[2.6 patch] the scheduled -EINVAL for invalid timevals in setitimer

From: Adrian Bunk
Date: Fri Apr 06 2007 - 06:21:25 EST


As scheduled, do_setitimer() now returns -EINVAL for invalid timeval.

Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>

---

Documentation/feature-removal-schedule.txt | 12 ----
kernel/itimer.c | 58 ---------------------
2 files changed, 2 insertions(+), 68 deletions(-)

--- linux-2.6.21-rc5-mm4/Documentation/feature-removal-schedule.txt.old 2007-04-05 21:02:30.000000000 +0200
+++ linux-2.6.21-rc5-mm4/Documentation/feature-removal-schedule.txt 2007-04-05 21:02:42.000000000 +0200
@@ -104,18 +104,6 @@ Who: Adrian Bunk <bunk@xxxxxxxxx>

---------------------------

-What: Usage of invalid timevals in setitimer
-When: March 2007
-Why: POSIX requires to validate timevals in the setitimer call. This
- was never done by Linux. The invalid (e.g. negative timevals) were
- silently converted to more or less random timeouts and intervals.
- Until the removal a per boot limited number of warnings is printed
- and the timevals are sanitized.
-
-Who: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
-
----------------------------
-
What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
(temporary transition config option provided until then)
The transition config option will also be removed at the same time.
--- linux-2.6.21-rc5-mm4/kernel/itimer.c.old 2007-04-05 21:02:50.000000000 +0200
+++ linux-2.6.21-rc5-mm4/kernel/itimer.c 2007-04-05 21:06:05.000000000 +0200
@@ -138,59 +138,11 @@ enum hrtimer_restart it_real_fn(struct h
}

/*
- * We do not care about correctness. We just sanitize the values so
- * the ktime_t operations which expect normalized values do not
- * break. This converts negative values to long timeouts similar to
- * the code in kernel versions < 2.6.16
- *
- * Print a limited number of warning messages when an invalid timeval
- * is detected.
- */
-static void fixup_timeval(struct timeval *tv, int interval)
-{
- static int warnlimit = 10;
- unsigned long tmp;
-
- if (warnlimit > 0) {
- warnlimit--;
- printk(KERN_WARNING
- "setitimer: %s (pid = %d) provided "
- "invalid timeval %s: tv_sec = %ld tv_usec = %ld\n",
- current->comm, current->pid,
- interval ? "it_interval" : "it_value",
- tv->tv_sec, (long) tv->tv_usec);
- }
-
- tmp = tv->tv_usec;
- if (tmp >= USEC_PER_SEC) {
- tv->tv_usec = tmp % USEC_PER_SEC;
- tv->tv_sec += tmp / USEC_PER_SEC;
- }
-
- tmp = tv->tv_sec;
- if (tmp > LONG_MAX)
- tv->tv_sec = LONG_MAX;
-}
-
-/*
* Returns true if the timeval is in canonical form
*/
#define timeval_valid(t) \
(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))

-/*
- * Check for invalid timevals, sanitize them and print a limited
- * number of warnings.
- */
-static void check_itimerval(struct itimerval *value) {
-
- if (unlikely(!timeval_valid(&value->it_value)))
- fixup_timeval(&value->it_value, 0);
-
- if (unlikely(!timeval_valid(&value->it_interval)))
- fixup_timeval(&value->it_interval, 1);
-}
-
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
{
struct task_struct *tsk = current;
@@ -200,15 +152,9 @@ int do_setitimer(int which, struct itime

/*
* Validate the timevals in value.
- *
- * Note: Although the spec requires that invalid values shall
- * return -EINVAL, we just fixup the value and print a limited
- * number of warnings in order not to break users of this
- * historical misfeature.
- *
- * Scheduled for replacement in March 2007
*/
- check_itimerval(value);
+ if (unlikely(!timeval_valid(&value->it_value) || !timeval_valid(&value->it_interval)))
+ return -EINVAL;

switch (which) {
case ITIMER_REAL:

-
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