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/cpufeature.h> 16 #include <linux/nospec.h> 17 #include <linux/errno.h> 18 #include <linux/sched.h> 19 #include <linux/mm.h> 20 #include <linux/fs.h> 21 #include <linux/smp.h> 22 #include <linux/sem.h> 23 #include <linux/msg.h> 24 #include <linux/shm.h> 25 #include <linux/stat.h> 26 #include <linux/syscalls.h> 27 #include <linux/mman.h> 28 #include <linux/file.h> 29 #include <linux/utsname.h> 30 #include <linux/personality.h> 31 #include <linux/unistd.h> 32 #include <linux/ipc.h> 33 #include <linux/uaccess.h> 34 #include <linux/string.h> 35 #include <linux/thread_info.h> 36 #include <linux/entry-common.h> 37 38 #include <asm/ptrace.h> 39 #include <asm/vtime.h> 40 41 #include "entry.h" 42 43 #define __SYSCALL(nr, sym) long __s390x_##sym(struct pt_regs *); 44 #include <asm/syscall_table.h> 45 #undef __SYSCALL 46 47 #define __SYSCALL(nr, sym) [nr] = (__s390x_##sym), 48 const sys_call_ptr_t sys_call_table[__NR_syscalls] = { 49 #include <asm/syscall_table.h> 50 }; 51 #undef __SYSCALL 52 53 #ifdef CONFIG_SYSVIPC 54 /* 55 * sys_ipc() is the de-multiplexer for the SysV IPC calls. 56 */ 57 SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second, 58 unsigned long, third, void __user *, ptr) 59 { 60 if (call >> 16) 61 return -EINVAL; 62 /* The s390 sys_ipc variant has only five parameters instead of six 63 * like the generic variant. The only difference is the handling of 64 * the SEMTIMEDOP subcall where on s390 the third parameter is used 65 * as a pointer to a struct timespec where the generic variant uses 66 * the fifth parameter. 67 * Therefore we can call the generic variant by simply passing the 68 * third parameter also as fifth parameter. 69 */ 70 return ksys_ipc(call, first, second, third, ptr, third); 71 } 72 #endif /* CONFIG_SYSVIPC */ 73 74 SYSCALL_DEFINE1(s390_personality, unsigned int, personality) 75 { 76 unsigned int ret = current->personality; 77 78 if (personality(current->personality) == PER_LINUX32 && 79 personality(personality) == PER_LINUX) 80 personality |= PER_LINUX32; 81 82 if (personality != 0xffffffff) 83 set_personality(personality); 84 85 if (personality(ret) == PER_LINUX32) 86 ret &= ~PER_LINUX32; 87 88 return ret; 89 } 90 91 SYSCALL_DEFINE0(ni_syscall) 92 { 93 return -ENOSYS; 94 } 95 96 void noinstr __do_syscall(struct pt_regs *regs, int per_trap) 97 { 98 unsigned long nr; 99 100 enter_from_user_mode(regs); 101 add_random_kstack_offset(); 102 regs->psw = get_lowcore()->svc_old_psw; 103 regs->int_code = get_lowcore()->svc_int_code; 104 update_timer_sys(); 105 if (cpu_has_bear()) 106 current->thread.last_break = regs->last_break; 107 local_irq_enable(); 108 regs->orig_gpr2 = regs->gprs[2]; 109 if (unlikely(per_trap)) 110 set_thread_flag(TIF_PER_TRAP); 111 regs->flags = 0; 112 set_pt_regs_flag(regs, PIF_SYSCALL); 113 nr = regs->int_code & 0xffff; 114 if (likely(!nr)) { 115 nr = regs->gprs[1] & 0xffff; 116 regs->int_code &= ~0xffffUL; 117 regs->int_code |= nr; 118 } 119 regs->gprs[2] = nr; 120 if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) { 121 regs->psw.addr = current->restart_block.arch_data; 122 current->restart_block.arch_data = 1; 123 } 124 nr = syscall_enter_from_user_mode_work(regs, nr); 125 /* 126 * In the s390 ptrace ABI, both the syscall number and the return value 127 * use gpr2. However, userspace puts the syscall number either in the 128 * svc instruction itself, or uses gpr1. To make at least skipping syscalls 129 * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here 130 * and if set, the syscall will be skipped. 131 */ 132 if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET))) 133 goto out; 134 regs->gprs[2] = -ENOSYS; 135 if (likely(nr < NR_syscalls)) { 136 nr = array_index_nospec(nr, NR_syscalls); 137 regs->gprs[2] = sys_call_table[nr](regs); 138 } 139 out: 140 syscall_exit_to_user_mode(regs); 141 } 142