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linux/drivers/ptp/ptp_chardev.c
Jacob Keller 2df4de1681 ptp: correctly disable flags on old ioctls 
Commit 415606588c ("PTP: introduce new versions of IOCTLs",
2019-09-13) introduced new versions of the PTP ioctls which actually
validate that the flags are acceptable values.

As part of this, it cleared the flags value using a bitwise
and+negation, in an attempt to prevent the old ioctl from accidentally
enabling new features.

This is incorrect for a couple of reasons. First, it results in
accidentally preventing previously working flags on the request ioctl.
By clearing the "valid" flags, we now no longer allow setting the
enable, rising edge, or falling edge flags.

Second, if we add new additional flags in the future, they must not be
set by the old ioctl. (Since the flag wasn't checked before, we could
potentially break userspace programs which sent garbage flag data.

The correct way to resolve this is to check for and clear all but the
originally valid flags.

Create defines indicating which flags are correctly checked and
interpreted by the original ioctls. Use these to clear any bits which
will not be correctly interpreted by the original ioctls.

In the future, new flags must be added to the VALID_FLAGS macros, but
*not* to the V1_VALID_FLAGS macros. In this way, new features may be
exposed over the v2 ioctls, but without breaking previous userspace
which happened to not clear the flags value properly. The old ioctl will
continue to behave the same way, while the new ioctl gains the benefit
of using the flags fields.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Christopher Hall <christopher.s.hall@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27 20:25:32 +02:00

