kernel.git/kernel/trace/ftrace.c, branch linux-2.6.33.y

ftrace: Only update the function code on write to filter files

2011-06-23T22:28:33Z

commit 058e297d34a404caaa5ed277de15698d8dc43000 upstream. If function tracing is enabled, a read of the filter files will cause the call to stop_machine to update the function trace sites. It should only call stop_machine on write. Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

ftrace: Fix memory leak with function graph and cpu hotplug

2011-03-21T19:45:37Z

commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream. When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt Suggested-by: Peter Zijlstra Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

function-graph: Init curr_ret_stack with ret_stack

2010-04-01T23:01:16Z

commit ea14eb714041d40fcc5180b5a586034503650149 upstream. If the graph tracer is active, and a task is forked but the allocating of the processes graph stack fails, it can cause crash later on. This is due to the temporary stack being NULL, but the curr_ret_stack variable is copied from the parent. If it is not -1, then in ftrace_graph_probe_sched_switch() the following: for (index = next->curr_ret_stack; index >= 0; index--) next->ret_stack[index].calltime += timestamp; Will cause a kernel OOPS. Found with Li Zefan's ftrace_stress_test. Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

ftrace: Fix MATCH_END_ONLY function filter

2010-01-15T03:38:03Z

For '*foo' pattern, we should allow any string ending with 'foo', but ftrace filter incorrectly disallows strings like bar_foo_foo: # echo '*io' > set_ftrace_filter # cat set_ftrace_filter | grep 'req_bio_endio' # cat available_filter_functions | grep 'req_bio_endio' req_bio_endio Signed-off-by: Li Zefan LKML-Reference: <4B4E870E.6060607@cn.fujitsu.com> Acked-by: Frederic Weisbecker Signed-off-by: Steven Rostedt

function-graph: Allow writing the same val to set_graph_function

2009-12-13T17:37:26Z

# echo 'do_open' > set_graph_function # echo 'do_open' >> set_graph_function bash: echo: write error: Invalid argument Make it valid to write the same value to set_graph_function, which is consistent with set_ftrace_filter interface. Signed-off-by: Li Zefan Acked-by: Steven Rostedt LKML-reference: <4B1DC4E1.1060303@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker

ftrace: Call trace_parser_clear() properly

2009-12-13T17:37:26Z

I found a weird behavior: # echo 'fuse:*' > set_ftrace_filter bash: echo: write error: Invalid argument # cat set_ftrace_filter fuse_dev_fasync fuse_dev_poll fuse_copy_do We should call trace_parser_clear() no matter ftrace_process_regex() returns 0 or -errno, otherwise we will actually take the unaccepted records from ftrace_regex_release(). Signed-off-by: Li Zefan Acked-by: Steven Rostedt LKML-Reference: <4B1DC4D2.3000406@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker

ftrace: Return EINVAL when writing invalid val to set_ftrace_filter

2009-12-13T17:37:25Z

Currently it doesn't warn user on invald value: # echo nonexist_symbol > set_ftrace_filter or: # echo 'nonexist_symbol:mod:fuse' > set_ftrace_filter Better make it return failure. Signed-off-by: Li Zefan Acked-by: Steven Rostedt LKML-Reference: <4B1DC4BF.2070003@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker

Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-12-05T17:53:36Z

* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (40 commits) tracing: Separate raw syscall from syscall tracer ring-buffer-benchmark: Add parameters to set produce/consumer priorities tracing, function tracer: Clean up strstrip() usage ring-buffer benchmark: Run producer/consumer threads at nice +19 tracing: Remove the stale include/trace/power.h tracing: Only print objcopy version warning once from recordmcount tracing: Prevent build warning: 'ftrace_graph_buf' defined but not used ring-buffer: Move access to commit_page up into function used tracing: do not disable interrupts for trace_clock_local ring-buffer: Add multiple iterations between benchmark timestamps kprobes: Sanitize struct kretprobe_instance allocations tracing: Fix to use __always_unused attribute compiler: Introduce __always_unused tracing: Exit with error if a weak function is used in recordmcount.pl tracing: Move conditional into update_funcs() in recordmcount.pl tracing: Add regex for weak functions in recordmcount.pl tracing: Move mcount section search to front of loop in recordmcount.pl tracing: Fix objcopy revision check in recordmcount.pl tracing: Check absolute path of input file in recordmcount.pl tracing: Correct the check for number of arguments in recordmcount.pl ...

tracing, function tracer: Clean up strstrip() usage

2009-11-23T10:04:07Z

Clean up strstrip() usage - which also addresses this build warning: kernel/trace/ftrace.c: In function 'ftrace_pid_write': kernel/trace/ftrace.c:3004: warning: ignoring return value of 'strstrip', declared with attribute warn_unused_result Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar

tracing: Prevent build warning: 'ftrace_graph_buf' defined but not used

2009-11-17T16:05:49Z

Prevent build warning when CONFIG_FUNCTION_GRAPH_TRACER is not set. Signed-off-by: Lai Jiangshan LKML-Reference: <4AF24381.5060307@cn.fujitsu.com> Signed-off-by: Steven Rostedt