linux-toradex.git/fs/pstore/ftrace.c, branch v4.2.4

pstore: Add hsize argument in write_buf call of pstore_ftrace_call

2013-07-02T08:39:37+00:00

Incorporate the addition of hsize argument in write_buf callback
of pstore. This was forgotten in

    6bbbca735936e15b9431882eceddcf6dff76e03c
    pstore: Pass header size in the pstore write callback

Causing a build failure when ftrace and pstore are enabled.

Signed-off-by: Aruna Balakrishnaiah 
Signed-off-by: Benjamin Herrenschmidt

pstore/ftrace: Adjust for ftrace_ops->func prototype change

2012-12-13T03:50:04+00:00

This commit fixes the following warning:

 fs/pstore/ftrace.c:51:2: warning: initialization from incompatible
 pointer type [enabled by default]
 fs/pstore/ftrace.c:51:2: warning: (near initialization for
 ‘pstore_ftrace_ops.func’) [enabled by defaula

Signed-off-by: Anton Vorontsov

pstore/ftrace: Convert to its own enable/disable debugfs knob

2012-09-07T05:16:58+00:00

With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.

It's a bit more code, but that is the only downside. On the bright side we
have:

- Ability to make persistent_ram module removable (when needed, we can
  move ftrace_ops struct into a module). Note that persistent_ram is still
  not removable for other reasons, but with this patch it's just one
  thing less to worry about;

- Pstore part is more isolated from the generic function tracer. We tried
  it already by registering our own tracer in available_tracers, but that
  way we're loosing ability to see the traces while we record them to
  pstore. This solution is somewhere in the middle: we only register
  "internal ftracer" back-end, but not the "front-end";

- When there is only pstore tracing enabled, the kernel will only write
  to the pstore buffer, omitting function tracer buffer (which, of course,
  still can be enabled via 'echo function > current_tracer').

Suggested-by: Steven Rostedt 
Signed-off-by: Anton Vorontsov

pstore: Add persistent function tracing

2012-07-17T17:05:52+00:00

With this support kernel can save function call chain log into a
persistent ram buffer that can be decoded and dumped after reboot
through pstore filesystem. It can be used to determine what function
was last called before a reset or panic.

We store the log in a binary format and then decode it at read time.

p.s.
Mostly the code comes from trace_persistent.c driver found in the
Android git tree, written by Colin Cross 
(according to sign-off history). I reworked the driver a little bit,
and ported it to pstore.

Signed-off-by: Anton Vorontsov 
Signed-off-by: Greg Kroah-Hartman