linux-kernel - [PATCH 2/2] x86/mm: replace a goto by merging two if clause

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Date:   Thu, 19 Sep 2019 10:08:44 +0800
From:   Wei Yang <richardw.yang@...ux.intel.com>
To:     dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org,
        Wei Yang <richardw.yang@...ux.intel.com>
Subject: [PATCH 2/2] x86/mm: replace a goto by merging two if clause

There is only one place to use good_area jump, which could be reduced by
merging the following two if clause.

Signed-off-by: Wei Yang <richardw.yang@...ux.intel.com>
---
 arch/x86/mm/fault.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9d18b73b5f77..72ce6c69e195 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1390,18 +1390,17 @@ void do_user_addr_fault(struct pt_regs *regs,
 	vma = find_vma(mm, address);
 	if (unlikely(!vma))
 		goto bad_area;
-	if (likely(vma->vm_start <= address))
-		goto good_area;
-	if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))
-		goto bad_area;
-	if (unlikely(expand_stack(vma, address)))
+	if (likely(vma->vm_start <= address)) {
+		/* good area, do nothing */
+	} else if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)) ||
+		   unlikely(expand_stack(vma, address))) {
 		goto bad_area;
+	}
 
 	/*
 	 * Ok, we have a good vm_area for this memory access, so
 	 * we can handle it..
 	 */
-good_area:
 	if (unlikely(access_error(hw_error_code, vma))) {
 		bad_area_access_error(regs, hw_error_code, address, vma);
 		return;
-- 
2.17.1