From: chengang@emindsoft.com.cn
To: riku.voipio@iki.fi, laurent@vivier.eu
Cc: peter.maydell@linaro.org, Chen Gang <gang.chen.5i5j@gmail.com>,
Chen Gang <chengang@emindsoft.com.cn>,
qemu-devel@nongnu.org, rth@twiddle.net
Subject: [Qemu-devel] [PATCH v2] linux-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag()
Date: Mon, 21 Dec 2015 10:33:34 +0800 [thread overview]
Message-ID: <1450665214-4467-1-git-send-email-chengang@emindsoft.com.cn> (raw)
From: Chen Gang <chengang@emindsoft.com.cn>
When mapping MAP_ANONYMOUS memory fragments, still need notice about to
set it zero, or it will cause issues.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
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
next reply other threads:[~2015-12-21 2:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-21 2:33 chengang [this message]
2015-12-21 9:43 ` [Qemu-devel] [PATCH v2] linux-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag() Laurent Vivier
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