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(to: &a, from: arg, n: sizeof(a))) |
62 | goto out; |
63 | error = ksys_mmap_pgoff(addr: a.addr, len: a.len, prot: a.prot, flags: a.flags, fd: a.fd, pgoff: 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, fifth: 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 | static 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 | if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) { |
125 | regs->psw.addr = current->restart_block.arch_data; |
126 | current->restart_block.arch_data = 1; |
127 | } |
128 | nr = syscall_enter_from_user_mode_work(regs, syscall: nr); |
129 | |
130 | /* |
131 | * In the s390 ptrace ABI, both the syscall number and the return value |
132 | * use gpr2. However, userspace puts the syscall number either in the |
133 | * svc instruction itself, or uses gpr1. To make at least skipping syscalls |
134 | * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here |
135 | * and if set, the syscall will be skipped. |
136 | */ |
137 | |
138 | if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET))) |
139 | goto out; |
140 | regs->gprs[2] = -ENOSYS; |
141 | if (likely(nr >= NR_syscalls)) |
142 | goto out; |
143 | do { |
144 | regs->gprs[2] = current->thread.sys_call_table[nr](regs); |
145 | } while (test_and_clear_pt_regs_flag(regs, PIF_EXECVE_PGSTE_RESTART)); |
146 | out: |
147 | syscall_exit_to_user_mode_work(regs); |
148 | } |
149 | |
150 | void noinstr __do_syscall(struct pt_regs *regs, int per_trap) |
151 | { |
152 | add_random_kstack_offset(); |
153 | enter_from_user_mode(regs); |
154 | regs->psw = S390_lowcore.svc_old_psw; |
155 | regs->int_code = S390_lowcore.svc_int_code; |
156 | update_timer_sys(); |
157 | if (static_branch_likely(&cpu_has_bear)) |
158 | current->thread.last_break = regs->last_break; |
159 | |
160 | local_irq_enable(); |
161 | regs->orig_gpr2 = regs->gprs[2]; |
162 | |
163 | if (per_trap) |
164 | set_thread_flag(TIF_PER_TRAP); |
165 | |
166 | regs->flags = 0; |
167 | set_pt_regs_flag(regs, PIF_SYSCALL); |
168 | do_syscall(regs); |
169 | exit_to_user_mode(); |
170 | } |
171 | |