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2013-01-22wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED taskOleg Nesterov
wake_up_process() should never wakeup a TASK_STOPPED/TRACED task. Change it to use TASK_NORMAL and add the WARN_ON(). TASK_ALL has no other users, probably can be killed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-22ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILLOleg Nesterov
putreg() assumes that the tracee is not running and pt_regs_access() can safely play with its stack. However a killed tracee can return from ptrace_stop() to the low-level asm code and do RESTORE_REST, this means that debugger can actually read/modify the kernel stack until the tracee does SAVE_REST again. set_task_blockstep() can race with SIGKILL too and in some sense this race is even worse, the very fact the tracee can be woken up breaks the logic. As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace() call, this ensures that nobody can ever wakeup the tracee while the debugger looks at it. Not only this fixes the mentioned problems, we can do some cleanups/simplifications in arch_ptrace() paths. Probably ptrace_unfreeze_traced() needs more callers, for example it makes sense to make the tracee killable for oom-killer before access_process_vm(). While at it, add the comment into may_ptrace_stop() to explain why ptrace_stop() still can't rely on SIGKILL and signal_pending_state(). Reported-by: Salman Qazi <sqazi@google.com> Reported-by: Suleiman Souhlal <suleiman@google.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-22ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()Oleg Nesterov
Cleanup and preparation for the next change. signal_wake_up(resume => true) is overused. None of ptrace/jctl callers actually want to wakeup a TASK_WAKEKILL task, but they can't specify the necessary mask. Turn signal_wake_up() into signal_wake_up_state(state), reintroduce signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up() which adds __TASK_TRACED. This way ptrace_signal_wake_up() can work "inside" ptrace_request() even if the tracee doesn't have the TASK_WAKEKILL bit set. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-20module: fix missing module_mutex unlockLinus Torvalds
Commit 1fb9341ac348 ("module: put modules in list much earlier") moved some of the module initialization code around, and in the process changed the exit paths too. But for the duplicate export symbol error case the change made the ddebug_cleanup path jump to after the module mutex unlock, even though it happens with the mutex held. Rusty has some patches to split this function up into some helper functions, hopefully the mess of complex goto targets will go away eventually. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-20Merge tag 'fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module fixes and a virtio block fix from Rusty Russell: "Various minor fixes, but a slightly more complex one to fix the per-cpu overload problem introduced recently by kvm id changes." * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: put modules in list much earlier. module: add new state MODULE_STATE_UNFORMED. module: prevent warning when finit_module a 0 sized file virtio-blk: Don't free ida when disk is in use
2013-01-20Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull misc syscall fixes from Al Viro: - compat syscall fixes (discussed back in December) - a couple of "make life easier for sigaltstack stuff by reducing inter-tree dependencies" - fix up compiler/asmlinkage calling convention disagreement of sys_clone() - misc * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: sys_clone() needs asmlinkage_protect make sure that /linuxrc has std{in,out,err} x32: fix sigtimedwait x32: fix waitid() switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h Ensure that kernel_init_freeable() is not inlined into non __init code
2013-01-20ia64: kill thread_matches(), unexport ptrace_check_attach()Oleg Nesterov
The ia64 function "thread_matches()" has no users since commit e868a55c2a8c ("[IA64] remove find_thread_for_addr()"). Remove it. This allows us to make ptrace_check_attach() static to kernel/ptrace.c, which is good since we'll need to change the semantics of it and fix up all the callers. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-19sys_clone() needs asmlinkage_protectAl Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-16module, async: async_synchronize_full() on module init iff async is usedTejun Heo
If the default iosched is built as module, the kernel may deadlock while trying to load the iosched module on device probe if the probing was running off async. This is because async_synchronize_full() at the end of module init ends up waiting for the async job which initiated the module loading. async A modprobe 1. finds a device 2. registers the block device 3. request_module(default iosched) 4. modprobe in userland 5. load and init module 6. async_synchronize_full() Async A waits for modprobe to finish in request_module() and modprobe waits for async A to finish in async_synchronize_full(). Because there's no easy to track dependency once control goes out to userland, implementing properly nested flushing is difficult. For now, make module init perform async_synchronize_full() iff module init has queued async jobs as suggested by Linus. This avoids the described deadlock because iosched module doesn't use async and thus wouldn't invoke async_synchronize_full(). This is hacky and incomplete. It will deadlock if async module loading nests; however, this works around the known problem case and seems to be the best of bad options. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Alex Riesen <raa.lkml@gmail.com> Tested-by: Ming Lei <ming.lei@canonical.com> Tested-by: Alex Riesen <raa.lkml@gmail.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-14Merge tag 'trace-3.8-rc3-regression-fix' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing regression fixes from Steven Rostedt: "The clean up patch commit 0fb9656d957d "tracing: Make tracing_enabled be equal to tracing_on" caused two regressions. 1) The irqs off latency tracer no longer starts if tracing_on is off when the tracer is set, and then tracing_on is enabled. The tracing_on file needs the hook that tracing_enabled had to enable tracers if they request it (call the tracer's start() method). 2) That commit had a separate change that really should have been a separate patch, but it must have been added accidently with the -a option of git commit. But as the change is still related to the commit it wasn't noticed in review. That change, changed the way blocking is done by the trace_pipe file with respect to the tracing_on settings. I've been told that this change breaks current userspace, and this specific change is being reverted." * tag 'trace-3.8-rc3-regression-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix regression of trace_pipe tracing: Fix regression with irqsoff tracer and tracing_on file
2013-01-14tracing: Fix regression of trace_pipeLiu Bo
Commit 0fb9656d "tracing: Make tracing_enabled be equal to tracing_on" changes the behaviour of trace_pipe, ie. it makes trace_pipe return if we've read something and tracing is enabled, and this means that we have to 'cat trace_pipe' again and again while running tests. IMO the right way is if tracing is enabled, we always block and wait for ring buffer, or we may lose what we want since ring buffer's size is limited. Link: http://lkml.kernel.org/r/1358132051-5410-1-git-send-email-bo.li.liu@oracle.com Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-01-12module: put modules in list much earlier.Rusty Russell
Prarit's excellent bug report: > In recent Fedora releases (F17 & F18) some users have reported seeing > messages similar to > > [ 15.478160] kvm: Could not allocate 304 bytes percpu data > [ 15.478174] PERCPU: allocation failed, size=304 align=32, alloc from > reserved chunk failed > > during system boot. In some cases, users have also reported seeing this > message along with a failed load of other modules. > > What is happening is systemd is loading an instance of the kvm module for > each cpu found (see commit e9bda3b). When the module load occurs the kernel > currently allocates the modules percpu data area prior to checking to see > if the module is already loaded or is in the process of being loaded. If > the module is already loaded, or finishes load, the module loading code > releases the current instance's module's percpu data. Now we have a new state MODULE_STATE_UNFORMED, we can insert the module into the list (and thus guarantee its uniqueness) before we allocate the per-cpu region. Reported-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Prarit Bhargava <prarit@redhat.com>
2013-01-12module: add new state MODULE_STATE_UNFORMED.Rusty Russell
You should never look at such a module, so it's excised from all paths which traverse the modules list. We add the state at the end, to avoid gratuitous ABI break (ksplice). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-11kernel/audit.c: avoid negative sleep durationsAndrew Morton
audit_log_start() performs the same jiffies comparison in two places. If sufficient time has elapsed between the two comparisons, the second one produces a negative sleep duration: schedule_timeout: wrong timeout value fffffffffffffff0 Pid: 6606, comm: trinity-child1 Not tainted 3.8.0-rc1+ #43 Call Trace: schedule_timeout+0x305/0x340 audit_log_start+0x311/0x470 audit_log_exit+0x4b/0xfb0 __audit_syscall_exit+0x25f/0x2c0 sysret_audit+0x17/0x21 Fix it by performing the comparison a single time. Reported-by: Dave Jones <davej@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11audit: catch possible NULL audit buffersKees Cook
