aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/syscall.c
blob: 53a7ef9a8f320c5b14c5abb2d3e1518c0ad7f756 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/unistd.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/compiler.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/elf.h>

#include <asm/asm.h>
#include <asm/branch.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#include <asm/signal.h>
#include <asm/sim.h>
#include <asm/shmparam.h>
#include <asm/sysmips.h>
#include <asm/uaccess.h>
#include <asm/switch_to.h>

/*
 * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
 * convention.	It returns results in registers $v0 / $v1 which means there
 * is no need for it to do verify the validity of a userspace pointer
 * argument.  Historically that used to be expensive in Linux.	These days
 * the performance advantage is negligible.
 */
asmlinkage int sysm_pipe(void)
{
	int fd[2];
	int error = do_pipe_flags(fd, 0);
	if (error)
		return error;
	current_pt_regs()->regs[3] = fd[1];
	return fd[0];
}

SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long,
	fd, off_t, offset)
{
	unsigned long result;

	result = -EINVAL;
	if (offset & ~PAGE_MASK)
		goto out;

	result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

out:
	return result;
}

SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	unsigned long, pgoff)
{
	if (pgoff & (~PAGE_MASK >> 12))
		return -EINVAL;

	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
}

save_static_function(sys_fork);
save_static_function(sys_clone);

SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
{
	struct thread_info *ti = task_thread_info(current);

	ti->tp_value = addr;
	if (cpu_has_userlocal)
		write_c0_userlocal(addr);

	return 0;
}

static inline int mips_atomic_set(unsigned long addr, unsigned long new)
{
	unsigned long old, tmp;
	struct pt_regs *regs;
	unsigned int err;

	if (unlikely(addr & 3))
		return -EINVAL;

	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
		return -EINVAL;

	if (cpu_has_llsc && R10000_LLSC_WAR) {
		__asm__ __volatile__ (
		"	.set	arch=r4000				\n"
		"	li	%[err], 0				\n"
		"1:	ll	%[old], (%[addr])			\n"
		"	move	%[tmp], %[new]				\n"
		"2:	sc	%[tmp], (%[addr])			\n"
		"	beqzl	%[tmp], 1b				\n"
		"3:							\n"
		"	.insn						\n"
		"	.section .fixup,\"ax\"				\n"
		"4:	li	%[err], %[efault]			\n"
		"	j	3b					\n"
		"	.previous					\n"
		"	.section __ex_table,\"a\"			\n"
		"	"STR(PTR)"	1b, 4b				\n"
		"	"STR(PTR)"	2b, 4b				\n"
		"	.previous					\n"
		"	.set	mips0					\n"
		: [old] "=&r" (old),
		  [err] "=&r" (err),
		  [tmp] "=&r" (tmp)
		: [addr] "r" (addr),
		  [new] "r" (new),
		  [efault] "i" (-EFAULT)
		: "memory");
	} else if (cpu_has_llsc) {
		__asm__ __volatile__ (
		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
		"	li	%[err], 0				\n"
		"1:	ll	%[old], (%[addr])			\n"
		"	move	%[tmp], %[new]				\n"
		"2:	sc	%[tmp], (%[addr])			\n"
		"	bnez	%[tmp], 4f				\n"
		"3:							\n"
		"	.insn						\n"
		"	.subsection 2					\n"
		"4:	b	1b					\n"
		"	.previous					\n"
		"							\n"
		"	.section .fixup,\"ax\"				\n"
		"5:	li	%[err], %[efault]			\n"
		"	j	3b					\n"
		"	.previous					\n"
		"	.section __ex_table,\"a\"			\n"
		"	"STR(PTR)"	1b, 5b				\n"
		"	"STR(PTR)"	2b, 5b				\n"
		"	.previous					\n"
		"	.set	mips0					\n"
		: [old] "=&r" (old),
		  [err] "=&r" (err),
		  [tmp] "=&r" (tmp)
		: [addr] "r" (addr),
		  [new] "r" (new),
		  [efault] "i" (-EFAULT)
		: "memory");
	} else {
		do {
			preempt_disable();
			ll_bit = 1;
			ll_task = current;
			preempt_enable();

			err = __get_user(old, (unsigned int *) addr);
			err |= __put_user(new, (unsigned int *) addr);
			if (err)
				break;
			rmb();
		} while (!ll_bit);
	}

	if (unlikely(err))
		return err;

	regs = current_pt_regs();
	regs->regs[2] = old;
	regs->regs[7] = 0;	/* No error */

	/*
	 * Don't let your children do this ...
	 */
	__asm__ __volatile__(
	"	move	$29, %0						\n"
	"	j	syscall_exit					\n"
	: /* no outputs */
	: "r" (regs));

	/* unreached.  Honestly.  */
	unreachable();
}

SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
{
	switch (cmd) {
	case MIPS_ATOMIC_SET:
		return mips_atomic_set(arg1, arg2);

	case MIPS_FIXADE:
		if (arg1 & ~3)
			return -EINVAL;

		if (arg1 & 1)
			set_thread_flag(TIF_FIXADE);
		else
			clear_thread_flag(TIF_FIXADE);
		if (arg1 & 2)
			set_thread_flag(TIF_LOGADE);
		else
			clear_thread_flag(TIF_LOGADE);

		return 0;

	case FLUSH_CACHE:
		__flush_cache_all();
		return 0;
	}

	return -EINVAL;
}

/*
 * No implemented yet ...
 */
SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
{
	return -ENOSYS;
}

/*
 * If we ever come here the user sp is bad.  Zap the process right away.
 * Due to the bad stack signaling wouldn't work.
 */
asmlinkage void bad_stack(void)
{
	do_exit(SIGSEGV);
}