linux-user: correct reboot()
According to man reboot(2), the 4th argument is only used with
LINUX_REBOOT_CMD_RESTART2. In other cases, trying to convert
the value can generate EFAULT.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 151f4f3..08538fc 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -101,6 +101,7 @@
#include <linux/fb.h>
#include <linux/vt.h>
#include <linux/dm-ioctl.h>
+#include <linux/reboot.h>
#include "linux_loop.h"
#include "cpu-uname.h"
@@ -6451,10 +6452,17 @@
break;
#endif
case TARGET_NR_reboot:
- if (!(p = lock_user_string(arg4)))
- goto efault;
- ret = reboot(arg1, arg2, arg3, p);
- unlock_user(p, arg4, 0);
+ if (arg3 == LINUX_REBOOT_CMD_RESTART2) {
+ /* arg4 must be ignored in all other cases */
+ p = lock_user_string(arg4);
+ if (!p) {
+ goto efault;
+ }
+ ret = get_errno(reboot(arg1, arg2, arg3, p));
+ unlock_user(p, arg4, 0);
+ } else {
+ ret = get_errno(reboot(arg1, arg2, arg3, NULL));
+ }
break;
#ifdef TARGET_NR_readdir
case TARGET_NR_readdir:
