Commit c3484c275db5abe88e01a7e1a80932112c9bbf69
Committed by
David S. Miller
1 parent
c7ec0badcc
Exists in
smarc-l5.0.0_1.0.0-ga
and in
5 other branches
ptp: reduce stack usage when measuring the system time offset
This patch removes the large buffer from the stack of the system offset ioctl and replaces it with a kmalloced buffer. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Showing 1 changed file with 14 additions and 7 deletions Inline Diff
drivers/ptp/ptp_chardev.c
1 | /* | 1 | /* |
2 | * PTP 1588 clock support - character device implementation. | 2 | * PTP 1588 clock support - character device implementation. |
3 | * | 3 | * |
4 | * Copyright (C) 2010 OMICRON electronics GmbH | 4 | * Copyright (C) 2010 OMICRON electronics GmbH |
5 | * | 5 | * |
6 | * This program is free software; you can redistribute it and/or modify | 6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by | 7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or | 8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * (at your option) any later version. | 9 | * (at your option) any later version. |
10 | * | 10 | * |
11 | * This program is distributed in the hope that it will be useful, | 11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. | 14 | * GNU General Public License for more details. |
15 | * | 15 | * |
16 | * You should have received a copy of the GNU General Public License | 16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, write to the Free Software | 17 | * along with this program; if not, write to the Free Software |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | 18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
19 | */ | 19 | */ |
20 | #include <linux/module.h> | 20 | #include <linux/module.h> |
21 | #include <linux/posix-clock.h> | 21 | #include <linux/posix-clock.h> |
22 | #include <linux/poll.h> | 22 | #include <linux/poll.h> |
23 | #include <linux/sched.h> | 23 | #include <linux/sched.h> |
24 | #include <linux/slab.h> | 24 | #include <linux/slab.h> |
25 | 25 | ||
26 | #include "ptp_private.h" | 26 | #include "ptp_private.h" |
27 | 27 | ||
28 | int ptp_open(struct posix_clock *pc, fmode_t fmode) | 28 | int ptp_open(struct posix_clock *pc, fmode_t fmode) |
29 | { | 29 | { |
30 | return 0; | 30 | return 0; |
31 | } | 31 | } |
32 | 32 | ||
33 | long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) | 33 | long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) |
34 | { | 34 | { |
35 | struct ptp_clock_caps caps; | 35 | struct ptp_clock_caps caps; |
36 | struct ptp_clock_request req; | 36 | struct ptp_clock_request req; |
37 | struct ptp_sys_offset sysoff; | 37 | struct ptp_sys_offset *sysoff = NULL; |
38 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); | 38 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
39 | struct ptp_clock_info *ops = ptp->info; | 39 | struct ptp_clock_info *ops = ptp->info; |
40 | struct ptp_clock_time *pct; | 40 | struct ptp_clock_time *pct; |
41 | struct timespec ts; | 41 | struct timespec ts; |
42 | int enable, err = 0; | 42 | int enable, err = 0; |
43 | unsigned int i; | 43 | unsigned int i; |
44 | 44 | ||
45 | switch (cmd) { | 45 | switch (cmd) { |
46 | 46 | ||
47 | case PTP_CLOCK_GETCAPS: | 47 | case PTP_CLOCK_GETCAPS: |
48 | memset(&caps, 0, sizeof(caps)); | 48 | memset(&caps, 0, sizeof(caps)); |
49 | caps.max_adj = ptp->info->max_adj; | 49 | caps.max_adj = ptp->info->max_adj; |
50 | caps.n_alarm = ptp->info->n_alarm; | 50 | caps.n_alarm = ptp->info->n_alarm; |
51 | caps.n_ext_ts = ptp->info->n_ext_ts; | 51 | caps.n_ext_ts = ptp->info->n_ext_ts; |
52 | caps.n_per_out = ptp->info->n_per_out; | 52 | caps.n_per_out = ptp->info->n_per_out; |
53 | caps.pps = ptp->info->pps; | 53 | caps.pps = ptp->info->pps; |
54 | if (copy_to_user((void __user *)arg, &caps, sizeof(caps))) | 54 | if (copy_to_user((void __user *)arg, &caps, sizeof(caps))) |
55 | err = -EFAULT; | 55 | err = -EFAULT; |
56 | break; | 56 | break; |
57 | 57 | ||
58 | case PTP_EXTTS_REQUEST: | 58 | case PTP_EXTTS_REQUEST: |
59 | if (copy_from_user(&req.extts, (void __user *)arg, | 59 | if (copy_from_user(&req.extts, (void __user *)arg, |
