linux/Documentation/filesystems
Andy Lutomirski b18cb64ead fs/proc: Stop trying to report thread stacks
This reverts more of:

  b76437579d ("procfs: mark thread stack correctly in proc/<pid>/maps")

... which was partially reverted by:

  65376df582 ("proc: revert /proc/<pid>/maps [stack:TID] annotation")

Originally, /proc/PID/task/TID/maps was the same as /proc/TID/maps.

In current kernels, /proc/PID/maps (or /proc/TID/maps even for
threads) shows "[stack]" for VMAs in the mm's stack address range.

In contrast, /proc/PID/task/TID/maps uses KSTK_ESP to guess the
target thread's stack's VMA.  This is racy, probably returns garbage
and, on arches with CONFIG_TASK_INFO_IN_THREAD=y, is also crash-prone:
KSTK_ESP is not safe to use on tasks that aren't known to be running
ordinary process-context kernel code.

This patch removes the difference and just shows "[stack]" for VMAs
in the mm's stack range.  This is IMO much more sensible -- the
actual "stack" address really is treated specially by the VM code,
and the current thread stack isn't even well-defined for programs
that frequently switch stacks on their own.

Reported-by: Jann Horn <jann@thejh.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20 09:21:41 +02:00
..
caching FS-Cache: Count the number of initialised operations 2015-04-02 14:28:53 +01:00
cifs Documentation: fix common spelling mistakes 2016-04-28 07:51:59 -06:00
configfs configfs: switch ->default groups to a linked list 2016-03-06 16:11:24 +01:00
nfs Various bugfixes, a RDMA update from Chuck Lever, and support for a new 2016-03-24 19:50:32 -07:00
pohmelfs Documentation: fix common spelling mistakes 2016-04-28 07:51:59 -06:00
9p.txt 9p: update documentation 2014-01-24 10:55:21 -06:00
00-INDEX Doc: update 00-INDEX files to reflect the runnable code move 2016-10-10 07:12:09 -06:00
adfs.txt
affs.txt affs: add mount option to avoid filename truncates 2014-04-07 16:36:08 -07:00
afs.txt
autofs4-mount-control.txt autofs: update struct autofs_dev_ioctl in Documentation 2016-10-11 15:06:31 -07:00
autofs4.txt autofs: fix typos in Documentation/filesystems/autofs4.txt 2016-10-11 15:06:31 -07:00
automount-support.txt Documentation: remove outdated information from automount-support.txt 2015-05-15 01:10:38 -04:00
befs.txt
bfs.txt
btrfs.txt Documentation: btrfs: remove usage specific information 2016-03-11 17:02:09 +01:00
ceph.txt ceph: fix description for rsize and rasize mount options 2016-10-03 16:13:50 +02:00
coda.txt
cramfs.txt mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage 2016-04-04 10:41:08 -07:00
dax.txt dax : Fix documentation with respect to struct pages 2016-10-01 00:52:18 -06:00
debugfs.txt debugfs: Pass bool pointer to debugfs_create_bool() 2015-10-04 11:36:07 +01:00
devpts.txt devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
directory-locking vfs: remove unused i_op->rename 2016-09-27 11:03:58 +02:00
dlmfs.txt ocfs2: update web page + git tree in documentation 2015-02-28 09:57:50 -08:00
dnotify.txt
ecryptfs.txt
efivarfs.txt efi: Make efivarfs entries immutable by default 2016-02-10 16:25:52 +00:00
exofs.txt
ext2.txt fs: Remove ext3 filesystem driver 2015-07-23 20:59:40 +02:00
ext3.txt fs: Remove ext3 filesystem driver 2015-07-23 20:59:40 +02:00
ext4.txt ext4: add DAX functionality 2015-02-16 17:56:04 -08:00
f2fs.txt f2fs: enable inline_dentry by default and add noinline_dentry option 2016-08-29 18:31:17 -07:00
fiemap.txt fsioctl.c: make generic_block_fiemap() signal-tolerant 2015-02-10 14:30:30 -08:00
files.txt
fuse.txt
gfs2-glocks.txt gfs2: Remove gl_spin define 2015-10-29 12:57:48 -05:00
gfs2-uevents.txt
gfs2.txt
hfs.txt
hfsplus.txt Documentation: update URL to hfsplus Technote 1150 2014-02-20 14:48:51 +01:00
hpfs.txt
inotify.txt inotify: update documentation to reflect code changes 2015-02-10 14:30:28 -08:00
isofs.txt
jfs.txt doc: fix misspellings with 'codespell' tool 2013-05-28 12:02:12 +02:00
Locking Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
locks.txt
logfs.txt
mandatory-locking.txt
ncpfs.txt
nilfs2.txt nilfs2: move ioctl interface and disk layout to uapi separately 2016-08-02 19:35:21 -04:00
ntfs.txt NTFS: Remove changelog from Documentation/filesystems/ntfs.txt. 2014-10-16 12:43:57 +01:00
ocfs2-online-filecheck.txt Doc: ocfs: Fix typo in filesystems/ocfs2-online-filecheck.txt 2016-07-01 16:17:15 -06:00
ocfs2.txt ocfs2: update web page + git tree in documentation 2015-02-28 09:57:50 -08:00
omfs.txt
orangefs.txt Orangefs: update orangefs.txt 2016-08-02 15:39:14 -04:00
overlayfs.txt ovl: update doc 2016-09-01 11:12:00 +02:00
path-lookup.md Documentation: add new description of path-name lookup. 2015-11-02 18:18:25 -07:00
path-lookup.txt Documentation: add new description of path-name lookup. 2015-11-02 18:18:25 -07:00
porting Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
proc.txt fs/proc: Stop trying to report thread stacks 2016-10-20 09:21:41 +02:00
qnx6.txt Documentation: fix common spelling mistakes 2016-04-28 07:51:59 -06:00
quota.txt quota: Update documentation 2015-05-18 11:23:07 +02:00
ramfs-rootfs-initramfs.txt initmpfs: use initramfs if rootfstype= or root= specified 2013-09-11 15:59:38 -07:00
relay.txt doc: Fix typo in doucmentations 2013-07-25 12:34:15 +02:00
romfs.txt
seq_file.txt Documentation: update seq_file 2014-12-29 15:40:18 -07:00
sharedsubtree.txt doc: fix grammar 2016-03-09 15:33:06 -07:00
spufs.txt
squashfs.txt Squashfs: Add LZ4 compression configuration option 2014-11-27 18:48:44 +00:00
sysfs-pci.txt
sysfs-tagging.txt sysfs-tagging.txt: fix pre-kernfs references 2015-09-13 14:38:51 -06:00
sysfs.txt sysfs.txt: mention that store method buffers are null-terminated 2015-09-13 14:38:51 -06:00
sysv-fs.txt
tmpfs.txt Documenation: update cgroup's document path 2016-08-03 15:43:58 -06:00
ubifs.txt
udf.txt
ufs.txt
vfat.txt fat: add config option to set UTF-8 mount option by default 2016-03-22 15:36:02 -07:00
vfs.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
xfs-delayed-logging-design.txt
xfs-self-describing-metadata.txt
xfs.txt xfs: Document error handlers behavior 2016-09-19 09:38:25 +10:00