powerpc fixes for 4.13 #7

A bug in the VSX register saving that could cause userspace FP/VMX register
 corruption. Never seen to happen (that we know of), was found by code
 inspection, but still tagged for stable given the consequences.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJZlt/PAAoJEFHr6jzI4aWAHW8P/iKMN08HDpvG49xRlhzxlVxA
 blHw5HPBcnBO4wiVO5Imi5uryj59erPmD49fbvnoS8iYeJjLw6VitRV4UCOm0Ssx
 1oprF4xkaahtd4TJmbdf8WIz5H5NlYhpw5CXV1PRdP0X9r64MLIgZihYCdCWqGzN
 GLVTHtbIuNewJTN8IbLkmEdhAThtriBwFVUxrNOQ3JLqUPWAWO5qKeKgaPeeBLlw
 LJ4Q7TbdHgXZa/QEW2RmB+IfFcew4WVf/7+4ZgHjMhtSsIGrgqEE2680SGNY/rNY
 kXqR/g0l/GbQUjWFDDlveeJY5W0RenD/L4VodjS0ODMop9ZB+0LcRV0qUR7vDvmU
 7xi571hBPpskVsPH1sUahwJtaWAYkf5JqROLVryAYDBNcqnlohk4HdWltigT7asi
 GyHvJ32MWzmCDc0obEskQtqNlbIyRDy2qoTtl8O4YnWWf5nASKGyiRJlvLyLlADK
 2g64jP7vppfRM5cskZ3JkQ1NH3ORzVgwfGUNWaAZW4jCE8XeqXQnPtGsWvqqQJOd
 1UmxNHjtjc0TlMmxNp0EjGjpRXj8eerzDXv0ecRH/xqo376Ies99uGo/vs+htjrp
 HQ+wjOZxRk/jB0KBOoNbTkM6FY04I/ZIvIwJWboyEHzqctwj1pA63I+bzRbzBxww
 TLP2TDPIKiwTVbHcb6XP
 =jIDJ
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-4.13-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "A bug in the VSX register saving that could cause userspace FP/VMX
  register corruption.

  Never seen to happen (that we know of), was found by code inspection,
  but still tagged for stable given the consequences"

* tag 'powerpc-4.13-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Fix VSX enabling/flushing to also test MSR_FP and MSR_VEC
This commit is contained in:
Linus Torvalds 2017-08-18 11:11:03 -07:00
commit 039a8e3847
1 changed files with 3 additions and 2 deletions

View File

@ -362,7 +362,8 @@ void enable_kernel_vsx(void)
cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
if (current->thread.regs &&
(current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
check_if_tm_restore_required(current);
/*
* If a thread has already been reclaimed then the
@ -386,7 +387,7 @@ void flush_vsx_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_VSX) {
if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
BUG_ON(tsk != current);
giveup_vsx(tsk);
}