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2016-05-17Merge branch 'for-linus' of ↵Linus Torvalds1-15/+20
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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 ...
2016-05-17Merge branch 'ovl-fixes' into for-linusAl Viro1-1/+2
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.
2016-05-10Revert "proc/base: make prompt shell start from new line after executing ↵Robin Humble1-1/+1
"cat /proc/$pid/wchan"" This reverts the 4.6-rc1 commit 7e2bc81da333 ("proc/base: make prompt shell start from new line after executing "cat /proc/$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 <plaguedbypenguins@gmail.com> Cc: Minfei Huang <mnfhuang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-06proc: prevent accessing /proc/<PID>/environ until it's readyMathias Krause1-1/+2
If /proc/<PID>/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/<PID>/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/<PID>/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 <minipli@googlemail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Pax Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-03switch all procfs directories ->iterate_shared()Al Viro1-10/+10
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-03proc_fill_cache(): switch to d_alloc_parallel()Al Viro1-5/+10
... making it usable with directory locked shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-18proc/base: make prompt shell start from new line after executing "cat ↵Minfei Huang1-1/+1
/proc/$pid/wchan" It is not elegant that prompt shell does not start from new line after executing "cat /proc/$pid/wchan". Make prompt shell start from new line. Signed-off-by: Minfei Huang <mnfhuang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-18procfs: add conditional compilation checkEric Engestrom1-0/+2
`proc_timers_operations` is only used when CONFIG_CHECKPOINT_RESTORE is enabled. Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-18proc: add /proc/<pid>/timerslack_ns interfaceJohn Stultz1-0/+67
This patch provides a proc/PID/timerslack_ns interface which exposes a task's timerslack value in nanoseconds and allows it to be changed. This allows power/performance management software to set timer slack for other threads according to its policy for the thread (such as when the thread is designated foreground vs. background activity) If the value written is non-zero, slack is set to that value. Otherwise sets it to the default for the thread. This interface checks that the calling task has permissions to to use PTRACE_MODE_ATTACH_FSCREDS on the target task, so that we can ensure arbitrary apps do not change the timer slack for other apps. Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21proc read mm's {arg,env}_{start,end} with mmap semaphore taken.Mateusz Guzik1-3/+10
Only functions doing more than one read are modified. Consumeres happened to deal with possibly changing data, but it does not seem like a good thing to rely on. Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anshuman Khandual <anshuman.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn1-10/+11
By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-13Merge branch 'work.misc' of ↵Linus Torvalds1-10/+7
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of stuff. That probably should've been 5 or 6 separate branches, but by the time I'd realized how large and mixed that bag had become it had been too close to -final to play with rebasing. Some fs/namei.c cleanups there, memdup_user_nul() introduction and switching open-coded instances, burying long-dead code, whack-a-mole of various kinds, several new helpers for ->llseek(), assorted cleanups and fixes from various people, etc. One piece probably deserves special mention - Neil's lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets called without ->i_mutex and tries to avoid ever taking it. That, of course, means that it's not useful for any directory modifications, but things like getting inode attributes in nfds readdirplus are fine with that. I really should've asked for moratorium on lookup-related changes this cycle, but since I hadn't done that early enough... I *am* asking for that for the coming cycle, though - I'm going to try and get conversion of i_mutex to rwsem with ->lookup() done under lock taken shared. There will be a patch closer to the end of the window, along the lines of the one Linus had posted last May - mechanical conversion of ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/ inode_is_locked()/inode_lock_nested(). To quote Linus back then: ----- | This is an automated patch using | | sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/' | sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/' | sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/' | sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/' | sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/' | | with a very few manual fixups ----- I'm going to send that once the ->i_mutex-affecting stuff in -next gets mostly merged (or when Linus says he's about to stop taking merges)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) nfsd: don't hold i_mutex over userspace upcalls fs:affs:Replace time_t with time64_t fs/9p: use fscache mutex rather than spinlock proc: add a reschedule point in proc_readfd_common() logfs: constify logfs_block_ops structures fcntl: allow to set O_DIRECT flag on pipe fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE fs: xattr: Use kvfree() [s390] page_to_phys() always returns a multiple of PAGE_SIZE nbd: use ->compat_ioctl() fs: use block_device name vsprintf helper lib/vsprintf: add %*pg format specifier fs: use gendisk->disk_name where possible poll: plug an unused argument to do_poll amdkfd: don't open-code memdup_user() cdrom: don't open-code memdup_user() rsxx: don't open-code memdup_user() mtip32xx: don't open-code memdup_user() [um] mconsole: don't open-code memdup_user_nul() [um] hostaudio: don't open-code memdup_user() ...
2016-01-12Merge branch 'work.symlinks' of ↵Linus Torvalds1-9/+15
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs RCU symlink updates from Al Viro: "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode even if the symlink is not an embedded one. No changes since the mailbomb on Jan 1" * 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->get_link() to delayed_call, kill ->put_link() kill free_page_put_link() teach nfs_get_link() to work in RCU mode teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode teach shmem_get_link() to work in RCU mode teach page_get_link() to work in RCU mode replace ->follow_link() with new method that could stay in RCU mode don't put symlink bodies in pagecache into highmem namei: page_getlink() and page_follow_link_light() are the same thing ufs: get rid of ->setattr() for symlinks udf: don't duplicate page_symlink_inode_operations logfs: don't duplicate page_symlink_inode_operations switch befs long symlinks to page_symlink_operations
2016-01-04proc_pid_attr_write(): switch to memdup_user()Al Viro1-10/+7
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30switch ->get_link() to delayed_call, kill ->put_link()Al Viro1-3/+5
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-19proc: fix -ESRCH error when writing to /proc/$pid/coredump_filterColin Ian King1-0/+1
Writing to /proc/$pid/coredump_filter always returns -ESRCH because commit 774636e19ed51 ("proc: convert to kstrto*()/kstrto*_from_user()") removed the setting of ret after the get_proc_task call and incorrectly left it as -ESRCH. Instead, return 0 when successful. Example breakage: echo 0 > /proc/self/coredump_filter bash: echo: write error: No such process Fixes: 774636e19ed51 ("proc: convert to kstrto*()/kstrto*_from_user()") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> [4.3+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-09replace ->follow_link() with new method that could stay in RCU modeAl Viro1-9/+13
new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-06mm, oom: add comment for why oom_adj existsDavid Rientjes1-0/+10
/proc/pid/oom_adj exists solely to avoid breaking existing userspace binaries that write to the tunable. Add a comment in the only possible location within the kernel tree to describe the situation and motivation for keeping it around. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01fs/proc, core/debug: Don't expose absolute kernel addresses via wchanIngo Molnar1-6/+3
So the /proc/PID/stat 'wchan' field (the 30th field, which contains the absolute kernel address of the kernel function a task is blocked in) leaks absolute kernel addresses to unprivileged user-space: seq_put_decimal_ull(m, ' ', wchan); The absolute address might also leak via /proc/PID/wchan as well, if KALLSYMS is turned off or if the symbol lookup fails for some reason: static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { unsigned long wchan; char symname[KSYM_NAME_LEN]; wchan = get_wchan(task); if (lookup_symbol_name(wchan, symname) < 0) { if (!ptrace_may_access(task, PTRACE_MODE_READ)) return 0; seq_printf(m, "%lu", wchan); } else { seq_printf(m, "%s", symname); } return 0; } This isn't ideal, because for example it trivially leaks the KASLR offset to any local attacker: fomalhaut:~> printf "%016lx\n" $(cat /proc/$$/stat | cut -d' ' -f35) ffffffff8123b380 Most real-life uses of wchan are symbolic: ps -eo pid:10,tid:10,wchan:30,comm and procps uses /proc/PID/wchan, not the absolute address in /proc/PID/stat: triton:~/tip> strace -f ps -eo pid:10,tid:10,wchan:30,comm 2>&1 | grep wchan | tail -1 open("/proc/30833/wchan", O_RDONLY) = 6 There's one compatibility quirk here: procps relies on whether the absolute value is non-zero - and we can provide that functionality by outputing "0" or "1" depending on whether the task is blocked (whether there's a wchan address). These days there appears to be very little legitimate reason user-space would be interested in the absolute address. The absolute address is mostly historic: from the days when we didn't have kallsyms and user-space procps had to do the decoding itself via the System.map. So this patch sets all numeric output to "0" or "1" and keeps only symbolic output, in /proc/PID/wchan. ( The absolute sleep address can generally still be profiled via perf, by tasks with sufficient privileges. ) Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150930135917.GA3285@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-10proc: convert to kstrto*()/kstrto*_from_user()Alexey Dobriyan1-49/+21
Convert from manual allocation/copy_from_user/... to kstrto*() family which were designed for exactly that. One case can not be converted to kstrto*_from_user() to make code even more simpler because of whitespace stripping, oh well... Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10procfs: always expose /proc/<pid>/map_files/ and make it readableCalvin Owens1-19/+24
Currently, /proc/<pid>/map_files/ is restricted to CAP_SYS_ADMIN, and is only exposed if CONFIG_CHECKPOINT_RESTORE is set. Each mapped file region gets a symlink in /proc/<pid>/map_files/ corresponding to the virtual address range at which it is mapped. The symlinks work like the symlinks in /proc/<pid>/fd/, so you can follow them to the backing file even if that backing file has been unlinked. Currently, files which are mapped, unlinked, and closed are impossible to stat() from userspace. Exposing /proc/<pid>/map_files/ closes this functionality "hole". Not being able to stat() such files makes noticing and explicitly accounting for the space they use on the filesystem impossible. You can work around this by summing up the space used by every file in the filesystem and subtracting that total from what statfs() tells you, but that obviously isn't great, and it becomes unworkable once your filesystem becomes large enough. This patch moves map_files/ out from behind CONFIG_CHECKPOINT_RESTORE, and adjusts the permissions enforced on it as follows: * proc_map_files_lookup() * proc_map_files_readdir() * map_files_d_revalidate() Remove the CAP_SYS_ADMIN restriction, leaving only the current restriction requiring PTRACE_MODE_READ. The information made available to userspace by these three functions is already available in /proc/PID/maps with MODE_READ, so I don't see any reason to limit them any further (see below for more detail). * proc_map_files_follow_link() This stub has been added, and requires that the user have CAP_SYS_ADMIN in order to follow the links in map_files/, since there was concern on LKML both about the potential for bypassing permissions on ancestor directories in the path to files pointed to, and about what happens with more exotic memory mappings created by some drivers (ie dma-buf). In older versions of this patch, I changed every permission check in the four functions above to enforce MODE_ATTACH instead of MODE_READ. This was an oversight on my part, and after revisiting the discussion it seems that nobody was concerned about anything outside of what is made possible by ->follow_link(). So in this version, I've left the checks for PTRACE_MODE_READ as-is. [akpm@linux-foundation.org: catch up with concurrent proc_pid_follow_link() changes] Signed-off-by: Calvin Owens <calvinowens@fb.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Joe Perches <joe@perches.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-18/proc/$PID/cmdline: fixup empty ARGV caseAlexey Dobriyan1-0/+5
/proc/*/cmdline code checks if it should look at ENVP area by checking last byte of ARGV area: rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); if (rv <= 0) goto out_free_page; If ARGV is somehow made empty (by doing execve(..., NULL, ...) or manually setting ->arg_start and ->arg_end to equal values), the decision will be based on byte which doesn't even belong to ARGV/ENVP. So, quickly check if ARGV area is empty and report 0 to match previous behaviour. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-04Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-4/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Debug info and other statistics fixes and related enhancements" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/numa: Fix numa balancing stats in /proc/pid/sched sched/numa: Show numa_group ID in /proc/sched_debug task listings sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=y sched/stat: Simplify the sched_info accounting dependency
2015-07-04sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=yNaveen N. Rao1-4/+7
Expand /proc/pid/schedstat output: - enable it on CONFIG_TASK_DELAY_ACCT=y && !CONFIG_SCHEDSTATS kernels. - dump all zeroes on kernels that are booted with the 'nodelayacct' option, which boot option disables delay accounting on CONFIG_TASK_DELAY_ACCT=y kernels. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: a.p.zijlstra@chello.nl Cc: ricklind@us.ibm.com Link: http://lkml.kernel.org/r/5ccbef17d4bc841084ea6e6421d4e4a23b7b806f.1435654789.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-26fs, proc: introduce CONFIG_PROC_CHILDRENIago López Galeiras1-1/+1
Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children entry") introduced the children entry for checkpoint restore and the file is only available on kernels configured with CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS) because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE. However, the children proc file is useful outside of checkpoint restore. I would like to use it in rkt. The rkt process exec() another program it does not control, and that other program will fork()+exec() a child process. I would like to find the pid of the child process from an external tool without iterating in /proc over all processes to find which one has a parent pid equal to rkt. This commit introduces CONFIG_PROC_CHILDREN and makes CONFIG_CHECKPOINT_RESTORE select it. This allows enabling /proc/<pid>/task/<tid>/children without needing to enable CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT. Alban tested that /proc/<pid>/task/<tid>/children is present when the kernel is configured with CONFIG_PROC_CHILDREN=y but without CONFIG_CHECKPOINT_RESTORE Signed-off-by: Iago López Galeiras <iago@endocode.com> Tested-by: Alban Crequy <alban@endocode.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Djalal Harouni <djalal@endocode.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26proc: fix PAGE_SIZE limit of /proc/$PID/cmdlineAlexey Dobriyan1-9/+196
/proc/$PID/cmdline truncates output at PAGE_SIZE. It is easy to see with $ cat /proc/self/cmdline $(seq 1037) 2>/dev/null However, command line size was never limited to PAGE_SIZE but to 128 KB and relatively recently limitation was removed altogether. People noticed and ask questions: http://stackoverflow.com/questions/199130/how-do-i-increase-the-proc-pid-cmdline-4096-byte-limit seq file interface is not OK, because it kmalloc's for whole output and open + read(, 1) + sleep will pin arbitrary amounts of kernel memory. To not do that, limit must be imposed which is incompatible with arbitrary sized command lines. I apologize for hairy code, but this it direct consequence of command line layout in memory and hacks to support things like "init [3]". The loops are "unrolled" otherwise it is either macros which hide control flow or functions with 7-8 arguments with equal line count. There should be real setproctitle(2) or something. [akpm@linux-foundation.org: fix a billion min() warnings] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Tested-by: Jarod Wilson <jarod@redhat.com> Acked-by: Jarod Wilson <jarod@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jan Stancek <jstancek@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-11don't pass nameidata to ->follow_link()Al Viro1-2/+2
its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new ->follow_link() and ->put_link() calling conventionsAl Viro1-1/+1
a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-27Merge branch 'for-linus' of ↵Linus Torvalds1-16/+16
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-16proc: remove use of seq_printf return valueJoe Perches1-35/+47
The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells1-16/+16
that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-17Merge branch 'for-linus' of ↵Linus Torvalds1-0/+53
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace related fixes from Eric Biederman: "As these are bug fixes almost all of thes changes are marked for backporting to stable. The first change (implicitly adding MNT_NODEV on remount) addresses a regression that was created when security issues with unprivileged remount were closed. I go on to update the remount test to make it easy to detect if this issue reoccurs. Then there are a handful of mount and umount related fixes. Then half of the changes deal with the a recently discovered design bug in the permission checks of gid_map. Unix since the beginning has allowed setting group permissions on files to less than the user and other permissions (aka ---rwx---rwx). As the unix permission checks stop as soon as a group matches, and setgroups allows setting groups that can not later be dropped, results in a situtation where it is possible to legitimately use a group to assign fewer privileges to a process. Which means dropping a group can increase a processes privileges. The fix I have adopted is that gid_map is now no longer writable without privilege unless the new file /proc/self/setgroups has been set to permanently disable setgroups. The bulk of user namespace using applications even the applications using applications using user namespaces without privilege remain unaffected by this change. Unfortunately this ix breaks a couple user space applications, that were relying on the problematic behavior (one of which was tools/selftests/mount/unprivileged-remount-test.c). To hopefully prevent needing a regression fix on top of my security fix I rounded folks who work with the container implementations mostly like to be affected and encouraged them to test the changes. > So far nothing broke on my libvirt-lxc test bed. :-) > Tested with openSUSE 13.2 and libvirt 1.2.9. > Tested-by: Richard Weinberger <richard@nod.at> > Tested on Fedora20 with libvirt 1.2.11, works fine. > Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> > Ok, thanks - yes, unprivileged lxc is working fine with your kernels. > Just to be sure I was testing the right thing I also tested using > my unprivileged nsexec testcases, and they failed on setgroup/setgid > as now expected, and succeeded there without your patches. > Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com> > I tested this with Sandstorm. It breaks as is and it works if I add > the setgroups thing. > Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :(" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Unbreak the unprivileged remount tests userns; Correct the comment in map_write userns: Allow setting gid_maps without privilege when setgroups is disabled userns: Add a knob to disable setgroups on a per user namespace basis userns: Rename id_map_mutex to userns_state_mutex userns: Only allow the creator of the userns unprivileged mappings userns: Check euid no fsuid when establishing an unprivileged uid mapping userns: Don't allow unprivileged creation of gid mappings userns: Don't allow setgroups until a gid mapping has been setablished userns: Document what the invariant required for safe unprivileged mappings. groups: Consolidate the setgroups permission checks mnt: Clear mnt_expire during pivot_root mnt: Carefully set CL_UNPRIVILEGED in clone_mnt mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers. umount: Do not allow unmounting rootfs. umount: Disallow unprivileged mount force mnt: Update unprivileged remount test mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
2014-12-12userns: Add a knob to disable setgroups on a per user namespace basisEric W. Biederman1-0/+53
- Expose the knob to user space through a proc file /proc/<pid>/setgroups A value of "deny" means the setgroups system call is disabled in the current processes user namespace and can not be enabled in the future in this user namespace. A value of "allow" means the segtoups system call is enabled. - Descendant user namespaces inherit the value of setgroups from their parents. - A proc file is used (instead of a sysctl) as sysctls currently do not allow checking the permissions at open time. - Writing to the proc file is restricted to before the gid_map for the user namespace is set. This ensures that disabling setgroups at a user namespace level will never remove the ability to call setgroups from a process that already has that ability. A process may opt in to the setgroups disable for itself by creating, entering and configuring a user namespace or by calling setns on an existing user namespace with setgroups disabled. Processes without privileges already can not call setgroups so this is a noop. Prodcess with privilege become processes without privilege when entering a user namespace and as with any other path to dropping privilege they would not have the ability to call setgroups. So this remains within the bounds of what is possible without a knob to disable setgroups permanently in a user namespace. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11Merge branch 'akpm' (patchbomb from Andrew)Linus Torvalds1-0/+3
Merge first patchbomb from Andrew Morton: - a few minor cifs fixes - dma-debug upadtes - ocfs2 - slab - about half of MM - procfs - kernel/exit.c - panic.c tweaks - printk upates - lib/ updates - checkpatch updates - fs/binfmt updates - the drivers/rtc tree - nilfs - kmod fixes - more kernel/exit.c - various other misc tweaks and fixes * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) exit: pidns: fix/update the comments in zap_pid_ns_processes() exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting exit: exit_notify: re-use "dead" list to autoreap current exit: reparent: call forget_original_parent() under tasklist_lock exit: reparent: avoid find_new_reaper() if no children exit: reparent: introduce find_alive_thread() exit: reparent: introduce find_child_reaper() exit: reparent: document the ->has_child_subreaper checks exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper() exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting exit: proc: don't try to flush /proc/tgid/task/tgid exit: release_task: fix the comment about group leader accounting exit: wait: drop tasklist_lock before psig->c* accounting exit: wait: don't use zombie->real_parent exit: wait: cleanup the ptrace_reparented() checks usermodehelper: kill the kmod_thread_locker logic usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races ...
2014-12-11exit: proc: don't try to flush /proc/tgid/task/tgidOleg Nesterov1-0/+3
proc_flush_task_mnt() always tries to flush task/pid, but this is pointless if we reap the leader. d_invalidate() is recursive, and if nothing else the next d_hash_and_lookup(tgid) should fail anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sterling Alexander <stalexan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-19procfs: get rid of ->f_dentryAl Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-13Merge branch 'for-linus' of ↵Linus Torvalds1-8/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...
