libxl: fix bootloader args setting

When bootloader_args = ['foo', 'bar'], then info->u.pv.bootloader_args =

    foo\0
    bar\0
    \0

Before this patch, 'p++' points to the next character of 'foo\0' and never
comes to 'bar\0' (because of the '\0' in 'foo\0'), so the args will be:

    args[0] = 'oo\0'
    args[1] = 'o\0'

After this patch, 'p++' points to the next string of pv.bootloader_args, so we
get the correct args:

    args[0] = 'foo\0'
    args[1] = 'bar\0'

Signed-off-by: Zhigang Wang <zhigang.x.wang@oracle.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/tools/libxl/libxl_bootloader.c b/tools/libxl/libxl_bootloader.c
index 2da1d90f34..907c871f65 100644
--- a/tools/libxl/libxl_bootloader.c
+++ b/tools/libxl/libxl_bootloader.c
@@ -49,9 +49,11 @@ static char **make_bootloader_args(libxl__gc *gc,
     flexarray_set(args, nr++, libxl__sprintf(gc, "--output-directory=%s", "/var/run/libxl/"));
 
     if (info->u.pv.bootloader_args) {
-        char *p = info->u.pv.bootloader_args[0];
-        while (*(p++))
-            flexarray_set(args, nr++, p);
+        char **p = info->u.pv.bootloader_args;
+        while (*p) {
+            flexarray_set(args, nr++, *p);
+            p++;
+        }
     }
 
     flexarray_set(args, nr++, disk);