On 20/11/18 16:27, Marc-André Lureau wrote:
It seems adding an assert is enough to silence GCC.
(sd_parse_snapid_or_tag() g_strlcpy() ensures that we don't get in
that situation)
~/src/qemu/block/sheepdog.c: In function 'find_vdi_name':
~/src/qemu/block/sheepdog.c:1239:5: error: 'strncpy' specified bound 256 equals
destination size [-Werror=stringop-truncation]
strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);
^~
cc1: all warnings being treated as errors
Fixes: https://bugs.launchpad.net/bugs/1803872
Signed-off-by: Marc-André Lureau
---
block/sheepdog.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 0125df9d49..f8877b611d 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1236,6 +1236,7 @@ static int find_vdi_name(BDRVSheepdogState *s, const char
*filename,
* don't want the send_req to read uninitialized data.
*/
strncpy(buf, filename, SD_MAX_VDI_LEN);
+assert(strlen(tag) < SD_MAX_VDI_TAG_LEN);
strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);
memset(&hdr, 0, sizeof(hdr));
I tried to fix this warning this way:
-char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN];
+struct {
+char vdi[SD_MAX_VDI_LEN];
+char vdi_tag[SD_MAX_VDI_TAG_LEN];
+} buf;
...
-strncpy(buf, filename, SD_MAX_VDI_LEN);
-strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);
+strncpy(buf.vdi, filename, SD_MAX_VDI_LEN);
+strncpy(buf.vdi_tag, tag, SD_MAX_VDI_TAG_LEN);
but your patch is simpler.
Reviewed-by: Philippe Mathieu-Daudé
Thanks,
Phil.
