random(4): Squash non-error timeout codes from tsleep(9).

In both scenarios a timeout (EWOULDBLOCK) is considered as a
normal condition and the error should not pop up to upper layers.

PR:		231181
Submitted by:	cem
Reported by:	lev
Reviewed by:	vangyzen, markm, delphij
Approved by:	re (kib)
Approved by:	secteam (delphij)
Differential Revision:	https://reviews.freebsd.org/D17049
This commit is contained in:
Xin LI 2018-09-09 17:12:31 +00:00
parent 7877f59352
commit 7a8d266139

View File

@ -156,6 +156,10 @@ READ_RANDOM_UIO(struct uio *uio, bool nonblock)
error = tsleep(&random_alg_context, PCATCH, "randseed", hz/10);
if (error == ERESTART || error == EINTR)
break;
/* Squash tsleep timeout condition */
if (error == EWOULDBLOCK)
error = 0;
KASSERT(error == 0, ("unexpected tsleep error %d", error));
}
if (error == 0) {
read_rate_increment((uio->uio_resid + sizeof(uint32_t))/sizeof(uint32_t));
@ -184,9 +188,13 @@ READ_RANDOM_UIO(struct uio *uio, bool nonblock)
* uninterruptible syscalls.
*/
if (error == 0 && uio->uio_resid != 0 &&
total_read % sigchk_period == 0)
total_read % sigchk_period == 0) {
error = tsleep_sbt(&random_alg_context, PCATCH,
"randrd", SBT_1NS, 0, C_HARDCLOCK);
/* Squash tsleep timeout condition */
if (error == EWOULDBLOCK)
error = 0;
}
}
if (error == ERESTART || error == EINTR)
error = 0;