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* proc: cleanup: remove unused assignmentsDan Carpenter2010-05-271-2/+2
| | | | | | | | | | | | | I removed 3 unused assignments. The first two get reset on the first statement of their functions. For "err" in root.c we don't return an error and we don't use the variable again. Signed-off-by: Dan Carpenter <error27@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: get_nr_threads() doesn't need ->siglock any longerOleg Nesterov2010-05-271-12/+0
| | | | | | | | | | | | | | | | | | | Now that task->signal can't go away get_nr_threads() doesn't need ->siglock to read signal->count. Also, make it inline, move into sched.h, and convert 2 other proc users of signal->count to use this (now trivial) helper. Henceforth get_nr_threads() is the only valid user of signal->count, we are ready to turn it into "int nr_threads" or, perhaps, kill it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'bkl/procfs' of ↵Linus Torvalds2010-05-191-1/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'bkl/procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: sunrpc: Include missing smp_lock.h procfs: Kill the bkl in ioctl procfs: Push down the bkl from ioctl procfs: Use generic_file_llseek in /proc/vmcore procfs: Use generic_file_llseek in /proc/kmsg procfs: Use generic_file_llseek in /proc/kcore procfs: Kill BKL in llseek on proc base
| * procfs: Kill BKL in llseek on proc baseArnd Bergmann2010-04-091-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't use the BKL elsewhere, so use generic_file_llseek so we can avoid default_llseek taking the BKL. Signed-off-by: Arnd Bergmann <arnd@arndb.de> [restore proc_fdinfo_file_operations as non-seekable] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: John Kacur <jkacur@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
* | procfs: fix tid fdinfoJerome Marchand2010-04-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct the file_operations struct in fdinfo entry of tid_base_stuff[]. Presently /proc/*/task/*/fdinfo contains symlinks to opened files like /proc/*/fd/. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'master' into export-slabhTejun Heo2010-04-051-2/+3
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| * | oom: fix the unsafe usage of badness() in proc_oom_score()Oleg Nesterov2010-04-011-2/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_oom_score(task) has a reference to task_struct, but that is all. If this task was already released before we take tasklist_lock - we can't use task->group_leader, it points to nowhere - it is not safe to call badness() even if this task is ->group_leader, has_intersects_mems_allowed() assumes it is safe to iterate over ->thread_group list. - even worse, badness() can hit ->signal == NULL Add the pid_alive() check to ensure __unhash_process() was not called. Also, use "task" instead of task->group_leader. badness() should return the same result for any sub-thread. Currently this is not true, but this should be changed anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2010-03-041-8/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) init: Open /dev/console from rootfs mqueue: fix typo "failues" -> "failures" mqueue: only set error codes if they are really necessary mqueue: simplify do_open() error handling mqueue: apply mathematics distributivity on mq_bytes calculation mqueue: remove unneeded info->messages initialization mqueue: fix mq_open() file descriptor leak on user-space processes fix race in d_splice_alias() set S_DEAD on unlink() and non-directory rename() victims vfs: add NOFOLLOW flag to umount(2) get rid of ->mnt_parent in tomoyo/realpath hppfs can use existing proc_mnt, no need for do_kern_mount() in there Mirror MS_KERNMOUNT in ->mnt_flags get rid of useless vfsmount_lock use in put_mnt_ns() Take vfsmount_lock to fs/internal.h get rid of insanity with namespace roots in tomoyo take check for new events in namespace (guts of mounts_poll()) to namespace.c Don't mess with generic_permission() under ->d_lock in hpfs sanitize const/signedness for udf nilfs: sanitize const/signedness in dealing with ->d_name.name ... Fix up fairly trivial (famous last words...) conflicts in drivers/infiniband/core/uverbs_main.c and security/tomoyo/realpath.c
| * take check for new events in namespace (guts of mounts_poll()) to namespace.cAl Viro2010-03-031-8/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | vfs: Apply lockdep-based checking to rcu_dereference() usesPaul E. McKenney2010-02-251-1/+5
|/ | | | | | | | | | | | | | | | | | | | | Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Alexander Viro <viro@zeniv.linux.org.uk> LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Switch proc/self to nd_set_link()Al Viro2010-02-191-5/+19
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fix autofs/afs/etc. magic mountpoint breakageAl Viro2010-01-141-1/+0
