BMC/Intel-BMC/linux.git/fs/proc/base.c, branch dev-4.7

mm: introduce get_task_exe_file

2016-09-24T08:09:28+00:00

commit cd81a9170e69e018bbaba547c1fd85a585f5697a upstream. For more convenient access if one has a pointer to the task. As a minor nit take advantage of the fact that only task lock + rcu are needed to safely grab ->exe_file. This saves mm refcount dance. Use the helper in proc_exe_link. Signed-off-by: Mateusz Guzik Acked-by: Konstantin Khlebnikov Acked-by: Richard Guy Briggs Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

procfs: fix pthread cross-thread naming if !PR_DUMPABLE

2016-05-21T00:58:30+00:00

The PR_DUMPABLE flag causes the pid related paths of the proc file system to be owned by ROOT. The implementation of pthread_set/getname_np however needs access to /proc//task//comm. If PR_DUMPABLE is false this implementation is locked out. This patch installs a special permission function for the file "comm" that grants read and write access to all threads of the same group regardless of the ownership of the inode. For all other threads the function falls back to the generic inode permission check. [akpm@linux-foundation.org: fix spello in comment] Signed-off-by: Janis Danisevskis Acked-by: Kees Cook Cc: Al Viro Cc: Cyrill Gorcunov Cc: Alexey Dobriyan Cc: Colin Ian King Cc: David Rientjes Cc: Minfei Huang Cc: John Stultz Cc: Calvin Owens Cc: Jann Horn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-05-17T18:01:31+00:00

Pull parallel filesystem directory handling update from Al Viro. This is the main parallel directory work by Al that makes the vfs layer able to do lookup and readdir in parallel within a single directory. That's a big change, since this used to be all protected by the directory inode mutex. The inode mutex is replaced by an rwsem, and serialization of lookups of a single name is done by a "in-progress" dentry marker. The series begins with xattr cleanups, and then ends with switching filesystems over to actually doing the readdir in parallel (switching to the "iterate_shared()" that only takes the read lock). A more detailed explanation of the process from Al Viro: "The xattr work starts with some acl fixes, then switches ->getxattr to passing inode and dentry separately. This is the point where the things start to get tricky - that got merged into the very beginning of the -rc3-based #work.lookups, to allow untangling the security_d_instantiate() mess. The xattr work itself proceeds to switch a lot of filesystems to generic_...xattr(); no complications there. After that initial xattr work, the series then does the following: - untangle security_d_instantiate() - convert a bunch of open-coded lookup_one_len_unlocked() to calls of that thing; one such place (in overlayfs) actually yields a trivial conflict with overlayfs fixes later in the cycle - overlayfs ended up switching to a variant of lookup_one_len_unlocked() sans the permission checks. I would've dropped that commit (it gets overridden on merge from #ovl-fixes in #for-next; proper resolution is to use the variant in mainline fs/overlayfs/super.c), but I didn't want to rebase the damn thing - it was fairly late in the cycle... - some filesystems had managed to depend on lookup/lookup exclusion for *fs-internal* data structures in a way that would break if we relaxed the VFS exclusion. Fixing hadn't been hard, fortunately. - core of that series - parallel lookup machinery, replacing ->i_mutex with rwsem, making lookup_slow() take it only shared. At that point lookups happen in parallel; lookups on the same name wait for the in-progress one to be done with that dentry. Surprisingly little code, at that - almost all of it is in fs/dcache.c, with fs/namei.c changes limited to lookup_slow() - making it use the new primitive and actually switching to locking shared. - parallel readdir stuff - first of all, we provide the exclusion on per-struct file basis, same as we do for read() vs lseek() for regular files. That takes care of most of the needed exclusion in readdir/readdir; however, these guys are trickier than lookups, so I went for switching them one-by-one. To do that, a new method '->iterate_shared()' is added and filesystems are switched to it as they are either confirmed to be OK with shared lock on directory or fixed to be OK with that. I hope to kill the original method come next cycle (almost all in-tree filesystems are switched already), but it's still not quite finished. - several filesystems get switched to parallel readdir. The interesting part here is dealing with dcache preseeding by readdir; that needs minor adjustment to be safe with directory locked only shared. Most of the filesystems doing that got switched to in those commits. Important exception: NFS. Turns out that NFS folks, with their, er, insistence on VFS getting the fuck out of the way of the Smart Filesystem Code That Knows How And What To Lock(tm) have grown the locking of their own. They had their own homegrown rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink is the reader there). Of course, with VFS getting the fuck out of the way, as requested, the actual smarts of the smart filesystem code etc. had become exposed... - do_last/lookup_open/atomic_open cleanups. As the result, open() without O_CREAT locks the directory only shared. Including the ->atomic_open() case. Backmerge from #for-linus in the middle of that - atomic_open() fix got brought in. - then comes NFS switch to saner (VFS-based ;-) locking, killing the homegrown "lookup and readdir are writers" kinda-sorta rwsem. All exclusion for sillyunlink/lookup is done by the parallel lookups mechanism. Exclusion between sillyunlink and rmdir is a real rwsem now - rmdir being the writer. Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel now. - the rest of the series consists of switching a lot of filesystems to parallel readdir; in a lot of cases ->llseek() gets simplified as well. One backmerge in there (again, #for-linus - rockridge fix)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits) ext4: switch to ->iterate_shared() hfs: switch to ->iterate_shared() hfsplus: switch to ->iterate_shared() hostfs: switch to ->iterate_shared() hpfs: switch to ->iterate_shared() hpfs: handle allocation failures in hpfs_add_pos() gfs2: switch to ->iterate_shared() f2fs: switch to ->iterate_shared() afs: switch to ->iterate_shared() befs: switch to ->iterate_shared() befs: constify stuff a bit isofs: switch to ->iterate_shared() get_acorn_filename(): deobfuscate a bit btrfs: switch to ->iterate_shared() logfs: no need to lock directory in lseek switch ecryptfs to ->iterate_shared 9p: switch to ->iterate_shared() fat: switch to ->iterate_shared() romfs, squashfs: switch to ->iterate_shared() more trivial ->iterate_shared conversions ...

