[PATCH v2 2/2] arm: mm: drop VM_FAULT_BADMAP/VM_FAULT_BADACCESS

[Kefeng Wang <wangkefeng.wang@huawei.com>]

If bad map or access, directly set code to SEGV_MAPRR or SEGV_ACCERR,
also set fault to 0 and goto error handling, which make us to drop the
arch's special vm fault reason.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 arch/arm/mm/fault.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 5c4b417e24f9..45c141a6e087 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -226,9 +226,6 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 }
 
 #ifdef CONFIG_MMU
-#define VM_FAULT_BADMAP		((__force vm_fault_t)0x010000)
-#define VM_FAULT_BADACCESS	((__force vm_fault_t)0x020000)
-
 static inline bool is_permission_fault(unsigned int fsr)
 {
 	int fs = fsr_fs(fsr);
@@ -295,7 +292,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (!(vma->vm_flags & vm_flags)) {
 		vma_end_read(vma);
 		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
-		fault = VM_FAULT_BADACCESS;
+		fault = 0;
+		code = SEGV_ACCERR;
 		goto bad_area;
 	}
 	fault = handle_mm_fault(vma, addr, flags | FAULT_FLAG_VMA_LOCK, regs);
@@ -321,7 +319,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 retry:
 	vma = lock_mm_and_find_vma(mm, addr, regs);
 	if (unlikely(!vma)) {
-		fault = VM_FAULT_BADMAP;
+		fault = 0;
+		code = SEGV_MAPERR;
 		goto bad_area;
 	}
 
@@ -329,10 +328,14 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	 * ok, we have a good vm_area for this memory access, check the
 	 * permissions on the VMA allow for the fault which occurred.
 	 */
-	if (!(vma->vm_flags & vm_flags))
-		fault = VM_FAULT_BADACCESS;
-	else
-		fault = handle_mm_fault(vma, addr & PAGE_MASK, flags, regs);
+	if (!(vma->vm_flags & vm_flags)) {
+		mmap_read_unlock(mm);
+		fault = 0;
+		code = SEGV_ACCERR;
+		goto bad_area;
+	}
+
+	fault = handle_mm_fault(vma, addr & PAGE_MASK, flags, regs);
 
 	/* If we need to retry but a fatal signal is pending, handle the
 	 * signal first. We do not need to release the mmap_lock because
@@ -358,12 +361,11 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	mmap_read_unlock(mm);
 done:
 
-	/*
-	 * Handle the "normal" case first - VM_FAULT_MAJOR
-	 */
-	if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
+	/* Handle the "normal" case first */
+	if (likely(!(fault & VM_FAULT_ERROR)))
 		return 0;
 
+        code = SEGV_MAPERR;
 bad_area:
 	/*
 	 * If we are in kernel mode at this point, we
@@ -395,8 +397,6 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 		 * isn't in our memory map..
 		 */
 		sig = SIGSEGV;
-		code = fault == VM_FAULT_BADACCESS ?
-			SEGV_ACCERR : SEGV_MAPERR;
 	}
 
 	__do_user_fault(addr, fsr, sig, code, regs);
-- 
2.41.0