| | | | | | | | | | | | | We end up trying to kfree() nd.last.name on open("/mnt/tmp", O_CREAT) if /mnt/tmp is an autofs direct mount. The reason is that nd.last_type is bogus here; we want LAST_BIND for everything of that kind and we get LAST_NORM left over from finding parent directory. So make sure that it *is* set properly; set to LAST_BIND before doing ->follow_link() - for normal symlinks it will be changed by __vfs_follow_link() and everything else needs it set that way. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* elf: kill USE_ELF_CORE_DUMPChristoph Hellwig2009-12-161-2/+2
| | | | | | | | | | | | | Currently all architectures but microblaze unconditionally define USE_ELF_CORE_DUMP. The microblaze omission seems like an error to me, so let's kill this ifdef and make sure we are the same everywhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <linux-arch@vger.kernel.org> Cc: Michal Simek <michal.simek@petalogix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* procfs: allow threads to rename siblings via /proc/pid/tasks/tid/commjohn stultz2009-12-151-0/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | Setting a thread's comm to be something unique is a very useful ability and is helpful for debugging complicated threaded applications. However currently the only way to set a thread name is for the thread to name itself via the PR_SET_NAME prctl. However, there may be situations where it would be advantageous for a thread dispatcher to be naming the threads its managing, rather then having the threads self-describe themselves. This sort of behavior is available on other systems via the pthread_setname_np() interface. This patch exports a task's comm via proc/pid/comm and proc/pid/task/tid/comm interfaces, and allows thread siblings to write to these values. [akpm@linux-foundation.org: cleanups] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Mike Fulton <fultonm@ca.ibm.com> Cc: Sean Foley <Sean_Foley@ca.ibm.com> Cc: Darren Hart <dvhltc@us.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pidns: fix a leak in /proc dentries and inodes with pid namespaces.Sukadev Bhattiprolu2009-11-121-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Lezcano reported a leak in 'struct pid' and 'struct pid_namespace' that is discussed in: http://lkml.org/lkml/2009/10/2/159. To summarize the thread, when container-init is terminated, it sets the PF_EXITING flag, zaps other processes in the container and waits to reap them. As a part of reaping, the container-init should flush any /proc dentries associated with the processes. But because the container-init is itself exiting and the following PF_EXITING check, the dentries are not flushed, resulting in leak in /proc inodes and dentries. This fix reverts the commit 7766755a2f249e7e0 ("Fix /proc dcache deadlock in do_exit") which introduced the check for PF_EXITING. At the time of the commit, shrink_dcache_parent() flushed dentries from other filesystems also and could have caused a deadlock which the commit fixed. But as pointed out by Eric Biederman, after commit 0feae5c47aabdde59, shrink_dcache_parent() no longer affects other filesystems. So reverting the commit is now safe. As pointed out by Jan Kara, the leak is not as critical since the unclaimed space will be reclaimed under memory pressure or by: echo 3 > /proc/sys/vm/drop_caches But since this check is no longer required, its best to remove it. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Jan Kara <jack@ucw.cz> Cc: Andrea Arcangeli <andrea@cpushare.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/base.c: fix proc_fault_inject_write() input sanity checkVincent Li2009-09-231-6/+5
| | | | | | | | | | | | | | | | | | | | | | | Remove obfuscated zero-length input check and return -EINVAL instead of -EIO error to make the error message clear to user. Add whitespace stripping. No functionality changes. The old code: echo 1 > /proc/pid/make-it-fail (ok) echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Input/output error) The new code: echo 1 > /proc/pid/make-it-fail (ok) echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Invalid argument) This patch is conservative in changes to not breaking existing scripts/applications. Signed-off-by: Vincent Li <macli@brc.ubc.