linux.git/kernel/trace/ftrace.c, branch v4.13-rc2

trace: fix the errors caused by incompatible type of RCU variables

2017-07-20T13:27:29+00:00

The variables which are processed by RCU functions should be annotated
as RCU, otherwise sparse will report the errors like below:

"error: incompatible types in comparison expression (different
address spaces)"

Link: http://lkml.kernel.org/r/1496823171-7758-1-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang 
[ Updated to not be 100% 80 column strict ]
Signed-off-by: Steven Rostedt (VMware)

ftrace: Fix uninitialized variable in match_records()

2017-07-12T13:48:31+00:00

My static checker complains that if "func" is NULL then "clear_filter"
is uninitialized.  This seems like it could be true, although it's
possible something subtle is happening that I haven't seen.

    kernel/trace/ftrace.c:3844 match_records()
    error: uninitialized symbol 'clear_filter'.

Link: http://lkml.kernel.org/r/20170712073556.h6tkpjcdzjaozozs@mwanda

Cc: stable@vger.kernel.org
Fixes: f0a3b154bd7 ("ftrace: Clarify code for mod command")
Signed-off-by: Dan Carpenter 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Remove an unneeded NULL check

2017-07-12T13:45:42+00:00

"func" can't be NULL and it doesn't make sense to check because we've
already derefenced it.

Link: http://lkml.kernel.org/r/20170712073340.4enzeojeoupuds5a@mwanda

Signed-off-by: Dan Carpenter 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Hide cached module code for !CONFIG_MODULES

2017-07-11T23:29:04+00:00

When modules are disabled, we get a harmless build warning:

kernel/trace/ftrace.c:4051:13: error: 'process_cached_mods' defined but not used [-Werror=unused-function]

This adds the same #ifdef around the new code that exists around
its caller.

Link: http://lkml.kernel.org/r/20170710084413.1820568-1-arnd@arndb.de

Fixes: d7fbf8df7ca0 ("ftrace: Implement cached modules tracing on module load")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Test for NULL iter->tr in regex for stack_trace_filter changes

2017-07-05T13:52:18+00:00

As writing into stack_trace_filter, the iter-tr is not set and is NULL.
Check if it is NULL before dereferencing it in ftrace_regex_release().

Fixes: 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter")
Signed-off-by: Steven Rostedt (VMware)

Merge commit '0f17976568b3f72e676450af0c0db6f8752253d6' into trace/ftrace/core

2017-07-05T13:51:24+00:00

Need to get the changes from 0f17976568b3 ("ftrace: Fix regression with
module command in stack_trace_filter") as it is required to fix some other
changes with stack_trace_filter and the new development code.

Signed-off-by: Steven Rostedt (VMware)

ftrace: Fix regression with module command in stack_trace_filter

2017-06-29T14:05:45+00:00

When doing the following command:

 # echo ":mod:kvm_intel" > /sys/kernel/tracing/stack_trace_filter

it triggered a crash.

This happened with the clean up of probes. It required all callers to the
regex function (doing ftrace filtering) to have ops->private be a pointer to
a trace_array. But for the stack tracer, that is not the case.

Allow for the ops->private to be NULL, and change the function command
callbacks to handle the trace_array pointer being NULL as well.

Fixes: d2afd57a4b96 ("tracing/ftrace: Allow instances to have their own function probes")
Signed-off-by: Steven Rostedt (VMware)

ftrace: Decrement count for dyn_ftrace_total_info for init functions

2017-06-28T15:57:03+00:00

Init boot up functions may be traced, but they are also freed when the
kernel finishes booting. These are removed from the ftrace tables, and the
debug variable for dyn_ftrace_total_info needs to reflect that as well.

Signed-off-by: Steven Rostedt (VMware)

ftrace: Unlock hash mutex on failed allocation in process_mod_list()

2017-06-28T13:09:38+00:00

If the new_hash fails to allocate, then unlock the hash mutex on error.

Reported-by: Julia Lawall 
Signed-off-by: Steven Rostedt (VMware)

ftrace: Decrement count for dyn_ftrace_total_info file

2017-06-27T17:30:27+00:00

The dyn_ftrace_total_info file is used to show how many functions have been
converted into nops and can be used by ftrace. The problem is that it does
not get decremented when functions are removed (init boot code being freed,
and modules being freed). That means the number is very inaccurate everytime
functions are removed from the ftrace tables. Decrement it when functions
are removed.

Signed-off-by: Steven Rostedt (VMware)