From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 5a69aec945d27e78abac9fd032533d3aaebf7c1e ]
VSX uses a combination of the old vector registers, the old FP
registers and new "second halves" of the FP registers.
Thus when we need to see the VSX state in the thread struct
(flush_vsx_to_thread()) or when we'll use the VSX in the kernel
(enable_kernel_vsx()) we need to ensure they are all flushed into
the thread struct if either of them is individually enabled.
Unfortunately we only tested if the whole VSX was enabled, not if they
were individually enabled.
Fixes: 72cd7b44bc99 ("powerpc: Uncomment and make enable_kernel_vsx() routine available")
Cc: stable@xxxxxxxxxxxxxxx # v4.3+
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
arch/powerpc/kernel/process.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dd023904bac5..9579f9c13315 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -209,7 +209,8 @@ void enable_kernel_vsx(void)
WARN_ON(preemptible());
#ifdef CONFIG_SMP
- if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
+ if (current->thread.regs &&
+ (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)))
giveup_vsx(current);
else
giveup_vsx(NULL); /* just enable vsx for kernel - force */
@@ -231,7 +232,7 @@ 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)) {
#ifdef CONFIG_SMP
BUG_ON(tsk != current);
#endif
--
2.14.1