linux/kernel/trace/trace.c, branch v4.8

Merge tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-09-26T01:40:13Z

Pull tracefs fixes from Steven Rostedt: "Al Viro has been looking at the tracefs code, and has pointed out some issues. This contains one fix by me and one by Al. I'm sure that he'll come up with more but for now I tested these patches and they don't appear to have any negative impact on tracing" * tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: fix memory leaks in tracing_buffers_splice_read() tracing: Move mutex to protect against resetting of seq data

fix memory leaks in tracing_buffers_splice_read()

2016-09-25T17:30:13Z

Cc: stable@vger.kernel.org Signed-off-by: Al Viro

tracing: Move mutex to protect against resetting of seq data

2016-09-25T14:27:08Z

The iter->seq can be reset outside the protection of the mutex. So can reading of user data. Move the mutex up to the beginning of the function. Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants") Cc: stable@vger.kernel.org # 2.6.30+ Reported-by: Al Viro Signed-off-by: Steven Rostedt

tracing: Using for_each_set_bit() to simplify trace_pid_write()

2016-07-05T15:22:40Z

Using for_each_set_bit() to simplify the code. Link: http://lkml.kernel.org/r/1467645004-11169-1-git-send-email-weiyj_lk@163.com Signed-off-by: Wei Yongjun Signed-off-by: Steven Rostedt

ftrace: Move toplevel init out of ftrace_init_tracefs()

2016-07-05T14:47:03Z

Commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the bitmap like events do") placed ftrace_init_tracefs into the instance creation, and encapsulated the top level updating with an if conditional, as the top level only gets updated at boot up. Unfortunately, this triggers section mismatch errors as the init functions are called from a function that can be called later, and the section mismatch logic is unaware of the if conditional that would prevent it from happening at run time. To make everyone happy, create a separate ftrace_init_tracefs_toplevel() routine that only gets called by init functions, and this will be what calls other init functions for the toplevel directory. Link: http://lkml.kernel.org/r/20160704102139.19cbc0d9@gandalf.local.home Reported-by: kbuild test robot Reported-by: Arnd Bergmann Fixes: 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the bitmap like events do") Signed-off-by: Steven Rostedt

tracing: Skip more functions when doing stack tracing of events

2016-06-23T22:48:56Z

# echo 1 > options/stacktrace # echo 1 > events/sched/sched_switch/enable # cat trace -0 [002] d..2 1982.525169: => save_stack_trace => __ftrace_trace_stack => trace_buffer_unlock_commit_regs => event_trigger_unlock_commit => trace_event_buffer_commit => trace_event_raw_event_sched_switch => __schedule => schedule => schedule_preempt_disabled => cpu_startup_entry => start_secondary The above shows that we are seeing 6 functions before ever making it to the caller of the sched_switch event. # echo stacktrace > events/sched/sched_switch/trigger # cat trace -0 [002] d..3 2146.335208: => trace_event_buffer_commit => trace_event_raw_event_sched_switch => __schedule => schedule => schedule_preempt_disabled => cpu_startup_entry => start_secondary The stacktrace trigger isn't as bad, because it adds its own skip to the stacktracing, but still has two events extra. One issue is that if the stacktrace passes its own "regs" then there should be no addition to the skip, as the regs will not include the functions being called. This was an issue that was fixed by commit 7717c6be6999 ("tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()" as adding the skip number for kprobes made the probes not have any stack at all. But since this is only an issue when regs is being used, a skip should be added if regs is NULL. Now we have: # echo 1 > options/stacktrace # echo 1 > events/sched/sched_switch/enable # cat trace -0 [000] d..2 1297.676333: => __schedule => schedule => schedule_preempt_disabled => cpu_startup_entry => rest_init => start_kernel => x86_64_start_reservations => x86_64_start_kernel # echo stacktrace > events/sched/sched_switch/trigger # cat trace -0 [002] d..3 1370.759745: => __schedule => schedule => schedule_preempt_disabled => cpu_startup_entry => start_secondary And kprobes are not touched. Reported-by: Peter Zijlstra Signed-off-by: Steven Rostedt

tracing: Choose static tp_printk buffer by explicit nesting count

2016-06-20T13:54:20Z

Currently, the trace_printk code chooses which static buffer to use based on what type of atomic context (NMI, IRQ, etc) it's in. Simplify the code and make it more robust: simply count the nesting depth and choose a buffer based on the current nesting depth. The new code will only drop an event if we nest more than 4 deep, and the old code was guaranteed to malfunction if that happened. Link: http://lkml.kernel.org/r/07ab03aecfba25fcce8f9a211b14c9c5e2865c58.1464289095.git.luto@kernel.org Acked-by: Namhyung Kim Signed-off-by: Andy Lutomirski Signed-off-by: Steven Rostedt

ftrace: Have set_ftrace_pid use the bitmap like events do

2016-06-20T13:54:19Z

Convert set_ftrace_pid to use the bitmap like set_event_pid does. This allows for instances to use the pid filtering as well, and will allow for function-fork option to set if the children of a traced function should be traced or not. Signed-off-by: Steven Rostedt

tracing: Move pid_list write processing into its own function

2016-06-20T13:54:18Z

The addition of PIDs into a pid_list via the write operation of set_event_pid is a bit complex. The same operation will be needed for function tracing pids. Move the code into its own generic function in trace.c, so that we can avoid duplication of this code. Signed-off-by: Steven Rostedt

tracing: Move the pid_list seq_file functions to be global

2016-06-20T13:54:17Z

To allow other aspects of ftrace to use the pid_list logic, we need to reuse the seq_file functions. Making the generic part into functions that can be called by other files will help in this regard. Signed-off-by: Steven Rostedt