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-rw-r--r--arch/powerpc/kernel/process.c6
-rw-r--r--arch/powerpc/kernel/signal_32.c21
-rw-r--r--arch/powerpc/kernel/signal_64.c20
-rw-r--r--include/asm-powerpc/system.h8
4 files changed, 31 insertions, 24 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 105d5609ff5..913f90692a3 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -201,13 +201,13 @@ int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
}
#endif /* CONFIG_SPE */
+#ifndef CONFIG_SMP
/*
* If we are doing lazy switching of CPU state (FP, altivec or SPE),
* and the current task has some state, discard it.
*/
-static inline void discard_lazy_cpu_state(void)
+void discard_lazy_cpu_state(void)
{
-#ifndef CONFIG_SMP
preempt_disable();
if (last_task_used_math == current)
last_task_used_math = NULL;
@@ -220,8 +220,8 @@ static inline void discard_lazy_cpu_state(void)
last_task_used_spe = NULL;
#endif
preempt_enable();
-#endif /* CONFIG_SMP */
}
+#endif /* CONFIG_SMP */
int set_dabr(unsigned long dabr)
{
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d3f0b6d452f..177bba78fb0 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -497,6 +497,15 @@ static long restore_user_regs(struct pt_regs *regs,
if (err)
return 1;
+ /*
+ * Do this before updating the thread state in
+ * current->thread.fpr/vr/evr. That way, if we get preempted
+ * and another task grabs the FPU/Altivec/SPE, it won't be
+ * tempted to save the current CPU state into the thread_struct
+ * and corrupt what we are writing there.
+ */
+ discard_lazy_cpu_state();
+
/* force the process to reload the FP registers from
current->thread when it next does FP instructions */
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
@@ -538,18 +547,6 @@ static long restore_user_regs(struct pt_regs *regs,
return 1;
#endif /* CONFIG_SPE */
-#ifndef CONFIG_SMP
- preempt_disable();
- if (last_task_used_math == current)
- last_task_used_math = NULL;
- if (last_task_used_altivec == current)
- last_task_used_altivec = NULL;
-#ifdef CONFIG_SPE
- if (last_task_used_spe == current)
- last_task_used_spe = NULL;
-#endif
- preempt_enable();
-#endif
return 0;
}
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 5462bef898f..7b9d999e211 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -207,10 +207,20 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
if (!sig)
regs->gpr[13] = save_r13;
- err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
if (set != NULL)
err |= __get_user(set->sig[0], &sc->oldmask);
+ /*
+ * Do this before updating the thread state in
+ * current->thread.fpr/vr. That way, if we get preempted
+ * and another task grabs the FPU/Altivec, it won't be
+ * tempted to save the current CPU state into the thread_struct
+ * and corrupt what we are writing there.
+ */
+ discard_lazy_cpu_state();
+
+ err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
+
#ifdef CONFIG_ALTIVEC
err |= __get_user(v_regs, &sc->v_regs);
err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
@@ -229,14 +239,6 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
current->thread.vrsave = 0;
#endif /* CONFIG_ALTIVEC */
-#ifndef CONFIG_SMP
- preempt_disable();
- if (last_task_used_math == current)
- last_task_used_math = NULL;
- if (last_task_used_altivec == current)
- last_task_used_altivec = NULL;
- preempt_enable();
-#endif
/* Force reload of FP/VEC */
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index 0c58e32a957..4c888303e85 100644
--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -133,6 +133,14 @@ extern int fix_alignment(struct pt_regs *);
extern void cvt_fd(float *from, double *to, struct thread_struct *thread);
extern void cvt_df(double *from, float *to, struct thread_struct *thread);
+#ifndef CONFIG_SMP
+extern void discard_lazy_cpu_state(void);
+#else
+static inline void discard_lazy_cpu_state(void)
+{
+}
+#endif
+
#ifdef CONFIG_ALTIVEC
extern void flush_altivec_to_thread(struct task_struct *);
#else