Merge branch 'ovl-fixes' into for-linus

2016-05-17T06:17:59+00:00

Backmerge to resolve a conflict in ovl_lookup_real(); "ovl_lookup_real(): use lookup_one_len_unlocked()" instead, but it was too late in the cycle to rebase.

Revert "proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan""

2016-05-10T00:40:59+00:00

This reverts the 4.6-rc1 commit 7e2bc81da333 ("proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan") because it breaks /proc/$PID/whcan formatting in ps and top. Revert also because the patch is inconsistent - it adds a newline at the end of only the '0' wchan, and does not add a newline when /proc/$PID/wchan contains a symbol name. eg. $ ps -eo pid,stat,wchan,comm PID STAT WCHAN COMMAND ... 1189 S - dbus-launch 1190 Ssl 0 dbus-daemon 1198 Sl 0 lightdm 1299 Ss ep_pol systemd 1301 S - (sd-pam) 1304 Ss wait sh Signed-off-by: Robin Humble Cc: Minfei Huang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: prevent accessing /proc//environ until it's ready

2016-05-06T00:38:53+00:00

If /proc//environ gets read before the envp[] array is fully set up in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to read more bytes than are actually written, as env_start will already be set but env_end will still be zero, making the range calculation underflow, allowing to read beyond the end of what has been written. Fix this as it is done for /proc//cmdline by testing env_end for zero. It is, apparently, intentionally set last in create_*_tables(). This bug was found by the PaX size_overflow plugin that detected the arithmetic underflow of 'this_len = env_end - (env_start + src)' when env_end is still zero. The expected consequence is that userland trying to access /proc//environ of a not yet fully set up process may get inconsistent data as we're in the middle of copying in the environment variables. Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461 Signed-off-by: Mathias Krause Cc: Emese Revfy Cc: Pax Team Cc: Al Viro Cc: Mateusz Guzik Cc: Alexey Dobriyan Cc: Cyrill Gorcunov Cc: Jarod Wilson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

switch all procfs directories ->iterate_shared()

2016-05-02T23:49:30+00:00

Signed-off-by: Al Viro

proc_fill_cache(): switch to d_alloc_parallel()

2016-05-02T23:49:29+00:00

... making it usable with directory locked shared Signed-off-by: Al Viro

proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan"

2016-03-17T22:09:34+00:00

It is not elegant that prompt shell does not start from new line after executing "cat /proc/$pid/wchan". Make prompt shell start from new line. Signed-off-by: Minfei Huang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: add conditional compilation check

2016-03-17T22:09:34+00:00

`proc_timers_operations` is only used when CONFIG_CHECKPOINT_RESTORE is enabled. Signed-off-by: Eric Engestrom Acked-by: Cyrill Gorcunov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds