1 files changed, 38 insertions, 18 deletions

diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 283aa4b50b7..0dc922dba91 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -20,7 +20,6 @@
 #include <linux/sched.h>
 #include <linux/io.h>
 
-#include <asm/system.h>
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
@@ -169,7 +168,7 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 }
 
 static int __do_pf(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
-		struct task_struct *tsk)
+		unsigned int flags, struct task_struct *tsk)
 {
 	struct vm_area_struct *vma;
 	int fault;
@@ -195,14 +194,7 @@ good_area:
 	 * If for any reason at all we couldn't handle the fault, make
 	 * sure we exit gracefully rather than endlessly redo the fault.
 	 */
-	fault = handle_mm_fault(mm, vma, addr & PAGE_MASK,
-			    (!(fsr ^ 0x12)) ? FAULT_FLAG_WRITE : 0);
-	if (unlikely(fault & VM_FAULT_ERROR))
-		return fault;
-	if (fault & VM_FAULT_MAJOR)
-		tsk->maj_flt++;
-	else
-		tsk->min_flt++;
+	fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
 	return fault;
 
 check_stack:
@@ -217,6 +209,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	int fault, sig, code;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	tsk = current;
 	mm = tsk->mm;
@@ -228,6 +221,11 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (in_atomic() || !mm)
 		goto no_context;
 
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+	if (!(fsr ^ 0x12))
+		flags |= FAULT_FLAG_WRITE;
+
 	/*
 	 * As per x86, we may deadlock here.  However, since the kernel only
 	 * validly references user space from well defined areas of the code,
@@ -237,6 +235,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		if (!user_mode(regs)
 		    && !search_exception_tables(regs->UCreg_pc))
 			goto no_context;
+retry:
 		down_read(&mm->mmap_sem);
 	} else {
 		/*
@@ -252,7 +251,28 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 #endif
 	}
 
-	fault = __do_pf(mm, addr, fsr, tsk);
+	fault = __do_pf(mm, addr, fsr, flags, tsk);
+
+	/* If we need to retry but a fatal signal is pending, handle the
+	 * signal first. We do not need to release the mmap_sem because
+	 * it would already be released in __lock_page_or_retry in
+	 * mm/filemap.c. */
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return 0;
+
+	if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) {
+		if (fault & VM_FAULT_MAJOR)
+			tsk->maj_flt++;
+		else
+			tsk->min_flt++;
+		if (fault & VM_FAULT_RETRY) {
+			/* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
+			* of starvation. */
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			goto retry;
+		}
+	}
+
 	up_read(&mm->mmap_sem);
 
 	/*
@@ -262,6 +282,13 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	       (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
 		return 0;
 
+	/*
+	 * If we are in kernel mode at this point, we
+	 * have no context to handle this fault with.
+	 */
+	if (!user_mode(regs))
+		goto no_context;
+
 	if (fault & VM_FAULT_OOM) {
 		/*
 		 * We ran out of memory, call the OOM killer, and return to
@@ -272,13 +299,6 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		return 0;
 	}
 
-	/*
-	 * If we are in kernel mode at this point, we
-	 * have no context to handle this fault with.
-	 */
-	if (!user_mode(regs))
-		goto no_context;
-
 	if (fault & VM_FAULT_SIGBUS) {
 		/*
 		 * We had some memory, but were unable to