Borrow the algorithm from kvm_getprocs() to fix procstat_getprocs() to

handle the case where the process tables grows in between the calls to
fetch the size and fetch the table.

MFC after:	1 week

1 files changed, 11 insertions, 7 deletions

diff --git a/lib/libprocstat/libprocstat.c b/lib/libprocstat/libprocstat.c
index cd38018..7626c19 100644
--- a/lib/libprocstat/libprocstat.c
+++ b/lib/libprocstat/libprocstat.c
@@ -253,7 +253,7 @@ procstat_getprocs(struct procstat *procstat, int what, int arg,
     unsigned int *count)
 {
 	struct kinfo_proc *p0, *p;
-	size_t len;
+	size_t len, olen;
 	int name[4];
 	int cnt;
 	int error;
@@ -290,12 +290,16 @@ procstat_getprocs(struct procstat *procstat, int what, int arg,
 			warnx("no processes?");
 			goto fail;
 		}
-		p = malloc(len);
-		if (p == NULL) {
-			warnx("malloc(%zu)", len);
-			goto fail;
-		}
-		error = sysctl(name, 4, p, &len, NULL, 0);
+		do {
+			len += len / 10;
+			p = reallocf(p, len);
+			if (p == NULL) {
+				warnx("reallocf(%zu)", len);
+				goto fail;
+			}
+			olen = len;
+			error = sysctl(name, 4, p, &len, NULL, 0);
+		} while (error < 0 && errno == ENOMEM && olen == len);
 		if (error < 0 && errno != EPERM) {
 			warn("sysctl(kern.proc)");
 			goto fail;