2017-03-10 23:21:16

by Matt Ranostay

[permalink] [raw]
Subject: [PATCH RESEND 0/2] pps: add ioctl_compat support

This series fixes issues with 32-bit userspace + 64-bit kernel data
structures, and along with fixing incorrect ioctl definitions in
a ABI stable way.

Changes from initial submission:
* add Rodolfo's Acked-by to patchsets
* add Greg K-H to Cc list, since there isn't a pps tree to merge in
changes

Matt Ranostay (2):
pps: add ioctl_compat function to correct ioctl definitions
pps: fix padding issue with PPS_FETCH for ioctl_compat

drivers/pps/pps.c | 123 +++++++++++++++++++++++++++++++++++------------
include/uapi/linux/pps.h | 19 ++++++++
2 files changed, 111 insertions(+), 31 deletions(-)

--
2.10.2


2017-03-10 23:21:01

by Matt Ranostay

[permalink] [raw]
Subject: [PATCH RESEND 1/2] pps: add ioctl_compat function to correct ioctl definitions

ioctl definitions use the pointer size of the architecture which
is fine when userspace and kernel are the same bitsize. This
patchset workarounds an issue with mixed bitsize kernel + userspace
by rewriting the cmd to the kernelspace architecture pointer size.

Cc: Greg Kroah-Hartman <[email protected]>
Acked-by: Rodolfo Giometti <[email protected]>
Signed-off-by: Matt Ranostay <[email protected]>
---
drivers/pps/pps.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 2f07cd615665..452ead5a5e52 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -242,6 +242,18 @@ static long pps_cdev_ioctl(struct file *file,
return 0;
}

+#ifdef CONFIG_COMPAT
+static long pps_cdev_compat_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
+
+ return pps_cdev_ioctl(file, cmd, arg);
+}
+#else
+#define pps_cdev_compat_ioctl NULL
+#endif
+
static int pps_cdev_open(struct inode *inode, struct file *file)
{
struct pps_device *pps = container_of(inode->i_cdev,
@@ -268,6 +280,7 @@ static const struct file_operations pps_cdev_fops = {
.llseek = no_llseek,
.poll = pps_cdev_poll,
.fasync = pps_cdev_fasync,
+ .compat_ioctl = pps_cdev_compat_ioctl,
.unlocked_ioctl = pps_cdev_ioctl,
.open = pps_cdev_open,
.release = pps_cdev_release,
--
2.10.2

2017-03-10 23:21:26

by Matt Ranostay

[permalink] [raw]
Subject: [PATCH RESEND 2/2] pps: fix padding issue with PPS_FETCH for ioctl_compat

Issue is that x86 32-bit aligns to 4-bytes instead of 8-bytes
so this patchset works around the issue and corrects the data
returned in pps_fdata_compat.

Cc: Greg Kroah-Hartman <[email protected]>
Acked-by: Rodolfo Giometti <[email protected]>
Signed-off-by: Matt Ranostay <[email protected]>
---
drivers/pps/pps.c | 110 ++++++++++++++++++++++++++++++++++-------------
include/uapi/linux/pps.h | 19 ++++++++
2 files changed, 98 insertions(+), 31 deletions(-)

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 452ead5a5e52..6eb0db37dd88 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -64,6 +64,43 @@ static int pps_cdev_fasync(int fd, struct file *file, int on)
return fasync_helper(fd, file, on, &pps->async_queue);
}

+static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)
+{
+ unsigned int ev = pps->last_ev;
+ int err = 0;
+
+ /* Manage the timeout */
+ if (fdata->timeout.flags & PPS_TIME_INVALID)
+ err = wait_event_interruptible(pps->queue,
+ ev != pps->last_ev);
+ else {
+ unsigned long ticks;
+
+ dev_dbg(pps->dev, "timeout %lld.%09d\n",
+ (long long) fdata->timeout.sec,
+ fdata->timeout.nsec);
+ ticks = fdata->timeout.sec * HZ;
+ ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ);
+
+ if (ticks != 0) {
+ err = wait_event_interruptible_timeout(
+ pps->queue,
+ ev != pps->last_ev,
+ ticks);
+ if (err == 0)
+ return -ETIMEDOUT;
+ }
+ }
+
+ /* Check for pending signals */
+ if (err == -ERESTARTSYS) {
+ dev_dbg(pps->dev, "pending signal caught\n");
+ return -EINTR;
+ }
+
+ return 0;
+}
+
static long pps_cdev_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
@@ -144,7 +181,6 @@ static long pps_cdev_ioctl(struct file *file,

case PPS_FETCH: {
struct pps_fdata fdata;
- unsigned int ev;

dev_dbg(pps->dev, "PPS_FETCH\n");

