util/cutils: Let qemu_strtosz*() optionally reject trailing crap

Change the qemu_strtosz() & friends to return -EINVAL when @endptr is
null and the conversion doesn't consume the string completely.
Matches how qemu_strtol() & friends work.

Only test_qemu_strtosz_simple() passes a null @endptr.  No functional
change there, because its conversion consumes the string.

Simplify callers that use @endptr only to fail when it doesn't point
to '\0' to pass a null @endptr instead.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-22-git-send-email-armbru@redhat.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index b3d9ed99dd..848bebc794 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -1267,10 +1267,8 @@ static void ivshmem_realize(PCIDevice *dev, Error **errp)
     if (s->sizearg == NULL) {
         s->legacy_size = 4 << 20; /* 4 MB default */
     } else {
-        char *end;
-        int64_t size = qemu_strtosz_MiB(s->sizearg, &end);
-        if (size < 0 || (size_t)size != size || *end != '\0'
-            || !is_power_of_2(size)) {
+        int64_t size = qemu_strtosz_MiB(s->sizearg, NULL);
+        if (size < 0 || (size_t)size != size || !is_power_of_2(size)) {
             error_setg(errp, "Invalid size %s", s->sizearg);
             return;
         }