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2009-09-11Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: pci/intr_remapping: Allocate irq_iommu on node irq: Add irq_node() primitive irq: Make sure irq_desc for legacy irq get correct node setting genirq: Add prototype for handle_nested_irq() irq: Remove superfluous NULL pointer check in check_irq_resend() irq: Clean up by removing irqfixup MODULE_PARM_DESC() genirq: Fix comment describing suspend_device_irqs() genirq: Remove obsolete defines and typedefs
2009-09-11Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits) rcu: Move end of special early-boot RCU operation earlier rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees rcu: Remove lockdep annotations from RCU's _notrace() API members rcu: Add #ifdef to suppress __rcu_offline_cpu() warning in !HOTPLUG_CPU builds rcu: Add CPU-offline processing for single-node configurations rcu: Add "notrace" to RCU function headers used by ftrace rcu: Remove CONFIG_PREEMPT_RCU rcu: Merge preemptable-RCU functionality into hierarchical RCU rcu: Simplify rcu_pending()/rcu_check_callbacks() API rcu: Use debugfs_remove_recursive() simplify code. rcu: Merge per-RCU-flavor initialization into pre-existing macro rcu: Fix online/offline indication for rcudata.csv trace file rcu: Consolidate sparse and lockdep declarations in include/linux/rcupdate.h rcu: Renamings to increase RCU clarity rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.h rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMP rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation. rcu: Fix typo in rcu_irq_exit() comment header rcu: Make rcupreempt_trace.c look at offline CPUs ...
2009-09-11Merge branch 'core-printk-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: printk: Fix "printk: Enable the use of more than one CON_BOOT (early console)" printk: Restore previous console_loglevel when re-enabling logging printk: Ensure that "console enabled" messages are printed on the console printk: Enable the use of more than one CON_BOOT (early console)
2009-09-11Merge branch 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (32 commits) locking, m68k/asm-offsets: Rename signal defines locking: Inline spinlock code for all locking variants on s390 locking: Simplify spinlock inlining locking: Allow arch-inlined spinlocks locking: Move spinlock function bodies to header file locking, m68k: Calculate thread_info offset with asm offset locking, m68k/asm-offsets: Rename pt_regs offset defines locking, sparc: Rename __spin_try_lock() and friends locking, powerpc: Rename __spin_try_lock() and friends lockdep: Remove recursion stattistics lockdep: Simplify lock_stat seqfile code lockdep: Simplify lockdep_chains seqfile code lockdep: Simplify lockdep seqfile code lockdep: Fix missing entries in /proc/lock_chains lockdep: Fix missing entry in /proc/lock_stat lockdep: Fix memory usage info of BFS lockdep: Reintroduce generation count to make BFS faster lockdep: Deal with many similar locks lockdep: Introduce lockdep_assert_held() lockdep: Fix style nits ...
2009-09-11Merge branch 'core-futexes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Detect mismatched requeue targets futex: Correct futex_wait_requeue_pi() commentary
2009-09-11Merge branch 'core-debug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debug lockups: Improve lockup detection, fix generic arch fallback debug lockups: Improve lockup detection
2009-09-11Merge branch 'core-cleanups-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: workqueues: Improve schedule_work() documentation
2009-09-11Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'writeback' of git://git.kernel.dk/linux-2.6-block: writeback: check for registered bdi in flusher add and inode dirty writeback: add name to backing_dev_info writeback: add some debug inode list counters to bdi stats writeback: get rid of pdflush completely writeback: switch to per-bdi threads for flushing data writeback: move dirty inodes from super_block to backing_dev_info writeback: get rid of generic_sync_sb_inodes() export
2009-09-11writeback: add name to backing_dev_infoJens Axboe
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11Merge branch 'next' into for-linusJames Morris
2009-09-07Security/SELinux: includecheck fix kernel/sysctl.cJaswinder Singh Rajput
fix the following 'make includecheck' warning: kernel/sysctl.c: linux/security.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-05Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter/powerpc: Fix cache event codes for POWER7 perf_counter: Fix /0 bug in swcounters perf_counters: Increase paranoia level
2009-09-04Merge branch 'linus' into core/rcuIngo Molnar
Merge reason: Avoid fuzz in init/main.c and update from rc6 to rc8. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-02KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]David Howells
Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include <stdio.h> #include <stdlib.h> #include <keyutils.h> #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02CRED: Add some configurable debugging [try #6]David Howells
Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking for credential management. The additional code keeps track of the number of pointers from task_structs to any given cred struct, and checks to see that this number never exceeds the usage count of the cred struct (which includes all references, not just those from task_structs). Furthermore, if SELinux is enabled, the code also checks that the security pointer in the cred struct is never seen to be invalid. This attempts to catch the bug whereby inode_has_perm() faults in an nfsd kernel thread on seeing cred->security be a NULL pointer (it appears that the credential struct has been previously released): http://www.kerneloops.org/oops.php?number=252883 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-08-31locking: Allow arch-inlined spinlocksHeiko Carstens
This allows an architecture to specify per lock variant if the locking code should be kept out-of-line or inlined. If an architecure wants out-of-line locking code no change is needed. To force inlining of e.g. spin_lock() the line: #define __always_inline__spin_lock needs to be added to arch/<...>/include/asm/spinlock.h If CONFIG_DEBUG_SPINLOCK or CONFIG_GENERIC_LOCKBREAK are defined the per architecture defines are (partly) ignored and still out-of-line spinlock code will be generated. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Horst Hartmann <horsth@linux.vnet.ibm.com> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <20090831124418.375299024@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-31locking: Move spinlock function bodies to header fileHeiko Carstens
Move spinlock function bodies to header file by creating a static inline version of each variant. Use the inline version on the out-of-line code. This shouldn't make any difference besides that the spinlock code can now be used to generate inlined spinlock code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Horst Hartmann <horsth@linux.vnet.ibm.com> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <20090831124417.859022429@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-31Merge commit 'v2.6.31-rc8' into core/lockingIngo Molnar
Merge reason: we were on -rc4, move to -rc8 before applying a new batch of locking infrastructure changes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29irq: Make sure irq_desc for legacy irq get correct node settingYinghai Lu
when there is no ram on node 0. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> LKML-Reference: <4A95C32D.5040605@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29rcu: Changes from reviews: avoid casts, fix/add warnings, improve commentsPaul E. McKenney
Changes suggested by review comments from Josh Triplett and Mathieu Desnoyers. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827220012.GA30525@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29rcu: Create rcutree plugins to handle hotplug CPU for multi-level treesPaul E. McKenney
When offlining CPUs from a multi-level tree, there is the possibility of offlining the last CPU from a given node when there are preempted RCU read-side critical sections that started life on one of the CPUs on that node. In this case, the corresponding tasks will be enqueued via the task_struct's rcu_node_entry list_head onto one of the rcu_node's blocked_tasks[] lists. These tasks need to be moved somewhere else so that they will prevent the current grace period from ending. That somewhere is the root rcu_node. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827215816.GA30472@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29lockdep: Remove recursion stattisticsMing Lei
Since lockdep has introduced BFS to avoid recursion, statistics for recursion does not make any sense now. So remove them. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Cc: a.p.zijlstra@chello.nl LKML-Reference: <1251542879-5211-1-git-send-email-tom.leiming@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29perf_counter: Fix /0 bug in swcountersPeter Zijlstra