60 | sizeof(req.extts))) { | 60 | sizeof(req.extts))) { |
61 | err = -EFAULT; | 61 | err = -EFAULT; |
62 | break; | 62 | break; |
63 | } | 63 | } |
64 | if (req.extts.index >= ops->n_ext_ts) { | 64 | if (req.extts.index >= ops->n_ext_ts) { |
65 | err = -EINVAL; | 65 | err = -EINVAL; |
66 | break; | 66 | break; |
67 | } | 67 | } |
68 | req.type = PTP_CLK_REQ_EXTTS; | 68 | req.type = PTP_CLK_REQ_EXTTS; |
69 | enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0; | 69 | enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0; |
70 | err = ops->enable(ops, &req, enable); | 70 | err = ops->enable(ops, &req, enable); |
71 | break; | 71 | break; |
72 | 72 | ||
73 | case PTP_PEROUT_REQUEST: | 73 | case PTP_PEROUT_REQUEST: |
74 | if (copy_from_user(&req.perout, (void __user *)arg, | 74 | if (copy_from_user(&req.perout, (void __user *)arg, |
75 | sizeof(req.perout))) { | 75 | sizeof(req.perout))) { |
76 | err = -EFAULT; | 76 | err = -EFAULT; |
77 | break; | 77 | break; |
78 | } | 78 | } |
79 | if (req.perout.index >= ops->n_per_out) { | 79 | if (req.perout.index >= ops->n_per_out) { |
80 | err = -EINVAL; | 80 | err = -EINVAL; |
81 | break; | 81 | break; |
82 | } | 82 | } |
83 | req.type = PTP_CLK_REQ_PEROUT; | 83 | req.type = PTP_CLK_REQ_PEROUT; |
84 | enable = req.perout.period.sec || req.perout.period.nsec; | 84 | enable = req.perout.period.sec || req.perout.period.nsec; |
85 | err = ops->enable(ops, &req, enable); | 85 | err = ops->enable(ops, &req, enable); |
86 | break; | 86 | break; |
87 | 87 | ||
88 | case PTP_ENABLE_PPS: | 88 | case PTP_ENABLE_PPS: |
89 | if (!capable(CAP_SYS_TIME)) | 89 | if (!capable(CAP_SYS_TIME)) |
90 | return -EPERM; | 90 | return -EPERM; |
91 | req.type = PTP_CLK_REQ_PPS; | 91 | req.type = PTP_CLK_REQ_PPS; |
92 | enable = arg ? 1 : 0; | 92 | enable = arg ? 1 : 0; |
93 | err = ops->enable(ops, &req, enable); | 93 | err = ops->enable(ops, &req, enable); |
94 | break; | 94 | break; |
95 | 95 | ||
96 | case PTP_SYS_OFFSET: | 96 | case PTP_SYS_OFFSET: |
97 | if (copy_from_user(&sysoff, (void __user *)arg, | 97 | sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL); |
98 | sizeof(sysoff))) { | 98 | if (!sysoff) { |
99 | err = -ENOMEM; | ||
100 | break; | ||
101 | } | ||
102 | if (copy_from_user(sysoff, (void __user *)arg, | ||
103 | sizeof(*sysoff))) { | ||
99 | err = -EFAULT; | 104 | err = -EFAULT; |
100 | break; | 105 | break; |
101 | } | 106 | } |
102 | if (sysoff.n_samples > PTP_MAX_SAMPLES) { | 107 | if (sysoff->n_samples > PTP_MAX_SAMPLES) { |
103 | err = -EINVAL; | 108 | err = -EINVAL; |
104 | break; | 109 | break; |
105 | } | 110 | } |
106 | pct = &sysoff.ts[0]; | 111 | pct = &sysoff->ts[0]; |
107 | for (i = 0; i < sysoff.n_samples; i++) { | 112 | for (i = 0; i < sysoff->n_samples; i++) { |
108 | getnstimeofday(&ts); | 113 | getnstimeofday(&ts); |
109 | pct->sec = ts.tv_sec; | 114 | pct->sec = ts.tv_sec; |
110 | pct->nsec = ts.tv_nsec; | 115 | pct->nsec = ts.tv_nsec; |
111 | pct++; | 116 | pct++; |
112 | ptp->info->gettime(ptp->info, &ts); | 117 | ptp->info->gettime(ptp->info, &ts); |
113 | pct->sec = ts.tv_sec; | 118 | pct->sec = ts.tv_sec; |
114 | pct->nsec = ts.tv_nsec; | 119 | pct->nsec = ts.tv_nsec; |
115 | pct++; | 120 | pct++; |
116 | } | 121 | } |
117 | getnstimeofday(&ts); | 122 | getnstimeofday(&ts); |
118 | pct->sec = ts.tv_sec; | 123 | pct->sec = ts.tv_sec; |
119 | pct->nsec = ts.tv_nsec; | 124 | pct->nsec = ts.tv_nsec; |
120 | if (copy_to_user((void __user *)arg, &sysoff, sizeof(sysoff))) | 125 | if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff))) |
121 | err = -EFAULT; | 126 | err = -EFAULT; |
122 | break; | 127 | break; |
123 | 128 | ||
124 | default: | 129 | default: |
125 | err = -ENOTTY; | 130 | err = -ENOTTY; |
126 | break; | 131 | break; |
127 | } | 132 | } |
133 | |||
134 | kfree(sysoff); | ||
128 | return err; | 135 | return err; |
129 | } | 136 | } |
130 | 137 | ||
131 | unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait) | 138 | unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait) |
