ftrace: Disable function tracing during suspend/resume and hibernation, again
authorSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Sat, 16 Jun 2012 13:30:45 +0000 (15:30 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Aug 2012 15:31:29 +0000 (08:31 -0700)
commitd3dd392851e014c90ce9e26d03a93188840a5a0b
treeb3c8bdf03765360c2d7b1eaf0bbb6f82ea06dbb3
parentfd3cca0a4e6ac0512e9122f59dfe0214b74049fb
ftrace: Disable function tracing during suspend/resume and hibernation, again

commit 443772d408a25af62498793f6f805ce3c559309a upstream.

If function tracing is enabled for some of the low-level suspend/resume
functions, it leads to triple fault during resume from suspend, ultimately
ending up in a reboot instead of a resume (or a total refusal to come out
of suspended state, on some machines).

This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
disable tracing for suspend to ram). However, the changes made by that commit
got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
suspend/resume & hibernation code again). So, unfortunately since things are
not yet robust enough to allow tracing of low-level suspend/resume functions,
suspend/resume is still broken when ftrace is enabled.

So fix this by disabling function tracing during suspend/resume & hibernation.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/power/hibernate.c
kernel/power/suspend.c