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* Merge branch 'for-linus' of ↵Linus Torvalds2017-05-051-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This is a set of small fixes that were mostly stumbled over during more significant development. This proc fix and the fix to posix-timers are the most significant of the lot. There is a lot of good development going on but unfortunately it didn't quite make the merge window" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Fix unbalanced hard link numbers signal: Make kill_proc_info static rlimit: Properly call security_task_setrlimit signal: Remove unused definition of sig_user_definied ia64: Remove unused IA64_TASK_SIGHAND_OFFSET and IA64_SIGHAND_SIGLOCK_OFFSET ipc: Remove unused declaration of recompute_msgmni posix-timers: Correct sanity check in posix_cpu_nsleep sysctl: Remove dead register_sysctl_root
| * rlimit: Properly call security_task_setrlimitEric W. Biederman2017-04-211-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify do_prlimit to call security_task_setrlimit passing the task whose rlimit we are changing not the tsk->group_leader. In general this should not matter as the lsms implementing security_task_setrlimit apparmor and selinux both examine the task->cred to see what should be allowed on the destination task. That task->cred is shared between tasks created with CLONE_THREAD unless thread keyrings are in play, in which case both apparmor and selinux create duplicate security contexts. So the only time when it will matter which thread is passed to security_task_setrlimit is if one of the threads of a process performs an operation that changes only it's credentials. At which point if a thread has done that we don't want to hide that information from the lsms. So fix the call of security_task_setrlimit. With the removal of tsk->group_leader this makes the code slightly faster, more comprehensible and maintainable. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | prlimit,security,selinux: add a security hook for prlimitStephen Smalley2017-03-061-12/+18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When SELinux was first added to the kernel, a process could only get and set its own resource limits via getrlimit(2) and setrlimit(2), so no MAC checks were required for those operations, and thus no security hooks were defined for them. Later, SELinux introduced a hook for setlimit(2) with a check if the hard limit was being changed in order to be able to rely on the hard limit value as a safe reset point upon context transitions. Later on, when prlimit(2) was added to the kernel with the ability to get or set resource limits (hard or soft) of another process, LSM/SELinux was not updated other than to pass the target process to the setrlimit hook. This resulted in incomplete control over both getting and setting the resource limits of another process. Add a new security_task_prlimit() hook to the check_prlimit_permission() function to provide complete mediation. The hook is only called when acting on another task, and only if the existing DAC/capability checks would allow access. Pass flags down to the hook to indicate whether the prlimit(2) call will read, write, or both read and write the resource limits of the target process. The existing security_task_setrlimit() hook is left alone; it continues to serve a purpose in supporting the ability to make decisions based on the old and/or new resource limit values when setting limits. This is consistent with the DAC/capability logic, where check_prlimit_permission() performs generic DAC/capability checks for acting on another task, while do_prlimit() performs a capability check based on a comparison of the old and new resource limits. Fix the inline documentation for the hook to match the code. Implement the new hook for SELinux. For setting resource limits, we reuse the existing setrlimit permission. Note that this does overload the setrlimit permission to mean the ability to set the resource limit (soft or hard) of another process or the ability to change one's own hard limit. For getting resource limits, a new getrlimit permission is defined. This was not originally defined since getrlimit(2) could only be used to obtain a process' own limits. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <james.l.morris@oracle.com>
* sched/headers: Prepare to move cputime functionality from <linux/sched.h> ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | into <linux/sched/cputime.h> Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/stat.h> We are going to split <linux/sched/stat.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/stat.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/coredump.h> We are going to split <linux/sched/coredump.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/coredump.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/autogroup.h> We are going to split <linux/sched/autogroup.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/autogroup.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/loadavg.h> We are going to split <linux/sched/loadavg.h> out of <linux/sched.h>, which will have to be picked up from a couple of .c files. Create a trivial placeholder <linux/sched/topology.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2017-02-231-0/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits
| * prctl: propagate has_child_subreaper flag to every descendantPavel Tikhomirov2017-02-031-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If process forks some children when it has is_child_subreaper flag enabled they will inherit has_child_subreaper flag - first group, when is_child_subreaper is disabled forked children will not inherit it - second group. So child-subreaper does not reparent all his descendants when their parents die. Having these two differently behaving groups can lead to confusion. Also it is a problem for CRIU, as when we restore process tree we need to somehow determine which descendants belong to which group and much harder - to put them exactly to these group. To simplify these we can add a propagation of has_child_subreaper flag on PR_SET_CHILD_SUBREAPER, walking all descendants of child- subreaper to setup has_child_subreaper flag. In common cases when process like systemd first sets itself to be a child-subreaper and only after that forks its services, we will have zero-length list of descendants to walk. Testing with binary subtree of 2^15 processes prctl took < 0.007 sec and has shown close to linear dependency(~0.2 * n * usec) on lower numbers of processes. Moreover, I doubt someone intentionaly pre-forks the children whitch should reparent to init before becoming subreaper, because some our ancestor migh have had is_child_subreaper flag while forking our sub-tree and our childs will all inherit has_child_subreaper flag, and we have no way to influence it. And only way to check if we have no has_child_subreaper flag is to create some childs, kill them and see where they will reparent to. Using walk_process_tree helper to walk subtree, thanks to Oleg! Timing seems to be the same. Optimize: a) When descendant already has has_child_subreaper flag all his subtree has it too already. * for a) to be true need to move has_child_subreaper inheritance under the same tasklist_lock with adding task to its ->real_parent->children as without it process can inherit zero has_child_subreaper, then we set 1 to it's parent flag, check that parent has no more children, and only after child with wrong flag is added to the tree. * Also make these inheritance more clear by using real_parent instead of current, as on clone(CLONE_PARENT) if current has is_child_subreaper and real_parent has no is_child_subreaper or has_child_subreaper, child will have has_child_subreaper flag set without actually having a subreaper in it's ancestors. b) When some descendant is child_reaper, it's subtree is in different pidns from us(original child-subreaper) and processes from other pidns will never reparent to us. So we can skip their(a,b) subtree from walk. v2: switch to walk_process_tree() general helper, move has_child_subreaper inheritance v3: remove csr_descendant leftover, change current to real_parent in has_child_subreaper inheritance v4: small commit message fix Fixes: ebec18a6d3aa ("prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervision") Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | sched/cputime: Convert task/group cputime to nsecsFrederic Weisbecker2017-02-011-8/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | Now that most cputime readers use the transition API which return the task cputime in old style cputime_t, we can safely store the cputime in nsecs. This will eventually make cputime statistics less opaque and more granular. Back and forth convertions between cputime_t and nsecs in order to deal with cputime_t random granularity won't be needed anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2016-12-121-10/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - various misc bits - most of MM (quite a lot of MM material is awaiting the merge of linux-next dependencies) - kasan - printk updates - procfs updates - MAINTAINERS - /lib updates - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (123 commits) init: reduce rootwait polling interval time to 5ms binfmt_elf: use vmalloc() for allocation of vma_filesz checkpatch: don't emit unified-diff error for rename-only patches checkpatch: don't check c99 types like uint8_t under tools checkpatch: avoid multiple line dereferences checkpatch: don't check .pl files, improve absolute path commit log test scripts/checkpatch.pl: fix spelling checkpatch: don't try to get maintained status when --no-tree is given lib/ida: document locking requirements a bit better lib/rbtree.c: fix typo in comment of ____rb_erase_color lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM MAINTAINERS: add drm and drm/i915 irc channels MAINTAINERS: add "C:" for URI for chat where developers hang out MAINTAINERS: add drm and drm/i915 bug filing info MAINTAINERS: add "B:" for URI where to file bugs get_maintainer: look for arbitrary letter prefixes in sections printk: add Kconfig option to set default console loglevel printk/sound: handle more message headers printk/btrfs: handle more message headers printk/kdb: handle more message headers ...
| * prctl: remove one-shot limitation for changing exe linkStanislav Kinsburskiy2016-12-121-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This limitation came with the reason to remove "another way for malicious code to obscure a compromised program and masquerade as a benign process" by allowing "security-concious program can use this prctl once during its early initialization to ensure the prctl cannot later be abused for this purpose": http://marc.info/?l=linux-kernel&m=133160684517468&w=2 This explanation doesn't look sufficient. The only thing "exe" link is indicating is the file, used to execve, which is basically nothing and not reliable immediately after process has returned from execve system call. Moreover, to use this feture, all the mappings to previous exe file have to be unmapped and all the new exe file permissions must be satisfied. Which means, that changing exe link is very similar to calling execve on the binary. The need to remove this limitations comes from migration of NFS mount point, which is not accessible during restore and replaced by other file system. Because of this exe link has to be changed twice. [akpm@linux-foundation.org: fix up comment] Link: http://lkml.kernel.org/r/20160927153755.9337.69650.stgit@localhost.localdomain Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: John Stultz <john.stultz@linaro.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Vlastimil Babka <vbabka@suse.cz> 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>
* | posix-timers: Make them configurableNicolas Pitre2016-11-161-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some embedded systems have no use for them. This removes about 25KB from the kernel binary size when configured out. Corresponding syscalls are routed to a stub logging the attempt to use those syscalls which should be enough of a clue if they were disabled without proper consideration. They are: timer_create, timer_gettime: timer_getoverrun, timer_settime, timer_delete, clock_adjtime, setitimer, getitimer, alarm. The clock_settime, clock_gettime, clock_getres and clock_nanosleep syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast majority of use cases with very little code. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* prctl: make PR_SET_THP_DISABLE wait for mmap_sem killableMichal Hocko2016-05-231-1/+2