2014-10-10Merge branch 'for-3.18' of ↵Linus Torvalds1-35/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Nothing too interesting. Just a handful of cleanup patches" * 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "cgroup: remove redundant variable in cgroup_mount()" cgroup: remove redundant variable in cgroup_mount() cgroup: fix missing unlock in cgroup_release_agent() cgroup: remove CGRP_RELEASABLE flag perf/cgroup: Remove perf_put_cgroup() cgroup: remove redundant check in cgroup_ino() cpuset: simplify proc_cpuset_show() cgroup: simplify proc_cgroup_show() cgroup: use a per-cgroup work for release agent cgroup: remove bogus comments cgroup: remove redundant code in cgroup_rmdir() cgroup: remove some useless forward declarations cgroup: fix a typo in comment.
2014-10-10proc: introduce proc_mem_open()Oleg Nesterov1-15/+21
Extract the mm_access() code from __mem_open() into the new helper, proc_mem_open(), the next patch will add another caller. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09proc: Update proc_flush_task_mnt to use d_invalidateEric W. Biederman1-4/+2
Now that d_invalidate always succeeds and flushes mount points use it in stead of a combination of shrink_dcache_parent and d_drop in proc_flush_task_mnt. This removes the danger of a mount point under /proc/<pid>/... becoming unreachable after the d_drop. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09vfs: Remove d_drop calls from d_revalidate implementationsEric W. Biederman1-4/+0
Now that d_invalidate always succeeds it is not longer necessary or desirable to hard code d_drop calls into filesystem specific d_revalidate implementations. Remove the unnecessary d_drop calls and rely on d_invalidate to drop the dentries. Using d_invalidate ensures that paths to mount points will not be dropped. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-09-18cpuset: simplify proc_cpuset_show()Zefan Li1-18/+2
Use the ONE macro instead of REG, and we can simplify proc_cpuset_show(). Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-09-18cgroup: simplify proc_cgroup_show()Zefan Li1-17/+2
Use the ONE macro instead of REG, and we can simplify proc_cgroup_show(). Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-10Merge branch 'for-linus' of ↵Linus Torvalds1-5/+13
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This is a bunch of small changes built against 3.16-rc6. The most significant change for users is the first patch which makes setns drmatically faster by removing unneded rcu handling. The next chunk of changes are so that "mount -o remount,.." will not allow the user namespace root to drop flags on a mount set by the system wide root. Aks this forces read-only mounts to stay read-only, no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec mounts to stay no exec and it prevents unprivileged users from messing with a mounts atime settings. I have included my test case as the last patch in this series so people performing backports can verify this change works correctly. The next change fixes a bug in NFS that was discovered while auditing nsproxy users for the first optimization. Today you can oops the kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever with pid namespaces. I rebased and fixed the build of the !CONFIG_NFS_FS case yesterday when a build bot caught my typo. Given that no one to my knowledge bases anything on my tree fixing the typo in place seems more responsible that requiring a typo-fix to be backported as well. The last change is a small semantic cleanup introducing /proc/thread-self and pointing /proc/mounts and /proc/net at it. This prevents several kinds of problemantic corner cases. It is a user-visible change so it has a minute chance of causing regressions so the change to /proc/mounts and /proc/net are individual one line commits that can be trivially reverted. Unfortunately I lost and could not find the email of the original reporter so he is not credited. From at least one perspective this change to /proc/net is a refgression fix to allow pthread /proc/net uses that were broken by the introduction of the network namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net proc: Implement /proc/thread-self to point at the directory of the current thread proc: Have net show up under /proc/<tgid>/task/<tid> NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes mnt: Add tests for unprivileged remount cases that have found to be faulty mnt: Change the default remount atime from relatime to the existing value mnt: Correct permission checks in do_remount mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount mnt: Only change user settable mount flags in remount namespaces: Use task_lock and not rcu to protect nsproxy
2014-08-09proc: remove INF macroAlexey Dobriyan1-41/+0
If you're applying this patch, all /proc/$PID/* files were converted to seq_file interface and this code became unused. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09proc: convert /proc/$PID/hardwall to seq_file interfaceAlexey Dobriyan1-2/+2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09proc: convert /proc/$PID/io to seq_file interfaceAlexey Dobriyan1-8/+10
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09proc: convert /proc/$PID/oom_score to seq_file interfaceAlexey Dobriyan1-4/+5
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09proc: convert /proc/$PID/schedstat to seq_file interfaceAlexey Dobriyan1-4/+5
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09proc: convert /proc/$PID/wchan to seq_file interfaceAlexey Dobriyan1-5/+6
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>