x86: fix fpu restore from sig return

If the task never used fpu, initialize the fpu before restoring the FP
state from the signal handler context. This will allocate the fpu
state, if the task never needed it before.

Reported-and-bisected-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Cc: Frederik Deweerdt <deweerdt@free.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Suresh Siddha
2008-05-10 19:31:45 +02:00
committed by Thomas Gleixner
parent 0646153921
commit fd3c3ed5d1
2 changed files with 19 additions and 3 deletions
+9 -1
View File
@@ -175,7 +175,15 @@ static inline int save_i387(struct _fpstate __user *buf)
*/
static inline int restore_i387(struct _fpstate __user *buf)
{
set_used_math();
struct task_struct *tsk = current;
int err;
if (!used_math()) {
err = init_fpu(tsk);
if (err)
return err;
}
if (!(task_thread_info(current)->status & TS_USEDFPU)) {
clts();
task_thread_info(current)->status |= TS_USEDFPU;