linux-toradex.git/kernel/trace/trace_probe.h, branch v3.15-rc7

tracing/uprobes: Support ftrace_event_file base multibuffer

2014-02-20T17:30:09+00:00

Support multi-buffer on uprobe-based dynamic events by
using ftrace_event_file.

This patch is based kprobe-based dynamic events multibuffer
support work initially, commited by Masami(commit 41a7dd420c),
but revised as below:

Oleg changed the kprobe-based multibuffer design from
array-pointers of ftrace_event_file into simple list,
so this patch also change to the list design.

rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
to synchronize with ftrace_event_file list add and delete.

Even though we allow multi-uprobes instances now,
but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
in probe_event_enable currently, this means we cannot allow
one user is using uprobe-tracer, and another user is using
perf-probe on same uprobe concurrently.
(Perhaps this will be fix in future, kprobe don't have this
limitation now)

Link: http://lkml.kernel.org/r/1389946120-19610-4-git-send-email-namhyung@kernel.org

Reviewed-by: Masami Hiramatsu 
Reviewed-by: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
Cc: Srikar Dronamraju 
Signed-off-by: zhangwei(Jovi) 
Signed-off-by: Namhyung Kim 
Signed-off-by: Steven Rostedt

tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT

2014-01-03T20:27:18+00:00

When kprobe-based dynamic event tracer is not enabled, it caused
following build error:

   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c8dd): undefined reference to `fetch_symbol_u8'
   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c8e9): undefined reference to `fetch_symbol_u16'
   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c8f5): undefined reference to `fetch_symbol_u32'
   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c901): undefined reference to `fetch_symbol_u64'
   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c909): undefined reference to `fetch_symbol_string'
   kernel/built-in.o: In function `traceprobe_update_arg':
   (.text+0x10c913): undefined reference to `fetch_symbol_string_size'
   ...

It was due to the fetch methods are referred from CHECK_FETCH_FUNCS
macro and since it was only defined in trace_kprobe.c.  Move NULL
definition of such fetch functions to the header file.

Note, it also requires CONFIG_BRANCH_PROFILING enabled to trigger
this failure as well. This is because the "fetch_symbol_*" variables
are referenced in a "else if" statement that will only call
update_symbol_cache(), which is a static inline stub function
when CONFIG_KPROBE_EVENT is not enabled. gcc is smart enough
to optimize this "else if" out and that also removes the code that
references the undefined variables.

But when BRANCH_PROFILING is enabled, it fools gcc into keeping
the if statement around and thus references the undefined symbols
and fails to build.

Reported-by: kbuild test robot 
Signed-off-by: Namhyung Kim 
Signed-off-by: Steven Rostedt

tracing/uprobes: Add @+file_offset fetch method

2014-01-03T01:57:05+00:00

Enable to fetch data from a file offset.  Currently it only supports
fetching from same binary uprobe set.  It'll translate the file offset
to a proper virtual address in the process.

The syntax is "@+OFFSET" as it does similar to normal memory fetching
(@ADDR) which does no address translation.

Suggested-by: Oleg Nesterov 
Acked-by: Masami Hiramatsu 
Acked-by: Oleg Nesterov 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Implement 'memory' fetch method for uprobes

2014-01-02T21:17:43+00:00

Use separate method to fetch from memory.  Move existing functions to
trace_kprobe.c and make them static.  Also add new memory fetch
implementation for uprobes.

Acked-by: Masami Hiramatsu 
Acked-by: Oleg Nesterov 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Move 'symbol' fetch method to kprobes

2014-01-02T21:17:41+00:00

Move existing functions to trace_kprobe.c and add NULL entries to the
uprobes fetch type table.  I don't make them static since some generic
routines like update/free_XXX_fetch_param() require pointers to the
functions.

Acked-by: Oleg Nesterov 
Cc: Masami Hiramatsu 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Implement 'stack' fetch method for uprobes

2014-01-02T21:17:40+00:00

Use separate method to fetch from stack.  Move existing functions to
trace_kprobe.c and make them static.  Also add new stack fetch
implementation for uprobes.

Acked-by: Oleg Nesterov 
Cc: Masami Hiramatsu 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Split [ku]probes_fetch_type_table

2014-01-02T21:17:39+00:00

Use separate fetch_type_table for kprobes and uprobes.  It currently
shares all fetch methods but some of them will be implemented
differently later.

This is not to break build if [ku]probes is configured alone (like
!CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT).  So I added '__weak'
to the table declaration so that it can be safely omitted when it
configured out.

Acked-by: Oleg Nesterov 
Acked-by: Masami Hiramatsu 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Move fetch function helpers to trace_probe.h

2014-01-02T21:17:38+00:00

Move fetch function helper macros/functions to the header file and
make them external.  This is preparation of supporting uprobe fetch
table in next patch.

Acked-by: Masami Hiramatsu 
Acked-by: Oleg Nesterov 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/probes: Integrate duplicate set_print_fmt()

2014-01-02T21:17:38+00:00

The set_print_fmt() functions are implemented almost same for
[ku]probes.  Move it to a common place and get rid of the duplication.

Acked-by: Masami Hiramatsu 
Acked-by: Oleg Nesterov 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

tracing/kprobes: Move common functions to trace_probe.h

2014-01-02T21:17:37+00:00

The __get_data_size() and store_trace_args() will be used by uprobes
too.  Move them to a common location.

Acked-by: Masami Hiramatsu 
Acked-by: Oleg Nesterov 
Cc: Srikar Dronamraju 
Cc: zhangwei(Jovi) 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim