user/sven/linux.git/kernel/trace/trace_uprobe.c, branch v3.10.44

tracing/uprobes: Fail to unregister if probe event files are in use

2013-08-29T16:47:34Z

commit c6c2401d8bbaf9edc189b4c35a8cb2780b8b988e upstream. Uprobes suffer the same problem that kprobes have. There's a race between writing to the "enable" file and removing the probe. The probe checks for it being in use and if it is not, goes about deleting the probe and the event that represents it. But the problem with that is, after it checks if it is in use it can be enabled, and the deletion of the event (access to the probe) will fail, as it is in use. But the uprobe will still be deleted. This is a problem as the event can reference the uprobe that was deleted. The fix is to remove the event first, and check to make sure the event removal succeeds. Then it is safe to remove the probe. When the event exists, either ftrace or perf can enable the probe and prevent the event from being removed. Link: http://lkml.kernel.org/r/20130704034038.991525256@goodmis.org Acked-by: Oleg Nesterov Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

uprobes: Fix return value in error handling path

2013-07-25T21:07:31Z

commit fa44063f9ef163c3a4c8d8c0465bb8a056b42035 upstream. When wrong argument is passed into uprobe_events it does not return an error: [root@jovi tracing]# echo 'p:myprobe /bin/bash' > uprobe_events [root@jovi tracing]# The proper response is: [root@jovi tracing]# echo 'p:myprobe /bin/bash' > uprobe_events -bash: echo: write error: Invalid argument Link: http://lkml.kernel.org/r/51B964FF.5000106@huawei.com Signed-off-by: zhangwei(Jovi) Cc: Frederic Weisbecker Cc: Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty

2013-04-15T15:39:52Z

perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense if this task/CPU has no active counters. Change uprobe_perf_print() to return if hlist_empty(call->perf_events). Note: this is not uprobe-specific, we can change other users too. Signed-off-by: Oleg Nesterov

uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()

2013-04-13T13:32:04Z

uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR, we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP. Signed-off-by: Oleg Nesterov Acked-by: Masami Hiramatsu Acked-by: Srikar Dronamraju

uprobes/tracing: Change create_trace_uprobe() to support uretprobes

2013-04-13T13:32:03Z

Finally change create_trace_uprobe() to check if argv[0][0] == 'r' and pass the correct "is_ret" to alloc_trace_uprobe(). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov

uprobes/tracing: Make seq_printf() code uretprobe-friendly

2013-04-13T13:32:03Z

Change probes_seq_show() and print_uprobe_event() to check is_ret_probe() and print the correct data. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov

uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly

2013-04-13T13:32:03Z

Change uprobe_event_define_fields(), and __set_print_fmt() to check is_ret_probe() and use the appropriate format/fields. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov

uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendly

2013-04-13T13:32:03Z

Change uprobe_trace_print() and uprobe_perf_print() to check is_ret_probe() and fill ring_buffer_event accordingly. Also change uprobe_trace_func() and uprobe_perf_func() to not _print() if is_ret_probe() is true. Note that we keep ->handler() nontrivial even for uretprobe, we need this for filtering and for other potential extensions. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov

uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()

2013-04-13T13:32:02Z

Create the new functions we need to support uretprobes, and change alloc_trace_uprobe() to initialize consumer.ret_handler if the new "is_ret" argument is true. Curently this argument is always false, so the new code is never called and is_ret_probe(tu) is false too. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov

uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpers

2013-04-13T13:32:01Z

Extract the output code from uprobe_trace_func() and uprobe_perf_func() into the new helpers, they will be used by ->ret_handler() too. We also add the unused "unsigned long func" argument in advance, to simplify the next changes. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Tested-by: Anton Arapov