projects/linux·blob uaccess-cleanups · refs

243 lines · 5.5 KiB

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