From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: [PATCH] proc.5: Add info about /proc/[pid]/map_files directory (v2) Date: Tue, 16 Apr 2013 21:37:37 +0400 Message-ID: <516D8C61.5090004@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michael Kerrisk , "linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-man@vger.kernel.org It was added into Linux v3.3 and provides info about files being mmap-ed in a way _very_ similar to how /proc/[pid]/fd works. Thus I thought that the best place for the map_files' doc is where where the fd's doc is. v2: Added examples of how links look like and dependency on kernel config option CONFIG_CHECKPOINT_RESTORE. Signed-off-by: Pavel Emelyanov --- diff --git a/man5/proc.5 b/man5/proc.5 index 520c5fc..1bfc63c 100644 --- a/man5/proc.5 +++ b/man5/proc.5 @@ -286,6 +286,42 @@ Thus the example command above could be written as: .RB "$" " foobar \-i /dev/stdin \-o /dev/stdout ..." .fi .in +.TP +.IR /proc/[pid]/map_files/ " (since kernel 3.3) +This subdirectory contains entries corresponding to memory mapped +files (see +.BR mmap (2)). +Entries are named by memory region start and end pair, +and are symbolic links to the files themselves. Like this +.in +4n +.nf + +.RB "$" " ls -l /proc/self/map_files/" +lr--------. 1 root root 64 Apr 16 21:31 3252e00000-3252e20000 -> /usr/lib64/ld-2.15.so +\&... +.fi +.in + +Although these entries are present for memory regions that were +mapped with +.BR MAP_FILE +flag, the way anonymous shared memory (regions created with +.B MAP_ANON | MAP_SHARED +flags) +is implemented in Linux +makes such regions also appear on this directory. In that case +the target file would be the deleted /dev/zero one: +.in +4n +.nf + +.RB +lrw-------. 1 root root 64 Apr 16 21:33 7fc075d2f000-7fc075e6f000 -> /dev/zero (deleted) +.fi +.in + +This directory appears only if the +.B CONFIG_CHECKPOINT_RESTORE +kernel configuration option is enabled. .\" FIXME Describe /proc/[pid]/loginuid .\" Added in 2.6.11; updating requires CAP_AUDIT_CONTROL .\" CONFIG_AUDITSYSCALL -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html