ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs
authorSteven Rostedt <srostedt@redhat.com>
Tue, 7 Jun 2011 13:26:46 +0000 (09:26 -0400)
committerSteven Rostedt <rostedt@goodmis.org>
Tue, 7 Jun 2011 18:49:19 +0000 (14:49 -0400)
commita4f18ed11a4ddf327dd91cd19e237278600ad327
treebbe96241c6db2be16e881920a3312ec937ed7cd1
parent265a5b7ee3eb21a4d0e53e17d59ba6eada91af39
ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs

Revert the commit that removed the disabling of interrupts around
the initial modifying of mcount callers to nops, and update the comment.

The original comment was outdated and stated that the interrupts were
being disabled to prevent kstop machine, which was required with the
old ftrace daemon, but was no longer the case.

What the comment failed to mention was that interrupts needed to be
disabled to keep interrupts from preempting the modifying of the code
and then executing the code that was partially modified.

Revert the commit and update the comment.

Reported-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
kernel/trace/ftrace.c