Merge tag 'v3.18.44' into linux-linaro-lsk-v3.18lsk-v3.18-16.11

 This is the 3.18.44 stable release

6 files changed, 57 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index 22d83902b894..a13eee331533 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 3
 PATCHLEVEL = 18
-SUBLEVEL = 43
+SUBLEVEL = 44
 EXTRAVERSION =
 NAME = Diseased Newt
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 88635b301694..69608a4f554b 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -291,10 +291,9 @@ __setup("nosmap", setup_disable_smap);
 
 static __always_inline void setup_smap(struct cpuinfo_x86 *c)
 {
-	unsigned long eflags;
+	unsigned long eflags = native_save_fl();
 
 	/* This should have been cleared long ago */
-	raw_local_save_flags(eflags);
 	BUG_ON(eflags & X86_EFLAGS_AC);
 
 	if (cpu_has(c, X86_FEATURE_SMAP)) {
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index dfe835d21b15..0fa8fd9adeba 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -619,8 +619,30 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 		if ((raw_port_status & PORT_RESET) ||
 				!(raw_port_status & PORT_PE))
 			return 0xffffffff;
-		if (time_after_eq(jiffies,
-					bus_state->resume_done[wIndex])) {
+		/* did port event handler already start resume timing? */
+		if (!bus_state->resume_done[wIndex]) {
+			/* If not, maybe we are in a host initated resume? */
+			if (test_bit(wIndex, &bus_state->resuming_ports)) {
+				/* Host initated resume doesn't time the resume
+				 * signalling using resume_done[].
+				 * It manually sets RESUME state, sleeps 20ms
+				 * and sets U0 state. This should probably be
+				 * changed, but not right now.
+				 */
+			} else {
+				/* port resume was discovered now and here,
+				 * start resume timing
+				 */
+				unsigned long timeout = jiffies +
+					msecs_to_jiffies(USB_RESUME_TIMEOUT);
+
+				set_bit(wIndex, &bus_state->resuming_ports);
+				bus_state->resume_done[wIndex] = timeout;
+				mod_timer(&hcd->rh_timer, timeout);
+			}
+		/* Has resume been signalled for USB_RESUME_TIME yet? */
+		} else if (time_after_eq(jiffies,
+					 bus_state->resume_done[wIndex])) {
 			int time_left;
 
 			xhci_dbg(xhci, "Resume USB2 port %d\n",
@@ -661,13 +683,24 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 		} else {
 			/*
 			 * The resume has been signaling for less than
-			 * 20ms. Report the port status as SUSPEND,
-			 * let the usbcore check port status again
-			 * and clear resume signaling later.
+			 * USB_RESUME_TIME. Report the port status as SUSPEND,
+			 * let the usbcore check port status again and clear
+			 * resume signaling later.
 			 */
 			status |= USB_PORT_STAT_SUSPEND;
 		}
 	}
+	/*
+	 * Clear stale usb2 resume signalling variables in case port changed
+	 * state during resume signalling. For example on error
+	 */
+	if ((bus_state->resume_done[wIndex] ||
+	     test_bit(wIndex, &bus_state->resuming_ports)) &&
+	    (raw_port_status & PORT_PLS_MASK) != XDEV_U3 &&
+	    (raw_port_status & PORT_PLS_MASK) != XDEV_RESUME) {
+		bus_state->resume_done[wIndex] = 0;
+		clear_bit(wIndex, &bus_state->resuming_ports);
+	}
 	if ((raw_port_status & PORT_PLS_MASK) == XDEV_U0
 			&& (raw_port_status & PORT_POWER)
 			&& (bus_state->suspended_ports & (1 << wIndex))) {
@@ -998,6 +1031,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				if ((temp & PORT_PE) == 0)
 					goto error;
 
+				set_bit(wIndex, &bus_state->resuming_ports);
 				xhci_set_link_state(xhci, port_array, wIndex,
 							XDEV_RESUME);
 				spin_unlock_irqrestore(&xhci->lock, flags);
@@ -1005,6 +1039,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				spin_lock_irqsave(&xhci->lock, flags);
 				xhci_set_link_state(xhci, port_array, wIndex,
 							XDEV_U0);
+				clear_bit(wIndex, &bus_state->resuming_ports);
 			}
 			bus_state->port_c_suspend |= 1 << wIndex;
 
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index c15dbffe660b..cd88034c7a83 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1595,7 +1595,8 @@ static void handle_port_status(struct xhci_hcd *xhci,
 			 */
 			bogus_port_status = true;
 			goto cleanup;
-		} else {
+		} else if (!test_bit(faked_port_index,
+				     &bus_state->resuming_ports)) {
 			xhci_dbg(xhci, "resume HS port %d\n", port_id);
 			bus_state->resume_done[faked_port_index] = jiffies +
 				msecs_to_jiffies(USB_RESUME_TIMEOUT);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9eef3a1f2291..db853dee1ec5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2029,6 +2029,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma,
 #define FOLL_NUMA	0x200	/* force NUMA hinting page fault */
 #define FOLL_MIGRATION	0x400	/* wait for page to replace migration entry */
 #define FOLL_TRIED	0x800	/* a retry, previous pass started an IO */
+#define FOLL_COW	0x4000	/* internal GUP flag */
 
 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
 			void *data);
diff --git a/mm/gup.c b/mm/gup.c
index 377a5a796242..3cec4df06e6b 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -32,6 +32,16 @@ static struct page *no_page_table(struct vm_area_struct *vma,
 	return NULL;
 }
 
+/*
+ * FOLL_FORCE can write to even unwritable pte's, but only
+ * after we've gone through a COW cycle and they are dirty.
+ */
+static inline bool can_follow_write_pte(pte_t pte, unsigned int flags)
+{
+	return pte_write(pte) ||
+		((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte));
+}
+
 static struct page *follow_page_pte(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmd, unsigned int flags)
 {
@@ -66,7 +76,7 @@ retry:
 	}
 	if ((flags & FOLL_NUMA) && pte_numa(pte))
 		goto no_page;
-	if ((flags & FOLL_WRITE) && !pte_write(pte)) {
+	if ((flags & FOLL_WRITE) && !can_follow_write_pte(pte, flags)) {
 		pte_unmap_unlock(ptep, ptl);
 		return NULL;
 	}
@@ -315,7 +325,7 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
 	 * reCOWed by userspace write).
 	 */
 	if ((ret & VM_FAULT_WRITE) && !(vma->vm_flags & VM_WRITE))
-		*flags &= ~FOLL_WRITE;
+	        *flags |= FOLL_COW;
 	return 0;
 }