1 files changed, 25 insertions, 32 deletions

diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
index b3bc71680ae4..3771fb453898 100644
--- a/arch/hexagon/mm/vm_fault.c
+++ b/arch/hexagon/mm/vm_fault.c
@@ -11,14 +11,15 @@
  * execptions.
  */
 
-#include <asm/pgtable.h>
 #include <asm/traps.h>
+#include <asm/vm_fault.h>
 #include <linux/uaccess.h>
 #include <linux/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/signal.h>
 #include <linux/extable.h>
 #include <linux/hardirq.h>
+#include <linux/perf_event.h>
 
 /*
  * Decode of hardware exception sends us to one of several
@@ -33,7 +34,7 @@
 /*
  * Canonical page fault handler
  */
-void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
+static void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
@@ -41,7 +42,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 	int si_code = SEGV_MAPERR;
 	vm_fault_t fault;
 	const struct exception_table_entry *fixup;
-	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+	unsigned int flags = FAULT_FLAG_DEFAULT;
 
 	/*
 	 * If we're in an interrupt or have no user context,
@@ -54,22 +55,13 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 
 	if (user_mode(regs))
 		flags |= FAULT_FLAG_USER;
-retry:
-	down_read(&mm->mmap_sem);
-	vma = find_vma(mm, address);
-	if (!vma)
-		goto bad_area;
-
-	if (vma->vm_start <= address)
-		goto good_area;
 
-	if (!(vma->vm_flags & VM_GROWSDOWN))
-		goto bad_area;
-
-	if (expand_stack(vma, address))
-		goto bad_area;
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+retry:
+	vma = lock_mm_and_find_vma(mm, address, regs);
+	if (unlikely(!vma))
+		goto bad_area_nosemaphore;
 
-good_area:
 	/* Address space is OK.  Now check access rights. */
 	si_code = SEGV_ACCERR;
 
@@ -89,30 +81,30 @@ good_area:
 		break;
 	}
 
-	fault = handle_mm_fault(vma, address, flags);
+	fault = handle_mm_fault(vma, address, flags, regs);
+
+	if (fault_signal_pending(fault, regs)) {
+		if (!user_mode(regs))
+			goto no_context;
+		return;
+	}
 
-	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+	/* The fault is fully completed (including releasing mmap lock) */
+	if (fault & VM_FAULT_COMPLETED)
 		return;
 
 	/* The most common case -- we are done. */
 	if (likely(!(fault & VM_FAULT_ERROR))) {
-		if (flags & FAULT_FLAG_ALLOW_RETRY) {
-			if (fault & VM_FAULT_MAJOR)
-				current->maj_flt++;
-			else
-				current->min_flt++;
-			if (fault & VM_FAULT_RETRY) {
-				flags &= ~FAULT_FLAG_ALLOW_RETRY;
-				flags |= FAULT_FLAG_TRIED;
-				goto retry;
-			}
+		if (fault & VM_FAULT_RETRY) {
+			flags |= FAULT_FLAG_TRIED;
+			goto retry;
 		}
 
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 		return;
 	}
 
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	/* Handle copyin/out exception cases */
 	if (!user_mode(regs))
@@ -139,8 +131,9 @@ good_area:
 	return;
 
 bad_area:
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
+bad_area_nosemaphore:
 	if (user_mode(regs)) {
 		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
 		return;