Have utrace(2) return ENOMEM if malloc() fails. Document this error

return in its manual page.

Reviewed by:	jhb

2 files changed, 7 insertions, 5 deletions

diff --git a/lib/libc/sys/utrace.2 b/lib/libc/sys/utrace.2
index ca81672..64bef2a 100644
--- a/lib/libc/sys/utrace.2
+++ b/lib/libc/sys/utrace.2
@@ -65,15 +65,17 @@ Otherwise, a value of -1 is returned and
 is set to indicate the error.
 .Sh ERRORS
 .Bl -tag -width Er
-.It Bq Er ENOSYS
-Currently running kernel was compiled without
-.Xr ktrace 2
-support (option KTRACE).
 .It Bq Er EINVAL
 Specified data length
 .Fa len
 was bigger than
 .Dv KTR_USER_MAXLEN .
+.It Bq Er ENOMEM
+Insufficient memory to honor the request.
+.It Bq Er ENOSYS
+Currently running kernel was compiled without
+.Xr ktrace 2
+support (option KTRACE).
 .El
 .Sh SEE ALSO
 .Xr kdump 1 ,
diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 469d378..03e08b1 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -662,7 +662,7 @@ utrace(td, uap)
 	req = ktr_getrequest(KTR_USER);
 	if (req == NULL) {
 		free(cp, M_KTRACE);
-		return (0);
+		return (ENOMEM);
 	}
 	req->ktr_header.ktr_buffer = cp;
 	req->ktr_header.ktr_len = uap->len;