1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 */
10#include <linux/capability.h>
11#include <linux/errno.h>
12#include <linux/linkage.h>
13#include <linux/fs.h>
14#include <linux/smp.h>
15#include <linux/ptrace.h>
16#include <linux/string.h>
17#include <linux/syscalls.h>
18#include <linux/file.h>
19#include <linux/utsname.h>
20#include <linux/unistd.h>
21#include <linux/sem.h>
22#include <linux/msg.h>
23#include <linux/shm.h>
24#include <linux/compiler.h>
25#include <linux/ipc.h>
26#include <linux/uaccess.h>
27#include <linux/slab.h>
28#include <linux/elf.h>
29#include <linux/sched/task_stack.h>
30
31#include <asm/asm.h>
32#include <asm/asm-eva.h>
33#include <asm/branch.h>
34#include <asm/cachectl.h>
35#include <asm/cacheflush.h>
36#include <asm/asm-offsets.h>
37#include <asm/signal.h>
38#include <asm/sim.h>
39#include <asm/shmparam.h>
40#include <asm/sync.h>
41#include <asm/sysmips.h>
42#include <asm/switch_to.h>
43
44/*
45 * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
46 * convention. It returns results in registers $v0 / $v1 which means there
47 * is no need for it to do verify the validity of a userspace pointer
48 * argument. Historically that used to be expensive in Linux. These days
49 * the performance advantage is negligible.
50 */
51asmlinkage int sysm_pipe(void)
52{
53 int fd[2];
54 int error = do_pipe_flags(fd, 0);
55 if (error)
56 return error;
57 current_pt_regs()->regs[3] = fd[1];
58 return fd[0];
59}
60
61SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
62 unsigned long, prot, unsigned long, flags, unsigned long,
63 fd, off_t, offset)
64{
65 if (offset & ~PAGE_MASK)
66 return -EINVAL;
67 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
68 pgoff: offset >> PAGE_SHIFT);
69}
70
71SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
72 unsigned long, prot, unsigned long, flags, unsigned long, fd,
73 unsigned long, pgoff)
74{
75 if (pgoff & (~PAGE_MASK >> 12))
76 return -EINVAL;
77
78 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
79 pgoff: pgoff >> (PAGE_SHIFT - 12));
80}
81
82save_static_function(sys_fork);
83save_static_function(sys_clone);
84save_static_function(sys_clone3);
85
86SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
87{
88 struct thread_info *ti = task_thread_info(current);
89
90 ti->tp_value = addr;
91 if (cpu_has_userlocal)
92 write_c0_userlocal(addr);
93
94 return 0;
95}
96
97static inline int mips_atomic_set(unsigned long addr, unsigned long new)
98{
99 unsigned long old, tmp;
100 struct pt_regs *regs;
101 unsigned int err;
102
103 if (unlikely(addr & 3))
104 return -EINVAL;
105
106 if (unlikely(!access_ok((const void __user *)addr, 4)))
107 return -EINVAL;
108
109 if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
110 __asm__ __volatile__ (
111 " .set push \n"
112 " .set arch=r4000 \n"
113 " li %[err], 0 \n"
114 "1: ll %[old], (%[addr]) \n"
115 " move %[tmp], %[new] \n"
116 "2: sc %[tmp], (%[addr]) \n"
117 " beqzl %[tmp], 1b \n"
118 "3: \n"
119 " .insn \n"
120 " .section .fixup,\"ax\" \n"
121 "4: li %[err], %[efault] \n"
122 " j 3b \n"
123 " .previous \n"
124 " .section __ex_table,\"a\" \n"
125 " "STR(PTR_WD)" 1b, 4b \n"
126 " "STR(PTR_WD)" 2b, 4b \n"
127 " .previous \n"
128 " .set pop \n"
129 : [old] "=&r" (old),
130 [err] "=&r" (err),
131 [tmp] "=&r" (tmp)
132 : [addr] "r" (addr),
133 [new] "r" (new),
134 [efault] "i" (-EFAULT)
135 : "memory");
136 } else if (cpu_has_llsc) {
137 __asm__ __volatile__ (
138 " .set push \n"
139 " .set "MIPS_ISA_ARCH_LEVEL" \n"
140 " li %[err], 0 \n"
141 "1: \n"
142 " " __SYNC(full, loongson3_war) " \n"
143 user_ll("%[old]", "(%[addr])")
144 " move %[tmp], %[new] \n"
145 "2: \n"
146 user_sc("%[tmp]", "(%[addr])")
147 " beqz %[tmp], 1b \n"
148 "3: \n"
149 " .insn \n"
150 " .section .fixup,\"ax\" \n"
151 "5: li %[err], %[efault] \n"
152 " j 3b \n"
153 " .previous \n"
154 " .section __ex_table,\"a\" \n"
155 " "STR(PTR_WD)" 1b, 5b \n"
156 " "STR(PTR_WD)" 2b, 5b \n"
157 " .previous \n"
158 " .set pop \n"
159 : [old] "=&r" (old),
160 [err] "=&r" (err),
161 [tmp] "=&r" (tmp)
162 : [addr] "r" (addr),
163 [new] "r" (new),
164 [efault] "i" (-EFAULT)
165 : "memory");
166 } else {
167 do {
168 preempt_disable();
169 ll_bit = 1;
170 ll_task = current;
171 preempt_enable();
172
173 err = __get_user(old, (unsigned int *) addr);
174 err |= __put_user(new, (unsigned int *) addr);
175 if (err)
176 break;
177 rmb();
178 } while (!ll_bit);
179 }
180
181 if (unlikely(err))
182 return err;
183
184 regs = current_pt_regs();
185 regs->regs[2] = old;
186 regs->regs[7] = 0; /* No error */
187
188 /*
189 * Don't let your children do this ...
190 */
191 __asm__ __volatile__(
192 " move $29, %0 \n"
193 " j syscall_exit \n"
194 : /* no outputs */
195 : "r" (regs));
196
197 /* unreached. Honestly. */
198 unreachable();
199}
200
201/*
202 * mips_atomic_set() normally returns directly via syscall_exit potentially
203 * clobbering static registers, so be sure to preserve them.
204 */
205save_static_function(sys_sysmips);
206
207SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
208{
209 switch (cmd) {
210 case MIPS_ATOMIC_SET:
211 return mips_atomic_set(addr: arg1, new: arg2);
212
213 case MIPS_FIXADE:
214 if (arg1 & ~3)
215 return -EINVAL;
216
217 if (arg1 & 1)
218 set_thread_flag(TIF_FIXADE);
219 else
220 clear_thread_flag(TIF_FIXADE);
221 if (arg1 & 2)
222 set_thread_flag(TIF_LOGADE);
223 else
224 clear_thread_flag(TIF_LOGADE);
225
226 return 0;
227
228 case FLUSH_CACHE:
229 __flush_cache_all();
230 return 0;
231 }
232
233 return -EINVAL;
234}
235
236/*
237 * No implemented yet ...
238 */
239SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
240{
241 return -ENOSYS;
242}
243

source code of linux/arch/mips/kernel/syscall.c