ide: fix races in handling of user-space SET XFER commands
[linux-2.6.git] / drivers / ide / ide-ioctls.c
1 /*
2  * IDE ioctls handling.
3  */
4
5 #include <linux/hdreg.h>
6 #include <linux/ide.h>
7
8 static const struct ide_ioctl_devset ide_ioctl_settings[] = {
9 { HDIO_GET_32BIT,        HDIO_SET_32BIT,        &ide_devset_io_32bit  },
10 { HDIO_GET_KEEPSETTINGS, HDIO_SET_KEEPSETTINGS, &ide_devset_keepsettings },
11 { HDIO_GET_UNMASKINTR,   HDIO_SET_UNMASKINTR,   &ide_devset_unmaskirq },
12 { HDIO_GET_DMA,          HDIO_SET_DMA,          &ide_devset_using_dma },
13 { -1,                    HDIO_SET_PIO_MODE,     &ide_devset_pio_mode  },
14 { 0 }
15 };
16
17 int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev,
18                       unsigned int cmd, unsigned long arg,
19                       const struct ide_ioctl_devset *s)
20 {
21         const struct ide_devset *ds;
22         int err = -EOPNOTSUPP;
23
24         for (; (ds = s->setting); s++) {
25                 if (ds->get && s->get_ioctl == cmd)
26                         goto read_val;
27                 else if (ds->set && s->set_ioctl == cmd)
28                         goto set_val;
29         }
30
31         return err;
32
33 read_val:
34         mutex_lock(&ide_setting_mtx);
35         err = ds->get(drive);
36         mutex_unlock(&ide_setting_mtx);
37         return err >= 0 ? put_user(err, (long __user *)arg) : err;
38
39 set_val:
40         if (bdev != bdev->bd_contains)
41                 err = -EINVAL;
42         else {
43                 if (!capable(CAP_SYS_ADMIN))
44                         err = -EACCES;
45                 else {
46                         mutex_lock(&ide_setting_mtx);
47                         err = ide_devset_execute(drive, ds, arg);
48                         mutex_unlock(&ide_setting_mtx);
49                 }
50         }
51         return err;
52 }
53 EXPORT_SYMBOL_GPL(ide_setting_ioctl);
54
55 static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,
56                                   unsigned long arg)
57 {
58         u16 *id = NULL;
59         int size = (cmd == HDIO_GET_IDENTITY) ? (ATA_ID_WORDS * 2) : 142;
60         int rc = 0;
61
62         if ((drive->dev_flags & IDE_DFLAG_ID_READ) == 0) {
63                 rc = -ENOMSG;
64                 goto out;
65         }
66
67         /* ata_id_to_hd_driveid() relies on 'id' to be fully allocated. */
68         id = kmalloc(ATA_ID_WORDS * 2, GFP_KERNEL);
69         if (id == NULL) {
70                 rc = -ENOMEM;
71                 goto out;
72         }
73
74         memcpy(id, drive->id, size);
75         ata_id_to_hd_driveid(id);
76
77         if (copy_to_user((void __user *)arg, id, size))
78                 rc = -EFAULT;
79
80         kfree(id);
81 out:
82         return rc;
83 }
84
85 static int ide_get_nice_ioctl(ide_drive_t *drive, unsigned long arg)
86 {
87         return put_user((!!(drive->dev_flags & IDE_DFLAG_DSC_OVERLAP)
88                          << IDE_NICE_DSC_OVERLAP) |
89                         (!!(drive->dev_flags & IDE_DFLAG_NICE1)
90                          << IDE_NICE_1), (long __user *)arg);
91 }
92
93 static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg)
94 {
95         if (arg != (arg & ((1 << IDE_NICE_DSC_OVERLAP) | (1 << IDE_NICE_1))))
96                 return -EPERM;
97
98         if (((arg >> IDE_NICE_DSC_OVERLAP) & 1) &&
99             (drive->media != ide_tape))
100                 return -EPERM;
101
102         if ((arg >> IDE_NICE_DSC_OVERLAP) & 1)
103                 drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
104         else
105                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
106
107         if ((arg >> IDE_NICE_1) & 1)
108                 drive->dev_flags |= IDE_DFLAG_NICE1;
109         else
110                 drive->dev_flags &= ~IDE_DFLAG_NICE1;
111
112         return 0;
113 }
114
115 static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
116 {
117         u8 *buf = NULL;
118         int bufsize = 0, err = 0;
119         u8 args[4], xfer_rate = 0;
120         struct ide_cmd cmd;
121         struct ide_taskfile *tf = &cmd.tf;
122
123         if (NULL == (void *) arg) {
124                 struct request *rq;
125
126                 rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
127                 rq->cmd_type = REQ_TYPE_ATA_TASKFILE;
128                 err = blk_execute_rq(drive->queue, NULL, rq, 0);
129                 blk_put_request(rq);
130
131                 return err;
132         }
133
134         if (copy_from_user(args, (void __user *)arg, 4))
135                 return -EFAULT;
136
137         memset(&cmd, 0, sizeof(cmd));
138         tf->feature = args[2];
139         if (args[0] == ATA_CMD_SMART) {
140                 tf->nsect = args[3];
141                 tf->lbal  = args[1];
142                 tf->lbam  = 0x4f;
143                 tf->lbah  = 0xc2;
144                 cmd.valid.out.tf = IDE_VALID_OUT_TF;
145                 cmd.valid.in.tf  = IDE_VALID_NSECT;
146         } else {
147                 tf->nsect = args[1];
