diff options
| -rw-r--r-- | sys/amd64/amd64/bios.c | 13 | ||||
| -rw-r--r-- | sys/i386/i386/bios.c | 13 |
2 files changed, 22 insertions, 4 deletions
diff --git a/sys/amd64/amd64/bios.c b/sys/amd64/amd64/bios.c index 980c0b52a4d28..cc8e30bf36ba4 100644 --- a/sys/amd64/amd64/bios.c +++ b/sys/amd64/amd64/bios.c @@ -24,7 +24,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: bios.c,v 1.17 1999/08/18 02:19:52 msmith Exp $ + * $Id: bios.c,v 1.18 1999/08/20 21:08:41 msmith Exp $ */ /* @@ -315,7 +315,16 @@ bios16(struct bios_args *args, char *fmt, ...) arg_start = 0xffffffff; arg_end = 0; - stack = (caddr_t)PAGE_SIZE; + /* + * Some BIOS entrypoints attempt to copy the largest-case + * argument frame (in order to generalise handling for + * different entry types). If our argument frame is + * smaller than this, the BIOS will reach off the top of + * our constructed stack segment. Pad the top of the stack + * with some garbage to avoid this. + */ + stack = (caddr_t)PAGE_SIZE - 32; + va_start(ap, fmt); for (p = fmt; p && *p; p++) { switch (*p) { diff --git a/sys/i386/i386/bios.c b/sys/i386/i386/bios.c index 980c0b52a4d28..cc8e30bf36ba4 100644 --- a/sys/i386/i386/bios.c +++ b/sys/i386/i386/bios.c @@ -24,7 +24,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: bios.c,v 1.17 1999/08/18 02:19:52 msmith Exp $ + * $Id: bios.c,v 1.18 1999/08/20 21:08:41 msmith Exp $ */ /* @@ -315,7 +315,16 @@ bios16(struct bios_args *args, char *fmt, ...) arg_start = 0xffffffff; arg_end = 0; - stack = (caddr_t)PAGE_SIZE; + /* + * Some BIOS entrypoints attempt to copy the largest-case + * argument frame (in order to generalise handling for + * different entry types). If our argument frame is + * smaller than this, the BIOS will reach off the top of + * our constructed stack segment. Pad the top of the stack + * with some garbage to avoid this. + */ + stack = (caddr_t)PAGE_SIZE - 32; + va_start(ap, fmt); for (p = fmt; p && *p; p++) { switch (*p) { |