tree 11f550a59b9b653fbd6c54b37effbf2d4a750fb5
parent 60a5317ff0f42dd313094b88f809f63041568b08
author Tejun Heo <tj@kernel.org> 1234337460 +0900
committer Ingo Molnar <mingo@elte.hu> 1234348429 +0100

x86: fix x86_32 stack protector bugs

Impact: fix x86_32 stack protector

Brian Gerst found out that %gs was being initialized to stack_canary
instead of stack_canary - 20, which basically gave the same canary
value for all threads.  Fixing this also exposed the following bugs.

* cpu_idle() didn't call boot_init_stack_canary()

* stack canary switching in switch_to() was being done too late making
  the initial run of a new thread use the old stack canary value.

Fix all of them and while at it update comment in cpu_idle() about
calling boot_init_stack_canary().

Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>