functions when tracing_on does not changeSteven Rostedt (VMware)
commit f143641bfef9a4a60c57af30de26c63057e7e695 upstream. Currently, when one echo's in 1 into tracing_on, the current tracer's "start()" function is executed, even if tracing_on was already one. This can lead to strange side effects. One being that if the hwlat tracer is enabled, and someone does "echo 1 > tracing_on" into tracing_on, the hwlat tracer's start() function is called again which will recreate another kernel thread, and make it unable to remove the old one. Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de Cc: stable@vger.kernel.org Fixes: 2df8f8a6a897e ("tracing: Fix regression with irqsoff tracer and tracing_on file") Reported-by: Erica Bugden <erica.bugden@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05printk/nmi: Prevent deadlock when accessing the main log buffer in NMIPetr Mladek
commit 03fc7f9c99c1e7ae2925d459e8487f1a6f199f79 upstream. The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") brought back the possible deadlocks in printk() and NMI. The check of logbuf_lock is done only in printk_nmi_enter() to prevent mixed output. But another CPU might take the lock later, enter NMI, and: + Both NMIs might be serialized by yet another lock, for example, the one in nmi_cpu_backtrace(). + The other CPU might get stopped in NMI, see smp_send_stop() in panic(). The only safe solution is to use trylock when storing the message into the main log-buffer. It might cause reordering when some lines go to the main lock buffer directly and others are delayed via the per-CPU buffer. It means that it is not useful in general. This patch replaces the problematic NMI deferred context with NMI direct context. It can be used to mark a code that might produce many messages in NMI and the risk of losing them is more critical than problems with eventual reordering. The context is then used when dumping trace buffers on oops. It was the primary motivation for the original fix. Also the reordering is even smaller issue there because some traces have their own time stamps. Finally, nmi_cpu_backtrace() need not longer be serialized because it will always us the per-CPU buffers again. Fixes: 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-24tracing: Use __printf markup to silence compilerMathieu Malaterre
[ Upstream commit 26b68dd2f48fe7699a89f0cfbb9f4a650dc1c837 ] Silence warnings (triggered at W=1) by adding relevant __printf attributes. CC kernel/trace/trace.o kernel/trace/trace.c: In function ‘__trace_array_vprintk’: kernel/trace/trace.c:2979:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format] len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); ^~~ AR kernel/trace/built-in.o Link: http://lkml.kernel.org/r/20180308205843.27447-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-09ring_buffer: tracing: Inherit the tracing setting to next ring bufferMasami Hiramatsu
commit 73c8d8945505acdcbae137c2e00a1232e0be709f upstream. Maintain the tracing on/off setting of the ring_buffer when switching to the trace buffer snapshot. Taking a snapshot is done by swapping the backup ring buffer (max_tr_buffer). But since the tracing on/off setting is defined by the ring buffer, when swapping it, the tracing on/off setting can also be changed. This causes a strange result like below: /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 0 > tracing_on /sys/kernel/debug/tracing # cat tracing_on 0 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 0 We don't touch tracing_on, but snapshot changes tracing_on setting each time. This is an anomaly, because user doesn't know that each "ring_buffer" stores its own tracing-enable state and the snapshot is done by swapping ring buffers. Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp> Cc: stable@vger.kernel.org Fixes: debdd57f5145 ("tracing: Make a snapshot feature available from userspace") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [ Updated commit log and comment in the code ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-17tracing: Reorder display of TGID to be after PIDJoel Fernandes (Google)
commit f8494fa3dd10b52eab47a9666a8bc34719a129aa upstream. Currently ftrace displays data in trace output like so: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU TGID |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 [000] ( 1091) d..2 28.313544: sched_switch: However Android's trace visualization tools expect a slightly different format due to an out-of-tree patch patch that was been carried for a decade, notice that the TGID and CPU fields are reversed: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID TGID CPU |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 ( 1091) [002] d..2 64.965177: sched_switch: From kernel v4.13 onwards, during which TGID was introduced, tracing with systrace on all Android kernels will break (most Android kernels have been on 4.9 with Android patches, so this issues hasn't been seen yet). From v4.13 onwards things will break. The chrome browser's tracing tools also embed the systrace viewer which uses the legacy TGID format and updates to that are known to be difficult to make. Considering this, I suggest we make this change to the upstream kernel and backport it to all Android kernels. I believe this feature is merged recently enough into the upstream kernel that it shouldn't be a problem. Also logically, IMO it makes more sense to group the TGID with the TASK-PID and the CPU after these. Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org Cc: jreck@google.com Cc: tkjos@google.com Cc: stable@vger.kernel.org Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05tracing: Make the snapshot trigger work with instancesSteven Rostedt (VMware)
