1ecff5ef0a
Patch series "s390: rework compat wrapper generation". As promised, I gave this a go and changed the SYSCALL_DEFINEx() infrastructure to always include the wrappers for doing the 31-bit argument conversion on s390 compat mode. This does three main things: - The UID16 rework saved a lot of duplicated code, and would probably make sense by itself, but is also required as we can no longer call sys_*() functions directly after the last step. - Removing the compat_wrapper.c file is of course the main goal here, in order to remove the need to maintain the compat_wrapper.c file when new system calls get added. Unfortunately, this requires adding some complexity in syscall_wrapper.h, and trades a small reduction in source code lines for a small increase in binary size for unused wrappers. - As an added benefit, the use of syscall_wrapper.h now makes it easy to change the syscall wrappers so they no longer see all user space register contents, similar to changes done in commitsfa697140f9("syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls") and4378a7d4be("arm64: implement syscall wrappers"). I leave the actual implementation of this for you, if you want to do it later. I did not test the changes at runtime, but I looked at the generated object code, which seems fine here and includes the same conversions as before. This patch(of 5): The sys_personality function is not meant to be called from other system calls. We could introduce an intermediate ksys_personality function, but it does almost nothing, so this just moves the implementation into the caller. Link: https://lore.kernel.org/lkml/20190116131527.2071570-1-arnd@arndb.de Link: https://lore.kernel.org/lkml/20190116131527.2071570-2-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
96 lines
2.5 KiB
C
96 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* S390 version
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* Copyright IBM Corp. 1999, 2000
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Thomas Spatzier (tspat@de.ibm.com)
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*
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* Derived from "arch/i386/kernel/sys_i386.c"
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*
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* This file contains various random system calls that
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* have a non-standard calling sequence on the Linux/s390
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* platform.
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/stat.h>
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#include <linux/syscalls.h>
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#include <linux/mman.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/personality.h>
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#include <linux/unistd.h>
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#include <linux/ipc.h>
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#include <linux/uaccess.h>
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#include "entry.h"
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/*
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* Perform the mmap() system call. Linux for S/390 isn't able to handle more
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* than 5 system call parameters, so this system call uses a memory block
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* for parameter passing.
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*/
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struct s390_mmap_arg_struct {
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unsigned long addr;
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unsigned long len;
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unsigned long prot;
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unsigned long flags;
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unsigned long fd;
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unsigned long offset;
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};
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SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
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{
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struct s390_mmap_arg_struct a;
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int error = -EFAULT;
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if (copy_from_user(&a, arg, sizeof(a)))
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goto out;
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error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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out:
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return error;
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}
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/*
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* sys_ipc() is the de-multiplexer for the SysV IPC calls.
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*/
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SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
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unsigned long, third, void __user *, ptr)
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{
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if (call >> 16)
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return -EINVAL;
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/* The s390 sys_ipc variant has only five parameters instead of six
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* like the generic variant. The only difference is the handling of
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* the SEMTIMEDOP subcall where on s390 the third parameter is used
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* as a pointer to a struct timespec where the generic variant uses
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* the fifth parameter.
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* Therefore we can call the generic variant by simply passing the
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* third parameter also as fifth parameter.
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*/
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return sys_ipc(call, first, second, third, ptr, third);
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}
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SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
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{
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unsigned int ret = current->personality;
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if (personality(current->personality) == PER_LINUX32 &&
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personality(personality) == PER_LINUX)
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personality |= PER_LINUX32;
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if (personality != 0xffffffff)
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set_personality(personality);
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if (personality(ret) == PER_LINUX32)
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ret &= ~PER_LINUX32;
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return ret;
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}
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