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc_flush_task: flush /proc/tid/task/pid when a sub-thread exitsOleg Nesterov2009-09-231-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The exiting sub-thread flushes /proc/pid only, but this doesn't buy too much: ps and friends mostly use /proc/tid/task/pid. Remove "if (thread_group_leader())" checks from proc_flush_task() path, this means we always remove /proc/tid/task/pid dentry on exit, and this actually matches the comment above proc_flush_task(). The test-case: static void* tfunc(void *arg) { char name[256]; sprintf(name, "/proc/%d/task/%ld/status", getpid(), gettid()); close(open(name, O_RDONLY)); return NULL; } int main(void) { pthread_t t; for (;;) { if (!pthread_create(&t, NULL, &tfunc, NULL)) pthread_join(t, NULL); } } slabtop shows that pid/proc_inode_cache/etc grow quickly and "indefinitely" until the task is killed or shrink_slab() is called, not good. And the main thread needs a lot of time to exit. The same can happen if something like "ps -efL" runs continuously, while some application spawns short-living threads. Reported-by: "James M. Leddy" <jleddy@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dominic Duval <dduval@redhat.com> Cc: Frank Hirtz <fhirtz@redhat.com> Cc: "Fuller, Johnray" <Johnray.Fuller@gs.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Paul Batkowski <pbatkowski@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: fix reported unit for RLIMIT_CPUKees Cook2009-09-231-1/+1
| | | | | | | | | | | | | | | | | /proc/$pid/limits should show RLIMIT_CPU as seconds, which is the unit used in kernel/posix-cpu-timers.c: unsigned long psecs = cputime_to_secs(ptime); ... if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) { ... __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); Signed-off-by: Kees Cook <kees.cook@canonical.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: fix oom_adjust_write() input sanity checkKOSAKI Motohiro2009-09-221-8/+10
| | | | | | | | | | | | | Andrew Morton pointed out oom_adjust_write() has very strange EIO and new line handling. this patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: make oom_score to per-process valueKOSAKI Motohiro2009-09-221-1/+1
| | | | | | | | | | | | | | oom-killer kills a process, not task. Then oom_score should be calculated as per-process too. it makes consistency more and makes speed up select_bad_process(). Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: move oom_adj value from task_struct to signal_structKOSAKI Motohiro2009-09-221-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, OOM logic callflow is here. __out_of_memory() select_bad_process() for each task badness() calculate badness of one task oom_kill_process() search child oom_kill_task() kill target task and mm shared tasks with it example, process-A have two thread, thread-A and thread-B and it have very fat memory and each thread have following oom_adj and oom_score. thread-A: oom_adj = OOM_DISABLE, oom_score = 0 thread-B: oom_adj = 0, oom_score = very-high Then, select_bad_process() select thread-B, but oom_kill_task() refuse kill the task because thread-A have OOM_DISABLE. Thus __out_of_memory() call select_bad_process() again. but select_bad_process() select the same task. It mean kernel fall in livelock. The fact is, select_bad_process() must select killable task. otherwise OOM logic go into livelock. And root cause is, oom_adj shouldn't be per-thread value. it should be per-process value because OOM-killer kill a process, not thread. Thus This patch moves oomkilladj (now more appropriately named oom_adj) from struct task_struct to struct signal_struct. it naturally prevent select_bad_process() choose wrong task. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: revert "oom: move oom_adj value"KOSAKI Motohiro2009-08-181-16/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to the mm_struct. It was a very good first step for sanitize OOM. However Paul Menage reported the commit makes regression to his job scheduler. Current OOM logic can kill OOM_DISABLED process. Why? His program has the code of similar to the following. ... set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */ ... if (vfork() == 0) { set_oom_adj(0); /* Invoked child can be killed */ execve("foo-bar-cmd"); } .... vfork() parent and child are shared the same mm_struct. then above set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also change oom_adj for vfork() parent. Then, vfork() parent (job scheduler) lost OOM immune and it was killed. Actually, fork-setting-exec idiom is very frequently used in userland program. We must not break this assumption. Then, this patch revert commit 2ff05b2b and related commit. Reverted commit list --------------------- - commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct) - commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE) - commit 8123681022 (oom: only oom kill exiting tasks with attached memory) - commit 933b787b57 (mm: copy over oom_adj value at fork time) Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm_for_maps: take ->cred_guard_mutex to fix the race with execOleg Nesterov2009-08-101-11/+11
| | | | | | | | | | | | | | | | The problem is minor, but without ->cred_guard_mutex held we can race with exec() and get the new ->mm but check old creds. Now we do not need to re-check task->mm after ptrace_may_access(), it can't be changed to the new mm under us. Strictly speaking, this also fixes another very minor problem. Unless security check fails or the task exits mm_for_maps() should never return NULL, the caller should get either old or new ->mm. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* mm_for_maps: shift down_read(mmap_sem) to the callerOleg Nesterov2009-08-101-5/+3
| | | | | | | | | | mm_for_maps() takes ->mmap_sem after security checks, this looks strange and obfuscates the locking rules. Move this lock to its single caller, m_start(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* mm_for_maps: simplify, use ptrace_may_access()Oleg Nesterov2009-08-101-12/+11
| | | | | | | | | | | | | | | | | | | It would be nice to kill __ptrace_may_access(). It requires task_lock(), but this lock is only needed to read mm->flags in the middle. Convert mm_for_maps() to use ptrace_may_access(), this also simplifies the code a little bit. Also, we do not need to take ->mmap_sem in advance. In fact I think mm_for_maps() should not play with ->mmap_sem at all, the caller should take this lock. With or without this patch, without ->cred_guard_mutex held we can race with exec() and get the new ->mm but check old creds. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* oom: move oom_adj value from task_struct to mm_structDavid Rientjes2009-06-161-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The per-task oom_adj value is a characteristic of its mm more than the task itself since it's not possible to oom kill any thread that shares the mm. If a task were to be killed while attached to an mm that could not be freed because another thread were set to OOM_DISABLE, it would have needlessly been terminated since there is no potential for future memory freeing. This patch moves oomkilladj (now more appropriately named oom_adj) from struct task_struct to struct mm_struct. This requires task_lock() on a task to check its oom_adj value to protect against exec, but it's already necessary to take the lock when dereferencing the mm to find the total VM size for the badness heuristic. This fixes a livelock if the oom killer chooses a task and another thread sharing the same memory has an oom_adj value of OOM_DISABLE. This occurs because oom_kill_task() repeatedly returns 1 and refuses to kill the chosen task while select_bad_process() will repeatedly choose the same task during the next retry. Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in oom_kill_task() to check for threads sharing the same memory will be removed in the next patch in this series where it will no longer be necessary. Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since these threads are immune from oom killing already. They simply report an oom_adj value of OOM_DISABLE. Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> 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>
* Merge branch 'master' into nextJames Morris2009-06-091-1/+1
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| * procfs: make errno values consistent when open pident vs exit(2) race occursKOSAKI Motohiro2009-05-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_pident_instantiate() has following call flow. proc_pident_lookup() proc_pident_instantiate() proc_pid_make_inode() And, proc_pident_lookup() has following error handling. const struct pid_entry *p, *last; error = ERR_PTR(-ENOENT); if (!task) goto out_no_task; Then, proc_pident_instantiate should return ENOENT too when racing against exit(2) occur. EINAL has two bad reason. - it implies caller is wrong. bad the race isn't caller's mistake. - man 2 open don't explain EINVAL. user often don't handle it. Note: Other proc_pid_make_inode() caller already use ENOENT properly. Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | CRED: Guard the setprocattr security hook against ptraceDavid Howells2009-05-111-0/+6
|/ | | | | | | | | | | Guard the setprocattr security hook against ptrace by taking the target task's cred_guard_mutex around it. The problem is that setprocattr() may otherwise note the lack of a debugger, and then perform an action on that basis whilst letting a debugger attach between the two points. Holding cred_guard_mutex across the test and the action prevents ptrace_attach() from doing that. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* proc: avoid information leaks to non-privileged processesJake Edge2009-05-041-1/+4