commit 2824f5033248600673e3e126a4d135363cbfd9ac upstream. The snapshot trigger currently only affects the main ring buffer, even when it is used by the instances. This can be confusing as the snapshot trigger is listed in the instance. > # cd /sys/kernel/tracing > # mkdir instances/foo > # echo snapshot > instances/foo/events/syscalls/sys_enter_fchownat/trigger > # echo top buffer > trace_marker > # echo foo buffer > instances/foo/trace_marker > # touch /tmp/bar > # chown rostedt /tmp/bar > # cat instances/foo/snapshot # tracer: nop # # # * 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 or free) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') > # cat snapshot # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | bash-1189 [000] .... 111.488323: tracing_mark_write: top buffer Not only did the snapshot occur in the top level buffer, but the instance snapshot buffer should have been allocated, and it is still free. Cc: stable@vger.kernel.org Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02tracing: Fix crash when it fails to alloc ring bufferJing Xia
commit 24f2aaf952ee0b59f31c3a18b8b36c9e3d3c2cf5 upstream. Double free of the ring buffer happens when it fails to alloc new ring buffer instance for max_buffer if TRACER_MAX_TRACE is configured. The root cause is that the pointer is not set to NULL after the buffer is freed in allocate_trace_buffers(), and the freeing of the ring buffer is invoked again later if the pointer is not equal to Null, as: instance_mkdir() |-allocate_trace_buffers() |-allocate_trace_buffer(tr, &tr->trace_buffer...) |-allocate_trace_buffer(tr, &tr->max_buffer...) // allocate fail(-ENOMEM),first free // and the buffer pointer is not set to null |-ring_buffer_free(tr->trace_buffer.buffer) // out_free_tr |-free_trace_buffers() |-free_trace_buffer(&tr->trace_buffer); //if trace_buffer is not null, free again |-ring_buffer_free(buf->buffer) |-rb_free_cpu_buffer(buffer->buffers[cpu]) // ring_buffer_per_cpu is null, and // crash in ring_buffer_per_cpu->pages Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@spreadtrum.com Fixes: 737223fbca3b1 ("tracing: Consolidate buffer allocation code") Signed-off-by: Jing Xia <jing.xia@spreadtrum.com> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02tracing: Fix possible double free on failure of allocating trace bufferSteven Rostedt (VMware)
commit 4397f04575c44e1440ec2e49b6302785c95fd2f8 upstream. Jing Xia and Chunyan Zhang reported that on failing to allocate part of the tracing buffer, memory is freed, but the pointers that point to them are not initialized back to NULL, and later paths may try to free the freed memory again. Jing and Chunyan fixed one of the locations that does this, but missed a spot. Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@spreadtrum.com Fixes: 737223fbca3b1 ("tracing: Consolidate buffer allocation code") Reported-by: Jing Xia <jing.xia@spreadtrum.com> Reported-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02tracing: Remove extra zeroing out of the ring buffer pageSteven Rostedt (VMware)
commit 6b7e633fe9c24682df550e5311f47fb524701586 upstream. The ring_buffer_read_page() takes care of zeroing out any extra data in the page that it returns. There's no need to zero it out again from the consumer. It was removed from one consumer of this function, but read_buffers_splice_read() did not remove it, and worse, it contained a nasty bug because of it. Fixes: 2711ca237a084 ("ring-buffer: Move zeroing out excess in page to ring buffer code") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-20tracing: Allocate mask_str buffer dynamicallyChangbin Du
commit 90e406f96f630c07d631a021fd4af10aac913e77 upstream. The default NR_CPUS can be very large, but actual possible nr_cpu_ids usually is very small. For my x86 distribution, the NR_CPUS is 8192 and nr_cpu_ids is 4. About 2 pages are wasted. Most machines don't have so many CPUs, so define a array with NR_CPUS just wastes memory. So let's allocate the buffer dynamically when need. With this change, the mutext tracing_cpumask_update_lock also can be removed now, which was used to protect mask_str. Link: http://lkml.kernel.org/r/1512013183-19107-1-git-send-email-changbin.du@intel.com Fixes: 36dfe9252bd4c ("ftrace: make use of tracing_cpumask") Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-19tracing: Fix trace_pipe behavior for instance tracesTahsin Erdogan
When reading data from trace_pipe, tracing_wait_pipe() performs a check to see if tracing has been turned off after some data was read. Currently, this check always looks at global trace state, but it should be checking the trace instance where trace_pipe is located at. Because of this bug, cat instances/i1/trace_pipe in the following script will immediately exit instead of waiting for data: cd /sys/kernel/debug/tracing echo 0 > tracing_on mkdir -p instances/i1 echo 1 > instances/i1/tracing_on echo 1 > instances/i1/events/sched/sched_process_exec/enable cat instances/i1/trace_pipe Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com Cc: stable@vger.kernel.org Fixes: 10246fa35d4f ("tracing: give easy way to clear trace buffer") Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-09-19tracing: Ignore mmiotrace from kernel commandlineZiqian SUN (Zamir)
The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel commandline. With this patch, noboot is added to the tracer struct, and when system boot with a tracer that has noboot=true, it will print out a warning message and continue booting. Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.com Signed-off-by: Ziqian SUN (Zamir) <zsun@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-09-19tracing: Erase irqsoff trace with empty writeBo Yan
One convenient way to erase trace is "echo > trace". However, this is currently broken if the current tracer is irqsoff tracer. This is because irqsoff tracer use max_buffer as the default trace buffer. Set the max_buffer as the one to be cleared when it's the trace buffer currently in use. Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com Cc: <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer") Signed-off-by: Bo Yan <byan@nvidia.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-09-06tracing: Apply trace_clock changes to instance max bufferBaohong Liu
Currently trace_clock timestamps are applied to both regular and max buffers only for global trace. For instance trace, trace_clock timestamps are applied only to regular buffer. But, regular and max buffers can be swapped, for example, following a snapshot. So, for instance trace, bad timestamps can be seen following a snapshot. Let's apply trace_clock timestamps to instance max buffer as well. Link: http://lkml.kernel.org/r/ebdb168d0be042dcdf51f81e696b17fabe3609c1.1504642143.git.tom.zanussi@linux.intel.com Cc: stable@vger.kernel.org Fixes: 277ba0446 ("tracing: Add interface to allow multiple trace buffers") Signed-off-by: Baohong Liu <baohong.liu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-09-05tracing: Add barrier to trace_printk() buffer nesting modificationSteven Rostedt (VMware)
trace_printk() uses 4 buffers, one for each context (normal, softirq, irq and NMI), such that it does not need to worry about one context preempting the other. There's a nesting counter that gets incremented to figure out which buffer to use. If the context gets preempted by another context which calls trace_printk() it will increment the counter and use the next buffer, and restore the counter when it is finished. The problem is that gcc may optimize the modification of the buffer nesting counter and it may not be incremented in memory before the buffer is used. If this happens, and the context gets interrupted by another context, it could pick the same buffer and corrupt the one that is being used. Compiler barriers need to be added after the nesting variable is incremented and before it is decremented to prevent usage of the context buffers by more than one context at the same time. Cc: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Fixes: e2ace00117 ("tracing: Choose static tp_printk buffer by explicit nesting count") Hat-tip-to: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-08-31tracing: Only have rmmod clear buffers that its events were active inSteven Rostedt (VMware)
Currently, when a module event is enabled, when that module is removed, it clears all ring buffers. This is to prevent another module from being loaded and having one of its trace event IDs from reusing a trace event ID of the removed module. This could cause undesirable effects as the trace event of the new module would be using its own processing algorithms to process raw data of another event. To prevent this, when a module is loaded, if any of its events have been used (signified by the WAS_ENABLED event call flag, which is never cleared), all ring buffers are cleared, just in case any one of them contains event data of the removed event. The problem is, there's no reason to clear all ring buffers if only one (or less than all of them) uses one of the events. Instead, only clear the ring buffers that recorded the events of a module that is being removed. To do this, instead of keeping the WAS_ENABLED flag with the trace event call, move it to the per instance (per ring buffer) event file descriptor. The event file descriptor maps each event to a separate ring buffer instance. Then when the module is removed, only the ring buffers that activated one of the module's events get cleared. The rest are not touched. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-08-02ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPUSteven Rostedt (VMware)
Chunyu Hu reported: "per_cpu trace directories and files are created for all possible cpus, but only the cpus which have ever been on-lined have their own per cpu ring buffer (allocated by cpuhp threads). While trace_buffers_open, the open handler for trace file 'trace_pipe_raw' is always trying to access field of ring_buffer_per_cpu, and would panic with the NULL pointer. Align the behavior of trace_pipe_raw with trace_pipe, that returns -NODEV when openning it if that cpu does not have trace ring buffer. Reproduce: cat /sys/kernel/debug/tracing/per_cpu/cpu31/trace_pipe_raw (cpu31 is never on-lined, this is a 16 cores x86_64 box) Tested with: 1) boot with maxcpus=14, read trace_pipe_raw of cpu15. Got -NODEV. 2) oneline cpu15, read trace_pipe_raw of cpu15. Get the raw trace data. Call trace: [ 5760.950995] RIP: 0010:ring_buffer_alloc_read_page+0x32/0xe0 [ 5760.961678] tracing_buffers_read+0x1f6/0x230 [ 5760.962695] __vfs_read+0x37/0x160 [ 5760.963498] ? __vfs_read+0x5/0x160 [ 5760.964339] ? security_file_permission+0x9d/0xc0 [ 5760.965451] ? __vfs_read+0x5/0x160 [ 5760.966280] vfs_read+0x8c/0x130 [ 5760.967070] SyS_read+0x55/0xc0 [ 5760.967779] do_syscall_64+0x67/0x150 [ 5760.968687] entry_SYSCALL64_slow_path+0x25/0x25" This was introduced by the addition of the feature to reuse reader pages instead of re-allocating them. The problem is that the allocation of a reader page (which is per cpu) does not check if the cpu is online and set up for the ring buffer. Link: http://lkml.kernel.org/r/1500880866-1177-1-git-send-email-chuhu@redhat.com Cc: stable@vger.kernel.org Fixes: 73a757e63114 ("ring-buffer: Return reader page back into existing ring buffer") Reported-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-08-02tracing: Missing error code in tracer_alloc_buffers()Dan Carpenter
If ring_buffer_alloc() or one of the next couple function calls fail then we should return -ENOMEM but the current code returns success. Link: http://lkml.kernel.org/r/20170801110201.ajdkct7vwzixahvx@mwanda Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: b32614c03413 ('tracing/rb: Convert to hotplug state machine') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-08-02tracing: Call clear_boot_tracer() at lateinit_syncSteven Rostedt (VMware)
The clear_boot_tracer function is used to reset the default_bootup_tracer string to prevent it from being accessed after boot, as it originally points to init data. But since clear_boot_tracer() is called via the init_lateinit() call, it races with the initcall for registering the hwlat tracer. If someone adds "ftrace=hwlat" to the kernel command line, depending on how the linker sets up the text, the saved command line may be cleared, and the hwlat tracer never is initialized. Simply have the clear_boot_tracer() be called by initcall_lateinit_sync() as that's for tasks to be called after lateinit. Link: https://bugzilla.kernel.org/show_bug.cgi?id=196551 Cc: stable@vger.kernel.org Fixes: e7c15cd8a ("tracing: Added hardware latency tracer") Reported-by: Zamir SUN <sztsian@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-20tracing: Fix kmemleak in instance_rmdirChunyu Hu
Hit the kmemleak when executing instance_rmdir, it forgot releasing mem of tracing_cpumask. With this fix, the warn does not appear any more. unreferenced object 0xffff93a8dfaa7c18 (size 8): comm "mkdir", pid 1436, jiffies 4294763622 (age 9134.308s) hex dump (first 8 bytes): ff ff ff ff ff ff ff ff ........ backtrace: [<ffffffff88b6567a>] kmemleak_alloc+0x4a/0xa0 [<ffffffff8861ea41>] __kmalloc_node+0xf1/0x280 [<ffffffff88b505d3>] alloc_cpumask_var_node+0x23/0x30 [<ffffffff88b5060e>] alloc_cpumask_var+0xe/0x10 [<ffffffff88571ab0>] instance_mkdir+0x90/0x240 [<ffffffff886e5100>] tracefs_syscall_mkdir+0x40/0x70 [<ffffffff886565c9>] vfs_mkdir+0x109/0x1b0 [<ffffffff8865b1d0>] SyS_mkdir+0xd0/0x100 [<ffffffff88403857>] do_syscall_64+0x67/0x150 [<ffffffff88b710e7>] return_from_SYSCALL_64+0x0/0x6a [<ffffffffffffffff>] 0xffffffffffffffff Link: http://lkml.kernel.org/r/1500546969-12594-1-git-send-email-chuhu@redhat.com Cc: stable@vger.kernel.org Fixes: ccfe9e42e451 ("tracing: Make tracing_cpumask available for all instances") Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-13Merge tag 'trace-v4.13-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull more tracing updates from Steven Rostedt: "A few more minor updates: - Show the tgid mappings for user space trace tools to use - Fix and optimize the comm and tgid cache recording - Sanitize derived kprobe names - Ftrace selftest updates - trace file header fix - Update of Documentation/trace/ftrace.txt - Compiler warning fixes - Fix possible uninitialized variable" * tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix uninitialized variable in match_records() ftrace: Remove an unneeded NULL check ftrace: Hide cached module code for !CONFIG_MODULES tracing: Do note expose stack_trace_filter without DYNAMIC_FTRACE tracing: Update Documentation/trace/ftrace.txt tracing: Fixup trace file header alignment selftests/ftrace: Add a testcase for kprobe event naming selftests/ftrace: Add a test to probe module functions selftests/ftrace: Update multiple kprobes test for powerpc trace/kprobes: Sanitize derived event names tracing: Attempt to record other information even if some fail tracing: Treat recording tgid for idle task as a success tracing: Treat recording comm for idle task as a success tracing: Add saved_tgids file to show cached pid to tgid mappings
