diff options
| -rw-r--r-- | arch/powerpc/kernel/process.c | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 21 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 20 | ||||
| -rw-r--r-- | include/asm-powerpc/system.h | 8 |
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(¤t->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(¤t->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 |