s390/startup: correct command line options parsing

Check val is not NULL before accessing it. This might happen if
corresponding kernel command line options are used without specifying
values.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c
index 4a052a8..80b8d87 100644 (file)
--- a/arch/s390/boot/ipl_parm.c
+++ b/arch/s390/boot/ipl_parm.c
@@ -223,12 +223,12 @@ void parse_boot_command_line(void)
        while (*args) {
                args = next_arg(args, &param, &val);
 
-               if (!strcmp(param, "mem")) {
+               if (!strcmp(param, "mem") && val) {
                        memory_end = round_down(memparse(val, NULL), PAGE_SIZE);
                        memory_end_set = 1;
                }
 
-               if (!strcmp(param, "vmalloc"))
+               if (!strcmp(param, "vmalloc") && val)
                        vmalloc_size = round_up(memparse(val, NULL), PAGE_SIZE);
 
                if (!strcmp(param, "noexec")) {
@@ -237,7 +237,7 @@ void parse_boot_command_line(void)
                                noexec_disabled = 1;
                }
 
-               if (!strcmp(param, "facilities"))
+               if (!strcmp(param, "facilities") && val)
                        modify_fac_list(val);
 
                if (!strcmp(param, "nokaslr"))