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* cgroup: fix the retry path of cgroup_mount()Li Zefan2014-04-171-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | If we hit the retry path, we'll call parse_cgroupfs_options() again, but the string we pass to it has been modified by the previous call to this function. This bug can be observed by: # mount -t cgroup -o name=foo,cpuset xxx /mnt && umount /mnt && \ mount -t cgroup -o name=foo,cpuset xxx /mnt mount: wrong fs type, bad option, bad superblock on xxx, missing codepage or helper program, or other error ... The second mount passed "name=foo,cpuset" to the parser, and then it hit the retry path and call the parser again, but this time the string passed to the parser is "name=foo". To fix this, we avoid calling parse_cgroupfs_options() again in this case. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* futex: update documentation for ordering guaranteesDavidlohr Bueso2014-04-121-9/+23
| | | | | | | | | | | | | | Commits 11d4616bd07f ("futex: revert back to the explicit waiter counting code") and 69cd9eba3886 ("futex: avoid race between requeue and wake") changed some of the finer details of how we think about futexes. One was a late fix and the other a consequence of overlooking the whole requeuing logic. The first change caused our documentation to be incorrect, and the second made us aware that we need to explicitly add more details to it. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-04-122-9/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
| * missing bits of "splice: fix racy pipe->buffers uses"Al Viro2014-04-122-3/+3
| | | | | | | | | | | | | | that commit has fixed only the parts of that mess in fs/splice.c itself; there had been more in several other ->splice_read() instances... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * pipe: kill ->map() and ->unmap()Al Viro2014-04-012-6/+0
| | | | | | | | | | | | all pipe_buffer_operations have the same instances of those... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'trace-3.15-v2' of ↵Linus Torvalds2014-04-128-335/+289
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull more tracing updates from Steven Rostedt: "This includes the final patch to clean up and fix the issue with the design of tracepoints and how a user could register a tracepoint and have that tracepoint not be activated but no error was shown. The design was for an out of tree module but broke in tree users. The clean up was to remove the saving of the hash table of tracepoint names such that they can be enabled before they exist (enabling a module tracepoint before that module is loaded). This added more complexity than needed. The clean up was to remove that code and just enable tracepoints that exist or fail if they do not. This removed a lot of code as well as the complexity that it brought. As a side effect, instead of registering a tracepoint by its name, the tracepoint needs to be registered with the tracepoint descriptor. This removes having to duplicate the tracepoint names that are enabled. The second patch was added that simplified the way modules were searched for. This cleanup required changes that were in the 3.15 queue as well as some changes that were added late in the 3.14-rc cycle. This final change waited till the two were merged in upstream and then the change was added and full tests were run. Unfortunately, the test found some errors, but after it was already submitted to the for-next branch and not to be rebased. Sparse errors were detected by Fengguang Wu's bot tests, and my internal tests discovered that the anonymous union initialization triggered a bug in older gcc compilers. Luckily, there was a bugzilla for the gcc bug which gave a work around to the problem. The third and fourth patch handled the sparse error and the gcc bug respectively. A final patch was tagged along to fix a missing documentation for the README file" * tag 'trace-3.15-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add missing function triggers dump and cpudump to README tracing: Fix anonymous unions in struct ftrace_event_call tracepoint: Fix sparse warnings in tracepoint.c tracepoint: Simplify tracepoint module search tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints
| * | tracing: Add missing function triggers dump and cpudump to READMESteven Rostedt (Red Hat)2014-04-101-0/+2
| | | | | | | | | | | | | | | | | | | | | The debugfs tracing README file lists all the function triggers except for dump and cpudump. These should be added too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Fix anonymous unions in struct ftrace_event_callMathieu Desnoyers2014-04-091-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc <= 4.5.x has significant limitations with respect to initialization of anonymous unions within structures. They need to be surrounded by brackets, _and_ they need to be initialized in the same order in which they appear in the structure declaration. Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676 Link: http://lkml.kernel.org/r/1397077568-3156-1-git-send-email-mathieu.desnoyers@efficios.com Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracepoint: Fix sparse warnings in tracepoint.cMathieu Desnoyers2014-04-091-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following sparse warnings: CHECK kernel/tracepoint.c kernel/tracepoint.c:184:18: warning: incorrect type in assignment (different address spaces) kernel/tracepoint.c:184:18: expected struct tracepoint_func *tp_funcs kernel/tracepoint.c:184:18: got struct tracepoint_func [noderef] <asn:4>*funcs kernel/tracepoint.c:216:18: warning: incorrect type in assignment (different address spaces) kernel/tracepoint.c:216:18: expected struct tracepoint_func *tp_funcs kernel/tracepoint.c:216:18: got struct tracepoint_func [noderef] <asn:4>*funcs kernel/tracepoint.c:392:24: error: return expression in void function CC kernel/tracepoint.o kernel/tracepoint.c: In function tracepoint_module_going: kernel/tracepoint.c:491:6: warning: symbol 'syscall_regfunc' was not declared. Should it be static? kernel/tracepoint.c:508:6: warning: symbol 'syscall_unregfunc' was not declared. Should it be static? Link: http://lkml.kernel.org/r/1397049883-28692-1-git-send-email-mathieu.desnoyers@efficios.com Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracepoint: Simplify tracepoint module searchSteven Rostedt (Red Hat)2014-04-081-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of copying the num_tracepoints and tracepoints_ptrs from the module structure to the tp_mod structure, which only uses it to find the module associated to tracepoints of modules that are coming and going, simply copy the pointer to the module struct to the tracepoint tp_module structure. Also removed un-needed brackets around an if statement. Link: http://lkml.kernel.org/r/20140408201705.4dad2c4a@gandalf.local.home Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracepoint: Use struct pointer instead of name hash for reg/unreg tracepointsMathieu Desnoyers2014-04-086-331/+280
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar <mingo@kernel.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frank Ch. Eigler <fche@redhat.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge git://git.infradead.org/users/eparis/auditLinus Torvalds2014-04-125-54/+149
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull audit updates from Eric Paris. * git://git.infradead.org/users/eparis/audit: (28 commits) AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range audit: do not cast audit_rule_data pointers pointlesly AUDIT: Allow login in non-init namespaces audit: define audit_is_compat in kernel internal header kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c sched: declare pid_alive as inline audit: use uapi/linux/audit.h for AUDIT_ARCH declarations syscall_get_arch: remove useless function arguments audit: remove stray newline from audit_log_execve_info() audit_panic() call audit: remove stray newlines from audit_log_lost messages audit: include subject in login records audit: remove superfluous new- prefix in AUDIT_LOGIN messages audit: allow user processes to log from another PID namespace audit: anchor all pid references in the initial pid namespace audit: convert PPIDs to the inital PID namespace. pid: get pid_t ppid of task in init_pid_ns audit: rename the misleading audit_get_context() to audit_take_context() audit: Add generic compat syscall support audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL ...
| * | | audit: do not cast audit_rule_data pointers pointleslyEric Paris2014-04-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For some sort of legacy support audit_rule is a subset of (and first entry in) audit_rule_data. We don't actually need or use audit_rule. We just do a cast from one to the other for no gain what so ever. Stop the crazy casting. Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | AUDIT: Allow login in non-init namespacesEric Paris2014-03-311-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It its possible to configure your PAM stack to refuse login if audit messages (about the login) were unable to be sent. This is common in many distros and thus normal configuration of many containers. The PAM modules determine if audit is enabled/disabled in the kernel based on the return value from sending an audit message on the netlink socket. If userspace gets back ECONNREFUSED it believes audit is disabled in the kernel. If it gets any other error else it refuses to let the login proceed. Just about ever since the introduction of namespaces the kernel audit subsystem has returned EPERM if the task sending a message was not in the init user or pid namespace. So many forms of containers have never worked if audit was enabled in the kernel. BUT if the container was not in net_init then the kernel network code would send ECONNREFUSED (instead of the audit code sending EPERM). Thus by pure accident/dumb luck/bug if an admin configured the PAM stack to reject all logins that didn't talk to audit, but then ran the login untility in the non-init_net namespace, it would work!! Clearly this was a bug, but it is a bug some people expected. With the introduction of network namespace support in 3.14-rc1 the two bugs stopped cancelling each other out. Now, containers in the non-init_net namespace refused to let users log in (just like PAM was configfured!) Obviously some people were not happy that what used to let users log in, now didn't! This fix is kinda hacky. We return ECONNREFUSED for all non-init relevant namespaces. That means that not only will the old broken non-init_net setups continue to work, now the broken non-init_pid or non-init_user setups will 'work'. They don't really work, since audit isn't logging things. But it's what most users want. In 3.15 we should have patches to support not only the non-init_net (3.14) namespace but also the non-init_pid and non-init_user namespace. So all will be right in the world. This just opens the doors wide open on 3.14 and hopefully makes users happy, if not the audit system... Reported-by: Andre Tomt <andre@tomt.net> Reported-by: Adam Richter <adam_richter2004@yahoo.com> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Conflicts: kernel/audit.c