452 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PTP 1588 clock support - character device implementation.
*
* Copyright (C) 2010 OMICRON electronics GmbH
*/
#include <linux/module.h>
#include <linux/posix-clock.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timekeeping.h>
#include <linux/nospec.h>
#include "ptp_private.h"
static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
enum ptp_pin_function func, unsigned int chan)
{
struct ptp_clock_request rq;
int err = 0;
memset(&rq, 0, sizeof(rq));
switch (func) {
case PTP_PF_NONE:
break;
case PTP_PF_EXTTS:
rq.type = PTP_CLK_REQ_EXTTS;
rq.extts.index = chan;
err = ops->enable(ops, &rq, 0);
break;
case PTP_PF_PEROUT:
rq.type = PTP_CLK_REQ_PEROUT;
rq.perout.index = chan;
err = ops->enable(ops, &rq, 0);
break;
case PTP_PF_PHYSYNC:
break;
default:
return -EINVAL;
}
return err;
}
int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
enum ptp_pin_function func, unsigned int chan)
{
struct ptp_clock_info *info = ptp->info;
struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
unsigned int i;
/* Check to see if any other pin previously had this function. */
for (i = 0; i < info->n_pins; i++) {
if (info->pin_config[i].func == func &&
info->pin_config[i].chan == chan) {
pin1 = &info->pin_config[i];
break;
}
}
if (pin1 && i == pin)
return 0;
/* Check the desired function and channel. */
switch (func) {
case PTP_PF_NONE:
break;
case PTP_PF_EXTTS:
if (chan >= info->n_ext_ts)
return -EINVAL;
break;
case PTP_PF_PEROUT:
if (chan >= info->n_per_out)
return -EINVAL;
break;
case PTP_PF_PHYSYNC:
if (chan != 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
if (info->verify(info, pin, func, chan)) {
pr_err("driver cannot use function %u on pin %u\n", func, chan);
return -EOPNOTSUPP;
}
/* Disable whatever function was previously assigned. */
if (pin1) {
ptp_disable_pinfunc(info, func, chan);
pin1->func = PTP_PF_NONE;
pin1->chan = 0;
}
ptp_disable_pinfunc(info, pin2->func, pin2->chan);
pin2->func = func;
pin2->chan = chan;
return 0;
}
int ptp_open(struct posix_clock *pc, fmode_t fmode)
{
return 0;
}
long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
struct ptp_sys_offset_extended *extoff = NULL;
struct ptp_sys_offset_precise precise_offset;
struct system_device_crosststamp xtstamp;
struct ptp_clock_info *ops = ptp->info;
struct ptp_sys_offset *sysoff = NULL;
struct ptp_system_timestamp sts;
struct ptp_clock_request req;
struct ptp_clock_caps caps;
struct ptp_clock_time *pct;
unsigned int i, pin_index;
struct ptp_pin_desc pd;
struct timespec64 ts;
int enable, err = 0;
switch (cmd) {
case PTP_CLOCK_GETCAPS:
case PTP_CLOCK_GETCAPS2:
memset(&caps, 0, sizeof(caps));
caps.max_adj = ptp->info->max_adj;
caps.n_alarm = ptp->info->n_alarm;
caps.n_ext_ts = ptp->info->n_ext_ts;
caps.n_per_out = ptp->info->n_per_out;
caps.pps = ptp->info->pps;
caps.n_pins = ptp->info->n_pins;
caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
err = -EFAULT;
break;
case PTP_EXTTS_REQUEST:
case PTP_EXTTS_REQUEST2:
memset(&req, 0, sizeof(req));
if (copy_from_user(&req.extts, (void __user *)arg,
sizeof(req.extts))) {
err = -EFAULT;
break;
}
if (((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
req.extts.rsv[0] || req.extts.rsv[1]) &&
cmd == PTP_EXTTS_REQUEST2) {
err = -EINVAL;
break;
} else if (cmd == PTP_EXTTS_REQUEST) {
req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
req.extts.rsv[0] = 0;
req.extts.rsv[1] = 0;
}
if (req.extts.index >= ops->n_ext_ts) {
err = -EINVAL;
break;
}
req.type = PTP_CLK_REQ_EXTTS;
enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
err = ops->enable(ops, &req, enable);
break;
case PTP_PEROUT_REQUEST:
case PTP_PEROUT_REQUEST2:
memset(&req, 0, sizeof(req));
if (copy_from_user(&req.perout, (void __user *)arg,
sizeof(req.perout))) {
err = -EFAULT;
break;
}
if (((req.perout.flags & ~PTP_PEROUT_VALID_FLAGS) ||
req.perout.rsv[0] || req.perout.rsv[1] ||
req.perout.rsv[2] || req.perout.rsv[3]) &&
cmd == PTP_PEROUT_REQUEST2) {
err = -EINVAL;
break;
} else if (cmd == PTP_PEROUT_REQUEST) {
req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
req.perout.rsv[0] = 0;
req.perout.rsv[1] = 0;
req.perout.rsv[2] = 0;
req.perout.rsv[3] = 0;
}
if (req.perout.index >= ops->n_per_out) {
err = -EINVAL;
break;
}
req.type = PTP_CLK_REQ_PEROUT;
enable = req.perout.period.sec || req.perout.period.nsec;
err = ops->enable(ops, &req, enable);
break;
case PTP_ENABLE_PPS:
case PTP_ENABLE_PPS2:
memset(&req, 0, sizeof(req));
if (!capable(CAP_SYS_TIME))
return -EPERM;
req.type = PTP_CLK_REQ_PPS;
enable = arg ? 1 : 0;
err = ops->enable(ops, &req, enable);
break;
case PTP_SYS_OFFSET_PRECISE:
case PTP_SYS_OFFSET_PRECISE2:
if (!ptp->info->getcrosststamp) {
err = -EOPNOTSUPP;
break;
}
err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
if (err)
break;
memset(&precise_offset, 0, sizeof(precise_offset));
ts = ktime_to_timespec64(xtstamp.device);