| | | | | | | | | | | | | | | | | | | | By using the same test as is used for /proc/pid/maps and /proc/pid/smaps, only allow processes that can ptrace() a given process to see information that might be used to bypass address space layout randomization (ASLR). These include eip, esp, wchan, and start_stack in /proc/pid/stat as well as the non-symbolic output from /proc/pid/wchan. ASLR can be bypassed by sampling eip as shown by the proof-of-concept code at http://code.google.com/p/fuzzyaslr/ As part of a presentation (http://www.cr0.org/paper/to-jt-linux-alsr-leak.pdf) esp and wchan were also noted as possibly usable information leaks as well. The start_stack address also leaks potentially useful information. Cc: Stable Team <stable@kernel.org> Signed-off-by: Jake Edge <jake@lwn.net> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: mounts_poll() make consistent to mdstat_pollKOSAKI Motohiro2009-04-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | In recently sysfs_poll discussion, Neil Brown pointed out /proc/mounts also should be fixed. SUSv3 says "Regular files shall always poll TRUE for reading and writing". see http://www.opengroup.org/onlinepubs/009695399/functions/poll.html Then, mounts_poll()'s default should be "POLLIN | POLLRDNORM". it mean always readable. In addition, event trigger should use "POLLERR | POLLPRI" instead POLLERR. it makes consistent to mdstat_poll() and sysfs_poll(). and, select(2) can handle POLLPRI easily. Reported-by: Neil Brown <neilb@suse.de> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ram Pai <linuxram@us.ibm.com> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Get rid of indirect include of fs_struct.hAl Viro2009-03-311-0/+1
| | | | | | | | Don't pull it in sched.h; very few files actually need it and those can include directly. sched.h itself only needs forward declaration of struct fs_struct; Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fix setuid sometimes wouldn'tHugh Dickins2009-03-281-34/+16
| | | | | | | | | | | | | | | | | | | | | | | | check_unsafe_exec() also notes whether the fs_struct is being shared by more threads than will get killed by the exec, and if so sets LSM_UNSAFE_SHARE to make bprm_set_creds() careful about euid. But /proc/<pid>/cwd and /proc/<pid>/root lookups make transient use of get_fs_struct(), which also raises that sharing count. This might occasionally cause a setuid program not to change euid, in the same way as happened with files->count (check_unsafe_exec also looks at sighand->count, but /proc doesn't raise that one). We'd prefer exec not to unshare fs_struct: so fix this in procfs, replacing get_fs_struct() by get_fs_path(), which does path_get while still holding task_lock, instead of raising fs->count. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: stable@kernel.org ___ fs/proc/base.c | 50 +++++++++++++++-------------------------------- 1 file changed, 16 insertions(+), 34 deletions(-) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* constify dentry_operations: procfsAl Viro2009-03-271-3/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Avoid 64-bit "switch()" statements on 32-bit architecturesLinus Torvalds2009-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Commit ee6f779b9e0851e2f7da292a9f58e0095edf615a ("filp->f_pos not correctly updated in proc_task_readdir") changed the proc code to use filp->f_pos directly, rather than through a temporary variable. In the process, that caused the operations to be done on the full 64 bits, even though the offset is never that big. That's all fine and dandy per se, but for some unfathomable reason gcc generates absolutely horrid code when using 64-bit values in switch() statements. To the point of actually calling out to gcc helper functions like __cmpdi2 rather than just doing the trivial comparisons directly the way gcc does for normal compares. At which point we get link failures, because we really don't want to support that kind of crazy code. Fix this by just casting the f_pos value to "unsigned long", which is plenty big enough for /proc, and avoids the gcc code generation issue. Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Zhang Le <r0bertz@gentoo.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* filp->f_pos not correctly updated in proc_task_readdirZhang Le2009-03-161-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | filp->f_pos only get updated at the end of the function. Thus d_off of those dirents who are in the middle will be 0, and this will cause a problem in glibc's readdir implementation, specifically endless loop. Because when overflow occurs, f_pos will be set to next dirent to read, however it will be 0, unless the next one is the last one. So it will start over again and again. There is a sample program in man 2 gendents. This is the output of the program running on a multithread program's task dir before this patch is applied: $ ./a.out /proc/3807/task --------------- nread=128 --------------- i-node# file type d_reclen d_off d_name 506442 directory 16 1 . 506441 directory 16 0 .. 506443 directory 16 0 3807 506444 directory 16 0 3809 506445 directory 16 0 3812 506446 directory 16 0 3861 506447 directory 16 0 3862 506448 directory 16 8 3863 This is the output after this patch is applied $ ./a.out /proc/3807/task --------------- nread=128 --------------- i-node# file type d_reclen d_off d_name 506442 directory 16 1 . 506441 directory 16 2 .. 506443 directory 16 3 3807 506444 directory 16 4 3809 506445 directory 16 5 3812 506446 directory 16 6 3861 506447 directory 16 7 3862 506448 directory 16 8 3863 Signed-off-by: Zhang Le <r0bertz@gentoo.org> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'proc-linus' of ↵Linus Torvalds2009-01-071-101/+130
