vm: add VM_FAULT_SIGSEGV handling support

[firefly-linux-kernel-4.4.55.git] / arch / powerpc / kernel / signal_64.c

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index c1794286098ca2f78c5e32f4c01b0891ca04fc78..74d9615a6bb6d1d9053d15ac59a1dba1537459f7 100644 (file)
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -121,6 +121,12 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
        flush_fp_to_thread(current);
        /* copy fpr regs and fpscr */
        err |= copy_fpr_to_user(&sc->fp_regs, current);
+
+       /*
+        * Clear the MSR VSX bit to indicate there is no valid state attached
+        * to this context, except in the specific case below where we set it.
+        */
+       msr &= ~MSR_VSX;
 #ifdef CONFIG_VSX
        /*
         * Copy VSX low doubleword to local buffer for formatting,
@@ -154,11 +160,12 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
  * As above, but Transactional Memory is in use, so deliver sigcontexts
  * containing checkpointed and transactional register states.
  *
- * To do this, we treclaim to gather both sets of registers and set up the
- * 'normal' sigcontext registers with rolled-back register values such that a
- * simple signal handler sees a correct checkpointed register state.
- * If interested, a TM-aware sighandler can examine the transactional registers
- * in the 2nd sigcontext to determine the real origin of the signal.
+ * To do this, we treclaim (done before entering here) to gather both sets of
+ * registers and set up the 'normal' sigcontext registers with rolled-back
+ * register values such that a simple signal handler sees a correct
+ * checkpointed register state.  If interested, a TM-aware sighandler can
+ * examine the transactional registers in the 2nd sigcontext to determine the
+ * real origin of the signal.
  */
 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
                                 struct sigcontext __user *tm_sc,
@@ -184,16 +191,6 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 
        BUG_ON(!MSR_TM_ACTIVE(regs->msr));
 
-       /* tm_reclaim rolls back all reg states, saving checkpointed (older)
-        * GPRs to thread.ckpt_regs and (if used) FPRs to (newer)
-        * thread.transact_fp and/or VRs to (newer) thread.transact_vr.
-        * THEN we save out FP/VRs, if necessary, to the checkpointed (older)
-        * thread.fr[]/vr[]s.  The transactional (newer) GPRs are on the
-        * stack, in *regs.
-        */
-       tm_enable();
-       tm_reclaim(&current->thread, msr, TM_CAUSE_SIGNAL);
-
        flush_fp_to_thread(current);
 
 #ifdef CONFIG_ALTIVEC
@@ -419,6 +416,10 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
 
        /* get MSR separately, transfer the LE bit if doing signal return */
        err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
+       /* pull in MSR TM from user context */
+       regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
+
+       /* pull in MSR LE from user context */
        regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 
        /* The following non-GPR non-FPR non-VR state is also checkpointed: */
@@ -512,10 +513,10 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
        }
 #endif
        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(&current->thread, msr);
-       /* The task has moved into TM state S, so ensure MSR reflects this: */
-       regs->msr = (regs->msr & ~MSR_TS_MASK) | __MASK(33);
 
        /* This loads the speculative FP/VEC state, if used */
        if (msr & MSR_FP) {
@@ -663,7 +664,7 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
        if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
                goto badframe;
-       if (MSR_TM_SUSPENDED(msr)) {
+       if (MSR_TM_ACTIVE(msr)) {
                /* We recheckpoint on return. */
                struct ucontext __user *uc_transact;
                if (__get_user(uc_transact, &uc->uc_link))
@@ -711,7 +712,7 @@ int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
        unsigned long newsp = 0;
        long err = 0;
 
-       frame = get_sigframe(ka, regs, sizeof(*frame), 0);
+       frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0);
        if (unlikely(frame == NULL))
                goto badframe;