2017-07-11tracing: Fixup trace file header alignmentSteven Rostedt (VMware)
The addition of TGID to the tracing header added a check to see if TGID shoudl be displayed or not, and updated the header accordingly. Unfortunately, it broke the default header. Also add constant strings to use for spacing. This does remove the visibility of the header a bit, but cuts it down from the extended lines much greater than 80 characters. Before this change: # tracer: function # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU#|||| TIMESTAMP FUNCTION # | | | |||| | | swapper/0-1 [000] .... 0.277830: migration_init <-do_one_initcall swapper/0-1 [002] d... 13.861967: Unknown type 1201 swapper/0-1 [002] d..1 13.861970: Unknown type 1202 After this change: # tracer: function # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | swapper/0-1 [000] .... 0.278245: migration_init <-do_one_initcall swapper/0-1 [003] d... 13.861189: Unknown type 1201 swapper/0-1 [003] d..1 13.861192: Unknown type 1202 Cc: Joel Fernandes <joelaf@google.com> Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-07Merge tag 'linux-kselftest-4.13-rc1-update' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull Kselftest updates from Shuah Khan: "This update consists of: - TAP13 framework and changes to some tests to convert to TAP13. Converting kselftest output to standard format will help identify run to run differences and pin point failures easily. TAP13 format has been in use for several years and the output is human friendly. Please find the specification: https://testanything.org/tap-version-13-specification.html Credit goes to Tim Bird for recommending TAP13 as a suitable format, and to Grag KH for kick starting the work with help from Paul Elder and Alice Ferrazzi The first phase of the TAp13 conversion is included in this update. Future updates will include updates to rest of the tests. - Masami Hiramatsu fixed ftrace to run on 4.9 stable kernels. - Kselftest documnetation has been converted to ReST format. Document now has a new home under Documentation/dev-tools. - kselftest_harness.h is now available for general use as a result of Mickaël Salaün's work. - Several fixes to skip and/or fail tests gracefully on older releases" * tag 'linux-kselftest-4.13-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (48 commits) selftests: membarrier: use ksft_* var arg msg api selftests: breakpoints: breakpoint_test_arm64: convert test to use TAP13 selftests: breakpoints: step_after_suspend_test use ksft_* var arg msg api selftests: breakpoint_test: use ksft_* var arg msg api kselftest: add ksft_print_msg() function to output general information kselftest: make ksft_* output functions variadic selftests/capabilities: Fix the test_execve test selftests: intel_pstate: add .gitignore selftests: fix memory-hotplug test selftests: add missing test name in memory-hotplug test selftests: check percentage range for memory-hotplug test selftests: check hot-pluggagble memory for memory-hotplug test selftests: typo correction for memory-hotplug test selftests: ftrace: Use md5sum to take less time of checking logs tools/testing/selftests/sysctl: Add pre-check to the value of writes_strict kselftest.rst: do some adjustments after ReST conversion selftest/net/Makefile: Specify output with $(OUTPUT) selftest/intel_pstate/aperf: Use LDLIBS instead of LDFLAGS selftest/memfd/Makefile: Fix build error selftests: lib: Skip tests on missing test modules ...
2017-07-07tracing: Attempt to record other information even if some failJoel Fernandes
In recent patches where we record comm and tgid at the same time, we skip continuing to record if any fail. Fix that by trying to record as many things as we can even if some couldn't be recorded. If any information isn't recorded, then we don't set trace_taskinfo_save as before. Link: http://lkml.kernel.org/r/20170706230023.17942-3-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-07tracing: Treat recording tgid for idle task as a successJoel Fernandes
Currently we stop recording tgid for non-idle tasks when switching from/to idle task since we treat that as a record failure. Fix that by treat recording of tgid for idle task as a success. Link: http://lkml.kernel.org/r/20170706230023.17942-2-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Reported-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-07tracing: Treat recording comm for idle task as a successJoel Fernandes
Currently we stop recording comm for non-idle tasks when switching from/to idle task since we treat that as a record failure. Fix that by treat recording of comm for idle task as a success. Link: http://lkml.kernel.org/r/20170706230023.17942-1-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Reported-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-06tracing: Add saved_tgids file to show cached pid to tgid mappingsMichael Sartain
