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* Merge commit 'v3.0.31' into android-3.0Todd Poynor2012-05-084-1/+21
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| * efi: Add new variable attributesMatthew Garrett2012-05-071-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | commit 41b3254c93acc56adc3c4477fef7c9512d47659e upstream. More recent versions of the UEFI spec have added new attributes for variables. Add them. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * pipes: add a "packetized pipe" mode for writingLinus Torvalds2012-05-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9883035ae7edef3ec62ad215611cb8e17d6a1a5d upstream. The actual internal pipe implementation is already really about individual packets (called "pipe buffers"), and this simply exposes that as a special packetized mode. When we are in the packetized mode (marked by O_DIRECT as suggested by Alan Cox), a write() on a pipe will not merge the new data with previous writes, so each write will get a pipe buffer of its own. The pipe buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn will tell the reader side to break the read at that boundary (and throw away any partial packet contents that do not fit in the read buffer). End result: as long as you do writes less than PIPE_BUF in size (so that the pipe doesn't have to split them up), you can now treat the pipe as a packet interface, where each read() system call will read one packet at a time. You can just use a sufficiently big read buffer (PIPE_BUF is sufficient, since bigger than that doesn't guarantee atomicity anyway), and the return value of the read() will naturally give you the size of the packet. NOTE! We do not support zero-sized packets, and zero-sized reads and writes to a pipe continue to be no-ops. Also note that big packets will currently be split at write time, but that the size at which that happens is not really specified (except that it's bigger than PIPE_BUF). Currently that limit is the system page size, but we might want to explicitly support bigger packets some day. The main user for this is going to be the autofs packet interface, allowing us to stop having to care so deeply about exact packet sizes (which have had bugs with 32/64-bit compatibility modes). But user space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will fail with an EINVAL on kernels that do not support this interface. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: fix crash during suspend on ASUS computersAlan Stern2012-05-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 151b61284776be2d6f02d48c23c3625678960b97 upstream. This patch (as1545) fixes a problem affecting several ASUS computers: The machine crashes or corrupts memory when going into suspend if the ehci-hcd driver is bound to any controllers. Users have been forced to unbind or unload ehci-hcd before putting their systems to sleep. After extensive testing, it was determined that the machines don't like going into suspend when any EHCI controllers are in the PCI D3 power state. Presumably this is a firmware bug, but there's nothing we can do about it except to avoid putting the controllers in D3 during system sleep. The patch adds a new flag to indicate whether the problem is present, and avoids changing the controller's power state if the flag is set. Runtime suspend is unaffected; this matters only for system suspend. However as a side effect, the controller will not respond to remote wakeup requests while the system is asleep. Hence USB wakeup is not functional -- but of course, this is already true in the current state of affairs. This fixes Bugzilla #42728. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Andrey Rahmatullin <wrar@wrar.name> Tested-by: Oleksij Rempel (fishor) <bug-track@fisher-privat.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * KVM: unmap pages from the iommu when slots are removedAlex Williamson2012-05-071-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 32f6daad4651a748a58a3ab6da0611862175722f upstream. We've been adding new mappings, but not destroying old mappings. This can lead to a page leak as pages are pinned using get_user_pages, but only unpinned with put_page if they still exist in the memslots list on vm shutdown. A memslot that is destroyed while an iommu domain is enabled for the guest will therefore result in an elevated page reference count that is never cleared. Additionally, without this fix, the iommu is only programmed with the first translation for a gpa. This can result in peer-to-peer errors if a mapping is destroyed and replaced by a new mapping at the same gpa as the iommu will still be pointing to the original, pinned memory address. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | netfilter: xt_IDLETIMER: Use uevent instead of new netlink msg typeJP Abgrall2012-05-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Send netlink message notifications using a uevent with subsystem=xt_idletimer INTERFACE=... STATE={active,inactive} instead of needing a new netlink message type. Revert the netlink.h change added by commit beb914e987cbbd368988d2b94a6661cb907c4d5a Change-Id: I6881936bf754f3367ff3c8f6c1e9661cec0357d4 Signed-off-by: JP Abgrall <jpa@google.com>
* | Merge commit 'v3.0.30' into android-3.0Todd Poynor2012-04-301-1/+1
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| * tcp: allow splice() to build full TSO packetsEric Dumazet2012-04-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ This combines upstream commit 2f53384424251c06038ae612e56231b96ab610ee and the follow-on bug fix commit 35f9c09fe9c72eb8ca2b8e89a593e1c151f28fc2 ] vmsplice()/splice(pipe, socket) call do_tcp_sendpages() one page at a time, adding at most 4096 bytes to an skb. (assuming PAGE_SIZE=4096) The call to tcp_push() at the end of do_tcp_sendpages() forces an immediate xmit when pipe is not already filled, and tso_fragment() try to split these skb to MSS multiples. 4096 bytes are usually split in a skb with 2 MSS, and a remaining sub-mss skb (assuming MTU=1500) This makes slow start suboptimal because many small frames are sent to qdisc/driver layers instead of big ones (constrained by cwnd and packets in flight of course) In fact, applications using sendmsg() (adding an additional memory copy) instead of vmsplice()/splice()/sendfile() are a bit faster because of this anomaly, especially if serving small files in environments with large initial [c]wnd. Call tcp_push() only if MSG_MORE is not set in the flags parameter. This bit is automatically provided by splice() internals but for the last page, or on all pages if user specified SPLICE_F_MORE splice() flag. In some workloads, this can reduce number of sent logical packets by an order of magnitude, making zero-copy TCP actually faster than one-copy :) Reported-by: Tom Herbert <therbert@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge linux-stable 3.0.28 into android-3.0Todd Poynor2012-04-1942-84/+240