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc * 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: proc: remove write-only variable in proc_pident_lookup() proc: fix sparse warning proc: add /proc/*/stack proc: remove '##' usage proc: remove useless WARN_ONs proc: stop using BKL
| * proc: remove write-only variable in proc_pident_lookup()WANG Cong2009-01-051-2/+0
| | | | | | | | | | Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
| * proc: fix sparse warningHannes Eder2009-01-051-2/+2
| | | | | | | | | | | | | | fs/proc/base.c:312:4: warning: do-while statement is not a compound statement Signed-off-by: Hannes Eder <hannes@hanneseder.net> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
| * proc: add /proc/*/stackKen Chen2009-01-051-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /proc/*/stack adds the ability to query a task's stack trace. It is more useful than /proc/*/wchan as it provides full stack trace instead of single depth. Example output: $ cat /proc/self/stack [<c010a271>] save_stack_trace_tsk+0x17/0x35 [<c01827b4>] proc_pid_stack+0x4a/0x76 [<c018312d>] proc_single_show+0x4a/0x5e [<c016bdec>] seq_read+0xf3/0x29f [<c015a004>] vfs_read+0x6d/0x91 [<c015a0c1>] sys_read+0x3b/0x60 [<c0102eda>] syscall_call+0x7/0xb [<ffffffff>] 0xffffffff [add save_stack_trace_tsk() on mips, ACK Ralf --adobriyan] Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
| * proc: remove '##' usageAlexey Dobriyan2009-01-051-93/+90
| | | | | | | | | | | | Inability to jump to /proc/*/foo handlers with ctags is annoying. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
| * proc: remove useless WARN_ONsAlexey Dobriyan2009-01-051-4/+0
| | | | | | | | | | | | NULL "struct inode *" means VFS passed NULL inode to ->open. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* | zero i_uid/i_gid on inode allocationAl Viro2009-01-051-4/+0
|/ | | | | | | | | ... and don't bother in callers. Don't bother with zeroing i_blocks, while we are at it - it's already been zeroed. i_mode is not worth the effort; it has no common default value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2008-12-281-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) sched: fix warning in fs/proc/base.c schedstat: consolidate per-task cpu runtime stats sched: use RCU variant of list traversal in for_each_leaf_rt_rq() sched, cpuacct: export percpu cpuacct cgroup stats sched, cpuacct: refactoring cpuusage_read / cpuusage_write sched: optimize update_curr() sched: fix wakeup preemption clock sched: add missing arch_update_cpu_topology() call sched: let arch_update_cpu_topology indicate if topology changed sched: idle_balance() does not call load_balance_newidle() sched: fix sd_parent_degenerate on non-numa smp machine sched: add uid information to sched_debug for CONFIG_USER_SCHED sched: move double_unlock_balance() higher sched: update comment for move_task_off_dead_cpu sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares sched/rt: removed unneeded defintion sched: add hierarchical accounting to cpu accounting controller sched: include group statistics in /proc/sched_debug sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER sched: clean up SCHED_CPUMASK_ALLOC ...
| * sched: fix warning in fs/proc/base.cIngo Molnar2008-12-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stephen Rothwell reported this new (harmless) build warning on platforms that define u64 to long: fs/proc/base.c: In function 'proc_pid_schedstat': fs/proc/base.c:352: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'u64' asm-generic/int-l64.h platforms strike again: that file should be eliminated. Fix it by casting the parameters to long long. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * schedstat: consolidate per-task cpu runtime statsKen Chen2008-12-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: simplify code When we turn on CONFIG_SCHEDSTATS, per-task cpu runtime is accumulated twice. Once in task->se.sum_exec_runtime and once in sched_info.cpu_time. These two stats are exactly the same. Given that task->se.sum_exec_runtime is always accumulated by the core scheduler, sched_info can reuse that data instead of duplicate the accounting. Signed-off-by: Ken Chen <kenchen@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'next' into for-linusJames Morris2008-12-251-8/+24
|\ \ | |/ |/|
| * CRED: Use RCU to access another task's creds and to release a task's own credsDavid Howells2008-11-141-8/+24
| | | | | | | | | | | | | | | | | | | | | | | | Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
| * CRED: Separate task security context from task_structDavid Howells2008-11-141-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
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