We have a race in the swcounter stuff where we can start counting a counter that has never been enabled, this leads to a /0 situation. The below avoids the /0 but doesn't close the race, this would need a new counter state. The race is due to perf_swcounter_is_counting() which cannot discern between disabled due to scheduled out, and disabled for any other reason. Such a crash has been seen by Ingo: [ 967.092372] divide error: 0000 [#1] SMP [ 967.096499] last sysfs file: /sys/devices/system/cpu/cpu15/cache/index2/shared_cpu_map [ 967.104846] CPU 5 [ 967.106965] Modules linked in: [ 967.110169] Pid: 3351, comm: hackbench Not tainted 2.6.31-rc8-tip-01158-gd940a54-dirty #1568 X8DTN [ 967.119456] RIP: 0010:[<ffffffff810c0aba>] [<ffffffff810c0aba>] perf_swcounter_ctx_event+0x127/0x1af [ 967.129137] RSP: 0018:ffff8801a95abd70 EFLAGS: 00010046 [ 967.134699] RAX: 0000000000000002 RBX: ffff8801bd645c00 RCX: 0000000000000002 [ 967.142162] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801bd645d40 [ 967.149584] RBP: ffff8801a95abdb0 R08: 0000000000000001 R09: ffff8801a95abe00 [ 967.157042] R10: 0000000000000037 R11: ffff8801aa1245f8 R12: ffff8801a95abe00 [ 967.164481] R13: ffff8801a95abe00 R14: ffff8801aa1c0e78 R15: 0000000000000001 [ 967.171953] FS: 0000000000000000(0000) GS:ffffc90000a00000(0063) knlGS:00000000f7f486c0 [ 967.180406] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [ 967.186374] CR2: 000000004822c0ac CR3: 00000001b19a2000 CR4: 00000000000006e0 [ 967.193770] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 967.201224] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 967.208692] Process hackbench (pid: 3351, threadinfo ffff8801a95aa000, task ffff8801a96b0000) [ 967.217607] Stack: [ 967.219711] 0000000000000000 0000000000000037 0000000200000001 ffffc90000a1107c [ 967.227296] <0> ffff8801a95abe00 0000000000000001 0000000000000001 0000000000000037 [ 967.235333] <0> ffff8801a95abdf0 ffffffff810c0c20 0000000200a14f30 ffff8801a95abe40 [ 967.243532] Call Trace: [ 967.246103] [<ffffffff810c0c20>] do_perf_swcounter_event+0xde/0xec [ 967.252635] [<ffffffff810c0ca7>] perf_tpcounter_event+0x79/0x7b [ 967.258957] [<ffffffff81037f73>] ftrace_profile_sched_switch+0xc0/0xcb [ 967.265791] [<ffffffff8155f22d>] schedule+0x429/0x4c4 [ 967.271156] [<ffffffff8100c01e>] int_careful+0xd/0x14 Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1251472247.17617.74.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-28modules: Fix build error in the !CONFIG_KALLSYMS caseIngo Molnar
> James Bottomley (1): > module: workaround duplicate section names -tip testing found that this patch breaks the build on x86 if CONFIG_KALLSYMS is disabled: kernel/module.c: In function ‘load_module’: kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’ distcc[8269] ERROR: compile kernel/module.c on ph/32 failed make[1]: *** [kernel/module.o] Error 1 make: *** [kernel] Error 2 make: *** Waiting for unfinished jobs.... Commit 1b364bf misses the fact that section attributes are only built and dealt with if kallsyms is enabled. The patch below fixes this. ( note, technically speaking this should depend on CONFIG_SYSFS as well but this patch is correct too and keeps the #ifdef less intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. ) Signed-off-by: Ingo Molnar <mingo@elte.hu> [ Replaced patch with a slightly cleaner variation by James Bottomley ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-28perf_counters: Increase paranoia levelIngo Molnar
Per-cpu counters are an ASLR information leak as they show the execution other tasks do. Increase the paranoia level to 1, which disallows per-cpu counters. (they still allow counting/profiling of own tasks - and admin can profile everything.) Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-27module: workaround duplicate section namesJames Bottomley
The root cause is a duplicate section name (.text); is this legal? [ Amerigo Wang: "AFAIK, yes." ] However, there's a problem with commit 6d76013381ed28979cd122eb4b249a88b5e384fa in that if you fail to allocate a mod->sect_attrs (in this case it's null because of the duplication), it still gets used without checking in add_notes_attrs() This should fix it [ This patch leaves other problems, particularly the sections directory, but recent parisc toolchains seem to produce these modules and this prevents a crash and is a minimal change -- RR ] Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Helge Deller <deller@gmx.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-27module: fix BUG_ON() for powerpc (and other function descriptor archs)Rusty Russell
The rarely-used symbol_put_addr() needs to use dereference_function_descriptor on powerpc. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-26clone(): fix race between copy_process() and de_thread()Oleg Nesterov