| | | | | | | | | | | | | | PR_SET_THP_DISABLE requires mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Alex Thorlton <athorlton@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* timer: convert timer_slack_ns from unsigned long to u64John Stultz2016-03-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset introduces a /proc/<pid>/timerslack_ns interface which would allow controlling processes to be able to set the timerslack value on other processes in order to save power by avoiding wakeups (Something Android currently does via out-of-tree patches). The first patch tries to fix the internal timer_slack_ns usage which was defined as a long, which limits the slack range to ~4 seconds on 32bit systems. It converts it to a u64, which provides the same basically unlimited slack (500 years) on both 32bit and 64bit machines. The second patch introduces the /proc/<pid>/timerslack_ns interface which allows the full 64bit slack range for a task to be read or set on both 32bit and 64bit machines. With these two patches, on a 32bit machine, after setting the slack on bash to 10 seconds: $ time sleep 1 real 0m10.747s user 0m0.001s sys 0m0.005s The first patch is a little ugly, since I had to chase the slack delta arguments through a number of functions converting them to u64s. Let me know if it makes sense to break that up more or not. Other than that things are fairly straightforward. This patch (of 2): The timer_slack_ns value in the task struct is currently a unsigned long. This means that on 32bit applications, the maximum slack is just over 4 seconds. However, on 64bit machines, its much much larger (~500 years). This disparity could make application development a little (as well as the default_slack) to a u64. This means both 32bit and 64bit systems have the same effective internal slack range. Now the existing ABI via PR_GET_TIMERSLACK and PR_SET_TIMERSLACK specify the interface as a unsigned long, so we preserve that limitation on 32bit systems, where SET_TIMERSLACK can only set the slack to a unsigned long value, and GET_TIMERSLACK will return ULONG_MAX if the slack is actually larger then what can be stored by an unsigned long. This patch also modifies hrtimer functions which specified the slack delta as a unsigned long. Signed-off-by: John Stultz <john.stultz@linaro.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: Kees Cook <keescook@chromium.org> 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>
* prctl: take mmap sem for writing to protect against othersMateusz Guzik2016-01-201-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An unprivileged user can trigger an oops on a kernel with CONFIG_CHECKPOINT_RESTORE. proc_pid_cmdline_read takes mmap_sem for reading and obtains args + env start/end values. These get sanity checked as follows: BUG_ON(arg_start > arg_end); BUG_ON(env_start > env_end); These can be changed by prctl_set_mm. Turns out also takes the semaphore for reading, effectively rendering it useless. This results in: kernel BUG at fs/proc/base.c:240! invalid opcode: 0000 [#1] SMP Modules linked in: virtio_net CPU: 0 PID: 925 Comm: a.out Not tainted 4.4.0-rc8-next-20160105dupa+ #71 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff880077a68000 ti: ffff8800784d0000 task.ti: ffff8800784d0000 RIP: proc_pid_cmdline_read+0x520/0x530 RSP: 0018:ffff8800784d3db8 EFLAGS: 00010206 RAX: ffff880077c5b6b0 RBX: ffff8800784d3f18 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 00007f78e8857000 RDI: 0000000000000246 RBP: ffff8800784d3e40 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000050 R13: 00007f78e8857800 R14: ffff88006fcef000 R15: ffff880077c5b600 FS: 00007f78e884a740(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f78e8361770 CR3: 00000000790a5000 CR4: 00000000000006f0 Call Trace: __vfs_read+0x37/0x100 vfs_read+0x82/0x130 SyS_read+0x58/0xd0 entry_SYSCALL_64_fastpath+0x12/0x76 Code: 4c 8b 7d a8 eb e9 48 8b 9d 78 ff ff ff 4c 8b 7d 90 48 8b 03 48 39 45 a8 0f 87 f0 fe ff ff e9 d1 fe ff ff 4c 8b 7d 90 eb c6 0f 0b <0f> 0b 0f 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RIP proc_pid_cmdline_read+0x520/0x530 ---[ end trace 97882617ae9c6818 ]--- Turns out there are instances where the code just reads aformentioned values without locking whatsoever - namely environ_read and get_cmdline. Interestingly these functions look quite resilient against bogus values, but I don't believe this should be relied upon. The first patch gets rid of the oops bug by grabbing mmap_sem for writing. The second patch is optional and puts locking around aformentioned consumers for safety. Consumers of other fields don't seem to benefit from similar treatment and are left untouched. This patch (of 2): The code was taking the semaphore for reading, which does not protect against readers nor concurrent modifications. The problem could cause a sanity checks to fail in procfs's cmdline reader, resulting in an OOPS. Note that some functions perform an unlocked read of various mm fields, but they seem to be fine despite possible modificaton. 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> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pidns: fix set/getpriority and ioprio_set/get in PRIO_USER modeBen Segall2015-11-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | setpriority(PRIO_USER, 0, x) will change the priority of tasks outside of the current pid namespace. This is in contrast to both the other modes of setpriority and the example of kill(-1). Fix this. getpriority and ioprio have the same failure mode, fix them too. Eric said: : After some more thinking about it this patch sounds justifiable. : : My goal with namespaces is not to build perfect isolation mechanisms : as that can get into ill defined territory, but to build well defined : mechanisms. And to handle the corner cases so you can use only : a single namespace with well defined results. : : In this case you have found the two interfaces I am aware of that : identify processes by uid instead of by pid. Which quite frankly is : weird. Unfortunately the weird unexpected cases are hard to handle : in the usual way. : : I was hoping for a little more information. Changes like this one we : have to be careful of because someone might be depending on the current : behavior. I don't think they are and I do think this make sense as part : of the pid namespace. Signed-off-by: Ben Segall <bsegall@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ambrose Feinstein <ambrose@google.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: Commit to never having exectuables on proc and sysfs.Eric W. Biederman2015-07-101-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today proc and sysfs do not contain any executable files. Several applications today mount proc or sysfs without noexec and nosuid and then depend on there being no exectuables files on proc or sysfs. Having any executable files show on proc or sysfs would cause a user space visible regression, and most likely security problems. Therefore commit to never allowing executables on proc and sysfs by adding a new flag to mark them as filesystems without executables and enforce that flag. Test the flag where MNT_NOEXEC is tested today, so that the only user visible effect will be that exectuables will be treated as if the execute bit is cleared. The filesystems proc and sysfs do not currently incoporate any executable files so this does not result in any user visible effects. This makes it unnecessary to vet changes to proc and sysfs tightly for adding exectuable files or changes to chattr that would modify existing files, as no matter what the individual file say they will not be treated as exectuable files by the vfs. Not having to vet changes to closely is important as without this we are only one proc_create call (or another goof up in the implementation of notify_change) from having problematic executables on proc. Those mistakes are all too easy to make and would create a situation where there are security issues or the assumptions of some program having to be broken (and cause userspace regressions). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* prctl: more prctl(PR_SET_MM_*) checksAlexey Dobriyan2015-06-251-67/+91
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Individual prctl(PR_SET_MM_*) calls do some checking to maintain a consistent view of mm->arg_start et al fields, but not enough. In particular PR_SET_MM_ARG_START/PR_SET_MM_ARG_END/ R_SET_MM_ENV_START/ PR_SET_MM_ENV_END only check that the address lies in an existing VMA, but don't check that the start address is lower than the end address _at all_. Consolidate all consistency checks, so there will be no difference in the future between PR_SET_MM_MAP and individual PR_SET_MM_* calls. The program below makes both ARGV and ENVP areas be reversed. It makes /proc/$PID/cmdline show garbage (it doesn't oops by luck). #include <sys/mman.h> #include <sys/prctl.h> #include <unistd.h> enum {PAGE_SIZE=4096}; int main(void) { void *p; p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); #define PR_SET_MM 35 #define PR_SET_MM_ARG_START 8 #define PR_SET_MM_ARG_END 9 #define PR_SET_MM_ENV_START 10 #define PR_SET_MM_ENV_END 11 prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long)p + PAGE_SIZE - 1, 0, 0); prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long)p, 0, 0); prctl(PR_SET_MM, PR_SET_MM_ENV_START, (unsigned long)p + PAGE_SIZE - 1, 0, 0); prctl(PR_SET_MM, PR_SET_MM_ENV_END, (unsigned long)p, 0, 0); pause(); return 0; } [akpm@linux-foundation.org: tidy code, tweak comment] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/mpx: Clean up the code by not passing a task pointer around when unnecessaryDave Hansen2015-06-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | The MPX code can only work on the current task. You can not, for instance, enable MPX management in another process or thread. You can also not handle a fault for another process or thread. Despite this, we pass a task_struct around prolifically. This patch removes all of the task struct passing for code paths where the code can not deal with another task (which turns out to be all of them). This has no functional changes. It's just a cleanup. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave@sr71.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: bp@alien8.de Link: http://lkml.kernel.org/r/20150607183702.6A81DA2C@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* prctl: avoid using mmap_sem for exe_file serializationDavidlohr Bueso2015-04-171-19/+28
| | | | | | | | | | | | | | | | | | | Oleg cleverly suggested using xchg() to set the new mm->exe_file instead of calling set_mm_exe_file() which requires some form of serialization -- mmap_sem in this case. For archs that do not have atomic rmw instructions we still fallback to a spinlock alternative, so this should always be safe. As such, we only need the mmap_sem for looking up the backing vm_file, which can be done sharing the lock. Naturally, this means we need to manually deal with both the new and old file reference counting, and we need not worry about the MMF_EXE_FILE_CHANGED bits, which can probably be deleted in the future anyway. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel: conditionally support non-root users, groups and capabilitiesIulia Manda2015-04-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/sys.c: fix UNAME26 for 4.0Jon DeVree2015-02-281-1/+2
| | | | | | | | | | There's a uname workaround for broken userspace which can't handle kernel versions of 3.x. Update it for 4.x. Signed-off-by: Jon DeVree <nuxi@vault24.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds2015-02-211-0/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS: - a number of fixes that didn't make the 3.19 release. - a number of cleanups. - preliminary support for Cavium's Octeon 3 SOCs which feature up to 48 MIPS64 R3 cores with FPU and hardware virtualization. - support for MIPS R6 processors. Revision 6 of the MIPS architecture is a major revision of the MIPS architecture which does away with many of original sins of the architecture such as branch delay slots. This and other changes in R6 require major changes throughout the entire MIPS core architecture code and make up for the lion share of this pull request. - finally some preparatory work for eXtendend Physical Address support, which allows support of up to 40 bit of physical address space on 32 bit processors" [ Ahh, MIPS can't leave the PAE brain damage alone. It's like every CPU architect has to make that mistake, but pee in the snow by changing the TLA. But whether it's called PAE, LPAE or XPA, it's horrid crud - Linus ] * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (114 commits) MIPS: sead3: Corrected get_c0_perfcount_int MIPS: mm: Remove dead macro definitions MIPS: OCTEON: irq: add CIB and other fixes MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs. MIPS: OCTEON: More OCTEONIII support MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits. MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup. MIPS: OCTEON: Update octeon-model.h code for new SoCs. MIPS: OCTEON: Implement DCache errata workaround for all CN6XXX MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.h MIPS: OCTEON: Implement the core-16057 workaround MIPS: OCTEON: Delete unused COP2 saving code MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register MIPS: OCTEON: Save and restore CP2 SHA3 state MIPS: OCTEON: Fix FP context save. MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs MIPS: boot: Provide more uImage options MIPS: Remove unneeded #ifdef __KERNEL__ from asm/processor.h MIPS: ip22-gio: Remove legacy suspend/resume support mips: pci: Add ifdef around pci_proc_domain ...
| * MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPSPaul Burton2015-02-121-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userland code may be built using an ABI which permits linking to objects that have more restrictive floating point requirements. For example, userland code may be built to target the O32 FPXX ABI. Such code may be linked with other FPXX code, or code built for either one of the more restrictive FP32 or FP64. When linking with more restrictive code, the overall requirement of the process becomes that of the more restrictive code. The kernel has no way to know in advance which mode the process will need to be executed in, and indeed it may need to change during execution. The dynamic loader is the only code which will know the overall required mode, and so it needs to have a means to instruct the kernel to switch the FP mode of the process. This patch introduces 2 new options to the prctl syscall which provide such a capability. The FP mode of the process is represented as a simple bitmask combining a number of mode bits mirroring those present in the hardware. Userland can either retrieve the current FP mode of the process: mode = prctl(PR_GET_FP_MODE); or modify the current FP mode of the process: err = prctl(PR_SET_FP_MODE, new_mode); Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8899/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | x86, mpx: Strictly enforce empty prctl() argsDave Hansen2015-01-221-0/+4
|/ | | | | | | | | | | | | | | | | | | Description from Michael Kerrisk. He suggested an identical patch to one I had already coded up and tested. commit fe3d197f8431 "x86, mpx: On-demand kernel allocation of bounds tables" added two new prctl() operations, PR_MPX_ENABLE_MANAGEMENT and PR_MPX_DISABLE_MANAGEMENT. However, no checks were included to ensure that unused arguments are zero, as is done in many existing prctl()s and as should be done for all new prctl()s. This patch adds the required checks. Suggested-by: Andy Lutomirski <luto@amacapital.net> Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20150108223022.7F56FD13@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86, mpx: On-demand kernel allocation of bounds tablesDave Hansen2014-11-181-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is really the meat of the MPX patch set. If there is one patch to review in the entire series, this is the one. There is a new ABI here and this kernel code also interacts with userspace memory in a relatively unusual manner. (small FAQ below). Long Description: This patch adds two prctl() commands to provide enable or disable the management of bounds tables in kernel, including on-demand kernel allocation (See the patch "on-demand kernel allocation of bounds tables") and cleanup (See the patch "cleanup unused bound tables"). Applications do not strictly need the kernel to manage bounds tables and we expect some applications to use MPX without taking advantage of this kernel support. This means the kernel can not simply infer whether an application needs bounds table management from the MPX registers. The prctl() is an explicit signal from userspace. PR_MPX_ENABLE_MANAGEMENT is meant to be a signal from userspace to require kernel's help in managing bounds tables. PR_MPX_DISABLE_MANAGEMENT is the opposite, meaning that userspace don't want kernel's help any more. With PR_MPX_DISABLE_MANAGEMENT, the kernel won't allocate and free bounds tables even if the CPU supports MPX. PR_MPX_ENABLE_MANAGEMENT will fetch the base address of the bounds directory out of a userspace register (bndcfgu) and then cache it into a new field (->bd_addr) in the 'mm_struct'. PR_MPX_DISABLE_MANAGEMENT will set "bd_addr" to an invalid address. Using this scheme, we can use "bd_addr" to determine whether the management of bounds tables in kernel is enabled. Also, the only way to access that bndcfgu register is via an xsaves, which can be expensive. Caching "bd_addr" like this also helps reduce the cost of those xsaves when doing table cleanup at munmap() time. Unfortunately, we can not apply this optimization to #BR fault time because we need an xsave to get the value of BNDSTATUS. ==== Why does the hardware even have these Bounds Tables? ==== MPX only has 4 hardware registers for storing bounds information. If MPX-enabled code needs more than these 4 registers, it needs to spill them somewhere. It has two special instructions for this which allow the bounds to be moved between the bounds registers and some new "bounds tables". They are similar conceptually to a page fault and will be raised by the MPX hardware during both bounds violations or when the tables are not present. This patch handles those #BR exceptions for not-present tables by carving the space out of the normal processes address space (essentially calling the new mmap() interface indroduced earlier in this patch set.) and then pointing the bounds-directory over to it. The tables *need* to be accessed and controlled by userspace because the instructions for moving bounds in and out of them are extremely frequent. They potentially happen every time a register pointing to memory is dereferenced. Any direct kernel involvement (like a syscall) to access the tables would obviously destroy performance. ==== Why not do this in userspace? ==== This patch is obviously doing this allocation in the kernel. However, MPX does not strictly *require* anything in the kernel. It can theoretically be done completely from userspace. Here are a few ways this *could* be done. I don't think any of them are practical in the real-world, but here they are. Q: Can virtual space simply be reserved for the bounds tables so that we never have to allocate them? A: As noted earlier, these tables are *HUGE*. An X-GB virtual area needs 4*X GB of virtual space, plus 2GB for the bounds directory. If we were to preallocate them for the 128TB of user virtual address space, we would need to reserve 512TB+2GB, which is larger than the entire virtual address space today. This means they can not be reserved ahead of time. Also, a single process's pre-popualated bounds directory consumes 2GB of virtual *AND* physical memory. IOW, it's completely infeasible to prepopulate bounds directories. Q: Can we preallocate bounds table space at the same time memory is allocated which might contain pointers that might eventually need bounds tables? A: This would work if we could hook the site of each and every memory allocation syscall. This can be done for small, constrained applications. But, it isn't practical at a larger scale since a given app has no way of controlling how all the parts of the app might allocate memory (think libraries). The kernel is really the only place to intercept these calls. Q: Could a bounds fault be handed to userspace and the tables allocated there in a signal handler instead of in the kernel? A: (thanks to tglx) mmap() is not on the list of safe async handler functions and even if mmap() would work it still requires locking or nasty tricks to keep track of the allocation state there. Having ruled out all of the userspace-only approaches for managing bounds tables that we could think of, we create them on demand in the kernel. Based-on-patch-by: Qiaowei Ren <qiaowei.ren@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141114151829.AD4310DE@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2014-10-131-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave Hansen) - Various sched/idle refinements for better idle handling (Nicolas Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot) - sched/numa updates and optimizations (Rik van Riel) - sysbench speedup (Vincent Guittot) - capacity calculation cleanups/refactoring (Vincent Guittot) - Various cleanups to thread group iteration (Oleg Nesterov) - Double-rq-lock removal optimization and various refactorings (Kirill Tkhai) - various sched/deadline fixes ... and lots of other changes" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) sched/dl: Use dl_bw_of() under rcu_read_lock_sched() sched/fair: Delete resched_cpu() from idle_balance() sched, time: Fix build error with 64 bit cputime_t on 32 bit systems sched: Improve sysbench performance by fixing spurious active migration sched/x86: Fix up typo in topology detection x86, sched: Add new topology for multi-NUMA-node CPUs sched/rt: Use resched_curr() in task_tick_rt() sched: Use rq->rd in sched_setaffinity() under RCU read lock sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask' sched: Use dl_bw_of() under RCU read lock sched/fair: Remove duplicate code from can_migrate_task() sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW sched: print_rq(): Don't use tasklist_lock sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock() sched: Fix the task-group check in tg_has_rt_tasks() sched/fair: Leverage the idle state info when choosing the "idlest" cpu sched: Let the scheduler see CPU idle states sched/deadline: Fix inter- exclusive cpusets migrations sched/deadline: Clear dl_entity params when setscheduling to different class sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault() ...