@@ -152,36 +188,9 @@ static long pps_cdev_ioctl(struct file *file,
if (err)
return -EFAULT;

- ev = pps->last_ev;
-
- /* Manage the timeout */
- if (fdata.timeout.flags & PPS_TIME_INVALID)
- err = wait_event_interruptible(pps->queue,
- ev != pps->last_ev);
- else {
- unsigned long ticks;
-
- dev_dbg(pps->dev, "timeout %lld.%09d\n",
- (long long) fdata.timeout.sec,
- fdata.timeout.nsec);
- ticks = fdata.timeout.sec * HZ;
- ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
-
- if (ticks != 0) {
- err = wait_event_interruptible_timeout(
- pps->queue,
- ev != pps->last_ev,
- ticks);
- if (err == 0)
- return -ETIMEDOUT;
- }
- }
-
- /* Check for pending signals */
- if (err == -ERESTARTSYS) {
- dev_dbg(pps->dev, "pending signal caught\n");
- return -EINTR;
- }
+ err = pps_cdev_pps_fetch(pps, &fdata);
+ if (err)
+ return err;

/* Return the fetched timestamp */
spin_lock_irq(&pps->lock);
@@ -246,8 +255,47 @@ static long pps_cdev_ioctl(struct file *file,
static long pps_cdev_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
+ struct pps_device *pps = file->private_data;
+ void __user *uarg = (void __user *) arg;
+
cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));

+ if (cmd == PPS_FETCH) {
+ struct pps_fdata_compat compat;
+ struct pps_fdata fdata;
+ int err;
+
+ dev_dbg(pps->dev, "PPS_FETCH\n");
+
+ err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
+ if (err)
+ return -EFAULT;
+
+ memcpy(&fdata.timeout, &compat.timeout,
+ sizeof(struct pps_ktime_compat));
+
+ err = pps_cdev_pps_fetch(pps, &fdata);
+ if (err)
+ return err;
+
+ /* Return the fetched timestamp */
+ spin_lock_irq(&pps->lock);
+
+ compat.info.assert_sequence = pps->assert_sequence;
+ compat.info.clear_sequence = pps->clear_sequence;
+ compat.info.current_mode = pps->current_mode;
+
+ memcpy(&compat.info.assert_tu, &pps->assert_tu,
+ sizeof(struct pps_ktime_compat));
+ memcpy(&compat.info.clear_tu, &pps->clear_tu,
+ sizeof(struct pps_ktime_compat));
+
+ spin_unlock_irq(&pps->lock);
+
+ return copy_to_user(uarg, &compat,
+ sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
+ }
+
return pps_cdev_ioctl(file, cmd, arg);
}
#else
diff --git a/include/uapi/linux/pps.h b/include/uapi/linux/pps.h
index a9bb1d93451a..c1cb3825a8bc 100644
--- a/include/uapi/linux/pps.h
+++ b/include/uapi/linux/pps.h
@@ -55,6 +55,12 @@ struct pps_ktime {
__s32 nsec;
__u32 flags;
};
+
+struct pps_ktime_compat {
+ __s64 sec;
+ __s32 nsec;
+ __u32 flags;
+} __attribute__((packed, aligned(4)));
#define PPS_TIME_INVALID (1<<0) /* used to specify timeout==NULL */

struct pps_kinfo {
@@ -65,6 +71,14 @@ struct pps_kinfo {
int current_mode; /* current mode bits */
};

+struct pps_kinfo_compat {
+ __u32 assert_sequence; /* seq. num. of assert event */
+ __u32 clear_sequence; /* seq. num. of clear event */
+ struct pps_ktime_compat assert_tu; /* time of assert event */
+ struct pps_ktime_compat clear_tu; /* time of clear event */
+ int current_mode; /* current mode bits */
+};
+
struct pps_kparams {
int api_version; /* API version # */
int mode; /* mode bits */
@@ -114,6 +128,11 @@ struct pps_fdata {
struct pps_ktime timeout;
};

+struct pps_fdata_compat {
+ struct pps_kinfo_compat info;
+ struct pps_ktime_compat timeout;
+};
+
struct pps_bind_args {
int tsformat; /* format of time stamps */
int edge; /* selected event type */
--
2.10.2