[Qemu-devel] [PATCH v6 2/4] hw/core/loader.c: Read as long as possible in load_image_size()

[Li Zhijian]

Don't expect read(2) can always read as many as it's told.

CC: Richard Henderson <address@hidden>
CC: Stefano Garzarella <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Reviewed-by: Stefano Garzarella <address@hidden>

---
V5: update subject and add reviewed-by tag (Stefano Garzarella)
V4: add reviewed-by tag
---
 hw/core/loader.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index c4f62fe..bf2951f 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -77,21 +77,20 @@ int64_t get_image_size(const char *filename)
 ssize_t load_image_size(const char *filename, void *addr, size_t size)
 {
     int fd;
-    ssize_t actsize;
+    ssize_t actsize, l = 0;
 
     fd = open(filename, O_RDONLY | O_BINARY);
     if (fd < 0) {
         return -1;
     }
 
-    actsize = read(fd, addr, size);
-    if (actsize < 0) {
-        close(fd);
-        return -1;
+    while ((actsize = read(fd, addr + l, size - l)) > 0) {
+        l += actsize;
     }
+
     close(fd);
 
-    return actsize;
+    return actsize < 0 ? -1 : l;
 }
 
 /* read()-like version */
-- 
2.7.4