| * time, signal: Protect resource use statistics with seqlockRik van Riel2014-09-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both times() and clock_gettime(CLOCK_PROCESS_CPUTIME_ID) have scalability issues on large systems, due to both functions being serialized with a lock. The lock protects against reporting a wrong value, due to a thread in the task group exiting, its statistics reporting up to the signal struct, and that exited task's statistics being counted twice (or not at all). Protecting that with a lock results in times() and clock_gettime() being completely serialized on large systems. This can be fixed by using a seqlock around the events that gather and propagate statistics. As an additional benefit, the protection code can be moved into thread_group_cputime(), slightly simplifying the calling functions. In the case of posix_cpu_clock_get_task() things can be simplified a lot, because the calling function already ensures that the task sticks around, and the rest is now taken care of in thread_group_cputime(). This way the statistics reporting code can run lockless. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guillaume Morin <guillaume@morinfr.org> Cc: Ionut Alexa <ionut.m.alexa@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: umgwanakikbuti@gmail.com Cc: fweisbec@gmail.com Cc: srao@redhat.com Cc: lwoodman@redhat.com Cc: atheurer@redhat.com Link: http://lkml.kernel.org/r/20140816134010.26a9b572@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | kernel/sys.c: compat sysinfo syscall: fix undefined behaviorScotty Bauer2014-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | Fix undefined behavior and compiler warning by replacing right shift 32 with upper_32_bits macro Signed-off-by: Scotty Bauer <sbauer@eng.utah.edu> Cc: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kernel/sys.c: whitespace fixesvishnu.ps2014-10-091-128/+137
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix minor errors and warning messages in kernel/sys.c. These errors were reported by checkpatch while working with some modifications in sys.c file. Fixing this first will help me to improve my further patches. ERROR: trailing whitespace - 9 ERROR: do not use assignment in if condition - 4 ERROR: spaces required around that '?' (ctx:VxO) - 10 ERROR: switch and case should be at the same indent - 3 total 26 errors & 3 warnings fixed. Signed-off-by: vishnu.ps <vishnu.ps@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: use VM_BUG_ON_MM where possibleSasha Levin2014-10-091-1/+1
| | | | | | | | | | | | | | | | Dump the contents of the relevant struct_mm when we hit the bug condition. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | prctl: PR_SET_MM -- introduce PR_SET_MM_MAP operationCyrill Gorcunov2014-10-091-1/+189
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During development of c/r we've noticed that in case if we need to support user namespaces we face a problem with capabilities in prctl(PR_SET_MM, ...) call, in particular once new user namespace is created capable(CAP_SYS_RESOURCE) no longer passes. A approach is to eliminate CAP_SYS_RESOURCE check but pass all new values in one bundle, which would allow the kernel to make more intensive test for sanity of values and same time allow us to support checkpoint/restore of user namespaces. Thus a new command PR_SET_MM_MAP introduced. It takes a pointer of prctl_mm_map structure which carries all the members to be updated. prctl(PR_SET_MM, PR_SET_MM_MAP, struct prctl_mm_map *, size) struct prctl_mm_map { __u64 start_code; __u64 end_code; __u64 start_data; __u64 end_data; __u64 start_brk; __u64 brk; __u64 start_stack; __u64 arg_start; __u64 arg_end; __u64 env_start; __u64 env_end; __u64 *auxv; __u32 auxv_size; __u32 exe_fd; }; All members except @exe_fd correspond ones of struct mm_struct. To figure out which available values these members may take here are meanings of the members. - start_code, end_code: represent bounds of executable code area - start_data, end_data: represent bounds of data area - start_brk, brk: used to calculate bounds for brk() syscall - start_stack: used when accounting space needed for command line arguments, environment and shmat() syscall - arg_start, arg_end, env_start, env_end: represent memory area supplied for command line arguments and environment variables - auxv, auxv_size: carries auxiliary vector, Elf format specifics - exe_fd: file descriptor number for executable link (/proc/self/exe) Thus we apply the following requirements to the values 1) Any member except @auxv, @auxv_size, @exe_fd is rather an address in user space thus it must be laying inside [mmap_min_addr, mmap_max_addr) interval. 2) While @[start|end]_code and @[start|end]_data may point to an nonexisting VMAs (say a program maps own new .text and .data segments during execution) the rest of members should belong to VMA which must exist. 3) Addresses must be ordered, ie @start_ member must not be greater or equal to appropriate @end_ member. 4) As in regular Elf loading procedure we require that @start_brk and @brk be greater than @end_data. 5) If RLIMIT_DATA rlimit is set to non-infinity new values should not exceed existing limit. Same applies to RLIMIT_STACK. 6) Auxiliary vector size must not exceed existing one (which is predefined as AT_VECTOR_SIZE and depends on architecture). 7) File descriptor passed in @exe_file should be pointing to executable file (because we use existing prctl_set_mm_exe_file_locked helper it ensures that the file we are going to use as exe link has all required permission granted). Now about where these members are involved inside kernel code: - @start_code and @end_code are used in /proc/$pid/[stat|statm] output; - @start_data and @end_data are used in /proc/$pid/[stat|statm] output, also they are considered if there enough space for brk() syscall result if RLIMIT_DATA is set; - @start_brk shown in /proc/$pid/stat output and accounted in brk() syscall if RLIMIT_DATA is set; also this member is tested to find a symbolic name of mmap event for perf system (we choose if event is generated for "heap" area); one more aplication is selinux -- we test if a process has PROCESS__EXECHEAP permission if trying to make heap area being executable with mprotect() syscall; - @brk is a current value for brk() syscall which lays inside heap area, it's shown in /proc/$pid/stat. When syscall brk() succesfully provides new memory area to a user space upon brk() completion the mm::brk is updated to carry new value; Both @start_brk and @brk are