linux-toradex.git/kernel/trace/trace_uprobe.c, branch v3.10.2

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

2013-04-15T15:39:52+00:00

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()

2013-04-13T13:32:04+00:00

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

2013-04-13T13:32:03+00:00

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

2013-04-13T13:32:03+00:00

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

2013-04-13T13:32:03+00:00

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

2013-04-13T13:32:03+00:00

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()

2013-04-13T13:32:02+00:00

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

2013-04-13T13:32:01+00:00

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

uprobes/tracing: Generalize struct uprobe_trace_entry_head

2013-04-13T13:32:01+00:00

struct uprobe_trace_entry_head has a single member for reporting,
"unsigned long ip". If we want to support uretprobes we need to
create another struct which has "func" and "ret_ip" and duplicate
a lot of functions, like trace_kprobe.c does.

To avoid this copy-and-paste horror we turn ->ip into ->vaddr[]
and add couple of trivial helpers to calculate sizeof/data. This
uglifies the code a bit, but this allows us to avoid a lot more
complications later, when we add the support for ret-probes.

Signed-off-by: Oleg Nesterov 
Acked-by: Srikar Dronamraju 
Tested-by: Anton Arapov

uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls

2013-04-13T13:32:00+00:00

uprobe_trace_func() is never called with irqs or preemption
disabled, no need to ask preempt_count() or local_save_flags().

Signed-off-by: Oleg Nesterov 
Acked-by: Srikar Dronamraju 
Acked-by: Masami Hiramatsu 
Tested-by: Anton Arapov