exec: factor out duplicate mmap code

Anonymous and file-backed RAM allocation are now almost exactly the same.

Reduce code duplication by moving RAM mmap code out of oslib-posix.c and
exec.c.

Reported-by: Marc-André Lureau <mlureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Tested-by: Thibaut Collet <thibaut.collet@6wind.com>

1 files changed, 4 insertions, 24 deletions

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index a0fcdc2ede..892d2d8ad2 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -72,6 +72,8 @@ extern int daemon(int, int);
 #include <sys/sysctl.h>
 #endif
 
+#include <qemu/mmap-alloc.h>
+
 int qemu_get_thread_id(void)
 {
 #if defined(__linux__)
@@ -128,10 +130,7 @@ void *qemu_memalign(size_t alignment, size_t size)
 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
 {
     size_t align = QEMU_VMALLOC_ALIGN;
-    size_t total = size + align;
-    void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-    size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
-    void *ptr1;
+    void *ptr = qemu_ram_mmap(-1, size, align, false);
 
     if (ptr == MAP_FAILED) {
         return NULL;
@@ -141,23 +140,6 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
         *alignment = align;
     }
 
-    ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
-                MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-    if (ptr1 == MAP_FAILED) {
-        munmap(ptr, total);
-        return NULL;
-    }
-
-    ptr += offset;
-    total -= offset;
-
-    if (offset > 0) {
-        munmap(ptr - offset, offset);
-    }
-    if (total > size + getpagesize()) {
-        munmap(ptr + size + getpagesize(), total - size - getpagesize());
-    }
-
     trace_qemu_anon_ram_alloc(size, ptr);
     return ptr;
 }
@@ -171,9 +153,7 @@ void qemu_vfree(void *ptr)
 void qemu_anon_ram_free(void *ptr, size_t size)
 {
     trace_qemu_anon_ram_free(ptr, size);
-    if (ptr) {
-        munmap(ptr, size + getpagesize());
-    }
+    qemu_ram_munmap(ptr, size);
 }
 
 void qemu_set_block(int fd)