From dab46405d964a17f8df7df14cca5804537c3f590 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jan-Simon=20M=C3=B6ller?= Date: Sat, 17 Oct 2009 21:52:43 +0300 Subject: [PATCH] Re: linux-user/syscall.c - don't add GUEST_BASE to NULL pointer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch fixes the mount call. GUEST_BASE shouldn't be added to a NULL pointer on arg5 . failing call: mount("rootfs", "/", 0x47a78, MS_MGC_VAL|MS_REMOUNT, 0x10000) = -1 EFAULT (Bad address) correct call: mount("rootfs", "/", 0x37ab0, MS_MGC_VAL|MS_REMOUNT, NULL) = 0 Signed-off-by:  Jan-Simon Möller   Signed-off-by: Riku Voipio --- linux-user/syscall.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 31dfcb75c2..0254226a42 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4463,12 +4463,16 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, p3 = lock_user_string(arg3); if (!p || !p2 || !p3) ret = -TARGET_EFAULT; - else + else { /* FIXME - arg5 should be locked, but it isn't clear how to * do that since it's not guaranteed to be a NULL-terminated * string. */ - ret = get_errno(mount(p, p2, p3, (unsigned long)arg4, g2h(arg5))); + if ( ! arg5 ) + ret = get_errno(mount(p, p2, p3, (unsigned long)arg4, NULL)); + else + ret = get_errno(mount(p, p2, p3, (unsigned long)arg4, g2h(arg5))); + } unlock_user(p, arg1, 0); unlock_user(p2, arg2, 0); unlock_user(p3, arg3, 0); -- 2.11.0