linux-stable.git/arch/s390/kernel/compat_linux.c, branch master

s390: Remove compat support

2025-11-17T10:10:38+00:00

There shouldn't be any 31 bit code around anymore that matters.
Remove the compat layer support required to run 31 bit code.

Reason for removal is code simplification and reduced test effort.

Note that this comes without any deprecation warnings added to config
options, or kernel messages, since most likely those would be ignored
anyway.

If it turns out there is still a reason to keep the compat layer this
can be reverted at any time in the future.

Reviewed-by: Arnd Bergmann 
Signed-off-by: Heiko Carstens

s390: use generic UID16 implementation

2019-01-18T08:33:18+00:00

s390 has an almost identical copy of the code in kernel/uid16.c.

The problem here is that it requires calling the regular system calls,
which the generic implementation handles correctly, but the internal
interfaces are not declared in a global header for this.

The best way forward here seems to be to just use the generic code and
delete the s390 specific implementation.

I keep the changes to uapi/asm/posix_types.h inside of an #ifdef check
so user space does not observe any changes. As some of the system calls
pass pointers, we also need wrappers in compat_wrapper.c, which I add
for all calls with at least one argument. All those wrappers can be
removed in a later step.

Link: https://lore.kernel.org/lkml/20190116131527.2071570-4-arnd@arndb.de
Signed-off-by: Arnd Bergmann 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

2019-01-18T08:33:18+00:00

The sys_ipc() and compat_ksys_ipc() functions are meant to only
be used from the system call table, not called by another function.

Introduce ksys_*() interfaces for this purpose, as we have done
for many other system calls.

Link: https://lore.kernel.org/lkml/20190116131527.2071570-3-arnd@arndb.de
Signed-off-by: Arnd Bergmann 
Reviewed-by: Heiko Carstens 
[heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT]
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead()

2018-04-02T18:16:12+00:00

Using this helper allows us to avoid the in-kernel calls to the
sys_readahead() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_readahead().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton 
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski

mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()

2018-04-02T18:16:11+00:00

Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton 
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski

mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()

2018-04-02T18:16:10+00:00

Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel
calls to the sys_fadvise64_64() syscall. The ksys_ prefix denotes that
this function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as ksys_fadvise64_64().

Some compat stubs called sys_fadvise64(), which then just passed through
the arguments to sys_fadvise64_64(). Get rid of this indirection, and call
ksys_fadvise64_64() directly.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton 
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski

fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()

2018-04-02T18:16:09+00:00

Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_fallocate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro 
Cc: Andrew Morton 
Signed-off-by: Dominik Brodowski

fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls

2018-04-02T18:16:09+00:00

Using the ksys_p{read,write}64() wrappers allows us to get rid of
in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_p{read,write}64().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro 
Cc: Andrew Morton 
Signed-off-by: Dominik Brodowski

fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate()

2018-04-02T18:16:08+00:00

Using the ksys_truncate() wrapper allows us to get rid of in-kernel
calls to the sys_truncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_truncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro 
Cc: Andrew Morton 
Signed-off-by: Dominik Brodowski

fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall

2018-04-02T18:16:07+00:00

Using this helper allows us to avoid the in-kernel calls to the
sys_sync_file_range() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_sync_file_range().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro 
Cc: Andrew Morton 
Signed-off-by: Dominik Brodowski