Export the cached pid / tgid mappings in debugfs tracing saved_tgids file. This allows user apps to translate the pids from a trace to their respective thread group. Example saved_tgids file with pid / tgid values separated by ' ': # cat saved_tgids 1048 1048 1047 1047 7 7 1049 1047 1054 1047 1053 1047 Link: http://lkml.kernel.org/r/20170630004023.064965233@goodmis.org Link: http://lkml.kernel.org/r/20170706040713.unwkumbta5menygi@mikesart-cos Reviewed-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Michael Sartain <mikesart@fastmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-05Merge commit '0f17976568b3f72e676450af0c0db6f8752253d6' into trace/ftrace/coreSteven Rostedt (VMware)
Need to get the changes from 0f17976568b3 ("ftrace: Fix regression with module command in stack_trace_filter") as it is required to fix some other changes with stack_trace_filter and the new development code. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-29ftrace: Fix regression with module command in stack_trace_filterSteven Rostedt (VMware)
When doing the following command: # echo ":mod:kvm_intel" > /sys/kernel/tracing/stack_trace_filter it triggered a crash. This happened with the clean up of probes. It required all callers to the regex function (doing ftrace filtering) to have ops->private be a pointer to a trace_array. But for the stack tracer, that is not the case. Allow for the ops->private to be NULL, and change the function command callbacks to handle the trace_array pointer being NULL as well. Fixes: d2afd57a4b96 ("tracing/ftrace: Allow instances to have their own function probes") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-27tracing: Add support for display of tgid in trace outputJoel Fernandes
Earlier patches introduced ability to record the tgid using the 'record-tgid' option. Here we read the tgid and output it if the option is enabled. Link: http://lkml.kernel.org/r/20170626053844.5746-3-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Tested-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-27tracing: Add support for recording tgid of tasksJoel Fernandes
Inorder to support recording of tgid, the following changes are made: * Introduce a new API (tracing_record_taskinfo) to additionally record the tgid along with the task's comm at the same time. This has has the benefit of not setting trace_cmdline_save before all the information for a task is saved. * Add a new API tracing_record_taskinfo_sched_switch to record task information for 2 tasks at a time (previous and next) and use it from sched_switch probe. * Preserve the old API (tracing_record_cmdline) and create it as a wrapper around the new one so that existing callers aren't affected. * Reuse the existing sched_switch and sched_wakeup probes to record tgid information and add a new option 'record-tgid' to enable recording of tgid When record-tgid option isn't enabled to being with, we take care to make sure that there's isn't memory or runtime overhead. Link: http://lkml.kernel.org/r/20170627020155.5139-1-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Tested-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-27ftrace: Remove unused function ftrace_arch_read_dyn_info()Steven Rostedt (VMware)
ftrace_arch_read_dyn_info() was used so that archs could add its own debug information into the dyn_ftrace_total_info in the tracefs file system. That file is for debugging usage of dynamic ftrace. No arch uses that function anymore, so just get rid of it. This also allows for tracing_read_dyn_info() to be cleaned up a bit. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13tracing: Rename update the enum_map fileJeremy Linton
The enum_map file is used to display a list of symbol to name conversions. As its now used to resolve sizeof lets update the name and description. Link: http://lkml.kernel.org/r/20170531215653.3240-13-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename enum_map functionsJeremy Linton
Rename the core trace enum routines to use eval, to reflect their use by more than just enum to value mapping. Link: http://lkml.kernel.org/r/20170531215653.3240-8-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename trace.c enum functionsJeremy Linton
Rename the init and trace_enum_jmp_to_tail() routines to reflect their use by more than enumerated types. Link: http://lkml.kernel.org/r/20170531215653.3240-7-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename trace_enum_mutex to trace_eval_mutexJeremy Linton
There is a lock protecting the trace_enum_map, rename it to reflect the use by more than enums. Link: http://lkml.kernel.org/r/20170531215653.3240-6-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename trace enum data structures in trace.cJeremy Linton
The enum map entries can be exported to userspace via a sys enum_map file. Rename those functions and structures to reflect the fact that we are using them for more than enums. Link: http://lkml.kernel.org/r/20170531215653.3240-5-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename struct module entry for trace enumsJeremy Linton
Each module has a list of enum's its contributing to the enum map, rename that entry to reflect its use by more than enums. Link: http://lkml.kernel.org/r/20170531215653.3240-4-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename trace_enum_map to trace_eval_mapJeremy Linton
Each enum is loaded into the trace_enum_map, as we are now using this for more than enums rename it. Link: http://lkml.kernel.org/r/20170531215653.3240-3-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13trace: rename kernel enum section to evalJeremy Linton
The kernel and its modules have sections containing the enum string to value conversions. Rename this section because we intend to store more than enums in it. Link: http://lkml.kernel.org/r/20170531215653.3240-2-jeremy.linton@arm.com Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-13tracing: Remove unused declaration of trace_stop_cmdline_recordingJoel Fernandes
trace_stop_cmdline_recording declaration isn't in use, remove it. Link: http://lkml.kernel.org/r/20170609025327.9508-2-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-07ftrace/kprobes: selftests: Check kretprobe maxactive is supportedMasami Hiramatsu
Check the kretprobe maxactive is supported by kprobe_events interface. To ensure the kernel feature, this changes ftrace README to describe it. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-05-18tracing: Make sure RCU is watching before calling a stack traceSteven Rostedt (VMware)
As stack tracing now requires "rcu watching", force RCU to be watching when recording a stack trace. Link: http://lkml.kernel.org/r/20170512172449.879684501@goodmis.org Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stubSteven Rostedt (VMware)
No need to add ugly #ifdefs in the code. Having a standard stub file is much prettier. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17ftrace/instances: Clear function triggers when removing instancesNaveen N. Rao
If instance directories are deleted while there are registered function triggers: # cd /sys/kernel/debug/tracing/instances # mkdir test # echo "schedule:enable_event:sched:sched_switch" > test/set_ftrace_filter # rmdir test Unable to handle kernel paging request for data at address 0x00000008 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm iptable_filter fuse binfmt_misc pseries_rng rng_core vmx_crypto ib_iser rdma_cm iw_cm ib_cm ib_core libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c multipath virtio_net virtio_blk virtio_pci crc32c_vpmsum virtio_ring virtio CPU: 8 PID: 8694 Comm: rmdir Not tainted 4.11.0-nnr+ #113 task: c0000000bab52800 task.stack: c0000000baba0000 NIP: c0000000021edde8 LR: c0000000021f0590 CTR: c000000002119620 REGS: c0000000baba3870 TRAP: 0300 Not tainted (4.11.0-nnr+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22002422 XER: 20000000 CFAR: 00007fffabb725a8 DAR: 0000000000000008 DSISR: 40000000 SOFTE: 0 GPR00: c00000000220f750 c0000000baba3af0 c000000003157e00 0000000000000000 GPR04: 0000000000000040 00000000000000eb 0000000000000040 0000000000000000 GPR08: 0000000000000000 0000000000000113 0000000000000000 c00000000305db98 GPR12: c000000002119620 c00000000fd42c00 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c0000000bab52e90 0000000000000000 GPR24: 0000000000000000 00000000000000eb 0000000000000040 c0000000baba3bb0 GPR28: c00000009cb06eb0 c0000000bab52800 c00000009cb06eb0 c0000000baba3bb0 NIP [c0000000021edde8] ring_buffer_lock_reserve+0x8/0x4e0 LR [c0000000021f0590] trace_event_buffer_lock_reserve+0xe0/0x1a0 Call Trace: [c0000000baba3af0] [c0000000021f96c8] trace_event_buffer_commit+0x1b8/0x280 (unreliable) [c0000000baba3b60] [c00000000220f750] trace_event_buffer_reserve+0x80/0xd0 [c0000000baba3b90] [c0000000021196b8] trace_event_raw_event_sched_switch+0x98/0x180 [c0000000baba3c10] [c0000000029d9980] __schedule+0x6e0/0xab0 [c0000000baba3ce0] [c000000002122230] do_task_dead+0x70/0xc0 [c0000000baba3d10] [c0000000020ea9c8] do_exit+0x828/0xd00 [c0000000baba3dd0] [c0000000020eaf70] do_group_exit+0x60/0x100 [c0000000baba3e10] [c0000000020eb034] SyS_exit_group+0x24/0x30 [c0000000baba3e30] [c00000000200bcec] system_call+0x38/0x54 Instruction dump: 60000000 60420000 7d244b78 7f63db78 4bffaa09 393efff8 793e0020 39200000 4bfffecc 60420000 3c4c00f7 3842a020 <81230008> 2f890000 409e02f0 a14d0008 ---[ end trace b917b8985d0e650b ]--- Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Faulting instruction address: 0xc0000000021edde8 To address this, let's clear all registered function probes before deleting the ftrace instance. Link: http://lkml.kernel.org/r/c5f1ca624043690bd94642bb6bffd3f2fc504035.1494956770.git.naveen.n.rao@linux.vnet.ibm.com Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17tracing: Move postpone selftests to core from early_initcallSteven Rostedt
I hit the following lockdep splat when booting with ftrace selftests enabled, as well as CONFIG_PREEMPT and LOCKDEP. Testing dynamic ftrace ops #1: (1 0 1 0 0) (1 1 2 0 0) (2 1 3 0 169) (2 2 4 0 50066) ------------[ cut here ]------------ WARNING: CPU: 0 PID: 13 at kernel/rcu/srcutree.c:202 check_init_srcu_struct+0x60/0x70 Modules linked in: CPU: 0 PID: 13 Comm: rcu_tasks_kthre Not tainted 4.12.0-rc1-test+ #587 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 task: ffff880119628040 task.stack: ffffc900006a4000 RIP: 0010:check_init_srcu_struct+0x60/0x70 RSP: 0000:ffffc900006a7d98 EFLAGS: 00010246 RAX: 0000000000000246 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff880119628040 RSI: 00000000ffffffff RDI: ffffffff81e5fb40 RBP: ffffc900006a7e20 R08: 00000023b403c000 R09: 0000000000000001 