aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/kspd.c
blob: 29811f043399588604da9bbc00efd9f0997aa530 (plain)
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
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
/*
 * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/unistd.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/fs.h>
#include <linux/syscalls.h>
#include <linux/workqueue.h>
#include <linux/errno.h>
#include <linux/list.h>

#include <asm/vpe.h>
#include <asm/rtlx.h>
#include <asm/kspd.h>

static struct workqueue_struct *workqueue;
static struct work_struct work;

extern unsigned long cpu_khz;

struct mtsp_syscall {
	int cmd;
	unsigned char abi;
	unsigned char size;
};

struct mtsp_syscall_ret {
	int retval;
	int errno;
};

struct mtsp_syscall_generic {
	int arg0;
	int arg1;
	int arg2;
	int arg3;
	int arg4;
	int arg5;
	int arg6;
};

static struct list_head kspd_notifylist;
static int sp_stopping;

/* these should match with those in the SDE kit */
#define MTSP_SYSCALL_BASE	0
#define MTSP_SYSCALL_EXIT	(MTSP_SYSCALL_BASE + 0)
#define MTSP_SYSCALL_OPEN	(MTSP_SYSCALL_BASE + 1)
#define MTSP_SYSCALL_READ	(MTSP_SYSCALL_BASE + 2)
#define MTSP_SYSCALL_WRITE	(MTSP_SYSCALL_BASE + 3)
#define MTSP_SYSCALL_CLOSE	(MTSP_SYSCALL_BASE + 4)
#define MTSP_SYSCALL_LSEEK32	(MTSP_SYSCALL_BASE + 5)
#define MTSP_SYSCALL_ISATTY	(MTSP_SYSCALL_BASE + 6)
#define MTSP_SYSCALL_GETTIME	(MTSP_SYSCALL_BASE + 7)
#define MTSP_SYSCALL_PIPEFREQ	(MTSP_SYSCALL_BASE + 8)
#define MTSP_SYSCALL_GETTOD	(MTSP_SYSCALL_BASE + 9)
#define MTSP_SYSCALL_IOCTL     (MTSP_SYSCALL_BASE + 10)

#define MTSP_O_RDONLY		0x0000
#define MTSP_O_WRONLY		0x0001
#define MTSP_O_RDWR		0x0002
#define MTSP_O_NONBLOCK		0x0004
#define MTSP_O_APPEND		0x0008
#define MTSP_O_SHLOCK		0x0010
#define MTSP_O_EXLOCK		0x0020
#define MTSP_O_ASYNC		0x0040
/* XXX: check which of these is actually O_SYNC vs O_DSYNC */
#define MTSP_O_FSYNC		O_SYNC
#define MTSP_O_NOFOLLOW		0x0100
#define MTSP_O_SYNC		0x0080
#define MTSP_O_CREAT		0x0200
#define MTSP_O_TRUNC		0x0400
#define MTSP_O_EXCL		0x0800
#define MTSP_O_BINARY		0x8000

extern int tclimit;

struct apsp_table  {
	int sp;
	int ap;
};

/* we might want to do the mode flags too */
struct apsp_table open_flags_table[] = {
	{ MTSP_O_RDWR, O_RDWR },
	{ MTSP_O_WRONLY, O_WRONLY },
	{ MTSP_O_CREAT, O_CREAT },
	{ MTSP_O_TRUNC, O_TRUNC },
	{ MTSP_O_NONBLOCK, O_NONBLOCK },
	{ MTSP_O_APPEND, O_APPEND },
	{ MTSP_O_NOFOLLOW, O_NOFOLLOW }
};

struct apsp_table syscall_command_table[] = {
	{ MTSP_SYSCALL_OPEN, __NR_open },
	{ MTSP_SYSCALL_CLOSE, __NR_close },
	{ MTSP_SYSCALL_READ, __NR_read },
	{ MTSP_SYSCALL_WRITE, __NR_write },
	{ MTSP_SYSCALL_LSEEK32, __NR_lseek },
	{ MTSP_SYSCALL_IOCTL, __NR_ioctl }
};

static int sp_syscall(int num, int arg0, int arg1, int arg2, int arg3)
{
	register long int _num  __asm__("$2") = num;
	register long int _arg0  __asm__("$4") = arg0;
	register long int _arg1  __asm__("$5") = arg1;
	register long int _arg2  __asm__("$6") = arg2;
	register long int _arg3  __asm__("$7") = arg3;

	mm_segment_t old_fs;

	old_fs = get_fs();
 	set_fs(KERNEL_DS);