|\ \ | |/ | | | | | | Change-Id: Iee820738e53627f5d0447a87ceff34443aa72786 Signed-off-by: Todd Poynor <toddpoynor@google.com>
| * sched/x86: Fix overflow in cyc2ns_offsetSalman Qazi2012-04-131-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9993bc635d01a6ee7f6b833b4ee65ce7c06350b1 upstream. When a machine boots up, the TSC generally gets reset. However, when kexec is used to boot into a kernel, the TSC value would be carried over from the previous kernel. The computation of cycns_offset in set_cyc2ns_scale is prone to an overflow, if the machine has been up more than 208 days prior to the kexec. The overflow happens when we multiply *scale, even though there is enough room to store the final answer. We fix this issue by decomposing tsc_now into the quotient and remainder of division by CYC2NS_SCALE_FACTOR and then performing the multiplication separately on the two components. Refactor code to share the calculation with the previous fix in __cycles_2_ns(). Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20120310004027.19291.88460.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()Jason Wessel2012-04-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream. There has long been a limitation using software breakpoints with a kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For this particular patch, it will apply cleanly and has been tested all the way back to 2.6.36. The kprobes code uses the text_poke() function which accommodates writing a breakpoint into a read-only page. The x86 kgdb code can solve the problem similarly by overriding the default breakpoint set/remove routines and using text_poke() directly. The x86 kgdb code will first attempt to use the traditional probe_kernel_write(), and next try using a the text_poke() function. The break point install method is tracked such that the correct break point removal routine will get called later on. Cc: x86@kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * kgdb,debug_core: pass the breakpoint struct instead of address and memoryJason Wessel2012-04-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 98b54aa1a2241b59372468bd1e9c2d207bdba54b upstream. There is extra state information that needs to be exposed in the kgdb_bpt structure for tracking how a breakpoint was installed. The debug_core only uses the the probe_kernel_write() to install breakpoints, but this is not enough for all the archs. Some arch such as x86 need to use text_poke() in order to install a breakpoint into a read only page. Passing the kgdb_bpt structure to kgdb_arch_set_breakpoint() and kgdb_arch_remove_breakpoint() allows other archs to set the type variable which indicates how the breakpoint was installed. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * udlfb: remove sysfs framebuffer device with USB .disconnect()Kay Sievers2012-04-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ce880cb860f36694d2cdebfac9e6ae18176fe4c4 upstream. The USB graphics card driver delays the unregistering of the framebuffer device to a workqueue, which breaks the userspace visible remove uevent sequence. Recent userspace tools started to support USB graphics card hotplug out-of-the-box and rely on proper events sent by the kernel. The framebuffer device is a direct child of the USB interface which is removed immediately after the USB .disconnect() callback. But the fb device in /sys stays around until its final cleanup, at a time where all the parent devices have been removed already. To work around that, we remove the sysfs fb device directly in the USB .disconnect() callback and leave only the cleanup of the internal fb data to the delayed work. Before: add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb0 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) remove /2-1.2:1.0/graphics/fb0 (graphics) After: add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb1 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb1 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) Tested-by: Bernie Thompson <bernie@plugable.com> Acked-by: Bernie Thompson <bernie@plugable.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * math: Introduce div64_longSasha Levin2012-04-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f910381a55cdaa097030291f272f6e6e4380c39a upstream. Add a div64_long macro which is used to devide a 64bit number by a long (which can be 4 bytes on 32bit systems and 8 bytes on 64bit systems). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Cc: johnstul@us.ibm.com Link: http://lkml.kernel.org/r/1331829374-31543-1-git-send-email-levinsasha928@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Block: use a freezable workqueue for disk-event pollingAlan Stern2012-03-191-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 62d3c5439c534b0e6c653fc63e6d8c67be3a57b1 upstream. This patch (as1519) fixes a bug in the block layer's disk-events polling. The polling is done by a work routine queued on the system_nrt_wq workqueue. Since that workqueue isn't freezable, the polling continues even in the middle of a system sleep transition. Obviously, polling a suspended drive for media changes and such isn't a good thing to do; in the case of USB mass-storage devices it can lead to real problems requiring device resets and even re-enumeration. The patch fixes things by creating a new system-wide, non-reentrant, freezable workqueue and using it for disk-events polling. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * block: Fix NULL pointer dereference in sd_revalidate_diskJun'ichi Nomura2012-03-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fe316bf2d5847bc5dd975668671a7b1067603bc7 upstream. Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(), __blkdev_get() calls rescan_partitions() to remove in-kernel partition structures and raise KOBJ_CHANGE uevent. However it ends up calling driver's revalidate_disk without open and could cause oops. In the case of SCSI: process A process B ---------------------------------------------- sys_open __blkdev_get sd_open returns -ENOMEDIUM scsi_remove_device <scsi_device torn down> rescan_partitions sd_revalidate_disk <oops> Oopses are reported here: http://marc.info/?l=linux-scsi&m=132388619710052 This patch separates the partition invalidation from rescan_partitions() and use it for -ENOMEDIUM case. Reported-by: Huajun Li <huajun.li.lee@gmail.