2 files changed, 36 insertions, 5 deletions

diff --git a/usr.bin/elfctl/elfctl.1 b/usr.bin/elfctl/elfctl.1
index f93b558fdf0d..23e2dabea49c 100644
--- a/usr.bin/elfctl/elfctl.1
+++ b/usr.bin/elfctl/elfctl.1
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 12, 2021
+.Dd January 22, 2021
 .Dt ELFCTL 1
 .Os
 .Sh NAME
@@ -64,7 +64,8 @@ to turn on the features,
 to turn off the features,
 .Dq Li =
 to only turn on the given features.
-A comma separated list of feature names follows the operation.
+A comma separated list of feature names or numeric values follows the
+operation.
 .El
 .Pp
 If
@@ -86,6 +87,16 @@ command:
 elfctl file
 elfctl -e +aslr file
 .Ed
+.Pp
+Features may be specified as numerical values:
+.Bd -literal -offset -indent
+elfctl -e =0x0001,0x0004 file
+.Ed
+.Pp
+Features may also be specified as a single combined value:
+.Bd -literal -offset -indent
+elfctl -e =0x5 file
+.Ed
 .Sh HISTORY
 .Nm
 first appeared in
diff --git a/usr.bin/elfctl/elfctl.c b/usr.bin/elfctl/elfctl.c
index efc993302c60..15b35a5fec4b 100644
--- a/usr.bin/elfctl/elfctl.c
+++ b/usr.bin/elfctl/elfctl.c
@@ -33,12 +33,15 @@
 #include <sys/endian.h>
 #include <sys/stat.h>
 
+#include <ctype.h>
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <gelf.h>
 #include <getopt.h>
 #include <libelf.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -246,9 +249,26 @@ convert_to_feature_val(char *feature_str, uint32_t *feature_val)
 			}
 		}
 		if (i == len) {
-			warnx("%s is not a valid feature", feature);
-			if (!iflag)
-				return (false);
+			if (isdigit(feature[0])) {
+				char *eptr;
+				unsigned long long val;
+
+				errno = 0;
+				val = strtoll(feature, &eptr, 0);
+				if (eptr == feature || *eptr != '\0')
+					errno = EINVAL;
+				else if (val > UINT32_MAX)
+					errno = ERANGE;
+				if (errno != 0) {
+					warn("%s invalid", feature);
+					return (false);
+				}
+				input |= val;
+			} else {
+				warnx("%s is not a valid feature", feature);
+				if (!iflag)
+					return (false);
+			}
 		}
 	}