From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42193) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aAqIr-0002M0-VA for qemu-devel@nongnu.org; Sun, 20 Dec 2015 21:34:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aAqIo-0005gP-JO for qemu-devel@nongnu.org; Sun, 20 Dec 2015 21:34:25 -0500 Received: from out1134-219.mail.aliyun.com ([42.120.134.219]:36801) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aAqIo-0005fj-6s for qemu-devel@nongnu.org; Sun, 20 Dec 2015 21:34:22 -0500 From: chengang@emindsoft.com.cn Date: Mon, 21 Dec 2015 10:33:34 +0800 Message-Id: <1450665214-4467-1-git-send-email-chengang@emindsoft.com.cn> Subject: [Qemu-devel] [PATCH v2] linux-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: riku.voipio@iki.fi, laurent@vivier.eu Cc: peter.maydell@linaro.org, Chen Gang , Chen Gang , qemu-devel@nongnu.org, rth@twiddle.net From: Chen Gang When mapping MAP_ANONYMOUS memory fragments, still need notice about to set it zero, or it will cause issues. Signed-off-by: Chen Gang --- linux-user/mmap.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 7b459d5..29fe646 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -186,10 +186,12 @@ static int mmap_frag(abi_ulong real_start, if (prot_new != (prot1 | PROT_WRITE)) mprotect(host_start, qemu_host_page_size, prot_new); } else { - /* just update the protection */ if (prot_new != prot1) { mprotect(host_start, qemu_host_page_size, prot_new); } + if ((prot_new & PROT_WRITE) && ((flags & MAP_PRIVATE) || (fd == -1))) { + memset(g2h(start), 0, end - start); + } } return 0; } -- 1.7.3.4