Spotted by Hiroshi Shimamoto who also provided the test-case below. copy_process() uses signal->count as a reference counter, but it is not. This test case #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #include <stdio.h> #include <errno.h> #include <pthread.h> void *null_thread(void *p) { for (;;) sleep(1); return NULL; } void *exec_thread(void *p) { execl("/bin/true", "/bin/true", NULL); return null_thread(p); } int main(int argc, char **argv) { for (;;) { pid_t pid; int ret, status; pid = fork(); if (pid < 0) break; if (!pid) { pthread_t tid; pthread_create(&tid, NULL, exec_thread, NULL); for (;;) pthread_create(&tid, NULL, null_thread, NULL); } do { ret = waitpid(pid, &status, 0); } while (ret == -1 && errno == EINTR); } return 0; } quickly creates an unkillable task. If copy_process(CLONE_THREAD) races with de_thread() copy_signal()->atomic(signal->count) breaks the signal->notify_count logic, and the execing thread can hang forever in kernel space. Change copy_process() to increment count/live only when we know for sure we can't fail. In this case the forked thread will take care of its reference to signal correctly. If copy_process() fails, check CLONE_THREAD flag. If it it set - do nothing, the counters were not changed and current belongs to the same thread group. If it is not set, ->signal must be released in any case (and ->count must be == 1), the forked child is the only thread in the thread group. We need more cleanups here, in particular signal->count should not be used by de_thread/__exit_signal at all. This patch only fixes the bug. Reported-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Tested-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-25Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter: Fix typo in read() output generation perf tools: Check perf.data owner
2009-08-25Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clockevent: Prevent dead lock on clockevents_lock timers: Drop write permission on /proc/timer_list
2009-08-25Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix too large stack usage in do_one_initcall() tracing: handle broken names in ftrace filter ftrace: Unify effect of writing to trace_options and option/*
2009-08-25rcu: Add #ifdef to suppress __rcu_offline_cpu() warning in !HOTPLUG_CPU buildsPaul E. McKenney
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Paul Mundt <lethal@linux-sh.org> LKML-Reference: <20090825154025.GD6616@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-25Merge commit 'v2.6.31-rc7' into irq/coreIngo Molnar
Merge reason: move from an -rc2 base to -rc7. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-24rcu: Add CPU-offline processing for single-node configurationsPaul E. McKenney
Add preemptable-RCU plugin to handle the CPU-offline processing. An additional plugin is forthcoming to handle multinode RCU trees, but this current plugin works for configurations up to 32 CPUs (64 CPUs for 64-bit kernels). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12511321213336-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-24bsdacct: switch credentials for writing to the accounting fileMichal Schmidt
When process accounting is enabled, every exiting process writes a log to the account file. In addition, every once in a while one of the exiting processes checks whether there's enough free space for the log. SELinux policy may or may not allow the exiting process to stat the fs. So unsuspecting processes start generating AVC denials just because someone enabled process accounting. For these filesystem operations, the exiting process's credentials should be temporarily switched to that of the process which enabled accounting, because it's really that process which wanted to have the accounting information logged. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Morris <jmorris@namei.org>
2009-08-23rcu: Remove CONFIG_PREEMPT_RCUPaul E. McKenney
Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no further need for CONFIG_PREEMPT_RCU. Remove it, along with whatever subtle bugs it may (or may not) contain. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <125097461396-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Merge preemptable-RCU functionality into hierarchical RCUPaul E. McKenney
Create a kernel/rcutree_plugin.h file that contains definitions for preemptable RCU (or, under the #else branch of the #ifdef, empty definitions for the classic non-preemptable semantics). These definitions fit into plugins defined in kernel/rcutree.c for this purpose. This variant of preemptable RCU uses a new algorithm whose read-side expense is roughly that of classic hierarchical RCU under CONFIG_PREEMPT. This new algorithm's update-side expense is similar to that of classic hierarchical RCU, and, in absence of read-side preemption or blocking, is exactly that of classic hierarchical RCU. Perhaps more important, this new algorithm has a much simpler implementation, saving well over 1,000 lines of code compared to mainline's implementation of preemptable RCU, which will hopefully be retired in favor of this new algorithm. The simplifications are obtained by maintaining per-task nesting state for running tasks, and using a simple lock-protected algorithm to handle accounting when tasks block within RCU read-side critical sections, making use of lessons learned while creating numerous user-level RCU implementations over the past 18 months. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746134003-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Simplify rcu_pending()/rcu_check_callbacks() APIPaul E. McKenney
All calls from outside RCU are of the form: if (rcu_pending(cpu)) rcu_check_callbacks(cpu, user); This is silly, instead we put a call to rcu_pending() in rcu_check_callbacks(), and then make the outside calls be to rcu_check_callbacks(). This cuts down on the code a bit and also gives the compiler a better chance of optimizing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <125097461311-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Use debugfs_remove_recursive() simplify code.Paul E. McKenney
Suggested by Josh Triplett. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <12509746132173-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Merge per-RCU-flavor initialization into pre-existing macroPaul E. McKenney
Rename the RCU_DATA_PTR_INIT() macro to RCU_INIT_FLAVOR() and make it do the rcu_init_one() and rcu_boot_init_percpu_data() calls. Merge the loop that was in the original macro with the loops that were in __rcu_init(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746133916-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Fix online/offline indication for rcudata.csv trace filePaul E. McKenney
The heading said "Online?", but the column had "Y" for offline CPUs and "N" for online CPUs. Swap the "Y" and "N" to match the heading. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746132841-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Renamings to increase RCU clarityPaul E. McKenney
Make RCU-sched, RCU-bh, and RCU-preempt be underlying implementations, with "RCU" defined in terms of one of the three. Update the outdated rcu_qsctr_inc() names, as these functions no longer increment anything. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746132696-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.hPaul E. McKenney
Some information hiding that makes it easier to merge preemptability into rcutree without descending into #include hell. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <1250974613373-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21perf_counter: Fix typo in read() output generationPeter Zijlstra
When you iterate a list, using the iterator is useful. Before: ID: 5 ID: 5 ID: 5 ID: 5 EVNT: 0x40088b scale: nan ID: 5 CNT: 1006252 ID: 6 CNT: 1011090 ID: 7 CNT: 1011196 ID: 8 CNT: 1011095 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 2003065 ID: 6 CNT: 2011671 ID: 7 CNT: 2012620 ID: 8 CNT: 2013479 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 3002390 ID: 6 CNT: 3015996 ID: 7 CNT: 3018019 ID: 8 CNT: 3020006 EVNT: 0x40088b scale: 1.000000 ID: 5 CNT: 4002406 ID: 6 CNT: 4021120 ID: 7 CNT: 4024241 ID: 8 CNT: 4027059 After: ID: 1 ID: 2 ID: 3 ID: 4 EVNT: 0x400889 scale: nan ID: 1 CNT: 1005270 ID: 2 CNT: 1009833 ID: 3 CNT: 1010065 ID: 4 CNT: 1010088 EVNT: 0x400898 scale: nan ID: 1 CNT: 2001531 ID: 2 CNT: 2022309 ID: 3 CNT: 2022470 ID: 4 CNT: 2022627 EVNT: 0x400888 scale: 0.489467 ID: 1 CNT: 3001261 ID: 2 CNT: 3027088 ID: 3 CNT: 3027941 ID: 4 CNT: 3028762 Reported-by: stephane eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: perfmon2-devel <perfmon2-devel@lists.sourceforge.net> LKML-Reference: <1250867976.7538.73.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-20Merge branch 'master' into nextJames Morris
Conflicts: security/Kconfig Manual fix. Signed-off-by: James Morris <jmorris@namei.org>
2009-08-19Merge branch 'perfcounters-fixes-for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tools: Make 'make html' work perf annotate: Fix segmentation fault perf_counter: Fix the PARISC build perf_counter: Check task on counter read IPI perf: Rename perf-examples.txt to examples.txt perf record: Fix typo in pid_synthesize_comm_event
2009-08-19clockevent: Prevent dead lock on clockevents_lockSuresh Siddha