  	__asm__ __volatile__ (
 	"	syscall					\n"
 	: "=r" (_num), "=r" (_arg3)
 	: "r" (_num), "r" (_arg0), "r" (_arg1), "r" (_arg2), "r" (_arg3));

	set_fs(old_fs);

	/* $a3 is error flag */
	if (_arg3)
		return -_num;

	return _num;
}

static int translate_syscall_command(int cmd)
{
	int i;
	int ret = -1;

	for (i = 0; i < ARRAY_SIZE(syscall_command_table); i++) {
		if ((cmd == syscall_command_table[i].sp))
			return syscall_command_table[i].ap;
	}

	return ret;
}

static unsigned int translate_open_flags(int flags)
{
	int i;
	unsigned int ret = 0;

	for (i = 0; i < ARRAY_SIZE(open_flags_table); i++) {
		if( (flags & open_flags_table[i].sp) ) {
			ret |= open_flags_table[i].ap;
		}
	}

	return ret;
}


static int sp_setfsuidgid(uid_t uid, gid_t gid)
{
	struct cred *new;

	new = prepare_creds();
	if (!new)
		return -ENOMEM;

	new->fsuid = uid;
	new->fsgid = gid;

	commit_creds(new);

	return 0;
}

/*
 * Expects a request to be on the sysio channel. Reads it.  Decides whether
 * its a linux syscall and runs it, or whatever.  Puts the return code back
 * into the request and sends the whole thing back.
 */
void sp_work_handle_request(void)
{
	struct mtsp_syscall sc;
	struct mtsp_syscall_generic generic;
	struct mtsp_syscall_ret ret;
	struct kspd_notifications *n;
	unsigned long written;
	mm_segment_t old_fs;
	struct timeval tv;
	struct timezone tz;
	int err, cmd;

	char *vcwd;
	int size;

	ret.retval = -1;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	if (!rtlx_read(RTLX_CHANNEL_SYSIO, &sc, sizeof(struct mtsp_syscall))) {
		set_fs(old_fs);
		printk(KERN_ERR "Expected request but nothing to read\n");
		return;
	}

	size = sc.size;

	if (size) {
		if (!rtlx_read(RTLX_CHANNEL_SYSIO, &generic, size)) {
			set_fs(old_fs);
			printk(KERN_ERR "Expected request but nothing to read\n");
			return;
		}
	}

	/* Run the syscall at the privilege of the user who loaded the
	   SP program */

	if (vpe_getuid(tclimit)) {
		err = sp_setfsuidgid(vpe_getuid(tclimit), vpe_getgid(tclimit));
		if (!err)
			pr_err("Change of creds failed\n");
	}

	switch (sc.cmd) {
	/* needs the flags argument translating from SDE kit to
	   linux */
 	case MTSP_SYSCALL_PIPEFREQ:
 		ret.retval = cpu_khz * 1000;
 		ret.errno = 0;
 		break;

 	case MTSP_SYSCALL_GETTOD:
 		memset(&tz, 0, sizeof(tz));
 		if ((ret.retval = sp_syscall(__NR_gettimeofday, (int)&tv,
					     (int)&tz, 0, 0)) == 0)
			ret.retval = tv.tv_sec;
		break;

 	case MTSP_SYSCALL_EXIT:
		list_for_each_entry(n, &kspd_notifylist, list)
			n->kspd_sp_exit(tclimit);
		sp_stopping = 1;

		printk(KERN_DEBUG "KSPD got exit syscall from SP exitcode %d\n",
		       generic.arg0);
 		break;

 	case MTSP_SYSCALL_OPEN:
 		generic.arg1 = translate_open_flags(generic.arg1);

		vcwd = vpe_getcwd(tclimit);

