getauxval.3: Add some details for AT_SECURE

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man3/getauxval.3 b/man3/getauxval.3
index 93910e756863d9c384e8c773f337d62adb1ca390..c42891c0779a37c7a51dfae3b41adddaa7b34303 100644 (file)
--- a/man3/getauxval.3
+++ b/man3/getauxval.3
@@ -148,8 +148,10 @@ The address of sixteen bytes containing a random value.
 .BR AT_SECURE
 Has a nonzero value if this executable should be treated securely.
 Most commonly, a nonzero value indicates that the process is
-executing a set-user-ID or set-group-ID binary,
-or a binary file that has capabilities (see
+executing a set-user-ID or set-group-ID binary
+(so that it's real and effective UIDs or GIDs differ from one another),
+or that it gained capabilities by executing
+a binary file that has capabilities (see
 .BR capabilities (7)).
 Alternatively,
 a nonzero value may be triggered by a Linux Security Module.