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authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-08-08 11:32:20 +0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-08-08 18:32:57 +0400
commite85871218513c54f7dfdb6009043cb638f2fecbe (patch)
treeb50c4079fed166c1fd0e5b3de2a519bf617eb483 /arch
parent82aabdb6f1eb61e0034ec23901480f5dd23db7c4 (diff)
downloadlinux-e85871218513c54f7dfdb6009043cb638f2fecbe.tar.xz
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 <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/kernel/compat_linux.c2
1 files changed, 0 insertions, 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);
}