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[Qemu-devel] [PATCH] mmap-alloc: check before use for ptr pointer
From: |
Gonglei |
Subject: |
[Qemu-devel] [PATCH] mmap-alloc: check before use for ptr pointer |
Date: |
Wed, 12 Oct 2016 10:05:01 +0800 |
If ptr mmap failed, we don't need to do a superfluous
calculation for offset variable by ptr (MAP_FAILED).
Signed-off-by: Gonglei <address@hidden>
---
util/mmap-alloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 5a85aa3..577862b 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -61,13 +61,15 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool
shared)
#else
void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
#endif
- size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+ size_t offset;
void *ptr1;
if (ptr == MAP_FAILED) {
return MAP_FAILED;
}
+ offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+
/* Make sure align is a power of 2 */
assert(!(align & (align - 1)));
/* Always align to host page size */
--
1.8.3.1
- [Qemu-devel] [PATCH] mmap-alloc: check before use for ptr pointer,
Gonglei <=