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>
This commit is contained in:
parent
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1 changed files with 0 additions and 2 deletions
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@ -620,7 +620,6 @@ asmlinkage unsigned long old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
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return -EFAULT;
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if (a.offset & ~PAGE_MASK)
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return -EINVAL;
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a.addr = (unsigned long) compat_ptr(a.addr);
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
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a.offset >> PAGE_SHIFT);
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}
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@ -631,7 +630,6 @@ asmlinkage long sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg)
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if (copy_from_user(&a, arg, sizeof(a)))
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return -EFAULT;
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a.addr = (unsigned long) compat_ptr(a.addr);
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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}
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