It's possible for audit_log_start() to return NULL. Handle it in the various callers. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Jeff Layton <jlayton@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Julien Tinnes <jln@google.com> Cc: Will Drewry <wad@google.com> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11audit: create explicit AUDIT_SECCOMP event typeKees Cook
The seccomp path was using AUDIT_ANOM_ABEND from when seccomp mode 1 could only kill a process. While we still want to make sure an audit record is forced on a kill, this should use a separate record type since seccomp mode 2 introduces other behaviors. In the case of "handled" behaviors (process wasn't killed), only emit a record if the process is under inspection. This change also fixes userspace examination of seccomp audit events, since it was considered malformed due to missing fields of the AUDIT_ANOM_ABEND event type. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Jeff Layton <jlayton@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Julien Tinnes <jln@google.com> Acked-by: Will Drewry <wad@chromium.org> Acked-by: Steve Grubb <sgrubb@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11lockdep, rwsem: provide down_write_nest_lock()Jiri Kosina
down_write_nest_lock() provides a means to annotate locking scenario where an outer lock is guaranteed to serialize the order nested locks are being acquired. This is analogoue to already existing mutex_lock_nest_lock() and spin_lock_nest_lock(). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mel Gorman <mel@csn.ul.ie> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11tracing: Fix regression with irqsoff tracer and tracing_on fileSteven Rostedt
Commit 02404baf1b47 "tracing: Remove deprecated tracing_enabled file" removed the tracing_enabled file as it never worked properly and the tracing_on file should be used instead. But the tracing_on file didn't call into the tracers start/stop routines like the tracing_enabled file did. This caused trace-cmd to break when it enabled the irqsoff tracer. If you just did "echo irqsoff > current_tracer" then it would work properly. But the tool trace-cmd disables tracing first by writing "0" into the tracing_on file. Then it writes "irqsoff" into current_tracer and then writes "1" into tracing_on. Unfortunately, the above commit changed the irqsoff tracer to check the tracing_on status instead of the tracing_enabled status. If it's disabled then it does not start the tracer internals. The problem is that writing "1" into tracing_on does not call the tracers "start" routine like writing "1" into tracing_enabled did. This makes the irqsoff tracer not start when using the trace-cmd tool, and is a regression for userspace. Simple fix is to have the tracing_on file call the tracers start() method when being enabled (and the stop() method when disabled). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-01-10audit: fix auditfilter.c kernel-doc warningsRandy Dunlap
Fix new kernel-doc warning in auditfilter.c: Warning(kernel/auditfilter.c:1157): Excess function parameter 'uid' description in 'audit_receive_filter' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: linux-audit@redhat.com (subscribers-only) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-10Merge tag 'trace-3.8-rc2-regression-fix' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing regression fix from Steven Rostedt: "A change that came in this merge window broke the writing to the trace_options file. It causes garbage to be read during the compare of option names, and breaks setting options via the trace_options file, although options can still be set via the options/<option> files." * tag 'trace-3.8-rc2-regression-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix regression of trace_options file setting
2013-01-09tracing: Fix regression of trace_options file settingSteven Rostedt
The latest change to allow trace options to be set on the command line also broke the trace_options file. The zeroing of the last byte of the option name that is echoed into the trace_option file was removed with the consolidation of some of the code. The compare between the option and what was written to the trace_options file fails because the string holding the data written doesn't terminate with a null character. A zero needs to be added to the end of the string copied from user space. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-01-07Merge branch 'akpm' (fixes from Andrew)Linus Torvalds
Merge emailed fixes from Andrew Morton: "Bunch of fixes: - delayed IPC updates. I held back on this because of some possible outstanding bug reports, but they appear to have been addressed in later versions - A bunch of MAINTAINERS updates - Yet Another RTC driver. I'd held this back while a couple of little issues were being worked out. I'm expecting an intrusive-but-simple patchset from Joe Perches which splits up printk.c into kernel/printk/*. That will be a pig to maintain for two months so if it passes testing I'd like to get it upstream after a week or so." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) printk: fix incorrect length from print_time() when seconds > 99999 drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time drivers/rtc/rtc-vt8500.c: correct handling of CR_24H bitfield rtc: add RTC driver for TPS6586x MAINTAINERS: fix drivers/staging/sm7xx/ MAINTAINERS: remove include/linux/of_pwm.h MAINTAINERS: remove arch/*/lib/perf_event*.c MAINTAINERS: remove drivers/mmc/host/imxmmc.* MAINTAINERS: fix Documentation/mei/ MAINTAINERS: remove arch/x86/platform/mrst/pmu.* MAINTAINERS: remove firmware/isci/ MAINTAINERS: fix drivers/ieee802154/ MAINTAINERS: fix .../plat-mxc/include/mach/imxfb.h MAINTAINERS: remove drivers/video/epson1355fb.c MAINTAINERS: fix drivers/media/usb/dvb-usb/cxusb* MAINTAINERS: adjust for UAPI MAINTAINERS: fix drivers/media/platform/atmel-isi.c MAINTAINERS: fix arch/arm/mach-at91/include/mach/at_hdmac.h MAINTAINERS: fix drivers/rtc/rtc-vt8500.c MAINTAINERS: remove arch/arm/plat-s5p/ ...
2013-01-05signals: set_current_blocked() can use __set_current_blocked()Oleg Nesterov
Cleanup. And I think we need more cleanups, in particular __set_current_blocked() and sigprocmask() should die. Nobody should ever block SIGKILL or SIGSTOP. - Change set_current_blocked() to use __set_current_blocked() - Change sys_sigprocmask() to use set_current_blocked(), this way it should not worry about SIGKILL/SIGSTOP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-05signals: sys_ssetmask() uses uninitialized newmaskOleg Nesterov
Commit 77097ae503b1 ("most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set") removed the initialization of newmask by accident, causing ltp to complain like this: ssetmask01 1 TFAIL : sgetmask() failed: TEST_ERRNO=???(0): Success Restore the proper initialization. Reported-and-tested-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org # v3.5+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04printk: fix incorrect length from print_time() when seconds > 99999Roland Dreier
print_prefix() passes a NULL buf to print_time() to get the length of the time prefix; when printk times are enabled, the current code just returns the constant 15, which matches the format "[%5lu.%06lu] " used to print the time value. However, this is obviously incorrect when the whole seconds part of the time gets beyond 5 digits (100000 seconds is a bit more than a day of uptime). The simple fix is to use snprintf(NULL, 0, ...) to calculate the actual length of the time prefix. This could be micro-optimized but it seems better to have simpler, more readable code here. The bug leads to the syslog system call miscomputing which messages fit into the userspace buffer. If there are enough messages to fill log_buf_len and some have a timestamp >= 100000, dmesg may fail with: # dmesg klogctl: Bad address When this happens, strace shows that the failure is indeed EFAULT due to the kernel mistakenly accessing past the end of dmesg's buffer, since dmesg asks the kernel how big a buffer it needs, allocates a bit more, and then gets an error when it asks the kernel to fill it: syslog(0xa, 0, 0) = 1048576 mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fa4d25d2000 syslog(0x3, 0x7fa4d25d2010, 0x100008) = -1 EFAULT (Bad address) As far as I can see, the bug has been there as long as print_time(), which comes from commit 084681d14e42 ("printk: flush continuation lines immediately to console") in 3.5-rc5. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: Sylvain Munaut <s.munaut@whatever-company.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-03module: prevent warning when finit_module a 0 sized fileSasha Levin
If we try to finit_module on a file sized 0 bytes vmalloc will scream and spit out a warning. Since modules have to be bigger than 0 bytes anyways we can just check that beforehand and avoid the warning. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-26x32: fix sigtimedwaitAl Viro
It needs 64bit timespec. As it is, we end up truncating the timeout to whole seconds; usually it doesn't matter, but for having all sub-second timeouts truncated to one jiffy is visibly wrong. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26x32: fix waitid()Al Viro
It needs 64bit rusage and 32bit siginfo. glibc never calls it with non-NULL rusage pointer, or we would've seen breakage already... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINEAl Viro
Strictly speaking, ppc64 needs it for C ABI compliance. Realistically I would be very surprised if e.g. passing 0xffffffff as 'options' argument to waitid() from 32bit task would cause problems, but yes, it puts us into undefined behaviour territory. ppc64 expects int argument to be passed in 64bit register with bits 31..63 containing the same value. SYSCALL_DEFINE on ppc provides a wrapper that normalizes the value passed from userland; so does COMPAT_SYSCALL_DEFINE. Plain declaration of compat_sys_something() with an int argument obviously doesn't. Again, for wait4 and waitid I would be extremely surprised if gcc started to produce code depending on that value having been properly sign-extended - the argument(s) in question end up passed blindly to sys_wait4 and sys_waitid resp. and normalization for native syscalls takes care of their use there. Still, better to use COMPAT_SYSCALL_DEFINE here than worry about nasal daemons... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINEAl Viro
Makes sigaltstack conversion easier to split into per-architecture parts. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-25pidns: Stop pid allocation when init diesEric W. Biederman
Oleg pointed out that in a pid namespace the sequence. - pid 1 becomes a zombie - setns(thepidns), fork,... - reaping pid 1. - The injected processes exiting. Can lead to processes attempting access their child reaper and instead following a stale pointer. That waitpid for init can return before all of the processes in the pid namespace have exited is also unfortunate. Avoid these problems by disabling the allocation of new pids in a pid namespace when init dies, instead of when the last process in a pid namespace is reaped. Pointed-out-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-12-24pidns: Outlaw thread creation after unshare(CLONE_NEWPID)Eric W. Biederman
The sequence: unshare(CLONE_NEWPID) clone(CLONE_THREAD|CLONE_SIGHAND|CLONE_VM) Creates a new process in the new pid namespace without setting pid_ns->child_reaper. After forking this results in a NULL pointer dereference. Avoid this and other nonsense scenarios that can show up after creating a new pid namespace with unshare by adding a new check in copy_prodcess. Pointed-out-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-12-20Merge branch 'for-next' of git://git.infradead.org/users/eparis/notifyLinus Torvalds
Pull filesystem notification updates from Eric Paris: "This pull mostly is about locking changes in the fsnotify system. By switching the group lock from a spin_lock() to a mutex() we can now hold the lock across things like iput(). This fixes a problem involving unmounting a fs and having inodes be busy, first pointed out by FAT, but reproducible with tmpfs. This also restores signal driven I/O for inotify, which has been broken since about 2.6.32." Ugh. I *hate* the timing of this. It was rebased after the merge window opened, and then left to sit with the pull request coming the day before the merge window closes. That's just crap. But apparently the patches themselves have been around for over a year, just gathering dust, so now it's suddenly critical. Fixed up semantic conflict in fs/notify/fdinfo.c as per Stephen Rothwell's fixes from -next. * 'for-next' of git://git.infradead.org/users/eparis/notify: inotify: automatically restart syscalls inotify: dont skip removal of watch descriptor if creation of ignored event failed fanotify: dont merge permission events fsnotify: make fasync generic for both inotify and fanotify fsnotify: change locking order fsnotify: dont put marks on temporary list when clearing marks by group fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark() fsnotify: pass group to fsnotify_destroy_mark() fsnotify: use a mutex instead of a spinlock to protect a groups mark list fanotify: add an extra flag to mark_remove_from_mask that indicates wheather a mark should be destroyed fsnotify: take groups mark_lock before mark lock fsnotify: use reference counting for groups fsnotify: introduce fsnotify_get_group() inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()
2012-12-20Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge the rest of Andrew's patches for -rc1: "A bunch of fixes and misc missed-out-on things. That'll do for -rc1. I still have a batch of IPC patches which still have a possible bug report which I'm chasing down." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits) keys: use keyring_alloc() to create module signing keyring keys: fix unreachable code sendfile: allows bypassing of notifier events SGI-XP: handle non-fatal traps fat: fix incorrect function comment Documentation: ABI: remove testing/sysfs-devices-node proc: fix inconsistent lock state linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors memcg: don't register hotcpu notifier from ->css_alloc() checkpatch: warn on uapi #includes that #include <uapi/... revert "rtc: recycle id when unloading a rtc driver" mm: clean up transparent hugepage sysfs error messages hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method hfsplus: rework processing of hfs_btree_write() returned error hfsplus: rework processing errors in hfsplus_free_extents() hfsplus: avoid crash on failed block map free kcmp: include linux/ptrace.h drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h> mm: cma: WARN if freed memory is still in use exec: do not leave bprm->interp on stack ...
2012-12-20Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
2012-12-20keys: use keyring_alloc() to create module signing keyringDavid Howells
Use keyring_alloc() to create special keyrings now that it has a permissions parameter rather than using key_alloc() + key_instantiate_and_link(). Signed-off-by: David Howells <dhowells@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20kcmp: include linux/ptrace.hCyrill Gorcunov
This makes it compile on s390. After all the ptrace_may_access (which we use this file) is declared exactly in linux/ptrace.h. This is preparatory work to wire this syscall up on all archs. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20sched: numa: ksm: fix oops in task_numa_placment()Hugh Dickins
task_numa_placement() oopsed on NULL p->mm when task_numa_fault() got called in the handling of break_ksm() for ksmd. That might be a peculiar case, which perhaps KSM could takes steps to avoid? but it's more robust if task_numa_placement() allows for such a possibility. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-19Merge tag 'random_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random updates from Ted Ts'o: "A few /dev/random improvements for the v3.8 merge window." * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: Mix cputime from each thread that exits to the pool random: prime last_data value per fips requirements random: fix debug format strings random: make it possible to enable debugging without rebuild
2012-12-19new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to thoseAl Viro
note that they are relying on access_ok() already checked by caller. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19generic compat_sys_sigaltstack()Al Viro
Again, conditional on CONFIG_GENERIC_SIGALTSTACK Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19introduce generic sys_sigaltstack(), switch x86 and um to itAl Viro
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not select it are completely unaffected Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19new helper: restore_altstack()Al Viro
to be used by rt_sigreturn instances Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19Bury the conditionals from kernel_thread/kernel_execve seriesAl Viro
All architectures have CONFIG_GENERIC_KERNEL_THREAD CONFIG_GENERIC_KERNEL_EXECVE __ARCH_WANT_SYS_EXECVE None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers of kernel_execve() (which is a trivial wrapper for do_execve() now) left. Kill the conditionals and make both callers use do_execve(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19watchdog: Fix disable/enable regressionBjørn Mork
Commit 8d4516904b39 ("watchdog: Fix CPU hotplug regression") causes an oops or hard lockup when doing echo 0 > /proc/sys/kernel/nmi_watchdog echo 1 > /proc/sys/kernel/nmi_watchdog and the kernel is booted with nmi_watchdog=1 (default) Running laptop-mode-tools and disconnecting/connecting AC power will cause this to trigger, making it a common failure scenario on laptops. Instead of bailing out of watchdog_disable() when !watchdog_enabled we can initialize the hrtimer regardless of watchdog_enabled status. This makes it safe to call watchdog_disable() in the nmi_watchdog=0 case, without the negative effect on the enabled => disabled => enabled case. All these tests pass with this patch: - nmi_watchdog=1 echo 0 > /proc/sys/kernel/nmi_watchdog echo 1 > /proc/sys/kernel/nmi_watchdog - nmi_watchdog=0 echo 0 > /sys/devices/system/cpu/cpu1/online - nmi_watchdog=0 echo mem > /sys/power/state Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51661 Cc: <stable@vger.kernel.org> # v3.7 Cc: Norbert Warmuth <nwarmuth@t-online.de> Cc: Joseph Salisbury <joseph.salisbury@canonical.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-19Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module update from Rusty Russell: "Nothing all that exciting; a new module-from-fd syscall for those who want to verify the source of the module (ChromeOS) and/or use standard IMA on it or other security hooks." * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: MODSIGN: Fix kbuild output when using default extra_certificates MODSIGN: Avoid using .incbin in C source modules: don't hand 0 to vmalloc. module: Remove a extra null character at the top of module->strtab. ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants ASN.1: Define indefinite length marker constant moduleparam: use __UNIQUE_ID() __UNIQUE_ID() MODSIGN: Add modules_sign make target powerpc: add finit_module syscall. ima: support new kernel module syscall add finit_module syscall to asm-generic ARM: add finit_module syscall to ARM security: introduce kernel_module_from_file hook module: add flags arg to sys_finit_module() module: add syscall to load module from fd
2012-12-18Merge branch 'akpm' (more patches from Andrew)Linus Torvalds
Merge patches from Andrew Morton: "Most of the rest of MM, plus a few dribs and drabs. I still have quite a few irritating patches left around: ones with dubious testing results, lack of review, ones which should have gone via maintainer trees but the maintainers are slack, etc. I need to be more activist in getting these things wrapped up outside the merge window, but they're such a PITA." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (48 commits) mm/vmscan.c: avoid possible deadlock caused by too_many_isolated() vmscan: comment too_many_isolated() mm/kmemleak.c: remove obsolete simple_strtoul mm/memory_hotplug.c: improve comments mm/hugetlb: create hugetlb cgroup file in hugetlb_init mm/mprotect.c: coding-style cleanups Documentation: ABI: /sys/devices/system/node/ slub: drop mutex before deleting sysfs entry memcg: add comments clarifying aspects of cache attribute propagation kmem: add slab-specific documentation about the kmem controller slub: slub-specific propagation changes slab: propagate tunable values memcg: aggregate memcg cache values in slabinfo memcg/sl[au]b: shrink dead caches memcg/sl[au]b: track all the memcg children of a kmem_cache memcg: destroy memcg caches sl[au]b: allocate objects from memcg cache sl[au]b: always get the cache from its page in kmem_cache_free() memcg: skip memcg kmem allocations in specified code regions memcg: infrastructure to match an allocation to the right cache ...
2012-12-18fork: protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombsGlauber Costa
Because those architectures will draw their stacks directly from the page allocator, rather than the slab cache, we can directly pass __GFP_KMEMCG flag, and issue the corresponding free_pages. This code path is taken when the architecture doesn't define CONFIG_ARCH_THREAD_INFO_ALLOCATOR (only ia64 seems to), and has THREAD_SIZE >= PAGE_SIZE. Luckily, most - if not all - of the remaining architectures fall in this category. This will guarantee that every stack page is accounted to the memcg the process currently lives on, and will have the allocations to fail if they go over limit. For the time being, I am defining a new variant of THREADINFO_GFP, not to mess with the other path. Once the slab is also tracked by memcg, we can get rid of that flag. Tested to successfully protect against :(){ :|:& };: Signed-off-by: Glauber Costa <glommer@parallels.com> Acked-by: Frederic Weisbecker <fweisbec@redhat.com> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: JoonSoo Kim <js1304@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Rik van Riel <riel@redhat.com> Cc: Suleiman Souhlal <suleiman@google.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>
2012-12-18res_counter: return amount of charges after res_counter_uncharge()Glauber Costa
It is useful to know how many charges are still left after a call to res_counter_uncharge. While it is possible to issue a res_counter_read after uncharge, this can be racy. If we need, for instance, to take some action when the counters drop down to 0, only one of the callers should see it. This is the same semantics as the atomic variables in the kernel. Since the current return value is void, we don't need to worry about anything breaking due to this change: nobody relied on that, and only users appearing from now on will be checking this value. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: JoonSoo Kim <js1304@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18irq: tsk->comm is an arrayAlan Cox
The array check is useless so remove it. [akpm@linux-foundation.org: remove comment, per David] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>