Currently clockevents_notify() is called with interrupts enabled at some places and interrupts disabled at some other places. This results in a deadlock in this scenario. cpu A holds clockevents_lock in clockevents_notify() with irqs enabled cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled cpu C doing set_mtrr() which will try to rendezvous of all the cpus. This will result in C and A come to the rendezvous point and waiting for B. B is stuck forever waiting for the spinlock and thus not reaching the rendezvous point. Fix the clockevents code so that clockevents_lock is taken with interrupts disabled and thus avoid the above deadlock. Also call lapic_timer_propagate_broadcast() on the destination cpu so that we avoid calling smp_call_function() in the clockevents notifier chain. This issue left us wondering if we need to change the MTRR rendezvous logic to use stop machine logic (instead of smp_call_function) or add a check in spinlock debug code to see if there are other spinlocks which gets taken under both interrupts enabled/disabled conditions. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com> Cc: "Brown Len" <len.brown@intel.com> LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-19rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation.Paul E. McKenney
Ingo Molnar reported this lockup: [ 200.380003] Hangcheck: hangcheck value past margin! [ 248.192003] INFO: task S99local:2974 blocked for more than 120 seconds. [ 248.194532] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 248.202330] S99local D 0000000c 6256 2974 2687 0x00000000 [ 248.208929] 9c7ebe90 00000086 6b67ef8b 0000000c 9f25a610 81a69869 00000001 820b6990 [ 248.216123] 820b6990 820b6990 9c6e4c20 9c6e4eb4 82c78990 00000000 6b993559 0000000c [ 248.220616] 9c7ebe90 8105f22a 9c6e4eb4 9c6e4c20 00000001 9c7ebe98 9c7ebeb4 81a65cb3 [ 248.229990] Call Trace: [ 248.234049] [<81a69869>] ? _spin_unlock_irqrestore+0x22/0x37 [ 248.239769] [<8105f22a>] ? prepare_to_wait+0x48/0x4e [ 248.244796] [<81a65cb3>] rcu_barrier_cpu_hotplug+0xaa/0xc9 [ 248.250343] [<8105f029>] ? autoremove_wake_function+0x0/0x38 [ 248.256063] [<81062cf2>] notifier_call_chain+0x49/0x71 [ 248.261263] [<81062da0>] raw_notifier_call_chain+0x11/0x13 [ 248.266809] [<81a0b475>] _cpu_down+0x272/0x288 [ 248.271316] [<81a0b4d5>] cpu_down+0x4a/0xa2 [ 248.275563] [<81a0c48a>] store_online+0x2a/0x5e [ 248.280156] [<81a0c460>] ? store_online+0x0/0x5e [ 248.284836] [<814ddc35>] sysdev_store+0x20/0x28 [ 248.289429] [<8112e403>] sysfs_write_file+0xb8/0xe3 [ 248.294369] [<8112e34b>] ? sysfs_write_file+0x0/0xe3 [ 248.299396] [<810e4c8f>] vfs_write+0x91/0x120 [ 248.303817] [<810e4dc1>] sys_write+0x40/0x65 [ 248.308150] [<81002d73>] sysenter_do_call+0x12/0x28 This change moves an RCU grace period delay off of the critical path for CPU-hotunplug operations. Since RCU callback migration is only performed on CPU-hotunplug operations, and since the rcu_barrier() race is provoked only by consecutive CPU-hotunplug operations, it is not necessary to delay the end of a given CPU-hotunplug operation. We can instead choose to delay the beginning of the next CPU-hotunplug operation. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josht@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: hugh.dickins@tiscali.co.uk Cc: benh@kernel.crashing.org LKML-Reference: <20090819060614.GA14383@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18tracing: handle broken names in ftrace filterJiri Olsa
If one filter item (for set_ftrace_filter and set_ftrace_notrace) is being setup by more than 1 consecutive writes (FTRACE_ITER_CONT flag), it won't be handled corretly. I used following program to test/verify: [snip] #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> int main(int argc, char **argv) { int fd, i; char *file = argv[1]; if (-1 == (fd = open(file, O_WRONLY))) { perror("open failed"); return -1; } for(i = 0; i < (argc - 2); i++) { int len = strlen(argv[2+i]); int cnt, off = 0; while(len) { cnt = write(fd, argv[2+i] + off, len); len -= cnt; off += cnt; } } close(fd); return 0; } [snip] before change: sh-4.0# echo > ./set_ftrace_filter sh-4.0# /test ./set_ftrace_filter "sys" "_open " sh-4.0# cat ./set_ftrace_filter #### all functions enabled #### sh-4.0# after change: sh-4.0# echo > ./set_ftrace_notrace sh-4.0# test ./set_ftrace_notrace "sys" "_open " sh-4.0# cat ./set_ftrace_notrace sys_open sh-4.0# Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20090811152904.GA26065@jolsa.lab.eng.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-08-18mm: revert "oom: move oom_adj value"KOSAKI Motohiro
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>