| * | | kernel: Use RCU_INIT_POINTER(x, NULL) in audit.cMonam Agarwal2014-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structure. And in the case of the NULL pointer, there is no structure to initialize. So, rcu_assign_pointer(p, NULL) can be safely converted to RCU_INIT_POINTER(p, NULL) Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | syscall_get_arch: remove useless function argumentsEric Paris2014-03-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every caller of syscall_get_arch() uses current for the task and no implementors of the function need args. So just get rid of both of those things. Admittedly, since these are inline functions we aren't wasting stack space, but it just makes the prototypes better. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux390@de.ibm.com Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org
| * | | audit: remove stray newline from audit_log_execve_info() audit_panic() callJoe Perches2014-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | There's an unnecessary use of a \n in audit_panic. Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: remove stray newlines from audit_log_lost messagesJosh Boyer2014-03-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calling audit_log_lost with a \n in the format string leads to extra newlines in dmesg. That function will eventually call audit_panic which uses pr_err with an explicit \n included. Just make these calls match the others that lack \n. Reported-by: Jonathan Kamens <jik@kamens.brookline.ma.us> Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: include subject in login recordsEric Paris2014-03-201-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The login uid change record does not include the selinux context of the task logging in. Add that information. (Updated from 2011-01: RHBZ:670328 -- RGB) Reported-by: Steve Grubb <sgrubb@redhat.com> Acked-by: James Morris <jmorris@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Aristeu Rozanski <arozansk@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: remove superfluous new- prefix in AUDIT_LOGIN messagesRichard Guy Briggs2014-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The new- prefix on ses and auid are un-necessary and break ausearch. Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: allow user processes to log from another PID namespaceRichard Guy Briggs2014-03-201-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Still only permit the audit logging daemon and control to operate from the initial PID namespace, but allow processes to log from another PID namespace. Cc: "Eric W. Biederman" <ebiederm@xmission.com> (informed by ebiederman's c776b5d2) Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: anchor all pid references in the initial pid namespaceRichard Guy Briggs2014-03-203-10/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Store and log all PIDs with reference to the initial PID namespace and use the access functions task_pid_nr() and task_tgid_nr() for task->pid and task->tgid. Cc: "Eric W. Biederman" <ebiederm@xmission.com> (informed by ebiederman's c776b5d2) Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: convert PPIDs to the inital PID namespace.Richard Guy Briggs2014-03-202-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_getppid() returns the parent pid of the current process in its own pid namespace. Since audit filters are based in the init pid namespace, a process could avoid a filter or trigger an unintended one by being in an alternate pid namespace or log meaningless information. Switch to task_ppid_nr() for PPIDs to anchor all audit filters in the init_pid_ns. (informed by ebiederman's 6c621b7e) Cc: stable@vger.kernel.org Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: rename the misleading audit_get_context() to audit_take_context()Richard Guy Briggs2014-03-201-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "get" usually implies incrementing a refcount into a structure to indicate a reference being held by another part of code. Change this function name to indicate it is in fact being taken from it, returning the value while clearing it in the supplying structure. Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | audit: Send replies in the proper network namespace.Eric W. Biederman2014-03-202-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In perverse cases of file descriptor passing the current network namespace of a process and the network namespace of a socket used by that socket may differ. Therefore use the network namespace of the appropiate socket to ensure replies always go to the appropiate socket. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | audit: Use struct net not pid_t to remember the network namespce to reply inEric W. Biederman2014-03-203-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reading through 3.14-rc1 I found a pretty siginficant mishandling of network namespaces in the recent audit changes. In struct audit_netlink_list and audit_reply add a reference to the network namespace of the caller and remove the userspace pid of the caller. This cleanly remembers the callers network namespace, and removes a huge class of races and nasty failure modes that can occur when attempting to relook up the callers network namespace from a pid_t (including the caller's network namespace changing, pid wraparound, and the pid simply not being present). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | audit: Audit proc/<pid>/cmdline aka proctitleWilliam Roberts2014-03-202-0/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During an audit event, cache and print the value of the process's proctitle value (proc/<pid>/cmdline). This is useful in situations where processes are started via fork'd virtual machines where the comm field is incorrect. Often times, setting the comm field still is insufficient as the comm width is not very wide and most virtual machine "package names" do not fit. Also, during execution, many threads have their comm field set as well. By tying it back to the global cmdline value for the process, audit records will be more complete in systems with these properties. An example of where this is useful and applicable is in the realm of Android. With Android, their is no fork/exec for VM instances. The bare, preloaded Dalvik VM listens for a fork and specialize request. When this request comes in, the VM forks, and the loads the specific application (specializing). This was done to take advantage of COW and to not require a load of basic packages by the VM on very app spawn. When this spawn occurs, the package name is set via setproctitle() and shows up in procfs. Many of these package names are longer then 16 bytes, the historical width of task->comm. Having the cmdline in the audit records will couple the application back to the record directly. Also, on my Debian development box, some audit records were more useful then what was printed under comm. The cached proctitle is tied to the life-cycle of the audit_context structure and is built on demand. Proctitle is controllable by userspace, and thus should not be trusted. It is meant as an aid to assist in debugging. The proctitle event is emitted during syscall audits, and can be filtered with auditctl. Example: type=AVC msg=audit(1391217013.924:386): avc: denied { getattr } for pid=1971 comm="mkdir" name="/" dev="selinuxfs" ino=1 scontext=system_u:system_r:consolekit_t:s0-s0:c0.c255 tcontext=system_u:object_r:security_t:s0 tclass=filesystem type=SYSCALL msg=audit(1391217013.924:386): arch=c000003e syscall=137 success=yes exit=0 a0=7f019dfc8bd7 a1=7fffa6aed2c0 a2=fffffffffff4bd25 a3=7fffa6aed050 items=0 ppid=1967 pid=1971 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="mkdir" exe="/bin/mkdir" subj=system_u:system_r:consolekit_t:s0-s0:c0.c255 key=(null) type=UNKNOWN[1327] msg=audit(1391217013.924:386): proctitle=6D6B646972002D70002F7661722F72756E2F636F6E736F6C65 Acked-by: Steve Grubb <sgrubb@redhat.com> (wrt record formating) Signed-off-by: William Roberts <wroberts@tresys.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | audit: Use more current logging style againRichard Guy Briggs2014-03-072-21/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add pr_fmt to prefix "audit: " to output Convert printk(KERN_<LEVEL> to pr_<level> Coalesce formats Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| * | | Merge tag 'v3.13' into for-3.15Eric Paris2014-03-07147-2588/+6384
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 3.13 Conflicts: include/net/xfrm.h Simple merge where v3.13 removed 'extern' from definitions and the audit tree did s/u32/unsigned int/ to the same definitions.
* | | | | futex: avoid race between requeue and wakeLinus Torvalds2014-04-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jan Stancek reported: "pthread_cond_broadcast/4-1.c testcase from openposix testsuite (LTP) occasionally fails, because some threads fail to wake up. Testcase creates 5 threads, which are all waiting on same condition. Main thread then calls pthread_cond_broadcast() without holding mutex, which calls: futex(uaddr1, FUTEX_CMP_REQUEUE_PRIVATE, 1, 2147483647, uaddr2, ..) This immediately wakes up single thread A, which unlocks mutex and tries to wake up another thread: futex(uaddr2, FUTEX_WAKE_PRIVATE, 1) If thread A manages to call futex_wake() before any waiters are requeued for uaddr2, no other thread is woken up" The ordering constraints for the hash bucket waiter counting are that the waiter counts have to be incremented _before_ getting the spinlock (because the spinlock acts as part of the memory barrier), but the "requeue" operation didn't honor those rules, and nobody had even thought about that case. This fairly simple patch just increments the waiter count for the target hash bucket (hb2) when requeing a futex before taking the locks. It then decrements them again after releasing the lock - the code that actually moves the futex(es) between hash buckets will do the additional required waiter count housekeeping. Reported-and-tested-by: Jan Stancek <jstancek@redhat.com> Acked-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # 3.14 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge branch 'akpm' (incoming from Andrew)Linus Torvalds2014-04-0721-117/+155
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge second patch-bomb from Andrew Morton: - the rest of MM - zram updates - zswap updates - exit - procfs - exec - wait - crash dump - lib/idr - rapidio - adfs, affs, bfs, ufs - cris - Kconfig things - initramfs - small amount of IPC material - percpu enhancements - early ioremap support - various other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (156 commits) MAINTAINERS: update Intel C600 SAS driver maintainers fs/ufs: remove unused ufs_super_block_third pointer fs/ufs: remove unused ufs_super_block_second pointer fs/ufs: remove unused ufs_super_block_first pointer fs/ufs/super.c: add __init to init_inodecache() doc/kernel-parameters.txt: add early_ioremap_debug arm64: add early_ioremap support arm64: initialize pgprot info earlier in boot x86: use generic early_ioremap mm: create generic early_ioremap() support x86/mm: sparse warning fix for early_memremap lglock: map to spinlock when !CONFIG_SMP percpu: add preemption checks to __this_cpu ops vmstat: use raw_cpu_ops to avoid false positives on preemption checks slub: use raw_cpu_inc for incrementing statistics net: replace __this_cpu_inc in route.c with raw_cpu_inc modules: use raw_cpu_write for initialization of per cpu refcount. mm: use raw_cpu ops for determining current NUMA node percpu: add raw_cpu_ops slub: fix leak of 'name' in sysfs_slab_add ...
| * | | | | lglock: map to spinlock when !CONFIG_SMPJosh Triplett2014-04-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the system has only one CPU, lglock is effectively a spinlock; map it directly to spinlock to eliminate the indirection and duplicate code. In addition to removing overhead, this drops 1.6k of code with a defconfig modified to have !CONFIG_SMP, and 1.1k with a minimal config. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Howells <dhowells@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | modules: use raw_cpu_write for initialization of per cpu refcount.Christoph Lameter2014-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The initialization of a structure is not subject to synchronization. The use of __this_cpu would trigger a false positive with the additional preemption checks for __this_cpu ops. So simply disable the check through the use of raw_cpu ops. Trace: __this_cpu_write operation in preemptible [00000000] code: modprobe/286 caller is __this_cpu_preempt_check+0x38/0x60 CPU: 3 PID: 286 Comm: modprobe Tainted: GF 3.12.0-rc4+ #187 Call Trace: dump_stack+0x4e/0x82 check_preemption_disabled+0xec/0x110 __this_cpu_preempt_check+0x38/0x60 load_module+0xcfd/0x2650 SyS_init_module+0xa6/0xd0 tracesys+0xe1/0xe6 Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | kernel: use macros from compiler.h instead of __attribute__((...))Gideon Israel Dsouza2014-04-0713-21/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To increase compiler portability there is <linux/compiler.h> which provides convenience macros for various gcc constructs. Eg: __weak for __attribute__((weak)). I've replaced all instances of gcc attributes with the right macro in the kernel subsystem. Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | kernel/panic.c: display reason at end + pr_emergFabian Frederick2014-04-071-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, booting without initrd specified on 80x25 screen gives a call trace followed by atkbd : Spurious ACK. Original message ("VFS: Unable to mount root fs") is not available. Of course this could happen in other situations... This patch displays panic reason after call trace which could help lot of people even if it's not the very last line on screen. Also, convert all panic.c printk(KERN_EMERG to pr_emerg( [akpm@linux-foundation.org: missed a couple of pr_ conversions] Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | hung_task: check the value of "sysctl_hung_task_timeout_sec"Liu Hua2014-04-071-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As sysctl_hung_task_timeout_sec is unsigned long, when this value is larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in watchdog will return immediately without sleep and with print : schedule_timeout: wrong timeout value ffffffffffffff83 and then the funtion watchdog will call schedule_timeout_interruptible again and again. The screen will be filled with "schedule_timeout: wrong timeout value ffffffffffffff83" This patch does some check and correction in sysctl, to let the function schedule_timeout_interruptible allways get the valid parameter. Signed-off-by: Liu Hua <sdu.liu@huawei.com> Tested-by: Satoru Takeuchi <satoru.takeuchi@gmail.com> Cc: <stable@vger.kernel.org> [3.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: WSTOPPED|WCONTINUED doesn't work if a zombie leader is traced by ↵Oleg Nesterov2014-04-071-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | another process Even if the main thread is dead the process still can stop/continue. However, if the leader is ptraced wait_consider_task(ptrace => false) always skips wait_task_stopped/wait_task_continued, so WSTOPPED or WCONTINUED can never work for the natural parent in this case. Move the "A zombie ptracee is only visible to its ptracer" check into the "if (!delay_group_leader(p))" block. ->notask_error is cleared by the "fall through" code below. This depends on the previous change, wait_task_stopped/continued must be avoided if !delay_group_leader() and the tracer is ->real_parent. Otherwise WSTOPPED|WEXITED could wrongly report "stopped" when the child is already dead (single-threaded or not). If it is traced by another task then the "stopped" state is fine until the debugger detaches and reveals a zombie state. Stupid test-case: void *tfunc(void *arg) { sleep(1); // wait for zombie leader raise(SIGSTOP); exit(0x13); return NULL; } int run_child(void) { pthread_t thread; if (!fork()) { int tracee = getppid(); assert(ptrace(PTRACE_ATTACH, tracee, 0,0) == 0); do ptrace(PTRACE_CONT, tracee, 0,0); while (wait(NULL) > 0); return 0; } sleep(1); // wait for PTRACE_ATTACH assert(pthread_create(&thread, NULL, tfunc, NULL) == 0); pthread_exit(NULL); } int main(void) { int child, stat; child = fork(); if (!child) return run_child(); assert(child == waitpid(-1, &stat, WSTOPPED)); assert(stat == 0x137f); kill(child, SIGCONT); assert(child == waitpid(-1, &stat, WCONTINUED)); assert(stat == 0xffff); assert(child == waitpid(-1, &stat, 0)); assert(stat == 0x1300); return 0; } Without this patch it hangs in waitpid(WSTOPPED), wait_task_stopped() is never called. Note: this doesn't fix all problems with a zombie delay_group_leader(), WCONTINUED | WEXITED check is not exactly right. debugger can't assume it will be notified if another thread reaps the whole thread group. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: WSTOPPED|WCONTINUED hangs if a zombie child is traced by real_parentOleg Nesterov2014-04-071-13/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "A zombie is only visible to its ptracer" logic in wait_consider_task() is very wrong. Trivial test-case: #include <unistd.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <assert.h> int main(void) { int child = fork(); if (!child) { assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0); return 0x23; } assert(waitid(P_ALL, child, NULL, WEXITED | WNOWAIT) == 0); assert(waitid(P_ALL, 0, NULL, WSTOPPED) == -1); return 0; } it hangs in waitpid(WSTOPPED) despite the fact it has a single zombie child. This is because wait_consider_task(ptrace => 0) sees p->ptrace and cleares ->notask_error assuming that the debugger should detach and notify us. Change wait_consider_task(ptrace => 0) to pretend that ptrace == T if the child is traced by us. This really simplifies the logic and allows us to do more fixes, see the next changes. This also hides the unwanted group stop state automatically, we can remove another ptrace_reparented() check. Unfortunately, this adds the following behavioural changes: 1. Before this patch wait(WEXITED | __WNOTHREAD) does not reap a natural child if it is traced by the caller's sub-thread. Hopefully nobody will ever notice this change, and I think that nobody should rely on this behaviour anyway. 2. SIGNAL_STOP_CONTINUED is no longer hidden from debugger if it is real parent. While this change comes as a side effect, I think it is good by itself. The group continued state can not be consumed by another process in this case, it doesn't depend on ptrace, it doesn't make sense to hide it from real parent. Perhaps we should add the thread_group_leader() check before wait_task_continued()? May be, but this shouldn't depend on ptrace_reparented(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: completely ignore the EXIT_DEAD tasksOleg Nesterov2014-04-071-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that EXIT_DEAD is the terminal state it doesn't make sense to call eligible_child() or security_task_wait() if the task is really dead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: use EXIT_TRACE only if thread_group_leader(zombie)Oleg Nesterov2014-04-071-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait_task_zombie() always uses EXIT_TRACE/ptrace_unlink() if ptrace_reparented(). This is suboptimal and a bit confusing: we do not need do_notify_parent(p) if !thread_group_leader(p) and in this case we also do not need ptrace_unlink(), we can rely on ptrace_release_task(). Change wait_task_zombie() to check thread_group_leader() along with ptrace_reparented() and simplify the final p->exit_state transition. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: introduce EXIT_TRACE to avoid the racy EXIT_DEAD->EXIT_ZOMBIE transitionOleg Nesterov2014-04-071-29/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and drops tasklist_lock. If this task is not the natural child and it is traced, we change its state back to EXIT_ZOMBIE for ->real_parent. The last transition is racy, this is even documented in 50b8d257486a "ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE race". wait_consider_task() tries to detect this transition and clear ->notask_error but we can't rely on ptrace_reparented(), debugger can exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE. And there is another problem which were missed before: this transition can also race with reparent_leader() which doesn't reset >exit_signal if EXIT_DEAD, assuming that this task must be reaped by someone else. So the tracee can be re-parented with ->exit_signal != SIGCHLD, and if /sbin/init doesn't use __WALL it becomes unreapable. This was fixed by the previous commit, but it was the temporary hack. 1. Add the new exit_state, EXIT_TRACE. It means that the task is the traced zombie, debugger is going to detach and notify its natural parent. This new state is actually EXIT_ZOMBIE | EXIT_DEAD. This way we can avoid the changes in proc/kgdb code, get_task_state() still reports "X (dead)" in this case. Note: with or without this change userspace can see Z -> X -> Z transition. Not really bad, but probably makes sense to fix. 2. Change wait_task_zombie() to use EXIT_TRACE instead of EXIT_DEAD if we need to notify the ->real_parent. 