actively used in /proc/$pid/maps and /proc/$pid/smaps output to find a symbolic name "heap" for VMA being scanned; - @start_stack is printed out in /proc/$pid/stat and used to find a symbolic name "stack" for task and threads in /proc/$pid/maps and /proc/$pid/smaps output, and as the same as with @start_brk -- perf system uses it for event naming. Also kernel treat this member as a start address of where to map vDSO pages and to check if there is enough space for shmat() syscall; - @arg_start, @arg_end, @env_start and @env_end are printed out in /proc/$pid/stat. Another access to the data these members represent is to read /proc/$pid/environ or /proc/$pid/cmdline. Any attempt to read these areas kernel tests with access_process_vm helper so a user must have enough rights for this action; - @auxv and @auxv_size may be read from /proc/$pid/auxv. Strictly speaking kernel doesn't care much about which exactly data is sitting there because it is solely for userspace; - @exe_fd is referred from /proc/$pid/exe and when generating coredump. We uses prctl_set_mm_exe_file_locked helper to update this member, so exe-file link modification remains one-shot action. Still note that updating exe-file link now doesn't require sys-resource capability anymore, after all there is no much profit in preventing setup own file link (there are a number of ways to execute own code -- ptrace, ld-preload, so that the only reliable way to find which exactly code is executed is to inspect running program memory). Still we require the caller to be at least user-namespace root user. I believe the old interface should be deprecated and ripped off in a couple of kernel releases if no one against. To test if new interface is implemented in the kernel one can pass PR_SET_MM_MAP_SIZE opcode and the kernel returns the size of currently supported struct prctl_mm_map. [akpm@linux-foundation.org: fix 80-col wordwrap in macro definitions] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Acked-by: Andrew Vagin <avagin@openvz.org> Tested-by: Andrew Vagin <avagin@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Julien Tinnes <jln@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | prctl: PR_SET_MM -- factor out mmap_sem when updating mm::exe_fileCyrill Gorcunov2014-10-091-10/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of taking mm->mmap_sem inside prctl_set_mm_exe_file() move it out and rename the helper to prctl_set_mm_exe_file_locked(). This will allow to reuse this function in a next patch. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Julien Tinnes <jln@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: use may_adjust_brk helperCyrill Gorcunov2014-10-091-7/+4
|/ | | | | | | | | | | | | | | | | Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Julien Tinnes <jln@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: move no_new_privs into new atomic flagsKees Cook2014-07-181-2/+2
| | | | | | | | | | | Since seccomp transitions between threads requires updates to the no_new_privs flag to be atomic, the flag must be part of an atomic flag set. This moves the nnp flag into a separate task field, and introduces accessors. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net>
* sched: Consolidate open coded implementations of nice level frobbing into ↵Dongsheng Yang2014-05-221-3/+3
| | | | | | | | | nice_to_rlimit() and rlimit_to_nice() Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/a568a1e3cc8e78648f41b5035fa5e381d36274da.1399532322.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLEAlex Thorlton2014-04-071-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add VM_INIT_DEF_MASK, to allow us to set the default flags for VMs. It also adds a prctl control which allows us to set the THP disable bit in mm->def_flags so that VMs will pick up the setting as they are created. Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sys: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICEDongsheng Yang2014-02-221-4/+4
| | | | | | | | | | | | | | | Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Robin Holt <holt@sgi.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/0261f094b836f1acbcdf52e7166487c0c77323c8.1392103744.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kernel/sys.c: k_getrusage() can use while_each_thread()Oleg Nesterov2014-01-231-2/+1
| | | | | | | | | | | | | Change k_getrusage() to use while_each_thread(), no changes in the compiled code. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Sameer Nanda <snanda@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: kill task_struct->did_execOleg Nesterov2014-01-231-3/+2
| | | | | | | | | | | | We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually exclusive. The patch kills ->did_exec because it has a single user. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/sys.c: remove obsolete #include <linux/kexec.h>Geert Uytterhoeven2013-11-131-1/+0
| | | | | | | | | | | | Commit 15d94b82565e ("reboot: move shutdown/reboot related functions to kernel/reboot.c") moved all kexec-related functionality to kernel/reboot.c, so kernel/sys.c no longer needs to include <linux/kexec.h>. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* userns: Kill nsown_capable it makes the wrong thing easyEric W. Biederman2013-08-301-10/+10
| | | | | | | | | | nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and CAP_SETGID. For the existing users it doesn't noticably simplify things and from the suggested patches I have seen it encourages people to do the wrong thing. So remove nsown_capable. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* reboot: move shutdown/reboot related functions to kernel/reboot.cRobin Holt2013-07-091-331/+0
| | | | | | | | | | | | | | | This patch is preparatory. It moves reboot related syscall, etc functions from kernel/sys.c to kernel/reboot.c. Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reboot: remove -stable friendly PF_THREAD_BOUND defineRobin Holt2013-07-091-5/+0
| | | | | | | | | | | | | | | Remove the prior patch's #define for easier backporting to the stable releases. Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exit.c: unexport __set_special_pids()Oleg Nesterov2013-07-031-1/+12
| | | | | | | | | | | | | Move __set_special_pids() from exit.c to sys.c close to its single caller and make it static. And rename it to set_special_pids(), another helper with this name has gone away. Signed-off-by: Oleg Nesterov <oleg@redhat.com> 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>
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