[Adeos-main] [PATCH] x86: Always call fixup_if after event dispatching

[Jan Kiszka <jan.kiszka@domain.hid>]

As we may switch the Linux context as a result of calling
__ipipe_dispatch_event and, thus, may leave it with a different root
domain state independent of the return code, we have to call __fixup_if
unconditionally. Moreover, we should also always check for pending VIRQs
on return.

Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>

---
 arch/x86/kernel/ipipe.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

Index: b/arch/x86/kernel/ipipe.c
===================================================================
--- a/arch/x86/kernel/ipipe.c
+++ b/arch/x86/kernel/ipipe.c
@@ -540,6 +540,7 @@ asmlinkage void __ipipe_unstall_iret_roo
 asmlinkage int __ipipe_syscall_root(struct pt_regs regs)
 {
 	unsigned long flags;
+	int dont_pass;
 
 	__fixup_if(&regs);
 
@@ -551,8 +552,9 @@ asmlinkage int __ipipe_syscall_root(stru
 	   tail work has to be performed (for handling signals etc). */
 
 	if (__ipipe_syscall_watched_p(current, regs.orig_ax) &&
-	    __ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) &&
-	    __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL,&regs) > 0) {
+	    __ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL)) {
+		dont_pass = __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL,&regs);
+
 		/* We might enter here over a non-root domain and exit
 		 * over the root one as a result of the syscall
 		 * (i.e. by recycling the register set of the current
@@ -568,9 +570,10 @@ asmlinkage int __ipipe_syscall_root(stru
 			if ((ipipe_root_cpudom_var(irqpend_himask) & IPIPE_IRQMASK_VIRT) != 0)
 				__ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT);
 			local_irq_restore_hw(flags);
-			return -1;
-		}
-		return 1;
+			if (dont_pass)
+				return -1;
+		} else if (dont_pass)
+			return 1;
 	}
 
 	return 0;
@@ -610,6 +613,7 @@ asmlinkage int __ipipe_preempt_schedule_
 asmlinkage int __ipipe_syscall_root(struct pt_regs *regs)
 {
 	unsigned long flags;
+	int pass;
 
 	__fixup_if(regs);
 
@@ -621,8 +625,9 @@ asmlinkage int __ipipe_syscall_root(stru
 	   tail work has to be performed (for handling signals etc). */
 
 	if (__ipipe_syscall_watched_p(current, regs->orig_ax) &&
-	    __ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) &&
-	    __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs) > 0) {
+	    __ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL)) {
+		pass = !__ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs);
+
 		/* We might enter here over a non-root domain and exit
 		 * over the root one as a result of the syscall
 		 * (i.e. by recycling the register set of the current
@@ -632,6 +637,9 @@ asmlinkage int __ipipe_syscall_root(stru
 		 * stall bit on exit. */
 		__fixup_if(regs);
 
+		if (pass)
+			return 0;
+
 		if (ipipe_root_domain_p && !in_atomic()) {
 			/* Sync pending VIRQs before _TIF_NEED_RESCHED is tested. */
 			local_irq_save_hw(flags);
@@ -648,7 +656,7 @@ asmlinkage int __ipipe_syscall_root(stru
 		return 1;
 	}
 
-    return 0;
+	return 0;
 }
 
 #endif /* !CONFIG_X86_32 */