3. Revert the previous hack in reparent_leader(), now that EXIT_DEAD is always the final state we can safely ignore such a task. 4. Change wait_consider_task() to check EXIT_TRACE separately and kill the racy and no longer needed ptrace_reparented() case. If ptrace == T an EXIT_TRACE thread should be simply ignored, the owner of this state is going to ptrace_unlink() this task. We can pretend that it was already removed from ->ptraced list. Otherwise we should skip this thread too but clear ->notask_error, we must be the natural parent and debugger is going to untrace and notify us. IOW, this doesn't differ from "EXIT_ZOMBIE && p->ptrace" even if the task was already untraced. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Reported-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | wait: fix reparent_leader() vs EXIT_DEAD->EXIT_ZOMBIE raceOleg Nesterov2014-04-071-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and drops tasklist_lock. If this task is not the natural child and it is traced, we change its state back to EXIT_ZOMBIE for ->real_parent. The last transition is racy, this is even documented in 50b8d257486a "ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE race". wait_consider_task() tries to detect this transition and clear ->notask_error but we can't rely on ptrace_reparented(), debugger can exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE. And there is another problem which were missed before: this transition can also race with reparent_leader() which doesn't reset >exit_signal if EXIT_DEAD, assuming that this task must be reaped by someone else. So the tracee can be re-parented with ->exit_signal != SIGCHLD, and if /sbin/init doesn't use __WALL it becomes unreapable. Change reparent_leader() to update ->exit_signal even if EXIT_DEAD. Note: this is the simple temporary hack for -stable, it doesn't try to solve all problems, it will be reverted by the next changes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Reported-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | kernel/exit.c: call proc_exit_connector() after exit_state is setGuillaume Morin2014-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The process events connector delivers a notification when a process exits. This is really convenient for a process that spawns and wants to monitor its children through an epoll-able() interface. Unfortunately, there is a small window between when the event is delivered and the child become wait()-able. This is creates a race if the parent wants to make sure that it knows about the exit, e.g pid_t pid = fork(); if (pid > 0) { register_interest_for_pid(pid); if (waitpid(pid, NULL, WNOHANG) > 0) { /* We might have raced with exit() */ } return; } /* Child */ execve(...) register_interest_for_pid() would be telling the the connector socket reader to pay attention to events related to pid. Though this is not a bug, I think it would make the connector a bit more usable if this race was closed by simply moving the call to proc_exit_connector() from just before exit_notify() to right after. Oleg said: : Even with this patch the code above is still "racy" if the child is : multi-threaded. Plus it should obviously filter-out subthreads. And : afaics there is no way to make it reliable, even if you change the code : above so that waitpid() is called only after the last thread exits WNOHANG : still can fail. Signed-off-by: Guillaume Morin <guillaume@morinfr.org> Cc: Matt Helsley <matt.helsley@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | exit: move check_stack_usage() to the end of do_exit()Oleg Nesterov2014-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is not clear why check_stack_usage() is called so early and thus it never checks the stack usage in, say, exit_notify() or flush_ptrace_hw_breakpoint() or other functions which are only called by do_exit(). Move the callsite down to the last preempt_disable/schedule. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | exit: call disassociate_ctty() before exit_task_namespaces()Oleg Nesterov2014-04-071-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8aac62706ada ("move exit_task_namespaces() outside of exit_notify()") breaks pppd and the exiting service crashes the kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: ppp_register_channel+0x13/0x20 [ppp_generic] Call Trace: ppp_asynctty_open+0x12b/0x170 [ppp_async] tty_ldisc_open.isra.2+0x27/0x60 tty_ldisc_hangup+0x1e3/0x220 __tty_hangup+0x2c4/0x440 disassociate_ctty+0x61/0x270 do_exit+0x7f2/0xa50 ppp_register_channel() needs ->net_ns and current->nsproxy == NULL. Move disassociate_ctty() before exit_task_namespaces(), it doesn't make sense to delay it after perf_event_exit_task() or cgroup_exit(). This also allows to use task_work_add() inside the (nontrivial) code paths in disassociate_ctty(). Investigated by Peter Hurley. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Sree Harsha Totakura <sreeharsha@totakura.in> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Sree Harsha Totakura <sreeharsha@totakura.in> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | res_counter: remove interface for locked charging and unchargingDavid Rientjes2014-04-071-11/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The res_counter_{charge,uncharge}_locked() variants are not used in the kernel outside of the resource counter code itself, so remove the interface. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm, mempolicy: remove per-process flagDavid Rientjes2014-04-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users. There's no significant performance degradation to checking current->mempolicy rather than current->flags & PF_MEMPOLICY in the allocation path, especially since this is considered unlikely(). Running TCP_RR with netperf-2.4.5 through localhost on 16 cpu machine with 64GB of memory and without a mempolicy: threads before after 16 1249409 1244487 32 1281786 1246783 48 1239175 1239138 64 1244642 1241841 80 1244346 1248918 96 1266436 1254316 112 1307398 1312135 128 1327607 1326502 Per-process flags are a scarce resource so we should free them up whenever possible and make them available. We'll be using it shortly for memcg oom reserves. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | fork: collapse copy_flags into copy_processDavid Rientjes2014-04-071-10/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_flags() does not use the clone_flags formal and can be collapsed into copy_process() for cleaner code. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm: per-thread vma cachingDavidlohr Bueso2014-04-072-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a continuation of efforts trying to optimize find_vma(), avoiding potentially expensive rbtree walks to locate a vma upon faults. The original approach (https://lkml.org/lkml/2013/11/1/410), where the largest vma was also cached, ended up being too specific and random, thus further comparison with other approaches were needed. There are two things to consider when dealing with this, the cache hit rate and the latency of find_vma(). Improving the hit-rate does not necessarily translate in finding the vma any faster, as the overhead of any fancy caching schemes can be too high to consider. We currently cache the last used vma for the whole address space, which provides a nice optimization, reducing the total cycles in find_vma() by up to 250%, for workloads with good locality. On the other hand, this simple scheme is pretty much useless for workloads with poor locality. Analyzing ebizzy runs shows that, no matter how many threads are running, the mmap_cache hit rate is less than 2%, and in many situations below 1%. The proposed approach is to replace this scheme with a small per-thread cache, maximizing hit rates at a very low maintenance cost. Invalidations are performed by simply bumping up a 32-bit sequence number. The only expensive operation is in the rare case of a seq number overflow, where all caches that share the same address space are flushed. Upon a miss, the proposed replacement policy is based on the page number that contains the virtual address in question. Concretely, the following results are seen on an 80 core, 8 socket x86-64 box: 1) System bootup: Most programs are single threaded, so the per-thread scheme does improve ~50% hit rate by just adding a few more slots to the cache. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 50.61% | 19.90 | | patched | 73.45% | 13.58 | +----------------+----------+------------------+ 2) Kernel build: This one is already pretty good with the current approach as we're dealing with good locality. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 75.28% | 11.03 | | patched | 88.09% | 9.31 | +----------------+----------+------------------+ 3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 70.66% | 17.14 | | patched | 91.15% | 12.57 | +----------------+----------+------------------+ 4) Ebizzy: There's a fair amount of variation from run to run, but this approach always shows nearly perfect hit rates, while baseline is just about non-existent. The amounts of cycles can fluctuate between anywhere from ~60 to ~116 for the baseline scheme, but this approach reduces it considerably. For instance, with 80 threads: +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 1.06% | 91.54 | | patched | 99.97% | 14.18 | +----------------+----------+------------------+ [akpm@linux-foundation.org: fix nommu build, per Davidlohr] [akpm@linux-foundation.org: document vmacache_valid() logic] [akpm@linux-foundation.org: attempt to untangle header files] [akpm@linux-foundation.org: add vmacache_find() BUG_ON] [hughd@google.com: add vmacache_valid_mm() (from Oleg)] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: adjust and enhance comments] Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLEAlex Thorlton2014-04-072-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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