From e85871218513c54f7dfdb6009043cb638f2fecbe Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 8 Aug 2012 09:32:20 +0200 Subject: [PATCH] s390/compat: fix mmap compat system calls The native 31 bit and the compat behaviour for the mmap system calls differ: In native 31 bit mode the passed in address for the mmap system call will be unmodified passed to sys_mmap_pgoff(). In compat mode however the passed in address will be modified with compat_ptr() which masks out the most significant bit. The result is that in native 31 bit mode each mmap request (with MAP_FIXED) will fail where the most significat bit is set, while in compat mode it may succeed. This odd behaviour was introduced with d3815898 "[S390] mmap: add missing compat_ptr conversion to both mmap compat syscalls". To restore a consistent behaviour accross native and compat mode this patch functionally reverts the above mentioned commit. Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/compat_linux.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index d1225089a4bb..f606d935f495 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -620,7 +620,6 @@ asmlinkage unsigned long old32_mmap(struct mmap_arg_struct_emu31 __user *arg) return -EFAULT; if (a.offset & ~PAGE_MASK) return -EINVAL; - a.addr = (unsigned long) compat_ptr(a.addr); return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT); } @@ -631,7 +630,6 @@ asmlinkage long sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg) if (copy_from_user(&a, arg, sizeof(a))) return -EFAULT; - a.addr = (unsigned long) compat_ptr(a.addr); return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset); }