[RFC PATCH 7/8] x86: mpx: pass atomic parameter to do_munmap()

From: Yang Shi <yang.shi@linux.alibaba.com>
To: akpm@linux-foundation.org
Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Borislav Petkov <bp@suse.de>,
	x86@kernel.org
Subject: [RFC PATCH 7/8] x86: mpx: pass atomic parameter to do_munmap()
Date: Wed, 21 Mar 2018 05:31:25 +0800	[thread overview]
Message-ID: <1521581486-99134-8-git-send-email-yang.shi@linux.alibaba.com> (raw)
In-Reply-To: <1521581486-99134-1-git-send-email-yang.shi@linux.alibaba.com>

Pass "true" to do_munmap() to not do unlock/relock to mmap_sem when
manipulating mpx map.

This is API change only.

Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: x86@kernel.org
---
 arch/x86/mm/mpx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index e500949..a180e94 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -780,7 +780,7 @@ static int unmap_entire_bt(struct mm_struct *mm,
 	 * avoid recursion, do_munmap() will check whether it comes
 	 * from one bounds table through VM_MPX flag.
 	 */
-	return do_munmap(mm, bt_addr, mpx_bt_size_bytes(mm), NULL);
+	return do_munmap(mm, bt_addr, mpx_bt_size_bytes(mm), NULL, true);
 }
 
 static int try_unmap_single_bt(struct mm_struct *mm,
-- 
1.8.3.1
