1 files changed, 28 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3573d186505f..5fc5906ec337 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1296,6 +1296,19 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
         if (val & PR_FP_EXC_SW_ENABLE) {
 #ifdef CONFIG_SPE
                 if (cpu_has_feature(CPU_FTR_SPE)) {
+                        /*
+                         * When the sticky exception bits are set
+                         * directly by userspace, it must call prctl
+                         * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
+                         * in the existing prctl settings) or
+                         * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
+                         * the bits being set).  <fenv.h> functions
+                         * saving and restoring the whole
+                         * floating-point environment need to do so
+                         * anyway to restore the prctl settings from
+                         * the saved environment.
+                         */
+                        tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
                         tsk->thread.fpexc_mode = val &
                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
                         return 0;
@@ -1327,9 +1340,22 @@ int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
 
         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
 #ifdef CONFIG_SPE
-                if (cpu_has_feature(CPU_FTR_SPE))
+                if (cpu_has_feature(CPU_FTR_SPE)) {
+                        /*
+                         * When the sticky exception bits are set
+                         * directly by userspace, it must call prctl
+                         * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
+                         * in the existing prctl settings) or
+                         * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
+                         * the bits being set).  <fenv.h> functions
+                         * saving and restoring the whole
+                         * floating-point environment need to do so
+                         * anyway to restore the prctl settings from
+                         * the saved environment.
+                         */
+                        tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
                         val = tsk->thread.fpexc_mode;
-                else
+                } else
                         return -EINVAL;
 #else
                 return -EINVAL;