From 9bafd166e3d4d238339e78613cbb26c8665bd052 Mon Sep 17 00:00:00 2001
From: Tomoki Shirasawa <sira@popeye.cc.u-tokyo.ac.jp>
Date: Thu, 14 Jan 2016 16:18:49 +0900
Subject: [PATCH] futex: support FUTEX_CLOCK_REALTIME

---
 executer/user/mcexec.c | 10 +++----
 kernel/syscall.c       | 68 +++++++++++++++++++++++-------------------
 2 files changed, 43 insertions(+), 35 deletions(-)

diff --git a/executer/user/mcexec.c b/executer/user/mcexec.c
index a03a04ad..b4b001b1 100644
--- a/executer/user/mcexec.c
+++ b/executer/user/mcexec.c
@@ -1714,7 +1714,7 @@ int main_loop(int fd, int cpu, pthread_mutex_t *lock)
 	char *fn;
 	int sig;
 	int term;
-	struct timeval tv;
+	struct timespec tv;
 	char pathbuf[PATH_MAX];
 	char tmpbuf[PATH_MAX];
 
@@ -1753,13 +1753,13 @@ int main_loop(int fd, int cpu, pthread_mutex_t *lock)
 			break;
 
 		case __NR_futex:
-			ret = gettimeofday(&tv, NULL);
+			ret = clock_gettime(w.sr.args[1], &tv);
 			SET_ERR(ret);
-			__dprintf("gettimeofday=%016ld,%09ld\n",
+			__dprintf("clock_gettime=%016ld,%09ld\n",
 					tv.tv_sec,
-					tv.tv_usec);
+					tv.tv_nsec);
 			do_syscall_return(fd, cpu, ret, 1, (unsigned long)&tv,
-			                  w.sr.args[0], sizeof(struct timeval));
+			                  w.sr.args[0], sizeof(struct timespec));
 			break;
 
 		case __NR_kill: // interrupt syscall
diff --git a/kernel/syscall.c b/kernel/syscall.c
index a61ed68a..be22c167 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -2084,7 +2084,7 @@ getcred(int *_buf)
 	struct syscall_request request IHK_DMA_ALIGN;
 	unsigned long phys;
 
-	if(((unsigned long)_buf) & ((unsigned long)(_buf + 8)) & ~4095)
+	if((((unsigned long)_buf) ^ ((unsigned long)(_buf + 8))) & ~4095)
 		buf = _buf + 8;
 	else
 		buf = _buf;
@@ -3621,6 +3621,7 @@ SYSCALL_DECLARE(futex)
 	struct timespec *utime = (struct timespec*)ihk_mc_syscall_arg3(ctx);
 	uint32_t *uaddr2 = (uint32_t *)ihk_mc_syscall_arg4(ctx);
 	uint32_t val3 = (uint32_t)ihk_mc_syscall_arg5(ctx);
+	int flags = op;
     
 	/* Cross-address space futex? */
 	if (op & FUTEX_PRIVATE_FLAG) {
@@ -3629,7 +3630,7 @@ SYSCALL_DECLARE(futex)
 	op = (op & FUTEX_CMD_MASK);
 	
 	dkprintf("futex op=[%x, %s],uaddr=%lx, val=%x, utime=%lx, uaddr2=%lx, val3=%x, []=%x, shared: %d\n", 
-			op,
+			flags,
 			(op == FUTEX_WAIT) ? "FUTEX_WAIT" :
 			(op == FUTEX_WAIT_BITSET) ? "FUTEX_WAIT_BITSET" :
 			(op == FUTEX_WAKE) ? "FUTEX_WAKE" :
@@ -3641,38 +3642,45 @@ SYSCALL_DECLARE(futex)
 
 	if (utime && (op == FUTEX_WAIT_BITSET || op == FUTEX_WAIT)) {
 		unsigned long nsec_timeout;
-		struct timespec ats;
-
-		if (!gettime_local_support) {
-			struct syscall_request request IHK_DMA_ALIGN; 
-			struct timeval tv_now;
-			request.number = n;
-			unsigned long __phys;                                          
-
-			if (ihk_mc_pt_virt_to_phys(cpu_local_var(current)->vm->address_space->page_table, 
-						(void *)&tv_now, &__phys)) { 
-				return -EFAULT; 
-			}
-
-			request.args[0] = __phys;               
-
-			int r = do_syscall(&request, ihk_mc_get_processor_id(), 0);
-
-			if (r < 0) {
-				return -EFAULT;
-			}
-
-			ats.tv_sec = tv_now.tv_sec;
-			ats.tv_nsec = tv_now.tv_usec * 1000;
-		}
-		/* Compute timeout based on TSC/nanosec ratio */
-		else {
-			calculate_time_from_tsc(&ats);
-		}
 
 		/* As per the Linux implementation FUTEX_WAIT specifies the duration of
 		 * the timeout, while FUTEX_WAIT_BITSET specifies the absolute timestamp */
 		if (op == FUTEX_WAIT_BITSET) {
+			struct timespec ats;
+
+			if (!gettime_local_support ||
+			    !(flags & FUTEX_CLOCK_REALTIME)) {
+				struct syscall_request request IHK_DMA_ALIGN; 
+				struct timespec tv[2];
+				struct timespec *tv_now = tv;
+				request.number = n;
+				unsigned long __phys;                                          
+
+				if((((unsigned long)tv) ^ ((unsigned long)(tv + 1))) & ~4095)
+					tv_now = tv + 1;
+				if (ihk_mc_pt_virt_to_phys(cpu_local_var(current)->vm->address_space->page_table, 
+						(void *)tv_now, &__phys)) { 
+					return -EFAULT; 
+				}
+
+				request.args[0] = __phys;               
+				request.args[1] = (flags & FUTEX_CLOCK_REALTIME)?
+						      CLOCK_REALTIME: CLOCK_MONOTONIC;
+
+				int r = do_syscall(&request, ihk_mc_get_processor_id(), 0);
+
+				if (r < 0) {
+					return -EFAULT;
+				}
+
+				ats.tv_sec = tv_now->tv_sec;
+				ats.tv_nsec = tv_now->tv_nsec;
+			}
+			/* Compute timeout based on TSC/nanosec ratio */
+			else {
+				calculate_time_from_tsc(&ats);
+			}
+
 			nsec_timeout = (utime->tv_sec * NS_PER_SEC + utime->tv_nsec) -
 				(ats.tv_sec * NS_PER_SEC + ats.tv_nsec);
 		}