commit a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()")

Above commit copies a string before checking for null pointer, fix this, and add a pr_err. Also trim comment, and add return val info.

Fixes: a2d375eda771 Cc: stable@vger.kernel.org Signed-off-by: Jim Cromie jim.cromie@gmail.com --- lib/dynamic_debug.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index bd7b3aaa93c3..711a9def8c83 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -553,17 +553,23 @@ static int ddebug_exec_queries(char *query, const char *modname) * @query: query-string described in admin-guide/dynamic-debug-howto * @modname: string containing module name, usually &module.mod_name * - * This uses the >/proc/dynamic_debug/control reader, allowing module - * authors to modify their dynamic-debug callsites. The modname is - * canonically struct module.mod_name, but can also be null or a - * module-wildcard, for example: "drm*". + * This uses the >control reader, allowing module authors to modify + * their dynamic-debug callsites. The modname is canonically struct + * module.mod_name, but can also be null or a module-wildcard, for + * example: "drm*". + * Returns <0 on error, >=0 for callsites changed */ int dynamic_debug_exec_queries(const char *query, const char *modname) { int rc; - char *qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL); + char *qry; /* writable copy of query */

- if (!query) + if (!query) { + pr_err("non-null query/command string expected\n"); + return -EINVAL; + } + qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL); + if (!qry) return -ENOMEM;

rc = ddebug_exec_queries(qry, modname);