MIPS: TXx9: Make firmware parameter passing more robust
When booting Linux on a txx9 board with VxWorks boot loader, it crashes in
prom_getenv(), as VxWorks doesn't pass firmware parameters in a0-a3 (in my
case, the actual leftover values in these registers were 0x80002000,
0x80001fe0, 0x2000, and 0x20).
Make the parsing of argc, argv, and envp a bit more robust by checking if
argc is a number below CKSEG0, and argv/envp point to CKSEG0.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/txx9/generic/setup.c b/arch/mips/txx9/generic/setup.c
index 18086c5..a13a08b 100644
--- a/arch/mips/txx9/generic/setup.c
+++ b/arch/mips/txx9/generic/setup.c
@@ -156,11 +156,23 @@
static void __init prom_init_cmdline(void)
{
- int argc = (int)fw_arg0;
- int *argv32 = (int *)fw_arg1;
+ int argc;
+ int *argv32;
int i; /* Always ignore the "-c" at argv[0] */
char builtin[CL_SIZE];
+ if (fw_arg0 >= CKSEG0 || fw_arg1 < CKSEG0) {
+ /*
+ * argc is not a valid number, or argv32 is not a valid
+ * pointer
+ */
+ argc = 0;
+ argv32 = NULL;
+ } else {
+ argc = (int)fw_arg0;
+ argv32 = (int *)fw_arg1;
+ }
+
/* ignore all built-in args if any f/w args given */
/*
* But if built-in strings was started with '+', append them
@@ -414,10 +426,12 @@
const char *__init prom_getenv(const char *name)
{
- const s32 *str = (const s32 *)fw_arg2;
+ const s32 *str;
- if (!str)
+ if (fw_arg2 < CKSEG0)
return NULL;
+
+ str = (const s32 *)fw_arg2;
/* YAMON style ("name", "value" pairs) */
while (str[0] && str[1]) {
if (!strcmp((const char *)(unsigned long)str[0], name))