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[Qemu-devel] [PATCH] linux-user/mmap.c: Support shared memory mapping in
From: |
chengang |
Subject: |
[Qemu-devel] [PATCH] linux-user/mmap.c: Support shared memory mapping in mmap_frag() |
Date: |
Wed, 30 Dec 2015 09:11:44 +0800 |
From: Chen Gang <address@hidden>
It is a temporary fix for i386 target system running Windows.
Also remove useless variable 'p'.
Signed-off-by: Chen Gang <address@hidden>
---
linux-user/mmap.c | 22 +++++++++++++++++++---
1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 445e8c6..07758d4 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -156,12 +156,28 @@ static int mmap_frag(abi_ulong real_start,
prot1 |= page_get_flags(addr);
}
+ /*
+ * It is a temporary fix. Normally, target system will let shared memory
+ * aligned with 64KB, and allocate them near with each other, no any other
+ * kinds of mapping regions nearby. e.g. Windows on i386.
+ */
+ if ((start == real_start) && (flags & MAP_SHARED)) {
+ if (prot1) {
+ munmap(host_start, qemu_host_page_size);
+ }
+ if (mmap(host_start, qemu_host_page_size, prot, flags, fd, offset)
+ == MAP_FAILED) {
+ return -1;
+ }
+ return 0;
+ }
+
if (prot1 == 0) {
/* no page was there, so we allocate one */
- void *p = mmap(host_start, qemu_host_page_size, prot,
- flags | MAP_ANONYMOUS, -1, 0);
- if (p == MAP_FAILED)
+ if (mmap(host_start, qemu_host_page_size, prot, flags | MAP_ANONYMOUS,
+ -1, 0) == MAP_FAILED) {
return -1;
+ }
prot1 = prot;
}
prot1 &= PAGE_BITS;
--
1.7.3.4
- [Qemu-devel] [PATCH] linux-user/mmap.c: Support shared memory mapping in mmap_frag(),
chengang <=