1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * S390 version 4 * Copyright IBM Corp. 1999, 2000 5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 6 * Thomas Spatzier (tspat@de.ibm.com) 7 * 8 * Derived from "arch/i386/kernel/sys_i386.c" 9 * 10 * This file contains various random system calls that 11 * have a non-standard calling sequence on the Linux/s390 12 * platform. 13 */ 14 15 #include <linux/errno.h> 16 #include <linux/sched.h> 17 #include <linux/mm.h> 18 #include <linux/fs.h> 19 #include <linux/smp.h> 20 #include <linux/sem.h> 21 #include <linux/msg.h> 22 #include <linux/shm.h> 23 #include <linux/stat.h> 24 #include <linux/syscalls.h> 25 #include <linux/mman.h> 26 #include <linux/file.h> 27 #include <linux/utsname.h> 28 #include <linux/personality.h> 29 #include <linux/unistd.h> 30 #include <linux/ipc.h> 31 #include <linux/uaccess.h> 32 #include <linux/string.h> 33 #include <linux/thread_info.h> 34 #include <linux/entry-common.h> 35 36 #include <asm/ptrace.h> 37 #include <asm/vtime.h> 38 39 #include "entry.h" 40 41 /* 42 * Perform the mmap() system call. Linux for S/390 isn't able to handle more 43 * than 5 system call parameters, so this system call uses a memory block 44 * for parameter passing. 45 */ 46 47 struct s390_mmap_arg_struct { 48 unsigned long addr; 49 unsigned long len; 50 unsigned long prot; 51 unsigned long flags; 52 unsigned long fd; 53 unsigned long offset; 54 }; 55 56 SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg) 57 { 58 struct s390_mmap_arg_struct a; 59 int error = -EFAULT; 60 61 if (copy_from_user(&a, arg, sizeof(a))) 62 goto out; 63 error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset); 64 out: 65 return error; 66 } 67 68 #ifdef CONFIG_SYSVIPC 69 /* 70 * sys_ipc() is the de-multiplexer for the SysV IPC calls. 71 */ 72 SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second, 73 unsigned long, third, void __user *, ptr) 74 { 75 if (call >> 16) 76 return -EINVAL; 77 /* The s390 sys_ipc variant has only five parameters instead of six 78 * like the generic variant. The only difference is the handling of 79 * the SEMTIMEDOP subcall where on s390 the third parameter is used 80 * as a pointer to a struct timespec where the generic variant uses 81 * the fifth parameter. 82 * Therefore we can call the generic variant by simply passing the 83 * third parameter also as fifth parameter. 84 */ 85 return ksys_ipc(call, first, second, third, ptr, third); 86 } 87 #endif /* CONFIG_SYSVIPC */ 88 89 SYSCALL_DEFINE1(s390_personality, unsigned int, personality) 90 { 91 unsigned int ret = current->personality; 92 93 if (personality(current->personality) == PER_LINUX32 && 94 personality(personality) == PER_LINUX) 95 personality |= PER_LINUX32; 96 97 if (personality != 0xffffffff) 98 set_personality(personality); 99 100 if (personality(ret) == PER_LINUX32) 101 ret &= ~PER_LINUX32; 102 103 return ret; 104 } 105 106 SYSCALL_DEFINE0(ni_syscall) 107 { 108 return -ENOSYS; 109 } 110 111 void do_syscall(struct pt_regs *regs) 112 { 113 unsigned long nr; 114 115 nr = regs->int_code & 0xffff; 116 if (!nr) { 117 nr = regs->gprs[1] & 0xffff; 118 regs->int_code &= ~0xffffUL; 119 regs->int_code |= nr; 120 } 121 122 regs->gprs[2] = nr; 123 124 nr = syscall_enter_from_user_mode_work(regs, nr); 125 126 /* 127 * In the s390 ptrace ABI, both the syscall number and the return value 128 * use gpr2. However, userspace puts the syscall number either in the 129 * svc instruction itself, or uses gpr1. To make at least skipping syscalls 130 * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here 131 * and if set, the syscall will be skipped. 132 */ 133 if (!test_pt_regs_flag(regs, PIF_SYSCALL_RET_SET)) { 134 regs->gprs[2] = -ENOSYS; 135 if (likely(nr < NR_syscalls)) 136 regs->gprs[2] = current->thread.sys_call_table[nr](regs); 137 } else { 138 clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET); 139 } 140 syscall_exit_to_user_mode_work(regs); 141 } 142 143 void noinstr __do_syscall(struct pt_regs *regs, int per_trap) 144 { 145 enter_from_user_mode(regs); 146 147 memcpy(®s->gprs[8], S390_lowcore.save_area_sync, 8 * sizeof(unsigned long)); 148 memcpy(®s->int_code, &S390_lowcore.svc_ilc, sizeof(regs->int_code)); 149 regs->psw = S390_lowcore.svc_old_psw; 150 151 update_timer_sys(); 152 153 local_irq_enable(); 154 regs->orig_gpr2 = regs->gprs[2]; 155 156 if (per_trap) 157 set_thread_flag(TIF_PER_TRAP); 158 159 for (;;) { 160 regs->flags = 0; 161 set_pt_regs_flag(regs, PIF_SYSCALL); 162 do_syscall(regs); 163 if (!test_pt_regs_flag(regs, PIF_SYSCALL_RESTART)) 164 break; 165 local_irq_enable(); 166 } 167 exit_to_user_mode(); 168 } 169