R10: ffffc900006a7e40 R11: 0000000000000000 R12: ffffffff81e5fb40 R13: 0000000000000286 R14: ffff880119628040 R15: ffffc900006a7e98 FS: 0000000000000000(0000) GS:ffff88011ea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88011edff000 CR3: 0000000001e0f000 CR4: 00000000001406f0 Call Trace: ? __synchronize_srcu+0x6e/0x140 ? lock_acquire+0xdc/0x1d0 ? ktime_get_mono_fast_ns+0x5d/0xb0 synchronize_srcu+0x6f/0x110 ? synchronize_srcu+0x6f/0x110 rcu_tasks_kthread+0x20a/0x540 kthread+0x114/0x150 ? __rcu_read_unlock+0x70/0x70 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x2e/0x40 Code: f6 83 70 06 00 00 03 49 89 c5 74 0d be 01 00 00 00 48 89 df e8 42 fa ff ff 4c 89 ee 4c 89 e7 e8 b7 42 75 00 5b 41 5c 41 5d 5d c3 <0f> ff eb aa 66 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 ---[ end trace 5c3f4206ce50f6ac ]--- What happens is that the selftests include a creating of a dynamically allocated ftrace_ops, which requires the use of synchronize_rcu_tasks() which uses srcu, and triggers the above warning. It appears that synchronize_rcu_tasks() is not set up at early_initcall(), but it is at core_initcall(). By moving the tests down to that location works out properly. Link: http://lkml.kernel.org/r/20170517111435.7388c033@gandalf.local.home Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-08tracing: Use cpumask_available() to check if cpumask variable may be usedMatthias Kaehlcke
This fixes the following clang warning: kernel/trace/trace.c:3231:12: warning: address of array 'iter->started' will always evaluate to 'true' [-Wpointer-bool-conversion] if (iter->started) Link: http://lkml.kernel.org/r/20170421234110.117075-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-03tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()Amey Telawane
Strcpy is inherently not safe, and strlcpy() should be used instead. __trace_find_cmdline() uses strcpy() because the comms saved must have a terminating nul character, but it doesn't hurt to add the extra protection of using strlcpy() instead of strcpy(). Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org Signed-off-by: Amey Telawane <ameyt@codeaurora.org> [AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10 https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477] Signed-off-by: Amit Pundir <amit.pundir@linaro.org> [ Updated change log and removed the "- 1" from len parameter ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-03Merge tag 'trace-v4.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New features for this release: - Pretty much a full rewrite of the processing of function plugins. i.e. echo do_IRQ:stacktrace > set_ftrace_filter - The rewrite was needed to add plugins to be unique to tracing instances. i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter The old way was written very hacky. This removes a lot of those hacks. - New "function-fork" tracing option. When set, pids in the set_ftrace_pid will have their children added when the processes with their pids listed in the set_ftrace_pid file forks. - Exposure of "maxactive" for kretprobe in kprobe_events - Allow for builtin init functions to be traced by the function tracer (via the kernel command line). Module init function tracing will come in the next release. - Added more selftests, and have selftests also test in an instance" * tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits) ring-buffer: Return reader page back into existing ring buffer selftests: ftrace: Allow some event trigger tests to run in an instance selftests: ftrace: Have some basic tests run in a tracing instance too selftests: ftrace: Have event tests also run in an tracing instance selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances selftests: ftrace: Allow some tests to be run in a tracing instance tracing/ftrace: Allow for instances to trigger their own stacktrace probes tracing/ftrace: Allow for the traceonoff probe be unique to instances tracing/ftrace: Enable snapshot function trigger to work with instances tracing/ftrace: Allow instances to have their own function probes tracing/ftrace: Add a better way to pass data via the probe functions ftrace: Dynamically create the probe ftrace_ops for the trace_array tracing: Pass the trace_array into ftrace_probe_ops functions tracing: Have the trace_array hold the list of registered func probes ftrace: If the hash for a probe fails to update then free what was initialized ftrace: Have the function probes call their own function ftrace: Have each function probe use its own ftrace_ops ftrace: Have unregister_ftrace_function_probe_func() return a value ftrace: Add helper function ftrace_hash_move_and_update_ops() ftrace: Remove data field from ftrace_func_probe structure ...
2017-05-02Merge branch 'work.splice' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice updates from Al Viro: "These actually missed the last cycle; the branch itself is from last December" * 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: make nr_pages calculation in default_file_splice_read() a bit less ugly splice/tee/vmsplice: validate flags splice_pipe_desc: kill ->flags remove spd_release_page()
generated by cgit v1.3 (git 2.53.0) at 2026-04-18 13:34:02 +0000