signalfd.2: Note that signalfd info is available in /proc/PID/fdinfo

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

1 files changed, 9 insertions, 0 deletions

diff --git a/man2/signalfd.2 b/man2/signalfd.2
index f189866801..0a6ae56ce5 100644
--- a/man2/signalfd.2
+++ b/man2/signalfd.2
@@ -332,6 +332,15 @@ If a signal appears in the
 .I mask
 of more than one of the file descriptors, then occurrences
 of that signal can be read (once) from any one of the file descriptors.
+
+The signal mask employed by a signalfd file descriptor can be viewed
+via the entry for the corresponding file descriptor in the process's
+.IR /proc/[pid]/fdinfo
+directory.
+See
+.BR proc (5)
+for further details.
+.\"
 .SS C library/kernel differences
 The underlying Linux system call requires an additional argument,
 .IR "size_t sizemask" ,