---
arch/powerpc/kernel/process.c | 13 ++++++++++++-
arch/powerpc/kernel/signal.c | 11 ++++++-----
arch/powerpc/kernel/signal_32.c | 16 ++--------------
arch/powerpc/kernel/signal_64.c | 41 +++++++++++++++++++++++++++++------------
4 files changed, 49 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 8a32fd062a2b..cd3ae80a6878 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1070,9 +1070,20 @@ void restore_tm_state(struct pt_regs *regs)
* again, anything else could lead to an incorrect ckpt_msr being
* saved and therefore incorrect signal contexts.
*/
- clear_thread_flag(TIF_RESTORE_TM);
+
+ /*
+ * So, on signals we're going to have cleared the TM bits from
+ * the MSR, meaning that heading to userspace signal handler
+ * this will be true.
+ * I'm not convinced clearing the TIF_RESTORE_TM flag is a
+ * good idea however, we should do it only if we actually
+ * recheckpoint, which we'll need to do once the signal
+ * hanlder is done and we're returning to the main thread of
+ * execution.
+ */
if (!MSR_TM_ACTIVE(regs->msr))
return;
+ clear_thread_flag(TIF_RESTORE_TM);
msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 61db86ecd318..4f0398c6ce03 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -191,16 +191,17 @@ unsigned long get_tm_stackpointer(struct task_struct *tsk)
*
* For signals taken in non-TM or suspended mode, we use the
* normal/non-checkpointed stack pointer.
+ *
+ * We now do reclaims on kernel entry, we should absolutely
+ * never need to reclaim here.
+ * TODO Update the comment above if needed.
*/
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BUG_ON(tsk != current);
- if (MSR_TM_ACTIVE(tsk->thread.regs->msr)) {
- tm_reclaim_current(TM_CAUSE_SIGNAL);
- if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr))
- return tsk->thread.ckpt_regs.gpr[1];
- }
+ if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr))
+ return tsk->thread.ckpt_regs.gpr[1];
#endif
return tsk->thread.regs->gpr[1];
}
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index a46de0035214..a87a7c8b5d9e 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -860,21 +860,9 @@ static long restore_tm_user_regs(struct pt_regs *regs,
tm_enable();
/* Make sure the transaction is marked as failed */
current->thread.tm_texasr |= TEXASR_FS;
- /* This loads the checkpointed FP/VEC state, if used */
- tm_recheckpoint(¤t->thread);
- /* This loads the speculative FP/VEC state, if used */
- msr_check_and_set(msr & (MSR_FP | MSR_VEC));
- if (msr & MSR_FP) {
- load_fp_state(¤t->thread.fp_state);
- regs->msr |= (MSR_FP | current->thread.fpexc_mode);
- }
-#ifdef CONFIG_ALTIVEC
- if (msr & MSR_VEC) {
- load_vr_state(¤t->thread.vr_state);
- regs->msr |= MSR_VEC;
- }
-#endif
+ /* See comment in signal_64.c */
+ set_thread_flag(TIF_RESTORE_TM);
return 0;
}
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 720117690822..a7751d1fcac6 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -568,21 +568,20 @@ static long restore_tm_sigcontexts(struct task_struct
*tsk,
}
}
#endif
- tm_enable();
/* Make sure the transaction is marked as failed */
tsk->thread.tm_texasr |= TEXASR_FS;
- /* This loads the checkpointed FP/VEC state, if used */
- tm_recheckpoint(&tsk->thread);
- msr_check_and_set(msr & (MSR_FP | MSR_VEC));
- if (msr & MSR_FP) {
- load_fp_state(&tsk->thread.fp_state);
- regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
- }
- if (msr & MSR_VEC) {
- load_vr_state(&tsk->thread.vr_state);
- regs->msr |= MSR_VEC;
- }
+ /*
+ * I believe this is only nessesary if the
+ * clear_thread_flag(TIF_RESTORE_TM); in restore_tm_state()
+ * stays before the if (!MSR_TM_ACTIVE(regs->msr).
+ *
+ * Actually no, we should follow the comment in
+ * restore_tm_state() but this should ALSO be here if
+ * if the signal handler does something crazy like 'generate'
+ * a transaction.
+ */
+ set_thread_flag(TIF_RESTORE_TM);
return err;
}
@@ -734,6 +733,22 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4,
unsigned long r5,
if (MSR_TM_SUSPENDED(mfmsr()))
tm_reclaim_current(0);
+ /*
+ * There is a universe where the signal handler did something
+ * crazy like drop the transaction entirely. That is, the main
+ * thread was in transactional or suspended mode and the
+ * signal handler has put them in non transactional mode.
+ * In that case we'll need to clear the TIF_RESTORE_TM flag.
+ * I'll need to ponder it exactly but for now thats all I
+ * think that needs to be done. At the moment it all works
+ * because no signal hanlder is nuts enough to do it.
+ *
+ * Add... somewhere... I guess in the else block, in the
+ * after the #endif
+ *
+ * clear_thread_flag(TIF_RESTORE_TM);
+ */
+
if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
goto badframe;
if (MSR_TM_ACTIVE(msr)) {
@@ -748,6 +763,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4,
unsigned long r5,
else
/* Fall through, for non-TM restore */
#endif
+ clear_thread_flag(TIF_RESTORE_TM);
+
if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
goto badframe;
--
2.16.2
