Re: [PATCH] LinuxPPS (with new syscalls API)

Rodolfo Giometti
2007-06-27T17:44:30Z

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On Wed, Jun 27, 2007 at 05:11:00PM +0100, David Woodhouse wrote:

> No, because you're passing a _kernel_ pointer to sys_time_pps_fetch()
> where it expects a userspace pointer. Use compat_alloc_user_space() to
> find somewhere to put it in user space, instead. Or change your internal
> __sys_time_pps_fetch() function to take a number of ticks instead of a
> pointer to a timespec, then call that directly with appropriate
> arguments, from both the normal and compat syscall routines.

Ok. Please see the attached patch.

Thanks a lot,

Rodolfo

--

GNU/Linux Solutions e-mail: giometti@enneenne.com
Linux Device Driver giometti@gnudd.com
Embedded Systems giometti@linux.it
UNIX programming phone: +39 349 2432127

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diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index befe292..820cc9a 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -26,6 +26,7 @@
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/sched.h>
+#include <linux/compat.h>
#include <linux/pps.h>
#include <asm/uaccess.h>

@@ -284,13 +285,12 @@ sys_time_pps_getcap_exit:
return ret;
}

-asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+static long __sys_time_pps_fetch(int source, const int tsformat,
struct pps_info __user *info,
- const struct timespec __user *timeout)
+ const struct timespec *timeout)
{
unsigned long ticks;
struct pps_info pi;
- struct timespec to;
int ret;

pps_dbg("%s: source %d", __FUNCTION__, source);
@@ -317,24 +317,19 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
pps_source[source].go = 0;

/* Manage the timeout */
- if (timeout) {
- ret = copy_from_user(&to, timeout, sizeof(struct timespec));
- if (ret)
- goto sys_time_pps_fetch_exit;
- if (to.tv_sec != -1) {
- pps_dbg("timeout %ld.%09ld", to.tv_sec, to.tv_nsec);
- ticks = to.tv_sec * HZ;
- ticks += to.tv_nsec / (NSEC_PER_SEC / HZ);
-
- if (ticks != 0) {
- ret = wait_event_interruptible_timeout(
- pps_source[source].queue,
- pps_source[source].go, ticks);
- if (ret == 0) {
- pps_dbg("timeout expired");
- ret = -ETIMEDOUT;
- goto sys_time_pps_fetch_exit;
- }
+ if (timeout->tv_sec != -1) {
+ pps_dbg("timeout %ld.%09ld", timeout->tv_sec, timeout->tv_nsec);
+ ticks = timeout->tv_sec * HZ;
+ ticks += timeout->tv_nsec / (NSEC_PER_SEC / HZ);
+
+ if (ticks != 0) {
+ ret = wait_event_interruptible_timeout(
+ pps_source[source].queue,
+ pps_source[source].go, ticks);
+ if (ret == 0) {
+ pps_dbg("timeout expired");
+ ret = -ETIMEDOUT;
+ goto sys_time_pps_fetch_exit;
}
}
} else
@@ -362,6 +357,44 @@ sys_time_pps_fetch_exit:
return ret;
}

+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+ struct pps_info __user *info,
+ const struct timespec __user *timeout)
+{
+ int ret;
+ struct timespec to;
+
+ if (timeout) {
+ ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+ if (ret)
+ return ret;
+ }
+ else
+ to.tv_sec = -1;
+
+ return __sys_time_pps_fetch(source, tsformat, info, timeout);
+}
+
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_time_pps_fetch(int source, const int tsformat,
+ struct pps_info __user *info,
+ const struct compat_timespec __user *timeout)
+{
+ int ret;
+ struct timespec to;
+
+ if (timeout) {
+ ret = get_compat_timespec(&to, timeout);
+ if (ret)
+ return -EFAULT;
+ }
+ else
+ to.tv_sec = -1;
+
+ return __sys_time_pps_fetch(source, tsformat, info, &to);
+}
+#endif
+
/*
* Module staff
*/