[Qemu-devel] [PATCH for-1.5 2/2] osdep: introduce qemu_anon_ram_free to free qemu_anon_ram_alloc-ed memory

[Paolo Bonzini <pbonzini@redhat.com>]

We switched from qemu_memalign to mmap() but then we don't modify
qemu_vfree() to do a munmap() over free().  Which we cannot do
because qemu_vfree() frees memory allocated by qemu_{mem,block}align.

Introduce a new function that does the munmap(), luckily the size is
available in the RAMBlock.

Reported-by: Amos Kong <akong@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 exec.c               | 8 ++------
 include/qemu/osdep.h | 1 +
 trace-events         | 1 +
 util/oslib-posix.c   | 8 ++++++++
 util/oslib-win32.c   | 8 ++++++++
 5 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/exec.c b/exec.c
index b7e7494..7697be7 100644
--- a/exec.c
+++ b/exec.c
@@ -1156,21 +1156,17 @@ void qemu_ram_free(ram_addr_t addr)
                     munmap(block->host, block->length);
                     close(block->fd);
                 } else {
-                    qemu_vfree(block->host);
+                    qemu_anon_ram_free(block->host, block->length);
                 }
 #else
                 abort();
 #endif
             } else {
-#if defined(TARGET_S390X) && defined(CONFIG_KVM)
-                munmap(block->host, block->length);
-#else
                 if (xen_enabled()) {
                     xen_invalidate_map_cache_entry(block->host);
                 } else {
-                    qemu_vfree(block->host);
+                    qemu_anon_ram_free(block->host, block->length);
                 }
-#endif
             }
             g_free(block);
             break;
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index ae71042..d8e8500 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -98,6 +98,7 @@ int qemu_daemon(int nochdir, int noclose);
 void *qemu_memalign(size_t alignment, size_t size);
 void *qemu_anon_ram_alloc(size_t size);
 void qemu_vfree(void *ptr);
+void qemu_anon_ram_free(void *ptr, size_t size);
 
 #define QEMU_MADV_INVALID -1
 
diff --git a/trace-events b/trace-events
index acf0f5c..c7dbcf0 100644
--- a/trace-events
+++ b/trace-events
@@ -34,6 +34,7 @@ g_free(void *ptr) "ptr %p"
 qemu_memalign(size_t alignment, size_t size, void *ptr) "alignment %zu size %zu ptr %p"
 qemu_anon_ram_alloc(size_t size, void *ptr) "size %zu ptr %p"
 qemu_vfree(void *ptr) "ptr %p"
+qemu_anon_ram_free(void *ptr, size_t size) "size %zu ptr %p"
 
 # hw/virtio.c
 virtqueue_fill(void *vq, const void *elem, unsigned int len, unsigned int idx) "vq %p elem %p len %u idx %u"
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index e7e9c01..087edc9 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -135,6 +135,14 @@ void qemu_vfree(void *ptr)
     free(ptr);
 }
 
+void qemu_anon_ram_free(void *ptr, size_t size)
+{
+    trace_qemu_anon_ram_free(ptr, size);
+    if (ptr) {
+        munmap(ptr, size);
+    }
+}
+
 void qemu_set_block(int fd)
 {
     int f;
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index e83c22b..adcf514 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -76,6 +76,14 @@ void qemu_vfree(void *ptr)
     }
 }
 
+void qemu_anon_ram_free(void *ptr, size_t size)
+{
+    trace_qemu_anon_ram_free(ptr, size);
+    if (ptr) {
+        VirtualFree(ptr, 0, MEM_RELEASE);
+    }
+}
+
 /* FIXME: add proper locking */
 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 {
-- 
1.8.2.1