[PATCH] mm: Optimizing error condition detection in do_mprotect_pkey()

From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Shuah Khan <shuah@kernel.org>,
	haitao.huang@intel.com, Kai Huang <kai.huang@intel.com>,
	x86@kernel.org, linux-sgx@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-kselftest@vger.kernel.org,
	Jia Zhang <zhang.jia@linux.alibaba.com>
Cc: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Subject: [PATCH] mm: Optimizing error condition detection in do_mprotect_pkey()
Date: Mon, 18 Jan 2021 21:33:10 +0800	[thread overview]
Message-ID: <20210118133310.98375-1-tianjia.zhang@linux.alibaba.com> (raw)

Obviously, the error variable detection of the if statement is
for the mprotect callback function, so it is also put into the
scope of calling callbck.

Reported-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 mm/mprotect.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index ab709023e9aa..94188df1ee55 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -617,10 +617,11 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		if (tmp > end)
 			tmp = end;
 
-		if (vma->vm_ops && vma->vm_ops->mprotect)
+		if (vma->vm_ops && vma->vm_ops->mprotect) {
 			error = vma->vm_ops->mprotect(vma, nstart, tmp, newflags);
-		if (error)
-			goto out;
+			if (error)
+				goto out;
+		}
 
 		error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
 		if (error)
-- 
2.19.1.3.ge56e4f7