		/* change to cwd of the process that loaded the SP program */
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		sys_chdir(vcwd);
		set_fs(old_fs);

 		sc.cmd = __NR_open;

		/* fall through */

  	default:
 		if ((sc.cmd >= __NR_Linux) &&
		    (sc.cmd <= (__NR_Linux +  __NR_Linux_syscalls)) )
			cmd = sc.cmd;
		else
			cmd = translate_syscall_command(sc.cmd);

		if (cmd >= 0) {
			ret.retval = sp_syscall(cmd, generic.arg0, generic.arg1,
			                        generic.arg2, generic.arg3);
		} else
 			printk(KERN_WARNING
			       "KSPD: Unknown SP syscall number %d\n", sc.cmd);
		break;
 	} /* switch */

	if (vpe_getuid(tclimit)) {
		err = sp_setfsuidgid(0, 0);
		if (!err)
			pr_err("restoring old creds failed\n");
	}

	old_fs = get_fs();
	set_fs(KERNEL_DS);
	written = rtlx_write(RTLX_CHANNEL_SYSIO, &ret, sizeof(ret));
	set_fs(old_fs);
	if (written < sizeof(ret))
		printk("KSPD: sp_work_handle_request failed to send to SP\n");
}

static void sp_cleanup(void)
{
	struct files_struct *files = current->files;
	int i, j;
	struct fdtable *fdt;

	j = 0;

	/*
	 * It is safe to dereference the fd table without RCU or
	 * ->file_lock
	 */
	fdt = files_fdtable(files);
	for (;;) {
		unsigned long set;
		i = j * __NFDBITS;
		if (i >= fdt->max_fds)
			break;
		set = fdt->open_fds->fds_bits[j++];
		while (set) {
			if (set & 1) {
				struct file * file = xchg(&fdt->fd[i], NULL);
				if (file)
					filp_close(file, files);
			}
			i++;
			set >>= 1;
		}
	}

	/* Put daemon cwd back to root to avoid umount problems */
	sys_chdir("/");
}

static int channel_open;

/* the work handler */
static void sp_work(struct work_struct *unused)
{
	if (!channel_open) {
		if( rtlx_open(RTLX_CHANNEL_SYSIO, 1) != 0) {
			printk("KSPD: unable to open sp channel\n");
			sp_stopping = 1;
		} else {
			channel_open++;
			printk(KERN_DEBUG "KSPD: SP channel opened\n");
		}
	} else {
		/* wait for some data, allow it to sleep */
		rtlx_read_poll(RTLX_CHANNEL_SYSIO, 1);

		/* Check we haven't been woken because we are stopping */
		if (!sp_stopping)
			sp_work_handle_request();
	}

	if (!sp_stopping)
		queue_work(workqueue, &work);
	else
		sp_cleanup();
}

static void startwork(int vpe)
{
	sp_stopping = channel_open = 0;

	if (workqueue == NULL) {
		if ((workqueue = create_singlethread_workqueue("kspd")) == NULL) {
			printk(KERN_ERR "unable to start kspd\n");
			return;
		}

		INIT_WORK(&work, sp_work);
	}

	queue_work(workqueue, &work);
}

static void stopwork(int vpe)
{
	sp_stopping = 1;

	printk(KERN_DEBUG "KSPD: SP stopping\n");
}

void kspd_notify(struct kspd_notifications *notify)
{
	list_add(&notify->list, &kspd_notifylist);
}

static struct vpe_notifications notify;
static int kspd_module_init(void)
{
	INIT_LIST_HEAD(&kspd_notifylist);

	notify.start = startwork;
	notify.stop = stopwork;
	vpe_notify(tclimit, &notify);

	return 0;
}

static void kspd_module_exit(void)
{

}

module_init(kspd_module_init);
module_exit(kspd_module_exit);

MODULE_DESCRIPTION("MIPS KSPD");
MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
MODULE_LICENSE("GPL");

Privacy Policy