linux-toradex.git/arch/powerpc/kernel/trace/ftrace_64_pg.S, branch v5.1

powerpc: Only support DYNAMIC_FTRACE not static

2018-05-03T12:32:29+00:00

We've had dynamic ftrace support for over 9 years since Steve first
wrote it, all the distros use dynamic, and static is basically
untested these days, so drop support for static ftrace.

Signed-off-by: Michael Ellerman 
Acked-by: Steven Rostedt (VMware) 
Signed-off-by: Michael Ellerman

powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

2018-05-03T12:32:25+00:00

We have some C code that we call into from real mode where we cannot
take any exceptions. Though the C functions themselves are mostly safe,
if these functions are traced, there is a possibility that we may take
an exception. For instance, in certain conditions, the ftrace code uses
WARN(), which uses a 'trap' to do its job.

For such scenarios, introduce a new field in paca 'ftrace_enabled',
which is checked on ftrace entry before continuing. This field can then
be set to zero to disable/pause ftrace, and set to a non-zero value to
resume ftrace.

Signed-off-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman

powerpc/ftrace/64: Split further based on -mprofile-kernel

2017-04-27T12:20:29+00:00

Split ftrace_64.S further retaining the core ftrace 64-bit aspects
in ftrace_64.S and moving ftrace_caller() and ftrace_graph_caller() into
separate files based on -mprofile-kernel. The livepatch routines are all
now contained within the mprofile file.

Signed-off-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman