CHROMIUM: UBUNTU: SAUCE: trace: add trace events for open(), exec() and uselib()

BugLink: http://bugs.launchpad.net/bugs/462111



This patch uses TRACE_EVENT to add tracepoints for the open(),
exec() and uselib() syscalls so that ureadahead can cheaply trace
the boot sequence to determine what to read to speed up the next.

It's not upstream because it will need to be rebased onto the syscall
trace events whenever that gets merged, and is a stop-gap.

[benzh: 3.14 rebase. Squashed 2 warning fixes. Fixed a new incompatible
pointer type error for trace_open_exec() due to upstream change]

Signed-off-by: Scott James Remnant <scott@ubuntu.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Andy Whitcroft <andy.whitcroft@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Ben Zhang <benzh@chromium.org>

Conflicts:
	fs/exec.c
[rebase44(filbranden): Moved the trace_open_exec call to the block where
 fsnotify_open was.]
Signed-off-by: Filipe Brandenburger <filbranden@chromium.org>

Conflicts:
	fs/open.c
	fs/exec.c

[rebase412(groeck): Resolved conflicts]
[rebase510(groeck): Context conflicts (open syscalls rearranged)]
Signed-off-by: Guenter Roeck <groeck@chromium.org>
(cherry picked from commit 380de1b9172e380629163429c1cf45188615ffca)

BUG=b:180669321
BUG=b:180359699
TEST=emerge, /sys/kernel/debug/tracing/events/fs/do_sys_open/enable 1,
and /sys/kernel/debug/tracing/events/fs/open_exec/enable 1

[5.10-arcvm: picked from 5.10]
Signed-off-by: Alan Ding <alanding@chromium.org>
Change-Id: I5d8b303eb6c62a41965f8734234643f5f3a62e31
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3001421


Commit-Queue: Hikaru Nishida <hikalium@chromium.org>
Reviewed-by: Hikaru Nishida <hikalium@chromium.org>
Tested-by: Hikaru Nishida <hikalium@chromium.org>
Signed-off-by: Richard Fung <richardfung@google.com>