1 files changed, 170 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 75be20fdb270..a986effee1e0 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -24,7 +24,11 @@ notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7,
 	unsigned long ti_flags;
 	syscall_fn f;
 
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S))
+		BUG_ON(!(regs->msr & MSR_RI));
 	BUG_ON(!(regs->msr & MSR_PR));
+	BUG_ON(!FULL_REGS(regs));
+	BUG_ON(regs->softe != IRQS_ENABLED);
 
 	account_cpu_user_entry();
 
@@ -196,7 +200,7 @@ again:
 		trace_hardirqs_off();
 		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
 		local_irq_enable();
-		/* Took an interrupt which may have more exit work to do. */
+		/* Took an interrupt, may have more exit work to do. */
 		goto again;
 	}
 	local_paca->irq_happened = 0;
@@ -212,3 +216,168 @@ again:
 
 	return ret;
 }
+
+#ifdef CONFIG_PPC_BOOK3S /* BOOK3E not yet using this */
+notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
+{
+#ifdef CONFIG_PPC_BOOK3E
+	struct thread_struct *ts = &current->thread;
+#endif
+	unsigned long *ti_flagsp = &current_thread_info()->flags;
+	unsigned long ti_flags;
+	unsigned long flags;
+	unsigned long ret = 0;
+
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S))
+		BUG_ON(!(regs->msr & MSR_RI));
+	BUG_ON(!(regs->msr & MSR_PR));
+	BUG_ON(!FULL_REGS(regs));
+	BUG_ON(regs->softe != IRQS_ENABLED);
+
+	local_irq_save(flags);
+
+again:
+	ti_flags = READ_ONCE(*ti_flagsp);
+	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {
+		local_irq_enable(); /* returning to user: may enable */
+		if (ti_flags & _TIF_NEED_RESCHED) {
+			schedule();
+		} else {
+			if (ti_flags & _TIF_SIGPENDING)
+				ret |= _TIF_RESTOREALL;
+			do_notify_resume(regs, ti_flags);
+		}
+		local_irq_disable();
+		ti_flags = READ_ONCE(*ti_flagsp);
+	}
+
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && IS_ENABLED(CONFIG_PPC_FPU)) {
+		if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
+				unlikely((ti_flags & _TIF_RESTORE_TM))) {
+			restore_tm_state(regs);
+		} else {
+			unsigned long mathflags = MSR_FP;
+
+			if (cpu_has_feature(CPU_FTR_VSX))
+				mathflags |= MSR_VEC | MSR_VSX;
+			else if (cpu_has_feature(CPU_FTR_ALTIVEC))
+				mathflags |= MSR_VEC;
+
+			if ((regs->msr & mathflags) != mathflags)
+				restore_math(regs);
+		}
+	}
+
+	trace_hardirqs_on();
+	__hard_EE_RI_disable();
+	if (unlikely(lazy_irq_pending())) {
+		__hard_RI_enable();
+		trace_hardirqs_off();
+		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+		local_irq_enable();
+		local_irq_disable();
+		/* Took an interrupt, may have more exit work to do. */
+		goto again;
+	}
+	local_paca->irq_happened = 0;
+	irq_soft_mask_set(IRQS_ENABLED);
+
+#ifdef CONFIG_PPC_BOOK3E
+	if (unlikely(ts->debug.dbcr0 & DBCR0_IDM)) {
+		/*
+		 * Check to see if the dbcr0 register is set up to debug.
+		 * Use the internal debug mode bit to do this.
+		 */
+		mtmsr(mfmsr() & ~MSR_DE);
+		mtspr(SPRN_DBCR0, ts->debug.dbcr0);
+		mtspr(SPRN_DBSR, -1);
+	}
+#endif
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	local_paca->tm_scratch = regs->msr;
+#endif
+
+	kuap_check_amr();
+
+	account_cpu_user_exit();
+
+	return ret;
+}
+
+void unrecoverable_exception(struct pt_regs *regs);
+void preempt_schedule_irq(void);
+
+notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr)
+{
+	unsigned long *ti_flagsp = &current_thread_info()->flags;
+	unsigned long flags;
+	unsigned long ret = 0;
+
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && unlikely(!(regs->msr & MSR_RI)))
+		unrecoverable_exception(regs);
+	BUG_ON(regs->msr & MSR_PR);
+	BUG_ON(!FULL_REGS(regs));
+
+	if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) {
+		clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp);
+		ret = 1;
+	}
+
+	local_irq_save(flags);
+
+	if (regs->softe == IRQS_ENABLED) {
+		/* Returning to a kernel context with local irqs enabled. */
+		WARN_ON_ONCE(!(regs->msr & MSR_EE));
+again:
+		if (IS_ENABLED(CONFIG_PREEMPT)) {
+			/* Return to preemptible kernel context */
+			if (unlikely(*ti_flagsp & _TIF_NEED_RESCHED)) {
+				if (preempt_count() == 0)
+					preempt_schedule_irq();
+			}
+		}
+
+		trace_hardirqs_on();
+		__hard_EE_RI_disable();
+		if (unlikely(lazy_irq_pending())) {
+			__hard_RI_enable();
+			irq_soft_mask_set(IRQS_ALL_DISABLED);
+			trace_hardirqs_off();
+			local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+			/*
+			 * Can't local_irq_restore to replay if we were in
+			 * interrupt context. Must replay directly.
+			 */
+			if (irqs_disabled_flags(flags)) {
+				replay_soft_interrupts();
+			} else {
+				local_irq_restore(flags);
+				local_irq_save(flags);
+			}
+			/* Took an interrupt, may have more exit work to do. */
+			goto again;
+		}
+		local_paca->irq_happened = 0;
+		irq_soft_mask_set(IRQS_ENABLED);
+	} else {
+		/* Returning to a kernel context with local irqs disabled. */
+		__hard_EE_RI_disable();
+		if (regs->msr & MSR_EE)
+			local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
+	}
+
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	local_paca->tm_scratch = regs->msr;
+#endif
+
+	/*
+	 * We don't need to restore AMR on the way back to userspace for KUAP.
+	 * The value of AMR only matters while we're in the kernel.
+	 */
+	kuap_restore_amr(regs);
+
+	return ret;
+}
+#endif