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * ipsec: be careful of non existing mac headersEric Dumazet2012-03-191-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 03606895cd98c0a628b17324fd7b5ff15db7e3cd ] Niccolo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809 Reported-by: Niccolò Belli <darkbasic@linuxsystems.it> Tested-by: Niccolò Belli <darkbasic@linuxsystems.it> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * regset: Return -EFAULT, not -EIO, on host-side memory faultH. Peter Anvin2012-03-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5189fa19a4b2b4c3bec37c3a019d446148827717 upstream. There is only one error code to return for a bad user-space buffer pointer passed to a system call in the same address space as the system call is executed, and that is EFAULT. Furthermore, the low-level access routines, which catch most of the faults, return EFAULT already. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * regset: Prevent null pointer reference on readonly regsetsH. Peter Anvin2012-03-121-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c8e252586f8d5de906385d8cf6385fee289a825e upstream. The regset common infrastructure assumed that regsets would always have .get and .set methods, but not necessarily .active methods. Unfortunately people have since written regsets without .set methods. Rather than putting in stub functions everywhere, handle regsets with null .get or .set methods explicitly. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Fix autofs compile without CONFIG_COMPATLinus Torvalds2012-03-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3c761ea05a8900a907f32b628611873f6bef24b2 upstream. The autofs compat handling fix caused a compile failure when CONFIG_COMPAT isn't defined. Instead of adding random #ifdef'fery in autofs, let's just make the compat helpers earlier to use: without CONFIG_COMPAT, is_compat_task() just hardcodes to zero. We could probably do something similar for a number of other cases where we have #ifdef's in code, but this is the low-hanging fruit. Reported-and-tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * epoll: limit pathsJason Baron2012-02-292-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 28d82dc1c4edbc352129f97f4ca22624d1fe61de upstream. The current epoll code can be tickled to run basically indefinitely in both loop detection path check (on ep_insert()), and in the wakeup paths. The programs that tickle this behavior set up deeply linked networks of epoll file descriptors that cause the epoll algorithms to traverse them indefinitely. A couple of these sample programs have been previously posted in this thread: https://lkml.org/lkml/2011/2/25/297. To fix the loop detection path check algorithms, I simply keep track of the epoll nodes that have been already visited. Thus, the loop detection becomes proportional to the number of epoll file descriptor and links. This dramatically decreases the run-time of the loop check algorithm. In one diabolical case I tried it reduced the run-time from 15 mintues (all in kernel time) to .3 seconds. Fixing the wakeup paths could be done at wakeup time in a similar manner by keeping track of nodes that have already been visited, but the complexity is harder, since there can be multiple wakeups on different cpus...Thus, I've opted to limit the number of possible wakeup paths when the paths are created. This is accomplished, by noting that the end file descriptor points that are found during the loop detection pass (from the newly added link), are actually the sources for wakeup events. I keep a list of these file descriptors and limit the number and length of these paths that emanate from these 'source file descriptors'. In the current implemetation I allow 1000 paths of length 1, 500 of length 2, 100 of length 3, 50 of length 4 and 10 of length 5. Note that it is sufficient to check the 'source file descriptors' reachable from the newly added link, since no other 'source file descriptors' will have newly added links. This allows us to check only the wakeup paths that may have gotten too long, and not re-check all possible wakeup paths on the system. In terms of the path limit selection, I think its first worth noting that the most common case for epoll, is probably the model where you have 1 epoll file descriptor that is monitoring n number of 'source file descriptors'. In this case, each 'source file descriptor' has a 1 path of length 1. Thus, I believe that the limits I'm proposing are quite reasonable and in fact may be too generous. Thus, I'm hoping that the proposed limits will not prevent any workloads that currently work to fail. In terms of locking, I have extended the use of the 'epmutex' to all epoll_ctl add and remove operations. Currently its only used in a subset of the add paths. I need to hold the epmutex, so that we can correctly traverse a coherent graph, to check the number of paths. I believe that this additional locking is probably ok, since its in the setup/teardown paths, and doesn't affect the running paths, but it certainly is going to add some extra overhead. Also, worth noting is that the epmuex was recently added to the ep_ctl add operations in the initial path loop detection code using the argument that it was not on a critical path. Another thing to note here, is the length of epoll chains that is allowed. Currently, eventpoll.c defines: /* Maximum number of nesting allowed inside epoll sets */ #define EP_MAX_NESTS 4 This basically means that I am limited to a graph depth of 5 (EP_MAX_NESTS + 1). However, this limit is currently only enforced during the loop check detection code, and only when the epoll file descriptors are added in a certain order. Thus, this limit is currently easily bypassed. The newly added check for wakeup paths, stricly limits the wakeup paths to a length of 5, regardless of the order in which ep's are linked together. Thus, a side-effect of the new code is a more consistent enforcement of the graph depth. Thus far, I've tested this, using the sample programs previously mentioned, which now either return quickly or return -EINVAL. I've also testing using the piptest.c epoll tester, which showed no difference in performance. I've also created a number of different epoll networks and tested that they behave as expectded. I believe this solves the original diabolical test cases, while still preserving the sane epoll nesting. Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Nelson Elhage <nelhage@ksplice.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * epoll: introduce POLLFREE to flush ->signalfd_wqh before kfree()Oleg Nesterov2012-02-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d80e731ecab420ddcb79ee9d0ac427acbc187b4b upstream. This patch is intentionally incomplete to simplify the review. It ignores ep_unregister_pollwait() which plays with the same wqh. See the next change. epoll assumes that the EPOLL_CTL_ADD'ed file controls everything f_op->poll() needs. In particular it assumes that the wait queue can't go away until eventpoll_release(). This is not true in case of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand which is not connected to the file. This patch adds the special event, POLLFREE, currently only for epoll. It expects that init_poll_funcptr()'ed hook should do the necessary cleanup. Perhaps it should be defined as EPOLLFREE in eventpoll. __cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if ->signalfd_wqh is not empty, we add the new signalfd_cleanup() helper. ep_poll_callback(POLLFREE) simply does list_del_init(task_list). This make this poll entry inconsistent, but we don't care. If you share epoll fd which contains our sigfd with another process you should blame yourself. signalfd is "really special". I simply do not know how we can define the "right" semantics if it used with epoll. The main problem is, epoll calls signalfd_poll() once to establish the connection with the wait queue, after that signalfd_poll(NULL) returns the different/inconsistent results depending on who does EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd has nothing to do with the file, it works with the current thread. In short: this patch is the hack which tries to fix the symptoms. It also assumes that nobody can take tasklist_lock under epoll locks, this seems to be true. Note: - we do not have wake_up_all_poll() but wake_up_poll() is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE. - signalfd_cleanup() uses POLLHUP along with POLLFREE, we need a couple of simple changes in eventpoll.c to make sure it can't be "lost". Reported-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: Remove duplicate USB 3.0 hub feature #defines.Sarah Sharp2012-02-291-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d9f5343e35d9138432657202afa8e3ddb2ade360 upstream. Somehow we ended up with duplicate hub feature #defines in ch11.h. Tatyana Brokhman first created the USB 3.0 hub feature macros in 2.6.38 with commit 0eadcc09203349b11ca477ec367079b23d32ab91 "usb: USB3.0 ch11 definitions". In 2.6.39, I modified a patch from John Youn that added similar macros in a different place in the same file, and committed dbe79bbe9dcb22cb3651c46f18943477141ca452 "USB 3.0 Hub Changes". Some of the #defines used different names for the same values. Others used exactly the same names with the same values, like these gems: #define USB_PORT_FEAT_BH_PORT_RESET 28 ... #define USB_PORT_FEAT_BH_PORT_RESET 28 According to my very geeky husband (who looked it up in the C99 spec), it is allowed to have object-like macros with duplicate names as long as the replacement list is exactly the same. However, he recalled that some compilers will give warnings when they find duplicate macros. It's probably best to remove the duplicates in the stable tree, so that the code compiles for everyone. The macros are now fixed to move the feature requests that are specific to USB 3.0 hubs into a new section (out of the USB 2.0 hub feature section), and use the most common macro name. This patch should be backported to 2.6.39. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Tatyana Brokhman <tlinder@codeaurora.org> Cc: John Youn <johnyoun@synopsys.com> Cc: Jamey Sharp <jamey@minilop.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * crypto: sha512 - use standard ror64()Alexey Dobriyan2012-02-201-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f2ea0f5f04c97b48c88edccba52b0682fbe45087 upstream. Use standard ror64() instead of hand-written. There is no standard ror64, so create it. The difference is shift value being "unsigned int" instead of uint64_t (for which there is no reason). gcc starts to emit native ROR instructions which it doesn't do for some reason currently. This should make the code faster. Patch survives in-tree crypto test and ping flood with hmac(sha512) on. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * lib: proportion: lower PROP_MAX_SHIFT to 32 on 64-bit kernelWu Fengguang2012-02-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3310225dfc71a35a2cc9340c15c0e08b14b3c754 upstream. PROP_MAX_SHIFT should be set to <=32 on 64-bit box. This fixes two bugs in the below lines of bdi_dirty_limit(): bdi_dirty *= numerator; do_div(bdi_dirty, denominator); 1) divide error: do_div() only uses the lower 32 bit of the denominator, which may trimmed to be 0 when PROP_MAX_SHIFT > 32. 2) overflow: (bdi_dirty * numerator) could easily overflow if numerator used up to 48 bits, leaving only 16 bits to bdi_dirty Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Ilya Tumaykin <librarian_rus@yahoo.com> Tested-by: Ilya Tumaykin <librarian_rus@yahoo.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * PCI: Rework ASPM disable codeMatthew Garrett2012-02-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3c076351c4027a56d5005a39a0b518a4ba393ce2 upstream. Right now we forcibly clear ASPM state on all devices if the BIOS indicates that the feature isn't supported. Based on the Microsoft presentation "PCI Express In Depth for Windows Vista and Beyond", I'm starting to think that this may be an error. The implication is that unless the platform grants full control via _OSC, Windows will not touch any PCIe features - including ASPM. In that case clearing ASPM state would be an error unless the platform has granted us that control. This patch reworks the ASPM disabling code such that the actual clearing of state is triggered by a successful handoff of PCIe control to the OS. The general ASPM code undergoes some changes in order to ensure that the ability to clear the bits isn't overridden by ASPM having already been disabled. Further, this theoretically now allows for situations where only a subset of PCIe roots hand over control, leaving the others in the BIOS state. It's difficult to know for sure that this is the right thing to do - there's zero public documentation on the interaction between all of these components. But enough vendors enable ASPM on platforms and then set this bit that it seems likely that they're expecting the OS to leave them alone. Measured to save around 5W on an idle Thinkpad X220. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * block: fail SCSI passthrough ioctls on partition devicesPaolo Bonzini2012-01-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream. [ Changes with respect to 3.3: return -ENOTTY from scsi_verify_blk_ioctl and -ENOIOCTLCMD from sd_compat_ioctl. ] Linux allows executing the SG_IO ioctl on a partition or LVM volume, and will pass the command to the underlying block device. This is well-known, but it is also a large security problem when (via Unix permissions, ACLs, SELinux or a combination thereof) a program or user needs to be granted access only to part of the disk. This patch lets partitions forward a small set of harmless ioctls; others are logged with printk so that we can see which ioctls are actually sent. In my tests only CDROM_GET_CAPABILITY actually occurred. Of course it was being sent to a (partition on a) hard disk, so it would have failed with ENOTTY and the patch isn't changing anything in practice. Still, I'm treating it specially to avoid spamming the logs. In principle, this restriction should include programs running with CAP_SYS_RAWIO. If for example I let a program access /dev/sda2 and /dev/sdb, it still should not be able to read/write outside the boundaries of /dev/sda2 independent of the capabilities. However, for now programs with CAP_SYS_RAWIO will still be allowed to send the ioctls. Their actions will still be logged. This patch does not affect the non-libata IDE driver. That driver however already tests for bd != bd->bd_contains before issuing some ioctl; it could be restricted further to forbid these ioctls even for programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: James Bottomley <JBottomley@parallels.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ Make it also print the command name when warning - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * block: add and use scsi_blk_cmd_ioctlPaolo Bonzini2012-01-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream. Introduce a wrapper around scsi_cmd_ioctl that takes a block device. The function will then be enhanced to detect partition block devices and, in that case, subject the ioctls to whitelisting. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: James Bottomley <JBottomley@parallels.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * fix shrink_dcache_parent() livelockMiklos Szeredi2012-01-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit eaf5f9073533cde21c7121c136f1c3f072d9cf59 upstream. Two (or more) concurrent calls of shrink_dcache_parent() on the same dentry may cause shrink_dcache_parent() to loop forever. Here's what appears to happen: 1 - CPU0: select_parent(P) finds C and puts it on dispose list, returns 1 2 - CPU1: select_parent(P) locks P->d_lock 3 - CPU0: shrink_dentry_list() locks C->d_lock dentry_kill(C) tries to lock P->d_lock but fails, unlocks C->d_lock 4 - CPU1: select_parent(P) locks C->d_lock, moves C from dispose list being processed on CPU0 to the new dispose list, returns 1 5 - CPU0: shrink_dentry_list() finds dispose list empty, returns 6 - Goto 2 with CPU0 and CPU1 switched Basically select_parent() steals the dentry from shrink_dentry_list() and thinks it found a new one, causing shrink_dentry_list() to think it's making progress and loop over and over. One way to trigger this is to make udev calls stat() on the sysfs file while it is going away. Having a file in /lib/udev/rules.d/ with only this one rule seems to the trick: ATTR{vendor}=="0x8086", ATTR{device}=="0x10ca", ENV{PCI_SLOT_NAME}="%k", ENV{MATCHADDR}="$attr{address}", RUN+="/bin/true" Then execute the following loop: while true; do echo -bond0 > /sys/class/net/bonding_masters echo +bond0 > /sys/class/net/bonding_masters echo -bond1 > /sys/class/net/bonding_masters echo +bond1 > /sys/class/net/bonding_masters done One fix would be to check all callers and prevent concurrent calls to shrink_dcache_parent(). But I think a better solution is to stop the stealing behavior. This patch adds a new dentry flag that is set when the dentry is added to the dispose list. The flag is cleared in dentry_lru_del() in case the dentry gets a new reference just before being pruned. If the dentry has this flag, select_parent() will skip it and let shrink_dentry_list() retry pruning it. With select_parent() skipping those dentries there will not be the appearance of progress (new dentries found) when there is none, hence shrink_dcache_parent() will not loop forever. Set the flag is also set in prune_dcache_sb() for consistency as suggested by Linus. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * svcrpc: destroy server sockets all at onceJ. Bruce Fields2012-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | commit 2fefb8a09e7ed251ae8996e0c69066e74c5aa560 upstream. There's no reason I can see that we need to call sv_shutdown between closing the two lists of sockets. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy()Dan Carpenter2012-01-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6c06108be53ca5e94d8b0e93883d534dd9079646 upstream. If ctrls->count is too high the multiplication could overflow and array_size would be lower than expected. Mauro and Hans Verkuil suggested that we cap it at 1024. That comes from the maximum number of controls with lots of room for expantion. $ grep V4L2_CID include/linux/videodev2.h | wc -l 211 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * memcg: add mem_cgroup_replace_page_cache() to fix LRU issueKAMEZAWA Hiroyuki2012-01-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ab936cbcd02072a34b60d268f94440fd5cf1970b upstream. Commit ef6a3c6311 ("mm: add replace_page_cache_page() function") added a function replace_page_cache_page(). This function replaces a page in the radix-tree with a new page. WHen doing this, memory cgroup needs to fix up the accounting information. memcg need to check PCG_USED bit etc. In some(many?) cases, 'newpage' is on LRU before calling replace_page_cache(). So, memcg's LRU accounting information should be fixed, too. This patch adds mem_cgroup_replace_page_cache() and removes the old hooks. In that function, old pages will be unaccounted without touching res_counter and new page will be accounted to the memcg (of old page). WHen overwriting pc->mem_cgroup of newpage, take zone->lru_lock and avoid races with LRU handling. Background: replace_page_cache_page() is called by FUSE code in its splice() handling. Here, 'newpage' is replacing oldpage but this newpage is not a newly allocated page and may be on LRU. LRU mis-accounting will be critical for memory cgroup because rmdir() checks the whole LRU is empty and there is no account leak. If a page is on the other LRU than it should be, rmdir() will fail. This bug was added in March 2011, but no bug report yet. I guess there are not many people who use memcg and FUSE at the same time with upstream kernels. The result of this bug is that admin cannot destroy a memcg because of account leak. So, no panic, no deadlock. And, even if an active cgroup exist, umount can succseed. So no problem at shutdown. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * PCI: Fix PCI_EXP_TYPE_RC_EC valueAlex Williamson2012-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | commit 1830ea91c20b06608f7cdb2455ce05ba834b3214 upstream. Spec shows this as 1010b = 0xa Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * usb: ch9: fix up MaxStreams helperFelipe Balbi2012-01-121-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 18b7ede5f7ee2092aedcb578d3ac30bd5d4fc23c upstream. [ removed the dwc3 portion of the patch as it didn't apply to older kernels - gregkh] According to USB 3.0 Specification Table 9-22, if bmAttributes [4:0] are set to zero, it means "no streams supported", but the way this helper was defined on Linux, we will *always* have one stream which might cause several problems. For example on DWC3, we would tell the controller endpoint has streams enabled and yet start transfers with Stream ID set to 0, which would goof up the host side. While doing that, convert the macro to an inline function due to the different checks we now need. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * usb: fix number of mapped SG DMA entriesClemens Ladisch2012-01-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bc677d5b64644c399cd3db6a905453e611f402ab upstream. Add a new field num_mapped_sgs to struct urb so that we have a place to store the number of mapped entries and can also retain the original value of entries in num_sgs. Previously, usb_hcd_map_urb_for_dma() would overwrite this with the number of mapped entries, which would break dma_unmap_sg() because it requires the original number of entries. This fixes warnings like the following when using USB storage devices: ------------[ cut here ]------------ WARNING: at lib/dma-debug.c:902 check_unmap+0x4e4/0x695() ehci_hcd 0000:00:12.2: DMA-API: device driver frees DMA sg list with different entry count [map count=4] [unmap count=1] Modules linked in: ohci_hcd ehci_hcd Pid: 0, comm: kworker/0:1 Not tainted 3.2.0-rc2+ #319 Call Trace: <IRQ> [<ffffffff81036d3b>] warn_slowpath_common+0x80/0x98 [<ffffffff81036de7>] warn_slowpath_fmt+0x41/0x43 [<ffffffff811fa5ae>] check_unmap+0x4e4/0x695 [<ffffffff8105e92c>] ? trace_hardirqs_off+0xd/0xf [<ffffffff8147208b>] ? _raw_spin_unlock_irqrestore+0x33/0x50 [<ffffffff811fa84a>] debug_dma_unmap_sg+0xeb/0x117 [<ffffffff8137b02f>] usb_hcd_unmap_urb_for_dma+0x71/0x188 [<ffffffff8137b166>] unmap_urb_for_dma+0x20/0x22 [<ffffffff8137b1c5>] usb_hcd_giveback_urb+0x5d/0xc0 [<ffffffffa0000d02>] ehci_urb_done+0xf7/0x10c [ehci_hcd] [<ffffffffa0001140>] qh_completions+0x429/0x4bd [ehci_hcd] [<ffffffffa000340a>] ehci_work+0x95/0x9c0 [ehci_hcd] ... ---[ end trace f29ac88a5a48c580 ]--- Mapped at: [<ffffffff811faac4>] debug_dma_map_sg+0x45/0x139 [<ffffffff8137bc0b>] usb_hcd_map_urb_for_dma+0x22e/0x478 [<ffffffff8137c494>] usb_hcd_submit_urb+0x63f/0x6fa [<ffffffff8137d01c>] usb_submit_urb+0x2c7/0x2de [<ffffffff8137dcd4>] usb_sg_wait+0x55/0x161 Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * mfd: Turn on the twl4030-madc MADC clockKyle Manna2012-01-061-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3d6271f92e98094584fd1e609a9969cd33e61122 upstream. Without turning the MADC clock on, no MADC conversions occur. $ cat /sys/class/hwmon/hwmon0/device/in8_input [ 53.428436] twl4030_madc twl4030_madc: conversion timeout! cat: read error: Resource temporarily unavailable Signed-off-by: Kyle Manna <kyle@kylemanna.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * VFS: Fix race between CPU hotplug and lglocksSrivatsa S. Bhat2012-01-061-4/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e30e2fdfe56288576ee9e04dbb06b4bd5f282203 upstream. Currently, the *_global_[un]lock_online() routines are not at all synchronized with CPU hotplug. Soft-lockups detected as a consequence of this race was reported earlier at https://lkml.org/lkml/2011/8/24/185. (Thanks to Cong Meng for finding out that the root-cause of this issue is the race condition between br_write_[un]lock() and CPU hotplug, which results in the lock states getting messed up). Fixing this race by just adding {get,put}_online_cpus() at appropriate places in *_global_[un]lock_online() is not a good option, because, then suddenly br_write_[un]lock() would become blocking, whereas they have been kept as non-blocking all this time, and we would want to keep them that way. So, overall, we want to ensure 3 things: 1. br_write_lock() and br_write_unlock() must remain as non-blocking. 2. The corresponding lock and unlock of the per-cpu spinlocks must not happen for different sets of CPUs. 3. Either prevent any new CPU online operation in between this lock-unlock, or ensure that the newly onlined CPU does not proceed with its corresponding per-cpu spinlock unlocked. To achieve all this: (a) We introduce a new spinlock that is taken by the *_global_lock_online() routine and released by the *_global_unlock_online() routine. (b) We register a callback for CPU hotplug notifications, and this callback takes the same spinlock as above. (c) We maintain a bitmap which is close to the cpu_online_mask, and once it is initialized in the lock_init() code, all future updates to it are done in the callback, under the above spinlock. (d) The above bitmap is used (instead of cpu_online_mask) while locking and unlocking the per-cpu locks. The callback takes the spinlock upon the CPU_UP_PREPARE event. So, if the br_write_lock-unlock sequence is in progress, the callback keeps spinning, thus preventing the CPU online operation till the lock-unlock sequence is complete. This takes care of requirement (3). The bitmap that we maintain remains unmodified throughout the lock-unlock sequence, since all updates to it are managed