148                 cmd.valid.out.tf = IDE_VALID_FEATURE | IDE_VALID_NSECT;
149                 cmd.valid.in.tf  = IDE_VALID_NSECT;
150         }
151         tf->command = args[0];
152         cmd.protocol = args[3] ? ATA_PROT_PIO : ATA_PROT_NODATA;
153
154         if (args[3]) {
155                 cmd.tf_flags |= IDE_TFLAG_IO_16BIT;
156                 bufsize = SECTOR_SIZE * args[3];
157                 buf = kzalloc(bufsize, GFP_KERNEL);
158                 if (buf == NULL)
159                         return -ENOMEM;
160         }
161
162         if (tf->command == ATA_CMD_SET_FEATURES &&
163             tf->feature == SETFEATURES_XFER &&
164             tf->nsect >= XFER_SW_DMA_0) {
165                 xfer_rate = ide_find_dma_mode(drive, XFER_UDMA_6);
166                 if (xfer_rate != tf->nsect) {
167                         err = -EINVAL;
168                         goto abort;
169                 }
170
171                 cmd.tf_flags |= IDE_TFLAG_SET_XFER;
172         }
173
174         err = ide_raw_taskfile(drive, &cmd, buf, args[3]);
175
176         args[0] = tf->status;
177         args[1] = tf->error;
178         args[2] = tf->nsect;
179 abort:
180         if (copy_to_user((void __user *)arg, &args, 4))
181                 err = -EFAULT;
182         if (buf) {
183                 if (copy_to_user((void __user *)(arg + 4), buf, bufsize))
184                         err = -EFAULT;
185                 kfree(buf);
186         }
187         return err;
188 }
189
190 static int ide_task_ioctl(ide_drive_t *drive, unsigned long arg)
191 {
192         void __user *p = (void __user *)arg;
193         int err = 0;
194         u8 args[7];
195         struct ide_cmd cmd;
196
197         if (copy_from_user(args, p, 7))
198                 return -EFAULT;
199
200         memset(&cmd, 0, sizeof(cmd));
201         memcpy(&cmd.tf.feature, &args[1], 6);
202         cmd.tf.command = args[0];
203         cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
204         cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;
205
206         err = ide_no_data_taskfile(drive, &cmd);
207
208         args[0] = cmd.tf.command;
209         memcpy(&args[1], &cmd.tf.feature, 6);
210
211         if (copy_to_user(p, args, 7))
212                 err = -EFAULT;
213
214         return err;
215 }
216
217 static int generic_drive_reset(ide_drive_t *drive)
218 {
219         struct request *rq;
220         int ret = 0;
221
222         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
223         rq->cmd_type = REQ_TYPE_SPECIAL;
224         rq->cmd_len = 1;
225         rq->cmd[0] = REQ_DRIVE_RESET;
226         if (blk_execute_rq(drive->queue, NULL, rq, 1))
227                 ret = rq->errors;
228         blk_put_request(rq);
229         return ret;
230 }
231
232 int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
233                       unsigned int cmd, unsigned long arg)
234 {
235         int err;
236
237         err = ide_setting_ioctl(drive, bdev, cmd, arg, ide_ioctl_settings);
238         if (err != -EOPNOTSUPP)
239                 return err;
240
241         switch (cmd) {
242         case HDIO_OBSOLETE_IDENTITY:
243         case HDIO_GET_IDENTITY:
244                 if (bdev != bdev->bd_contains)
245                         return -EINVAL;
246                 return ide_get_identity_ioctl(drive, cmd, arg);
247         case HDIO_GET_NICE:
248                 return ide_get_nice_ioctl(drive, arg);
249         case HDIO_SET_NICE:
250                 if (!capable(CAP_SYS_ADMIN))
251                         return -EACCES;
252                 return ide_set_nice_ioctl(drive, arg);
253 #ifdef CONFIG_IDE_TASK_IOCTL
254         case HDIO_DRIVE_TASKFILE:
255                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
256                         return -EACCES;
257                 if (drive->media == ide_disk)
258                         return ide_taskfile_ioctl(drive, arg);
259                 return -ENOMSG;
260 #endif
261         case HDIO_DRIVE_CMD:
262                 if (!capable(CAP_SYS_RAWIO))
263                         return -EACCES;
264                 return ide_cmd_ioctl(drive, arg);
265         case HDIO_DRIVE_TASK:
266                 if (!capable(CAP_SYS_RAWIO))
267                         return -EACCES;
268                 return ide_task_ioctl(drive, arg);
269         case HDIO_DRIVE_RESET:
270                 if (!capable(CAP_SYS_ADMIN))
271                         return -EACCES;
272                 return generic_drive_reset(drive);
273         case HDIO_GET_BUSSTATE:
274                 if (!capable(CAP_SYS_ADMIN))
275                         return -EACCES;
276                 if (put_user(BUSSTATE_ON, (long __user *)arg))
277                         return -EFAULT;
278                 return 0;
279         case HDIO_SET_BUSSTATE:
280                 if (!capable(CAP_SYS_ADMIN))
281                         return -EACCES;
282                 return -EOPNOTSUPP;
283         default:
284                 return -EINVAL;
285         }
286 }
287 EXPORT_SYMBOL(generic_ide_ioctl);