// SPDX-License-Identifier: GPL-2.0/* *  S390 version *    Copyright IBM Corp. 1999, 2000 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), *               Thomas Spatzier (tspat@de.ibm.com) * *  Derived from "arch/i386/kernel/sys_i386.c" * *  This file contains various random system calls that *  have a non-standard calling sequence on the Linux/s390 *  platform. */ #include <linux/cpufeature.h>#include <linux/nospec.h>#include <linux/errno.h>#include <linux/sched.h>#include <linux/mm.h>#include <linux/fs.h>#include <linux/smp.h>#include <linux/sem.h>#include <linux/msg.h>#include <linux/shm.h>#include <linux/stat.h>#include <linux/syscalls.h>#include <linux/mman.h>#include <linux/file.h>#include <linux/utsname.h>#include <linux/personality.h>#include <linux/unistd.h>#include <linux/ipc.h>#include <linux/uaccess.h>#include <linux/string.h>#include <linux/thread_info.h>#include <linux/entry-common.h> #include <asm/ptrace.h>#include <asm/vtime.h> #include "entry.h" #define __SYSCALL(nr, sym) long __s390x_##sym(struct pt_regs *);#include <asm/syscall_table.h>#undef __SYSCALL #define __SYSCALL(nr, sym) [nr] = (__s390x_##sym),const sys_call_ptr_t sys_call_table[__NR_syscalls] = {#include <asm/syscall_table.h>};#undef __SYSCALL #ifdef CONFIG_SYSVIPC/* * sys_ipc() is the de-multiplexer for the SysV IPC calls. */SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,		unsigned long, third, void __user *, ptr){	if (call >> 16)		return -EINVAL;	/* The s390 sys_ipc variant has only five parameters instead of six	 * like the generic variant. The only difference is the handling of	 * the SEMTIMEDOP subcall where on s390 the third parameter is used	 * as a pointer to a struct timespec where the generic variant uses	 * the fifth parameter.	 * Therefore we can call the generic variant by simply passing the	 * third parameter also as fifth parameter.	 */	return ksys_ipc(call, first, second, third, ptr, third);}#endif /* CONFIG_SYSVIPC */ SYSCALL_DEFINE1(s390_personality, unsigned int, personality){	unsigned int ret = current->personality; 	if (personality(current->personality) == PER_LINUX32 &&	    personality(personality) == PER_LINUX)		personality |= PER_LINUX32; 	if (personality != 0xffffffff)		set_personality(personality); 	if (personality(ret) == PER_LINUX32)		ret &= ~PER_LINUX32; 	return ret;} SYSCALL_DEFINE0(ni_syscall){	return -ENOSYS;} void noinstr __do_syscall(struct pt_regs *regs, unsigned long flags){	unsigned long nr;	bool permit; 	enter_from_user_mode_randomize_stack(regs); 	regs->psw = get_lowcore()->svc_old_psw;	regs->int_code = get_lowcore()->svc_int_code;	update_timer_sys();	if (cpu_has_bear())		current->thread.last_break = regs->last_break;	local_irq_enable();	regs->orig_gpr2 = regs->gprs[2];	if (unlikely(flags & SYSCALL_FLAG_PER_TRAP))		set_thread_flag(TIF_PER_TRAP);	regs->flags = 0;	set_pt_regs_flag(regs, PIF_SYSCALL);	nr = regs->int_code & 0xffff;	if (likely(!nr)) {		nr = regs->gprs[1] & 0xffff;		regs->int_code &= ~0xffffUL;		regs->int_code |= nr;	}	regs->gprs[2] = nr;	if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) {		regs->psw.addr = current->restart_block.arch_data;		current->restart_block.arch_data = 1;	} 	permit = syscall_enter_from_user_mode_work(regs, &nr); 	/*	 * In the s390 ptrace ABI, both the syscall number and the return value	 * use gpr2. However, userspace puts the syscall number either in the	 * svc instruction itself, or uses gpr1. To make at least skipping syscalls	 * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here	 * and if set, the syscall will be skipped.	 */	if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET) || !permit))		goto out;	regs->gprs[2] = -ENOSYS;	if (likely(nr < NR_syscalls)) {		nr = array_index_nospec(nr, NR_syscalls);		regs->gprs[2] = sys_call_table[nr](regs);	}out:	syscall_exit_to_user_mode(regs);}