diff options
Diffstat (limited to 'kernel/arch/powerpc/kernel/process.c')
| -rw-r--r-- | kernel/arch/powerpc/kernel/process.c | 51 |
1 files changed, 43 insertions, 8 deletions
diff --git a/kernel/arch/powerpc/kernel/process.c b/kernel/arch/powerpc/kernel/process.c index 0596373cd..ef2ad2d68 100644 --- a/kernel/arch/powerpc/kernel/process.c +++ b/kernel/arch/powerpc/kernel/process.c @@ -86,7 +86,7 @@ void giveup_fpu_maybe_transactional(struct task_struct *tsk) if (tsk == current && tsk->thread.regs && MSR_TM_ACTIVE(tsk->thread.regs->msr) && !test_thread_flag(TIF_RESTORE_TM)) { - tsk->thread.tm_orig_msr = tsk->thread.regs->msr; + tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr; set_thread_flag(TIF_RESTORE_TM); } @@ -104,7 +104,7 @@ void giveup_altivec_maybe_transactional(struct task_struct *tsk) if (tsk == current && tsk->thread.regs && MSR_TM_ACTIVE(tsk->thread.regs->msr) && !test_thread_flag(TIF_RESTORE_TM)) { - tsk->thread.tm_orig_msr = tsk->thread.regs->msr; + tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr; set_thread_flag(TIF_RESTORE_TM); } @@ -540,7 +540,7 @@ static void tm_reclaim_thread(struct thread_struct *thr, * the thread will no longer be transactional. */ if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) { - msr_diff = thr->tm_orig_msr & ~thr->regs->msr; + msr_diff = thr->ckpt_regs.msr & ~thr->regs->msr; if (msr_diff & MSR_FP) memcpy(&thr->transact_fp, &thr->fp_state, sizeof(struct thread_fp_state)); @@ -551,6 +551,42 @@ static void tm_reclaim_thread(struct thread_struct *thr, msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1; } + /* + * Use the current MSR TM suspended bit to track if we have + * checkpointed state outstanding. + * On signal delivery, we'd normally reclaim the checkpointed + * state to obtain stack pointer (see:get_tm_stackpointer()). + * This will then directly return to userspace without going + * through __switch_to(). However, if the stack frame is bad, + * we need to exit this thread which calls __switch_to() which + * will again attempt to reclaim the already saved tm state. + * Hence we need to check that we've not already reclaimed + * this state. + * We do this using the current MSR, rather tracking it in + * some specific thread_struct bit, as it has the additional + * benifit of checking for a potential TM bad thing exception. + */ + if (!MSR_TM_SUSPENDED(mfmsr())) + return; + + /* + * Use the current MSR TM suspended bit to track if we have + * checkpointed state outstanding. + * On signal delivery, we'd normally reclaim the checkpointed + * state to obtain stack pointer (see:get_tm_stackpointer()). + * This will then directly return to userspace without going + * through __switch_to(). However, if the stack frame is bad, + * we need to exit this thread which calls __switch_to() which + * will again attempt to reclaim the already saved tm state. + * Hence we need to check that we've not already reclaimed + * this state. + * We do this using the current MSR, rather tracking it in + * some specific thread_struct bit, as it has the additional + * benifit of checking for a potential TM bad thing exception. + */ + if (!MSR_TM_SUSPENDED(mfmsr())) + return; + tm_reclaim(thr, thr->regs->msr, cause); /* Having done the reclaim, we now have the checkpointed @@ -591,10 +627,10 @@ static inline void tm_reclaim_task(struct task_struct *tsk) /* Stash the original thread MSR, as giveup_fpu et al will * modify it. We hold onto it to see whether the task used * FP & vector regs. If the TIF_RESTORE_TM flag is set, - * tm_orig_msr is already set. + * ckpt_regs.msr is already set. */ if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM)) - thr->tm_orig_msr = thr->regs->msr; + thr->ckpt_regs.msr = thr->regs->msr; TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " "ccr=%lx, msr=%lx, trap=%lx)\n", @@ -663,7 +699,7 @@ static inline void tm_recheckpoint_new_task(struct task_struct *new) tm_restore_sprs(&new->thread); return; } - msr = new->thread.tm_orig_msr; + msr = new->thread.ckpt_regs.msr; /* Recheckpoint to restore original checkpointed register state. */ TM_DEBUG("*** tm_recheckpoint of pid %d " "(new->msr 0x%lx, new->origmsr 0x%lx)\n", @@ -723,7 +759,7 @@ void restore_tm_state(struct pt_regs *regs) if (!MSR_TM_ACTIVE(regs->msr)) return; - msr_diff = current->thread.tm_orig_msr & ~regs->msr; + msr_diff = current->thread.ckpt_regs.msr & ~regs->msr; msr_diff &= MSR_FP | MSR_VEC | MSR_VSX; if (msr_diff & MSR_FP) { fp_enable(); @@ -1109,7 +1145,6 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) /* * Copy a thread.. */ -extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */ /* * Copy architecture-specific thread state |