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aa0d6e70d3
Any system call that takes a pointer argument on s390 requires a wrapper function to do a 31-to-64 zero-extension, these are currently generated in arch/s390/kernel/compat_wrapper.c. On arm64 and x86, we already generate similar wrappers for all system calls in the place of their definition, just for a different purpose (they load the arguments from pt_regs). We can do the same thing here, by adding an asm/syscall_wrapper.h file with a copy of all the relevant macros to override the generic version. Besides the addition of the compat entry point, these also rename the entry points with a __s390_ or __s390x_ prefix, similar to what we do on arm64 and x86. This in turn requires renaming a few things, and adding a proper ni_syscall() entry point. In order to still compile system call definitions that pass an loff_t argument, the __SC_COMPAT_CAST() macro checks for that and forces an -ENOSYS error, which was the best I could come up with. Those functions must obviously not get called from user space, but instead require hand-written compat_sys_*() handlers, which fortunately already exist. Link: https://lore.kernel.org/lkml/20190116131527.2071570-5-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> [heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
103 lines
2.6 KiB
C
103 lines
2.6 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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#ifdef CONFIG_SYSVIPC
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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 ksys_ipc(call, first, second, third, ptr, third);
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}
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#endif /* CONFIG_SYSVIPC */
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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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SYSCALL_DEFINE0(ni_syscall)
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{
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return -ENOSYS;
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}
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