132 | { | 139 | { |
133 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); | 140 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
134 | 141 | ||
135 | poll_wait(fp, &ptp->tsev_wq, wait); | 142 | poll_wait(fp, &ptp->tsev_wq, wait); |
136 | 143 | ||
137 | return queue_cnt(&ptp->tsevq) ? POLLIN : 0; | 144 | return queue_cnt(&ptp->tsevq) ? POLLIN : 0; |
138 | } | 145 | } |
139 | 146 | ||
140 | #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event)) | 147 | #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event)) |
141 | 148 | ||
142 | ssize_t ptp_read(struct posix_clock *pc, | 149 | ssize_t ptp_read(struct posix_clock *pc, |
143 | uint rdflags, char __user *buf, size_t cnt) | 150 | uint rdflags, char __user *buf, size_t cnt) |
144 | { | 151 | { |
145 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); | 152 | struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
146 | struct timestamp_event_queue *queue = &ptp->tsevq; | 153 | struct timestamp_event_queue *queue = &ptp->tsevq; |
147 | struct ptp_extts_event *event; | 154 | struct ptp_extts_event *event; |
148 | unsigned long flags; | 155 | unsigned long flags; |
149 | size_t qcnt, i; | 156 | size_t qcnt, i; |
150 | int result; | 157 | int result; |
151 | 158 | ||
152 | if (cnt % sizeof(struct ptp_extts_event) != 0) | 159 | if (cnt % sizeof(struct ptp_extts_event) != 0) |
153 | return -EINVAL; | 160 | return -EINVAL; |
154 | 161 | ||
155 | if (cnt > EXTTS_BUFSIZE) | 162 | if (cnt > EXTTS_BUFSIZE) |
156 | cnt = EXTTS_BUFSIZE; | 163 | cnt = EXTTS_BUFSIZE; |
157 | 164 | ||
158 | cnt = cnt / sizeof(struct ptp_extts_event); | 165 | cnt = cnt / sizeof(struct ptp_extts_event); |
159 | 166 | ||
160 | if (mutex_lock_interruptible(&ptp->tsevq_mux)) | 167 | if (mutex_lock_interruptible(&ptp->tsevq_mux)) |
161 | return -ERESTARTSYS; | 168 | return -ERESTARTSYS; |
162 | 169 | ||
163 | if (wait_event_interruptible(ptp->tsev_wq, | 170 | if (wait_event_interruptible(ptp->tsev_wq, |
164 | ptp->defunct || queue_cnt(queue))) { | 171 | ptp->defunct || queue_cnt(queue))) { |
165 | mutex_unlock(&ptp->tsevq_mux); | 172 | mutex_unlock(&ptp->tsevq_mux); |
166 | return -ERESTARTSYS; | 173 | return -ERESTARTSYS; |
167 | } | 174 | } |
168 | 175 | ||
169 | if (ptp->defunct) { | 176 | if (ptp->defunct) { |
170 | mutex_unlock(&ptp->tsevq_mux); | 177 | mutex_unlock(&ptp->tsevq_mux); |
171 | return -ENODEV; | 178 | return -ENODEV; |
172 | } | 179 | } |
173 | 180 | ||
174 | event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL); | 181 | event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL); |
175 | if (!event) { | 182 | if (!event) { |
176 | mutex_unlock(&ptp->tsevq_mux); | 183 | mutex_unlock(&ptp->tsevq_mux); |
177 | return -ENOMEM; | 184 | return -ENOMEM; |
178 | } | 185 | } |
179 | 186 | ||
180 | spin_lock_irqsave(&queue->lock, flags); | 187 | spin_lock_irqsave(&queue->lock, flags); |
181 | 188 | ||
182 | qcnt = queue_cnt(queue); | 189 | qcnt = queue_cnt(queue); |
183 | 190 | ||
184 | if (cnt > qcnt) | 191 | if (cnt > qcnt) |
185 | cnt = qcnt; | 192 | cnt = qcnt; |
186 | 193 | ||
187 | for (i = 0; i < cnt; i++) { | 194 | for (i = 0; i < cnt; i++) { |
188 | event[i] = queue->buf[queue->head]; | 195 | event[i] = queue->buf[queue->head]; |
189 | queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; | 196 | queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; |
190 | } | 197 | } |
191 | 198 | ||
192 | spin_unlock_irqrestore(&queue->lock, flags); | 199 | spin_unlock_irqrestore(&queue->lock, flags); |
193 | 200 | ||
194 | cnt = cnt * sizeof(struct ptp_extts_event); | 201 | cnt = cnt * sizeof(struct ptp_extts_event); |
195 | 202 | ||
196 | mutex_unlock(&ptp->tsevq_mux); | 203 | mutex_unlock(&ptp->tsevq_mux); |
197 | 204 | ||
198 | result = cnt; | 205 | result = cnt; |
199 | if (copy_to_user(buf, event, cnt)) | 206 | if (copy_to_user(buf, event, cnt)) |
200 | result = -EFAULT; | 207 | result = -EFAULT; |
201 | 208 | ||
202 | kfree(event); | 209 | kfree(event); |
203 | return result; | 210 | return result; |
204 | } | 211 | } |
205 | 212 |