Update /proc/[number]/cmdline description.

It used to be true that the command line arguments were
not accessible when the process had been swapped out.
In ancient kernels (circa 2.0.*) the problem was that the
kernel relied on get_phys_addr to access the user space buffer,
which stopped working as soon as the process was swapped out.
Recent kernels use get_user_pages for the same purpose and thus
they should not have that limitation.

diff --git a/man5/proc.5 b/man5/proc.5
index e833fd6c8b932610a55120000284e122bd72ab57..431a9dbb498f6aa3d7e040f8c89c9db6acfd033b 100644 (file)
--- a/man5/proc.5
+++ b/man5/proc.5
@@ -87,11 +87,12 @@ plus one \fIunsigned long\fP value for each entry.
 The last entry contains two zeros.
 .TP
 .I /proc/[number]/cmdline
-This holds the complete command line for the process, unless the whole
-process has been swapped out or the process is a zombie.
-In either of these latter cases, there is nothing in this file:
+This holds the complete command line for the process,
+unless the process is a zombie.
+.\" In 2.3.26, this also used to be true if the process was swapped out.
+In the latter case, there is nothing in this file:
 that is, a read on this file will return 0 characters.
-The command line arguments appear in this file as a set of
+The command-line arguments appear in this file as a set of
 null-separated strings, with a further null byte after the last string.
 .TP
 .I /proc/[number]/cwd