linux-stable.git/fs/proc/fd.c, branch v3.16

proc: show mnt_id in /proc/pid/fdinfo

2014-04-07T23:36:04+00:00

Currently we don't have a way how to determing from which mount point
file has been opened.  This information is required for proper dumping
and restoring file descriptos due to presence of mount namespaces.  It's
possible, that two file descriptors are opened using the same paths, but
one fd references mount point from one namespace while the other fd --
from other namespace.

$ ls -l /proc/1/fd/1
lrwx------ 1 root root 64 Mar 19 23:54 /proc/1/fd/1 -> /dev/null

$ cat /proc/1/fdinfo/1
pos:	0
flags:	0100002
mnt_id:	16

$ cat /proc/1/mountinfo | grep ^16
16 32 0:4 / /dev rw,nosuid shared:2 - devtmpfs devtmpfs rw,size=1013356k,nr_inodes=253339,mode=755

Signed-off-by: Andrey Vagin 
Acked-by: Pavel Emelyanov 
Acked-by: Cyrill Gorcunov 
Cc: Rob Landley 
Cc: Al Viro 
Cc: Oleg Nesterov 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: make proc_fd_permission() thread-friendly

2013-09-11T22:59:03+00:00

proc_fd_permission() says "process can still access /proc/self/fd after it
has executed a setuid()", but the "task_pid() = proc_pid() check only
helps if the task is group leader, /proc/self points to
/proc/.

Change this check to use task_tgid() so that the whole thread group can
access its /proc/self/fd or /proc//fd.

Notes:
	- CLONE_THREAD does not require CLONE_FILES so task->files
	  can differ, but I don't think this can lead to any security
	  problem. And this matches same_thread_group() in
	  __ptrace_may_access().

	- /proc/self should probably point to /proc/, but
	  it is too late to change the rules. Perhaps it makes sense
	  to add /proc/thread though.

Test-case:

	void *tfunc(void *arg)
	{
		assert(opendir("/proc/self/fd"));
		return NULL;
	}

	int main(void)
	{
		pthread_t t;
		pthread_create(&t, NULL, tfunc, NULL);
		pthread_join(t, NULL);
		return 0;
	}

fails if, say, this executable is not readable and suid_dumpable = 0.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: kill the extra proc_readfd_common()->dir_emit_dots()

2013-08-24T16:10:22+00:00

proc_readfd_common() does dir_emit_dots() twice in a row,
we need to do this only once.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Al Viro

proc_fill_cache(): just make instantiate_t return int

2013-06-29T08:57:18+00:00

all instances always return ERR_PTR(-E...) or NULL, anyway

Signed-off-by: Al Viro

[readdir] convert procfs

2013-06-29T08:56:32+00:00

Signed-off-by: Al Viro

procfs: add ability to plug in auxiliary fdinfo providers

2012-12-18T01:15:27+00:00

This patch brings ability to print out auxiliary data associated with
file in procfs interface /proc/pid/fdinfo/fd.

In particular further patches make eventfd, evenpoll, signalfd and
fsnotify to print additional information complete enough to restore
these objects after checkpoint.

To simplify the code we add show_fdinfo callback inside struct
file_operations (as Al and Pavel are proposing).

Signed-off-by: Cyrill Gorcunov 
Acked-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: Andrey Vagin 
Cc: Al Viro 
Cc: Alexey Dobriyan 
Cc: James Bottomley 
Cc: "Aneesh Kumar K.V" 
Cc: Alexey Dobriyan 
Cc: Matthew Helsley 
Cc: "J. Bruce Fields" 
Cc: "Aneesh Kumar K.V" 
Cc: Tvrtko Ursulin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

don't leak O_CLOEXEC into ->f_flags

2012-09-27T01:10:01+00:00

Signed-off-by: Al Viro

procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file v2

2012-09-27T01:10:01+00:00

This patch converts /proc/pid/fdinfo/ handling routines to seq-file which
is needed to extend seq operations and plug in auxiliary fdinfo provides
from subsystems like eventfd/eventpoll/fsnotify.

Note the proc_fd_link no longer call for proc_fd_info, simply because
the guts of proc_fd_info() got merged into ->show() of that seq_file

Signed-off-by: Al Viro

procfs: Move /proc/pid/fd[info] handling code to fd.[ch]

2012-09-27T01:10:01+00:00

This patch prepares the ground for further extension of
/proc/pid/fd[info] handling code by moving fdinfo handling
code into fs/proc/fd.c.

I think such move makes both fs/proc/base.c and fs/proc/fd.c
easier to read.

Signed-off-by: Cyrill Gorcunov 
Acked-by: Pavel Emelyanov 
CC: Al Viro 
CC: Alexey Dobriyan 
CC: Andrew Morton 
CC: James Bottomley 
CC: "Aneesh Kumar K.V" 
CC: Alexey Dobriyan 
CC: Matthew Helsley 
CC: "J. Bruce Fields" 
CC: "Aneesh Kumar K.V" 
Signed-off-by: Al Viro