Skip to content
Commit e8587121 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 82aabdb6
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment