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* NVMe: Merge issue on character device bring-upKeith Busch2013-09-061-4/+8
| | | | | | | | | | | A recent patch made it possible to bring up the character handle when the device is responsive but not accepting a set-features command. Another recent patch moved the initialization that requires we move where the checks for this condition occur. This patch merges these two ideas so it works much as before. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Handle ioremap failureKeith Busch2013-09-031-8/+22
| | | | | | | | | | | Decrement the number of queues required for doorbell remapping until the memory is successfully mapped for that size. Additional checks are done so that we don't call free_irq if it has already been freed. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Add pci suspend/resume driver callbacksKeith Busch2013-09-031-15/+58
| | | | | | | | | Used for going in and out of low power states. Resuming reuses the IO queues from the previous initialization, freeing any allocated queues that are no longer usable. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Use normal shutdownKeith Busch2013-09-032-0/+28
| | | | | | | | | | | The NVMe spec recommends using the shutdown normal sequence when safely taking the controller offline instead of hitting CC.EN on the next start-up to reset the controller. The spec recommends a minimum of 1 second for the shutdown complete. This patch waits 2 seconds to be on the safe side. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Separate controller init from disk discoveryKeith Busch2013-09-031-30/+47
| | | | | | | | | | This combines the controller initialization into one function, removing IO queue setup from namespace discovery, and creates symetric functions for device removal. The controller start and shutdown functions can now be called from resume/suspend context as well as probe/remove. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Separate queue alloc/free from create/deleteKeith Busch2013-09-031-39/+94
| | | | | | | | | | This separates nvme queue allocation from creation, and queue deletion from freeing. This is so that we may in the future temporarily disable queues and reuse the same memory when bringing them back online, like coming back from suspend state. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Group pci related actions in functionsKeith Busch2013-09-031-46/+66
| | | | | | | This will make it easier to reuse these outside probe/remove. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Disk stats for read/write commands onlyKeith Busch2013-09-031-3/+3
| | | | | | | Flush and discard requests would previously mess up the accounting. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Bring up cdev on set feature failureKeith Busch2013-09-031-2/+2
| | | | | | | | | | This patch creates the character device as long as a device's admin queues are usable so a user has an opprotunity to perform administration tasks. A device may be in a state that does not allow IO and setting the queue count feature in such a state returns an error. Previously the driver would bail and the controller would be unusable. Signed-off-by: Keith Busch <keith.busch@intel.com>
* NVMe: Fix checkpatch issuesKeith Busch2013-09-031-5/+4
| | | | Signed-off-by: Keith Busch <keith.busch@intel.com>
* NVMe: Namespace IDs are unsignedMatthew Wilcox2013-09-032-3/+6
| | | | | | | | | | The 'Number of Namespaces' read from the device was being treated as signed, which would cause us to not scan any namespaces for a device with more than 2 billion namespaces. That led to noticing that the namespace ID was also being treated as signed, which could lead to the result from NVME_IOCTL_ID being treated as an error code. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Update nvme_id_power_state with latest specKeith Busch2013-09-031-1/+7
| | | | | Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Split header file into user-visible and kernel-visible piecesMatthew Wilcox2013-09-033-456/+477
| | | | | | | | To build user programs that call the NVMe ioctls, we need to have a user header file. Catch up to the new way of doing that by splitting the header file into kernel and uapi portions. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Call nvme_process_cq from submission pathMatthew Wilcox2013-06-241-19/+20
| | | | | | | | | Since we have the queue locked, it makes sense to check if there are any completion queue entries on the queue before we release the lock. If there are, it may save an interrupt and reduce latency for the I/Os that happened to complete. This happens fairly often for some workloads. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Remove "process_cq did something" messageMatthew Wilcox2013-06-241-2/+1
| | | | | | | | | I was originally intending to log the fact that the kthread had done some work since it might help us find interrupt handling problems, but that hasn't been done yet, and spamming the logs with this message is just rude. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Return correct value from interrupt handlerMatthew Wilcox2013-06-241-5/+9
| | | | | | | | | | | | | The interrupt handler currently reports whether it found any new completion queue entries. If the completion queue is primarily being processed by a method other than the interrupt handler, it may return IRQ_NONE so often that Linux thinks that the interrupt is being falsely triggered. To solve this problem, report whether any completion queue entries have been seen since the last interrupt was received for this queue. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Disk IO statisticsKeith Busch2013-06-202-0/+29
| | | | | | | | Add io stats accounting for bio requests so nvme block devices show useful disk stats. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Restructure MSI / MSI-X setupMatthew Wilcox2013-06-201-21/+23
| | | | | | | | | | | | | The current code copies 'nr_io_queues' into 'q_count', modifies 'nr_io_queues' during MSI-X setup, then resets 'nr_io_queues' for MSI setup. Instead, copy 'nr_io_queues' into 'vecs' and modify 'vecs' during both MSI-X and MSI setup. This lets us simplify the for-loops that set up MSI-X and MSI, and opens the possibility of using more I/O queues than we have interrupt vectors, should future benchmarking prove that to be a useful feature. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* NVMe: Use kzalloc instead of kmalloc+memsetTushar Behera2013-06-191-16/+8
| | | | | | | | Use kzalloc instead of kmalloc and a susbsequent memset. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-06-133-9/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "This is an assortment of crash fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: stop all workers before cleaning up roots Btrfs: fix use-after-free bug during umount Btrfs: init relocate extent_io_tree with a mapping btrfs: Drop inode if inode root is NULL Btrfs: don't delete fs_roots until after we cleanup the transaction
| * Btrfs: stop all workers before cleaning up rootsJosef Bacik2013-06-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | Dave reported a panic because the extent_root->commit_root was NULL in the caching kthread. That is because we just unset it in free_root_pointers, which is not the correct thing to do, we have to either wait for the caching kthread to complete or hold the extent_commit_sem lock so we know the thread has exited. This patch makes the kthreads all stop first and then we do our cleanup. This should fix the race. Thanks, Reported-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
| * Btrfs: fix use-after-free bug during umountLiu Bo2013-06-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit be283b2e674a09457d4563729015adb637ce7cc1 ( Btrfs: use helper to cleanup tree roots) introduced the following bug, BUG: unable to handle kernel NULL pointer dereference at 0000000000000034 IP: [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs] [...] Pid: 2463, comm: btrfs-cache-1 Tainted: G O 3.9.0+ #4 innotek GmbH VirtualBox/VirtualBox RIP: 0010:[<ffffffffa039368c>] [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs] Process btrfs-cache-1 (pid: 2463, threadinfo ffff880112d60000, task ffff880117679730) [...] Call Trace: [<ffffffffa0398a99>] btrfs_search_slot+0x104/0x64d [btrfs] [<ffffffffa039aea4>] btrfs_next_old_leaf+0xa7/0x334 [btrfs] [<ffffffffa039b141>] btrfs_next_leaf+0x10/0x12 [btrfs] [<ffffffffa039ea13>] caching_thread+0x1a3/0x2e0 [btrfs] [<ffffffffa03d8811>] worker_loop+0x14b/0x48e [btrfs] [<ffffffffa03d86c6>] ? btrfs_queue_worker+0x25c/0x25c [btrfs] [<ffffffff81068d3d>] kthread+0x8d/0x95 [<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43 [<ffffffff8151e5ac>] ret_from_fork+0x7c/0xb0 [<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43 RIP [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs] We've free'ed commit_root before actually getting to free block groups where caching thread needs valid extent_root->commit_root. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
| * Btrfs: init relocate extent_io_tree with a mappingJosef Bacik2013-06-081-4/+5
| | | | | | | | | | | | | | | | | | | | | | Dave reported a NULL pointer deref. This is caused because he thought he'd be smart and add sanity checks to the extent_io bit operations, but he didn't expect a tree to have a NULL mapping. To fix this we just need to init the relocation's processed_blocks with the btree_inode->i_mapping. Thanks, Reported-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
| * btrfs: Drop inode if inode root is NULLNaohiro Aota2013-06-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | There is a path where btrfs_drop_inode() is called with its inode's root is NULL: In btrfs_new_inode(), when btrfs_set_inode_index() fails, iput() is called. We should handle this case before taking look at the root->root_item. Signed-off-by: Naohiro Aota <naota@elisp.net> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
| * Btrfs: don't delete fs_roots until after we cleanup the transactionJosef Bacik2013-06-081-1/+1
| | | | | | | | | | | | | | | | | | We get a use after free if we had a transaction to cleanup since there could be delayed inodes which refer to their respective fs_root. Thanks Reported-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
* | Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linuxLinus Torvalds2013-06-137-470/+521
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull device tree bug fixes from Grant Likely: "This branch contains the following bug fixes: - Fix locking vs. interrupts. Bug caught by lockdep checks - Fix parsing of cpp #line directive output by dtc - Fix 'make clean' for dtc temporary files. There is also a commit that regenerates the dtc lexer and parser files with Bison 2.5. The only purpose of this commit is to separate the functional change in the dtc bug fix from the code generation change caused by a different Bison version" * tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: dtc: ensure #line directives don't consume data from the next line dtc: Update generated files to output from Bison 2.5 of: Fix locking vs. interrupts kbuild: make sure we clean up DTB temporary files
| * | dtc: ensure #line directives don't consume data from the next lineGrant Likely2013-06-132-117/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the #line parsing regex ended with ({WS}+[0-9]+)?. The {WS} could match line-break characters. If the #line directive did not contain the optional flags field at the end, this could cause any integer data on the next line to be consumed as part of the #line directive parsing. This could cause syntax errors (i.e. #line parsing consuming the leading 0 from a hex literal 0x1234, leaving x1234 to be parsed as cell data, which is a syntax error), or invalid compilation results (i.e. simply consuming literal 1234 as part of the #line processing, thus removing it from the cell data). Fix this by replacing {WS} with [ \t] so that it can't match line-breaks. Convert all instances of {WS}, even though the other instances should be irrelevant for any well-formed #line directive. This is done for consistency and ultimate safety. [Cherry picked from DTC commit a1ee6f068e1c8dbc62873645037a353d7852d5cc] Reported-by: Ian Campbell <Ian.Campbell@citrix.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| * | dtc: Update generated files to output from Bison 2.5Grant Likely2013-06-132-341/+388
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch merely updates the generated dtc parser and lexer files to the output generated by Bison 2.5. The previous versions were generated from version 2.4.1. The only reason for this commit is to minimize the diff on the next commit which fixes a bug in the DTC #line directive parsing. Otherwise the Bison changes would be intermingled with the functional changes. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| * | of: Fix locking vs. interruptsBenjamin Herrenschmidt2013-06-132-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The OF code uses irqsafe locks everywhere except in a handful of functions for no obvious reasons. Since the conversion from the old rwlocks, this now triggers lockdep warnings when used at interrupt time. At least one driver (ibmvscsi) seems to be doing that from softirq context. This converts the few non-irqsafe locks into irqsafe ones, making them consistent with the rest of the code. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Grant Likely <grant.likely@linaro.org>
| * | kbuild: make sure we clean up DTB temporary filesIan Campbell2013-06-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various temporary files used when building DTB files were not suffixed with .tmp and therefore were not cleaned up by "make clean". Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
* | | Merge tag 'acpi-3.10-rc6' of ↵Linus Torvalds2013-06-132-4/+4
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI fix from Rafael Wysocki: "This is an alternative fix for the regression introduced in 3.9 whose previous fix had to be reverted right before 3.10-rc5, because it broke one of the Tony's machines. In this one the check is confined to the ACPI video driver (which is the only one causing the problem to happen in the first place) and the Tony's box shouldn't even notice it. - ACPI fix for an issue causing ACPI video driver to attempt to bind to devices it shouldn't touch from Rafael J Wysocki." * tag 'acpi-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / video: Do not bind to device objects with a scan handler
| * | | ACPI / video: Do not bind to device objects with a scan handlerRafael J. Wysocki2013-06-102-4/+4
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the introduction of ACPI scan handlers, ACPI device objects with an ACPI scan handler attached to them must not be bound to by ACPI drivers any more. Unfortunately, however, the ACPI video driver attempts to do just that if there is a _ROM ACPI control method defined under a device object with an ACPI scan handler. Prevent that from happening by making the video driver's "add" routine check if the device object already has an ACPI scan handler attached to it and return an error code in that case. That is not sufficient, though, because acpi_bus_driver_init() would then clear the device object's driver_data that may be set by its scan handler, so for the fix to work acpi_bus_driver_init() has to be modified to leave driver_data as is on errors. References: https://bugzilla.kernel.org/show_bug.cgi?id=58091 Bisected-and-tested-by: Dmitry S. Demin <dmitryy.demin@gmail.com> Reported-and-tested-by: Jason Cassell <bluesloth600@gmail.com> Tracked-down-by: Aaron Lu <aaron.lu@intel.com> Cc: 3.9+ <stable@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Aaron Lu <aaron.lu@intel.com>
* | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2013-06-137-185/+70
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "Another set of fixes, the biggest bit of this is yet another tweak to the UEFI anti-bricking code; apparently we finally got some feedback from Samsung as to what makes at least their systems fail. This set should actually fix the boot regressions that some other systems (e.g. SGI) have exhibited. Other than that, there is a patch to avoid a panic with particularly unhappy memory layouts and two minor protocol fixes which may or may not be manifest bugs" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Fix typo in kexec register clearing x86, relocs: Move __vvar_page from S_ABS to S_REL Modify UEFI anti-bricking code x86: Fix adjust_range_size_mask calling position
| * \ \ Merge tag 'efi-urgent' into x86/urgentH. Peter Anvin2013-06-134-178/+65
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * More tweaking to the EFI variable anti-bricking algorithm. Quite a few users were reporting boot regressions in v3.9. This has now been fixed with a more accurate "minimum storage requirement to avoid bricking" value from Samsung (5K instead of 50%) and code to trigger garbage collection when we near our limit - Matthew Garrett. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| | * | | Modify UEFI anti-bricking codeMatthew Garrett2013-06-104-178/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch reworks the UEFI anti-bricking code, including an effective reversion of cc5a080c and 31ff2f20. It turns out that calling QueryVariableInfo() from boot services results in some firmware implementations jumping to physical addresses even after entering virtual mode, so until we have 1:1 mappings for UEFI runtime space this isn't going to work so well. Reverting these gets us back to the situation where we'd refuse to create variables on some systems because they classify deleted variables as "used" until the firmware triggers a garbage collection run, which they won't do until they reach a lower threshold. This results in it being impossible to install a bootloader, which is unhelpful. Feedback from Samsung indicates that the firmware doesn't need more than 5KB of storage space for its own purposes, so that seems like a reasonable threshold. However, there's still no guarantee that a platform will attempt garbage collection merely because it drops below this threshold. It seems that this is often only triggered if an attempt to write generates a genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to create a variable larger than the remaining space. This should fail, but if it somehow succeeds we can then immediately delete it. I've tested this on the UEFI machines I have available, but I don't have a Samsung and so can't verify that it avoids the bricking problem. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ] Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
| * | | | x86: Fix typo in kexec register clearingKees Cook2013-06-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes a typo in register clearing code. Thanks to PaX Team for fixing this originally, and James Troup for pointing it out. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130605184718.GA8396@www.outflux.net Cc: <stable@vger.kernel.org> v2.6.30+ Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | x86, relocs: Move __vvar_page from S_ABS to S_RELKees Cook2013-06-121-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __vvar_page relocation should actually be listed in S_REL instead of S_ABS. Oddly, this didn't always cause things to break, presumably because there are no users for relocation information on 64 bits yet. [ hpa: Not for stable - new code in 3.10 ] Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130611185652.GA23674@www.outflux.net Reported-by: Michael Davidson <md@google.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | x86: Fix adjust_range_size_mask calling positionYinghai Lu2013-05-311-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8d57470d x86, mm: setup page table in top-down causes a kernel panic while setting mem=2G. [mem 0x00000000-0x000fffff] page 4k [mem 0x7fe00000-0x7fffffff] page 1G [mem 0x7c000000-0x7fdfffff] page 1G [mem 0x00100000-0x001fffff] page 4k [mem 0x00200000-0x7bffffff] page 2M for last entry is not what we want, we should have [mem 0x00200000-0x3fffffff] page 2M [mem 0x40000000-0x7bffffff] page 1G Actually we merge the continuous ranges with same page size too early. in this case, before merging we have [mem 0x00200000-0x3fffffff] page 2M [mem 0x40000000-0x7bffffff] page 2M after merging them, will get [mem 0x00200000-0x7bffffff] page 2M even we can use 1G page to map [mem 0x40000000-0x7bffffff] that will cause problem, because we already map [mem 0x7fe00000-0x7fffffff] page 1G [mem 0x7c000000-0x7fdfffff] page 1G with 1G page, aka [0x40000000-0x7fffffff] is mapped with 1G page already. During phys_pud_init() for [0x40000000-0x7bffffff], it will not reuse existing that pud page, and allocate new one then try to use 2M page to map it instead, as page_size_mask does not include PG_LEVEL_1G. At end will have [7c000000-0x7fffffff] not mapped, loop in phys_pmd_init stop mapping at 0x7bffffff. That is right behavoir, it maps exact range with exact page size that we ask, and we should explicitly call it to map [7c000000-0x7fffffff] before or after mapping 0x40000000-0x7bffffff. Anyway we need to make sure ranges' page_size_mask correct and consistent after split_mem_range for each range. Fix that by calling adjust_range_size_mask before merging range with same page size. -v2: update change log. -v3: add more explanation why [7c000000-0x7fffffff] is not mapped, and it causes panic. Bisected-by: "Xie, ChanglongX" <changlongx.xie@intel.com> Bisected-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1370015587-20835-1-git-send-email-yinghai@kernel.org Cc: <stable@vger.kernel.org> v3.9 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | | | | Merge branch 'rcu/urgent' of ↵Linus Torvalds2013-06-134-6/+22
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU fixes from Paul McKenney: "I must confess that this past merge window was not RCU's best showing. This series contains three more fixes for RCU regressions: 1. A fix to __DECLARE_TRACE_RCU() that causes it to act as an interrupt from idle rather than as a task switch from idle. This change is needed due to the recent use of _rcuidle() tracepoints that can be invoked from interrupt handlers as well as from idle. Without this fix, invoking _rcuidle() tracepoints from interrupt handlers results in splats and (more seriously) confusion on RCU's part as to whether a given CPU is idle or not. This confusion can in turn result in too-short grace periods and therefore random memory corruption. 2. A fix to a subtle deadlock that could result due to RCU doing a wakeup while holding one of its rcu_node structure's locks. Although the probability of occurrence is low, it really does happen. The fix, courtesy of Steven Rostedt, uses irq_work_queue() to avoid the deadlock. 3. A fix to a silent deadlock (invisible to lockdep) due to the interaction of timeouts posted by RCU debug code enabled by CONFIG_PROVE_RCU_DELAY=y, grace-period initialization, and CPU hotplug operations. This will not occur in production kernels, but really does occur in randconfig testing. Diagnosis courtesy of Steven Rostedt" * 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration rcu: Don't call wakeup() with rcu_node structure ->lock held trace: Allow idle-safe tracepoints to be called from irq
| * | | | | rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migrationPaul E. McKenney2013-06-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In Steven Rostedt's words: > I've been debugging the last couple of days why my tests have been > locking up. One of my tracing tests, runs all available tracers. The > lockup always happened with the mmiotrace, which is used to trace > interactions between priority drivers and the kernel. But to do this > easily, when the tracer gets registered, it disables all but the boot > CPUs. The lockup always happened after it got done disabling the CPUs. > > Then I decided to try this: > > while :; do > for i in 1 2 3; do > echo 0 > /sys/devices/system/cpu/cpu$i/online > done > for i in 1 2 3; do > echo 1 > /sys/devices/system/cpu/cpu$i/online > done > done > > Well, sure enough, that locked up too, with the same users. Doing a > sysrq-w (showing all blocked tasks): > > [ 2991.344562] task PC stack pid father > [ 2991.344562] rcu_preempt D ffff88007986fdf8 0 10 2 0x00000000 > [ 2991.344562] ffff88007986fc98 0000000000000002 ffff88007986fc48 0000000000000908 > [ 2991.344562] ffff88007986c280 ffff88007986ffd8 ffff88007986ffd8 00000000001d3c80 > [ 2991.344562] ffff880079248a40 ffff88007986c280 0000000000000000 00000000fffd4295 > [ 2991.344562] Call Trace: > [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66 > [ 2991.344562] [<ffffffff81541750>] schedule_timeout+0xbc/0xf9 > [ 2991.344562] [<ffffffff8154bec0>] ? ftrace_call+0x5/0x2f > [ 2991.344562] [<ffffffff81049513>] ? cascade+0xa8/0xa8 > [ 2991.344562] [<ffffffff815417ab>] schedule_timeout_uninterruptible+0x1e/0x20 > [ 2991.344562] [<ffffffff810c980c>] rcu_gp_kthread+0x502/0x94b > [ 2991.344562] [<ffffffff81062791>] ? __init_waitqueue_head+0x50/0x50 > [ 2991.344562] [<ffffffff810c930a>] ? rcu_gp_fqs+0x64/0x64 > [ 2991.344562] [<ffffffff81061cdb>] kthread+0xb1/0xb9 > [ 2991.344562] [<ffffffff81091e31>] ? lock_release_holdtime.part.23+0x4e/0x55 > [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58 > [ 2991.344562] [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0 > [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58 > [ 2991.344562] kworker/0:1 D ffffffff81a30680 0 47 2 0x00000000 > [ 2991.344562] Workqueue: events cpuset_hotplug_workfn > [ 2991.344562] ffff880078dbbb58 0000000000000002 0000000000000006 00000000000000d8 > [ 2991.344562] ffff880078db8100 ffff880078dbbfd8 ffff880078dbbfd8 00000000001d3c80 > [ 2991.344562] ffff8800779ca5c0 ffff880078db8100 ffffffff81541fcf 0000000000000000 > [ 2991.344562] Call Trace: > [ 2991.344562] [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609 > [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66 > [ 2991.344562] [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24 > [ 2991.344562] [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609 > [ 2991.344562] [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50 > [ 2991.344562] [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50 > [ 2991.344562] [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40 > [ 2991.344562] [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50 > [ 2991.344562] [<ffffffff810af7e6>] rebuild_sched_domains_locked+0x6e/0x3a8 > [ 2991.344562] [<ffffffff810b0ec6>] rebuild_sched_domains+0x1c/0x2a > [ 2991.344562] [<ffffffff810b109b>] cpuset_hotplug_workfn+0x1c7/0x1d3 > [ 2991.344562] [<ffffffff810b0ed9>] ? cpuset_hotplug_workfn+0x5/0x1d3 > [ 2991.344562] [<ffffffff81058e07>] process_one_work+0x2d4/0x4d1 > [ 2991.344562] [<ffffffff81058d3a>] ? process_one_work+0x207/0x4d1 > [ 2991.344562] [<ffffffff8105964c>] worker_thread+0x2e7/0x3b5 > [ 2991.344562] [<ffffffff81059365>] ? rescuer_thread+0x332/0x332 > [ 2991.344562] [<ffffffff81061cdb>] kthread+0xb1/0xb9 > [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58 > [ 2991.344562] [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0 > [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58 > [ 2991.344562] bash D ffffffff81a4aa80 0 2618 2612 0x10000000 > [ 2991.344562] ffff8800379abb58 0000000000000002 0000000000000006 0000000000000c2c > [ 2991.344562] ffff880077fea140 ffff8800379abfd8 ffff8800379abfd8 00000000001d3c80 > [ 2991.344562] ffff8800779ca5c0 ffff880077fea140 ffffffff81541fcf 0000000000000000 > [ 2991.344562] Call Trace: > [ 2991.344562] [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609 > [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66 > [ 2991.344562] [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24 > [ 2991.344562] [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609 > [ 2991.344562] [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e > [ 2991.344562] [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e > [ 2991.344562] [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40 > [ 2991.344562] [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e > [ 2991.344562] [<ffffffff81091c99>] ? __lock_is_held+0x32/0x53 > [ 2991.344562] [<ffffffff81548912>] notifier_call_chain+0x6b/0x98 > [ 2991.344562] [<ffffffff810671fd>] __raw_notifier_call_chain+0xe/0x10 > [ 2991.344562] [<ffffffff8103cf64>] __cpu_notify+0x20/0x32 > [ 2991.344562] [<ffffffff8103cf8d>] cpu_notify_nofail+0x17/0x36 > [ 2991.344562] [<ffffffff815225de>] _cpu_down+0x154/0x259 > [ 2991.344562] [<ffffffff81522710>] cpu_down+0x2d/0x3a > [ 2991.344562] [<ffffffff81526351>] store_online+0x4e/0xe7 > [ 2991.344562] [<ffffffff8134d764>] dev_attr_store+0x20/0x22 > [ 2991.344562] [<ffffffff811b3c5f>] sysfs_write_file+0x108/0x144 > [ 2991.344562] [<ffffffff8114c5ef>] vfs_write+0xfd/0x158 > [ 2991.344562] [<ffffffff8114c928>] SyS_write+0x5c/0x83 > [ 2991.344562] [<ffffffff8154c494>] tracesys+0xdd/0xe2 > > As well as held locks: > > [ 3034.728033] Showing all locks held in the system: > [ 3034.728033] 1 lock held by rcu_preempt/10: > [ 3034.728033] #0: (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff810c9471>] rcu_gp_kthread+0x167/0x94b > [ 3034.728033] 4 locks held by kworker/0:1/47: > [ 3034.728033] #0: (events){.+.+.+}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1 > [ 3034.728033] #1: (cpuset_hotplug_work){+.+.+.}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1 > [ 3034.728033] #2: (cpuset_mutex){+.+.+.}, at: [<ffffffff810b0ec1>] rebuild_sched_domains+0x17/0x2a > [ 3034.728033] #3: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50 > [ 3034.728033] 1 lock held by mingetty/2563: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > [ 3034.728033] 1 lock held by mingetty/2565: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > [ 3034.728033] 1 lock held by mingetty/2569: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > [ 3034.728033] 1 lock held by mingetty/2572: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > [ 3034.728033] 1 lock held by mingetty/2575: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > [ 3034.728033] 7 locks held by bash/2618: > [ 3034.728033] #0: (sb_writers#5){.+.+.+}, at: [<ffffffff8114bc3f>] file_start_write+0x2a/0x2c > [ 3034.728033] #1: (&buffer->mutex#2){+.+.+.}, at: [<ffffffff811b3b93>] sysfs_write_file+0x3c/0x144 > [ 3034.728033] #2: (s_active#54){.+.+.+}, at: [<ffffffff811b3c3e>] sysfs_write_file+0xe7/0x144 > [ 3034.728033] #3: (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff810217c2>] cpu_hotplug_driver_lock+0x17/0x19 > [ 3034.728033] #4: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8103d196>] cpu_maps_update_begin+0x17/0x19 > [ 3034.728033] #5: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103cfd8>] cpu_hotplug_begin+0x2c/0x6d > [ 3034.728033] #6: (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e > [ 3034.728033] 1 lock held by bash/2980: > [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8 > > Things looked a little weird. Also, this is a deadlock that lockdep did > not catch. But what we have here does not look like a circular lock > issue: > > Bash is blocked in rcu_cpu_notify(): > > 1961 /* Exclude any attempts to start a new grace period. */ > 1962 mutex_lock(&rsp->onoff_mutex); > > > kworker is blocked in get_online_cpus(), which makes sense as we are > currently taking down a CPU. > > But rcu_preempt is not blocked on anything. It is simply sleeping in > rcu_gp_kthread (really rcu_gp_init) here: > > 1453 #ifdef CONFIG_PROVE_RCU_DELAY > 1454 if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 && > 1455 system_state == SYSTEM_RUNNING) > 1456 schedule_timeout_uninterruptible(2); > 1457 #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */ > > And it does this while holding the onoff_mutex that bash is waiting for. > > Doing a function trace, it showed me where it happened: > > [ 125.940066] rcu_pree-10 3.... 28384115273: schedule_timeout_uninterruptible <-rcu_gp_kthread > [...] > [ 125.940066] rcu_pree-10 3d..3 28384202439: sched_switch: prev_comm=rcu_preempt prev_pid=10 prev_prio=120 prev_state=D ==> next_comm=watchdog/3 next_pid=38 next_prio=120 > > The watchdog ran, and then: > > [ 125.940066] watchdog-38 3d..3 28384692863: sched_switch: prev_comm=watchdog/3 prev_pid=38 prev_prio=120 prev_state=P ==> next_comm=modprobe next_pid=2848 next_prio=118 > > Not sure what modprobe was doing, but shortly after that: > > [ 125.940066] modprobe-2848 3d..3 28385041749: sched_switch: prev_comm=modprobe prev_pid=2848 prev_prio=118 prev_state=R+ ==> next_comm=migration/3 next_pid=40 next_prio=0 > > Where the migration thread took down the CPU: > > [ 125.940066] migratio-40 3d..3 28389148276: sched_switch: prev_comm=migration/3 prev_pid=40 prev_prio=0 prev_state=P ==> next_comm=swapper/3 next_pid=0 next_prio=120 > > which finally did: > > [ 125.940066] <idle>-0 3...1 28389282142: arch_cpu_idle_dead <-cpu_startup_entry > [ 125.940066] <idle>-0 3...1 28389282548: native_play_dead <-arch_cpu_idle_dead > [ 125.940066] <idle>-0 3...1 28389282924: play_dead_common <-native_play_dead > [ 125.940066] <idle>-0 3...1 28389283468: idle_task_exit <-play_dead_common > [ 125.940066] <idle>-0 3...1 28389284644: amd_e400_remove_cpu <-play_dead_common > > > CPU 3 is now offline, the rcu_preempt thread that ran on CPU 3 is still > doing a schedule_timeout_uninterruptible() and it registered it's > timeout to the timer base for CPU 3. You would think that it would get > migrated right? The issue here is that the timer migration happens at > the CPU notifier for CPU_DEAD. The problem is that the rcu notifier for > CPU_DOWN is blocked waiting for the onoff_mutex to be released, which is > held by the thread that just put itself into a uninterruptible sleep, > that wont wake up until the CPU_DEAD notifier of the timer > infrastructure is called, which wont happen until the rcu notifier > finishes. Here's our deadlock! This commit breaks this deadlock cycle by substituting a shorter udelay() for the previous schedule_timeout_uninterruptible(), while at the same time increasing the probability of the delay. This maintains the intensity of the testing. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | | rcu: Don't call wakeup() with rcu_node structure ->lock heldSteven Rostedt2013-06-103-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes a lockdep-detected deadlock by moving a wake_up() call out from a rnp->lock critical section. Please see below for the long version of this story. On Tue, 2013-05-28 at 16:13 -0400, Dave Jones wrote: > [12572.705832] ====================================================== > [12572.750317] [ INFO: possible circular locking dependency detected ] > [12572.796978] 3.10.0-rc3+ #39 Not tainted > [12572.833381] ------------------------------------------------------- > [12572.862233] trinity-child17/31341 is trying to acquire lock: > [12572.870390] (rcu_node_0){..-.-.}, at: [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0 > [12572.878859] > but task is already holding lock: > [12572.894894] (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0 > [12572.903381] > which lock already depends on the new lock. > > [12572.927541] > the existing dependency chain (in reverse order) is: > [12572.943736] > -> #4 (&ctx->lock){-.-...}: > [12572.960032] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12572.968337] [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80 > [12572.976633] [<ffffffff8113c987>] __perf_event_task_sched_out+0x2e7/0x5e0 > [12572.984969] [<ffffffff81088953>] perf_event_task_sched_out+0x93/0xa0 > [12572.993326] [<ffffffff816ea0bf>] __schedule+0x2cf/0x9c0 > [12573.001652] [<ffffffff816eacfe>] schedule_user+0x2e/0x70 > [12573.009998] [<ffffffff816ecd64>] retint_careful+0x12/0x2e > [12573.018321] > -> #3 (&rq->lock){-.-.-.}: > [12573.034628] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12573.042930] [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80 > [12573.051248] [<ffffffff8108e6a7>] wake_up_new_task+0xb7/0x260 > [12573.059579] [<ffffffff810492f5>] do_fork+0x105/0x470 > [12573.067880] [<ffffffff81049686>] kernel_thread+0x26/0x30 > [12573.076202] [<ffffffff816cee63>] rest_init+0x23/0x140 > [12573.084508] [<ffffffff81ed8e1f>] start_kernel+0x3f1/0x3fe > [12573.092852] [<ffffffff81ed856f>] x86_64_start_reservations+0x2a/0x2c > [12573.101233] [<ffffffff81ed863d>] x86_64_start_kernel+0xcc/0xcf > [12573.109528] > -> #2 (&p->pi_lock){-.-.-.}: > [12573.125675] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12573.133829] [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90 > [12573.141964] [<ffffffff8108e881>] try_to_wake_up+0x31/0x320 > [12573.150065] [<ffffffff8108ebe2>] default_wake_function+0x12/0x20 > [12573.158151] [<ffffffff8107bbf8>] autoremove_wake_function+0x18/0x40 > [12573.166195] [<ffffffff81085398>] __wake_up_common+0x58/0x90 > [12573.174215] [<ffffffff81086909>] __wake_up+0x39/0x50 > [12573.182146] [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50 > [12573.190119] [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0 > [12573.198023] [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930 > [12573.205860] [<ffffffff8107a91d>] kthread+0xed/0x100 > [12573.213656] [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0 > [12573.221379] > -> #1 (&rsp->gp_wq){..-.-.}: > [12573.236329] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12573.243783] [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90 > [12573.251178] [<ffffffff810868f3>] __wake_up+0x23/0x50 > [12573.258505] [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50 > [12573.265891] [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0 > [12573.273248] [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930 > [12573.280564] [<ffffffff8107a91d>] kthread+0xed/0x100 > [12573.287807] [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0 Notice the above call chain. rcu_start_future_gp() is called with the rnp->lock held. Then it calls rcu_start_gp_advance, which does a wakeup. You can't do wakeups while holding the rnp->lock, as that would mean that you could not do a rcu_read_unlock() while holding the rq lock, or any lock that was taken while holding the rq lock. This is because... (See below). > [12573.295067] > -> #0 (rcu_node_0){..-.-.}: > [12573.309293] [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0 > [12573.316568] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12573.323825] [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80 > [12573.331081] [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0 > [12573.338377] [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0 > [12573.345648] [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0 > [12573.352942] [<ffffffff8113938e>] find_get_context+0x4e/0x1f0 > [12573.360211] [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0 > [12573.367514] [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10 > [12573.374816] [<ffffffff816f4dd4>] tracesys+0xdd/0xe2 Notice the above trace. perf took its own ctx->lock, which can be taken while holding the rq lock. While holding this lock, it did a rcu_read_unlock(). The perf_lock_task_context() basically looks like: rcu_read_lock(); raw_spin_lock(ctx->lock); rcu_read_unlock(); Now, what looks to have happened, is that we scheduled after taking that first rcu_read_lock() but before taking the spin lock. When we scheduled back in and took the ctx->lock, the following rcu_read_unlock() triggered the "special" code. The rcu_read_unlock_special() takes the rnp->lock, which gives us a possible deadlock scenario. CPU0 CPU1 CPU2 ---- ---- ---- rcu_nocb_kthread() lock(rq->lock); lock(ctx->lock); lock(rnp->lock); wake_up(); lock(rq->lock); rcu_read_unlock(); rcu_read_unlock_special(); lock(rnp->lock); lock(ctx->lock); **** DEADLOCK **** > [12573.382068] > other info that might help us debug this: > > [12573.403229] Chain exists of: > rcu_node_0 --> &rq->lock --> &ctx->lock > > [12573.424471] Possible unsafe locking scenario: > > [12573.438499] CPU0 CPU1 > [12573.445599] ---- ---- > [12573.452691] lock(&ctx->lock); > [12573.459799] lock(&rq->lock); > [12573.467010] lock(&ctx->lock); > [12573.474192] lock(rcu_node_0); > [12573.481262] > *** DEADLOCK *** > > [12573.501931] 1 lock held by trinity-child17/31341: > [12573.508990] #0: (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0 > [12573.516475] > stack backtrace: > [12573.530395] CPU: 1 PID: 31341 Comm: trinity-child17 Not tainted 3.10.0-rc3+ #39 > [12573.545357] ffffffff825b4f90 ffff880219f1dbc0 ffffffff816e375b ffff880219f1dc00 > [12573.552868] ffffffff816dfa5d ffff880219f1dc50 ffff88023ce4d1f8 ffff88023ce4ca40 > [12573.560353] 0000000000000001 0000000000000001 ffff88023ce4d1f8 ffff880219f1dcc0 > [12573.567856] Call Trace: > [12573.575011] [<ffffffff816e375b>] dump_stack+0x19/0x1b > [12573.582284] [<ffffffff816dfa5d>] print_circular_bug+0x200/0x20f > [12573.589637] [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0 > [12573.596982] [<ffffffff810918f5>] ? sched_clock_cpu+0xb5/0x100 > [12573.604344] [<ffffffff810b9851>] lock_acquire+0x91/0x1f0 > [12573.611652] [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0 > [12573.619030] [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80 > [12573.626331] [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0 > [12573.633671] [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0 > [12573.640992] [<ffffffff811390ed>] ? perf_lock_task_context+0x7d/0x2d0 > [12573.648330] [<ffffffff810b429e>] ? put_lock_stats.isra.29+0xe/0x40 > [12573.655662] [<ffffffff813095a0>] ? delay_tsc+0x90/0xe0 > [12573.662964] [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0 > [12573.670276] [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0 > [12573.677622] [<ffffffff81139070>] ? __perf_event_enable+0x370/0x370 > [12573.684981] [<ffffffff8113938e>] find_get_context+0x4e/0x1f0 > [12573.692358] [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0 > [12573.699753] [<ffffffff8108cd9d>] ? get_parent_ip+0xd/0x50 > [12573.707135] [<ffffffff810b71fd>] ? trace_hardirqs_on_caller+0xfd/0x1c0 > [12573.714599] [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10 > [12573.721996] [<ffffffff816f4dd4>] tracesys+0xdd/0xe2 This commit delays the wakeup via irq_work(), which is what perf and ftrace use to perform wakeups in critical sections. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | | | | trace: Allow idle-safe tracepoints to be called from irqPaul E. McKenney2013-06-101-2/+2
| | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __DECLARE_TRACE_RCU() currently creates an _rcuidle() tracepoint which may safely be invoked from what RCU considers to be an idle CPU. However, these _rcuidle() tracepoints may -not- be invoked from the handler of an irq taken from idle, because rcu_idle_enter() zeroes RCU's nesting-level counter, so that the rcu_irq_exit() returning to idle will trigger a WARN_ON_ONCE(). This commit therefore substitutes rcu_irq_enter() for rcu_idle_exit() and rcu_irq_exit() for rcu_idle_enter() in order to make the _rcuidle() tracepoints usable from irq handlers as well as from process context. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org>
* | | | | Merge branch 'for-linus' of ↵Linus Torvalds2013-06-135-48/+95
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Martin Schwidefsky: "Three kvm related memory management fixes, a fix for show_trace, a fix for early console output and a patch from Ben to help prevent compile errors in regard to irq functions (or our lack thereof)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pci: Implement IRQ functions if !PCI s390/sclp: fix new line detection s390/pgtable: make pgste lock an explicit barrier s390/pgtable: Save pgste during modify_prot_start/commit s390/dumpstack: fix address ranges for asynchronous and panic stack s390/pgtable: Fix guest overindication for change bit
| * | | | | s390/pci: Implement IRQ functions if !PCIBen Hutchings2013-06-102-33/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All architectures must implement IRQ functions. Since various dependencies on !S390 were removed, there are various drivers that can be selected but will fail to link. Provide a dummy implementation of these functions for the !PCI case. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: stable@vger.kernel.org # 3.9 Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | s390/sclp: fix new line detectionPeter Oberparleiter2013-06-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When printing multi-line text using sclp_print, line endings are not correctly handled. The routine is expecting an EBCDIC new line character as line terminator while the input text is encoded in ASCII format. Fix this problem by modifying sclp_print to scan for ASCII new line characters. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | s390/pgtable: make pgste lock an explicit barrierChristian Borntraeger2013-06-051-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Getting and Releasing the pgste lock has lock semantics. Make the code an explicit barrier. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | s390/pgtable: Save pgste during modify_prot_start/commitChristian Borntraeger2013-06-051-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In modify_prot_start we update the pgste value but never store it back into the original location. Lets save the calculated result, since modify_prot_commit will use the value of the pgste. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | s390/dumpstack: fix address ranges for asynchronous and panic stackMartin Schwidefsky2013-06-051-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git commit dc7ee00d4771b321 "s390: lowcore stack pointer offsets" introduced a regression in regard to show_stack(). The stack pointer for the asynchronous and the panic stack in the lowcore now have an additional offset applied to them. This offset needs to be taken into account in the calculation for the low and high address for the stacks. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | | s390/pgtable: Fix guest overindication for change bitChristian Borntraeger2013-06-051-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing the transition invalid->valid in the host page table for a guest, then the guest view of C/R is in the pgste. After validation the view is pgste OR real key. We must zero out the real key C/R to avoid guest over-indication for change (and reference). Touching the real key is ok also for the host: The change bit is tracked via write protection and the reference bit is also ok because set_pte_at was called and the page will be touched anyway soon. Furthermore architecture defines reference as "substantially accurate", over- and underindication are ok. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | | | | Merge tag 'asoc-v3.10-rc5' of ↵Linus Torvalds2013-06-139-39/+54
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound Pull ASoC sound updates from Mark Brown: "Takashi is travelling at the minute and it'd be good to get the MAINTAINERS update in here merged so sending directly. As well as the usual driver specifics we've got a couple of core fixes here, one fixing capabilities for unidirectional streams and the other fixing suspend while audio streams are active. The suspend fix is a little involved but mostly as a result of removing some special casing that was doing the wrong thing." * tag 'asoc-v3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound: ASoC: tlv320aic3x: Remove deadlock from snd_soc_dapm_put_volsw_aic3x() ASoC: dapm: Treat DAI widgets like AIF widgets for power ASoC: arizona: Correct AEC loopback enable ASoC: pcm: Require both CODEC and CPU support when declaring stream caps MAINTAINERS: Remove myself from Wolfson maintainers ASoC: wm8994: Ensure microphone detection state is reset on removal ASoC: wm8994: Avoid leaking pm_runtime reference on removed jack race ASoC: cs42l52: fix hp_gain_enum shift value. ASoC: cs42l52: use correct PCM mixer TLV dB scale to match datasheet.
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