precise_offset.device.sec = ts.tv_sec;
precise_offset.device.nsec = ts.tv_nsec;
ts = ktime_to_timespec64(xtstamp.sys_realtime);
precise_offset.sys_realtime.sec = ts.tv_sec;
precise_offset.sys_realtime.nsec = ts.tv_nsec;
ts = ktime_to_timespec64(xtstamp.sys_monoraw);
precise_offset.sys_monoraw.sec = ts.tv_sec;
precise_offset.sys_monoraw.nsec = ts.tv_nsec;
if (copy_to_user((void __user *)arg, &precise_offset,
sizeof(precise_offset)))
err = -EFAULT;
break;
case PTP_SYS_OFFSET_EXTENDED:
case PTP_SYS_OFFSET_EXTENDED2:
if (!ptp->info->gettimex64) {
err = -EOPNOTSUPP;
break;
}
extoff = memdup_user((void __user *)arg, sizeof(*extoff));
if (IS_ERR(extoff)) {
err = PTR_ERR(extoff);
extoff = NULL;
break;
}
if (extoff->n_samples > PTP_MAX_SAMPLES
|| extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
err = -EINVAL;
break;
}
for (i = 0; i < extoff->n_samples; i++) {
err = ptp->info->gettimex64(ptp->info, &ts, &sts);
if (err)
goto out;
extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
extoff->ts[i][1].sec = ts.tv_sec;
extoff->ts[i][1].nsec = ts.tv_nsec;
extoff->ts[i][2].sec = sts.post_ts.tv_sec;
extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
}
if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
err = -EFAULT;
break;
case PTP_SYS_OFFSET:
case PTP_SYS_OFFSET2:
sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
if (IS_ERR(sysoff)) {
err = PTR_ERR(sysoff);
sysoff = NULL;
break;
}
if (sysoff->n_samples > PTP_MAX_SAMPLES) {
err = -EINVAL;
break;
}
pct = &sysoff->ts[0];
for (i = 0; i < sysoff->n_samples; i++) {
ktime_get_real_ts64(&ts);
pct->sec = ts.tv_sec;
pct->nsec = ts.tv_nsec;
pct++;
if (ops->gettimex64)
err = ops->gettimex64(ops, &ts, NULL);
else
err = ops->gettime64(ops, &ts);
if (err)
goto out;
pct->sec = ts.tv_sec;
pct->nsec = ts.tv_nsec;
pct++;
}
ktime_get_real_ts64(&ts);
pct->sec = ts.tv_sec;
pct->nsec = ts.tv_nsec;
if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
err = -EFAULT;
break;
case PTP_PIN_GETFUNC:
case PTP_PIN_GETFUNC2:
if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
err = -EFAULT;
break;
}
if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
|| pd.rsv[3] || pd.rsv[4])
&& cmd == PTP_PIN_GETFUNC2) {
err = -EINVAL;
break;
} else if (cmd == PTP_PIN_GETFUNC) {
pd.rsv[0] = 0;
pd.rsv[1] = 0;
pd.rsv[2] = 0;
pd.rsv[3] = 0;
pd.rsv[4] = 0;
}
pin_index = pd.index;
if (pin_index >= ops->n_pins) {
err = -EINVAL;
break;
}
pin_index = array_index_nospec(pin_index, ops->n_pins);
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
pd = ops->pin_config[pin_index];
mutex_unlock(&ptp->pincfg_mux);
if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
err = -EFAULT;
break;
case PTP_PIN_SETFUNC:
case PTP_PIN_SETFUNC2:
if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
err = -EFAULT;
break;
}
if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
|| pd.rsv[3] || pd.rsv[4])
&& cmd == PTP_PIN_SETFUNC2) {
err = -EINVAL;
break;
} else if (cmd == PTP_PIN_SETFUNC) {
pd.rsv[0] = 0;
pd.rsv[1] = 0;
pd.rsv[2] = 0;
pd.rsv[3] = 0;
pd.rsv[4] = 0;
}
pin_index = pd.index;
if (pin_index >= ops->n_pins) {
err = -EINVAL;
break;
}
pin_index = array_index_nospec(pin_index, ops->n_pins);
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
mutex_unlock(&ptp->pincfg_mux);
break;
default:
err = -ENOTTY;
break;
}
out:
kfree(extoff);
kfree(sysoff);
return err;
}
__poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
poll_wait(fp, &ptp->tsev_wq, wait);
return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
}
#define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
ssize_t ptp_read(struct posix_clock *pc,
uint rdflags, char __user *buf, size_t cnt)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
struct timestamp_event_queue *queue = &ptp->tsevq;
struct ptp_extts_event *event;
unsigned long flags;
size_t qcnt, i;
int result;
if (cnt % sizeof(struct ptp_extts_event) != 0)
return -EINVAL;
if (cnt > EXTTS_BUFSIZE)
cnt = EXTTS_BUFSIZE;
cnt = cnt / sizeof(struct ptp_extts_event);
if (mutex_lock_interruptible(&ptp->tsevq_mux))
return -ERESTARTSYS;
if (wait_event_interruptible(ptp->tsev_wq,
ptp->defunct || queue_cnt(queue))) {
mutex_unlock(&ptp->tsevq_mux);
return -ERESTARTSYS;
}
if (ptp->defunct) {
mutex_unlock(&ptp->tsevq_mux);
return -ENODEV;
}
event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
if (!event) {
mutex_unlock(&ptp->tsevq_mux);
return -ENOMEM;
}
spin_lock_irqsave(&queue->lock, flags);
qcnt = queue_cnt(queue);
if (cnt > qcnt)
cnt = qcnt;
for (i = 0; i < cnt; i++) {
event[i] = queue->buf[queue->head];
queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
}
spin_unlock_irqrestore(&queue->lock, flags);
cnt = cnt * sizeof(struct ptp_extts_event);
mutex_unlock(&ptp->tsevq_mux);
result = cnt;
if (copy_to_user(buf, event, cnt))
result = -EFAULT;
kfree(event);
return result;
}
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