by the callback, which takes the same spinlock as the one taken by the lock code and released only by the unlock routine. Combining this with (d) above, satisfies requirement (2). Overall, since we use a spinlock (mentioned in (a)) to prevent CPU hotplug operations from racing with br_write_lock-unlock, requirement (1) is also taken care of. By the way, it is to be noted that a CPU offline operation can actually run in parallel with our lock-unlock sequence, because our callback doesn't react to notifications earlier than CPU_DEAD (in order to maintain our bitmap properly). And this means, since we use our own bitmap (which is stale, on purpose) during the lock-unlock sequence, we could end up unlocking the per-cpu lock of an offline CPU (because we had locked it earlier, when the CPU was online), in order to satisfy requirement (2). But this is harmless, though it looks a bit awkward. Debugged-by: Cong Meng <mc@linux.vnet.ibm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * block: initialize request_queue's numa node duringMike Snitzer2012-01-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5151412dd4338b273afdb107c3772528e9e67d92 upstream. struct request_queue is allocated with __GFP_ZERO so its "node" field is zero before initialization. This causes an oops if node 0 is offline in the page allocator because its zonelists are not initialized. From Dave Young's dmesg: SRAT: Node 1 PXM 2 0-d0000000 SRAT: Node 1 PXM 2 100000000-330000000 SRAT: Node 0 PXM 1 330000000-630000000 Initmem setup node 1 0000000000000000-000000000affb000 ... Built 1 zonelists in Node order, mobility grouping on. ... BUG: unable to handle kernel paging request at 0000000000001c08 IP: [<ffffffff8111c355>] __alloc_pages_nodemask+0xb5/0x870 and __alloc_pages_nodemask+0xb5 translates to a NULL pointer on zonelist->_zonerefs. The fix is to initialize q->node at the time of allocation so the correct node is passed to the slab allocator later. Since blk_init_allocated_queue_node() is no longer needed, merge it with blk_init_allocated_queue(). [rientjes@google.com: changelog, initializing q->node] Reported-by: Dave Young <dyoung@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Tested-by: Dave Young <dyoung@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * linux/log2.h: Fix rounddown_pow_of_two(1)Linus Torvalds2011-12-211-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 13c07b0286d340275f2d97adf085cecda37ede37 upstream. Exactly like roundup_pow_of_two(1), the rounddown version was buggy for the case of a compile-time constant '1' argument. Probably because it originated from the same code, sharing history with the roundup version from before the bugfix (for that one, see commit 1a06a52ee1b0: "Fix roundup_pow_of_two(1)"). However, unlike the roundup version, the fix for rounddown is to just remove the broken special case entirely. It's simply not needed - the generic code 1UL << ilog2(n) does the right thing for the constant '1' argment too. The only reason roundup needed that special case was because rounding up does so by subtracting one from the argument (and then adding one to the result) causing the obvious problems with "ilog2(0)". But rounddown doesn't do any of that, since ilog2() naturally truncates (ie "rounds down") to the right rounded down value. And without the ilog2(0) case, there's no reason for the special case that had the wrong value. tl;dr: rounddown_pow_of_two(1) should be 1, not 0. Acked-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * fix apparmor dereferencing potentially freed dentry, sanitize __d_path() APIAl Viro2011-12-212-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 02125a826459a6ad142f8d91c5b6357562f96615 upstream. __d_path() API is asking for trouble and in case of apparmor d_namespace_path() getting just that. The root cause is that when __d_path() misses the root it had been told to look for, it stores the location of the most remote ancestor in *root. Without grabbing references. Sure, at the moment of call it had been pinned down by what we have in *path. And if we raced with umount -l, we could have very well stopped at vfsmount/dentry that got freed as soon as prepend_path() dropped vfsmount_lock. It is safe to compare these pointers with pre-existing (and known to be still alive) vfsmount and dentry, as long as all we are asking is "is it the same address?". Dereferencing is not safe and apparmor ended up stepping into that. d_namespace_path() really wants to examine the place where we stopped, even if it's not connected to our namespace. As the result, it looked at ->d_sb->s_magic of a dentry that might've been already freed by that point. All other callers had been careful enough to avoid that, but it's really a bad interface - it invites that kind of trouble. The fix is fairly straightforward, even though it's bigger than I'd like: * prepend_path() root argument becomes const. * __d_path() is never called with NULL/NULL root. It was a kludge to start with. Instead, we have an explicit function - d_absolute_root(). Same as __d_path(), except that it doesn't get root passed and stops where it stops. apparmor and tomoyo are using it. * __d_path() returns NULL on path outside of root. The main caller is show_mountinfo() and that's precisely what we pass root for - to skip those outside chroot jail. Those who don't want that can (and do) use d_path(). * __d_path() root argument becomes const. Everyone agrees, I hope. * apparmor does *NOT* try to use __d_path() or any of its variants when it sees that path->mnt is an internal vfsmount. In that case it's definitely not mounted anywhere and dentry_path() is exactly what we want there. Handling of sysctl()-triggered weirdness is moved to that place. * if apparmor is asked to do pathname relative to chroot jail and __d_path() tells it we it's not in that jail, the sucker just calls d_absolute_path() instead. That's the other remaining caller of __d_path(), BTW. * seq_path_root() does _NOT_ return -ENAMETOOLONG (it's stupid anyway - the normal seq_file logics will take care of growing the buffer and redoing the call of ->show() just fine). However, if it gets path not reachable from root, it returns SEQ_SKIP. The only caller adjusted (i.e. stopped ignoring the return value as it used to do). Reviewed-by: John Johansen <john.johansen@canonical.com> ACKed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * firmware: Sigma: Fix endianess issuesLars-Peter Clausen2011-12-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | commit bda63586bc5929e97288cdb371bb6456504867ed upstream. Currently the SigmaDSP firmware loader only works correctly on little-endian systems. Fix this by using the proper endianess conversion functions. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * firmware: Sigma: Prevent out of bounds memory accessLars-Peter Clausen2011-12-091-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4f718a29fe4908c2cea782f751e9805319684e2b upstream. The SigmaDSP firmware loader currently does not perform enough boundary size checks when processing the firmware. As a result it is possible that a malformed firmware can cause an out of bounds memory access. This patch adds checks which ensure that both the action header and the payload are completely inside the firmware data boundaries before processing them. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * nfs: when attempting to open a directory, fall back on normal lookup (try #5)Jeff Layton2011-11-262-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1788ea6e3b2a58cf4fb00206e362d9caff8d86a7 upstream. commit d953126 changed how nfs_atomic_lookup handles an -EISDIR return from an OPEN call. Prior to that patch, that caused the client to fall back to doing a normal lookup. When that patch went in, the code began returning that error to userspace. The d_revalidate codepath however never had the corresponding change, so it was still possible to end up with a NULL ctx->state pointer after that. That patch caused a regression. When we attempt to open a directory that does not have a cached dentry, that open now errors out with EISDIR. If you attempt the same open with a cached dentry, it will succeed. Fix this by reverting the change in nfs_atomic_lookup and allowing attempts to open directories to fall back to a normal lookup Also, add a NFSv4-specific f_ops->open routine that just returns -ENOTDIR. This should never be called if things are working properly, but if it ever is, then the dprintk may help in debugging. To facilitate this, a new file_operations field is also added to the nfs_rpc_ops struct. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * thp: share get_huge_page_tail()Andrea Arcangeli2011-11-111-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b35a35b556f5e6b7993ad0baf20173e75c09ce8c upstream. This avoids duplicating the function in every arch gup_fast. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * ext2,ext3,ext4: don't inherit APPEND_FL or IMMUTABLE_FL for new inodesTheodore Ts'o2011-11-112-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1cd9f0976aa4606db8d6e3dc3edd0aca8019372a upstream. This doesn't make much sense, and it exposes a bug in the kernel where attempts to create a new file in an append-only directory using O_CREAT will fail (but still leave a zero-length file). This was discovered when xfstests #79 was generalized so it could run on all file systems. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * mm: thp: tail page refcounting fixAndrea Arcangeli2011-11-112-38/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 70b50f94f1644e2aa7cb374819cfd93f3c28d725 upstream. Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * vfs pathname lookup: Add LOOKUP_AUTOMOUNT flagLinus Torvalds2011-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we've now turned around and made LOOKUP_FOLLOW *not* force an automount, we want to add the ability to force an automount event on lookup even if we don't happen to have one of the other flags that force it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..) Most cases will never want to use this, since you'd normally want to delay automounting as long as possible, which usually implies LOOKUP_OPEN (when we open a file or directory, we really cannot avoid the automount any more). But Trond argued sufficiently forcefully that at a minimum bind mounting a file and quotactl will want to force the automount lookup. Some other cases (like nfs_follow_remote_path()) could use it too, although LOOKUP_DIRECTORY would work there as well. This commit just adds the flag and logic, no users yet, though. It also doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and was made irrelevant by the same change that made us not follow on LOOKUP_FOLLOW. Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Ian Kent <raven@themaw.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * readlinkat: ensure we return ENOENT for the empty pathname for normal lookupsAndy Whitcroft2011-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 upstream. Since the commit below which added O_PATH support to the *at() calls, the error return for readlink/readlinkat for the empty pathname has switched from ENOENT to EINVAL: commit 65cfc6722361570bfe255698d9cd4dccaf47570d Author: Al Viro <viro@zeniv.linux.org.uk> Date: Sun Mar 13 15:56:26 2011 -0400 readlinkat(), fchownat() and fstatat() with empty relative pathnames This is both unexpected for userspace and makes readlink/readlinkat inconsistant with all other interfaces; and inconsistant with our stated return for these pathnames. As the readlinkat call does not have a flags parameter we cannot use the AT_EMPTY_PATH approach used in the other calls. Therefore expose whether the original path is infact entry via a new user_path_at_empty() path lookup function. Use this to determine whether to default to EINVAL or ENOENT for failures. Addresses http://bugs.launchpad.net/bugs/817187 [akpm@linux-foundation.org: remove unused getname_flags()] Signed-off-by: Andy Whitcroft <apw@canonical.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * mm: avoid null pointer access in vm_struct via /proc/vmallocinfoMitsuo Hayasaka2011-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f5252e009d5b87071a919221e4f6624184005368 upstream. The /proc/vmallocinfo shows information about vmalloc allocations in vmlist that is a linklist of vm_struct. It, however, may access pages field of vm_struct where a page was not allocated. This results in a null pointer access and leads to a kernel panic. Why this happens: In __vmalloc_node_range() called from vmalloc(), newly allocated vm_struct is added to vmlist at __get_vm_area_node() and then, some fields of vm_struct such as nr_pages and pages are set at __vmalloc_area_node(). In other words, it is added to vmlist before it is fully initialized. At the same time, when the /proc/vmallocinfo is read, it accesses the pages field of vm_struct according to the nr_pages field at show_numa_info(). Thus, a null pointer access happens. The patch adds the newly allocated vm_struct to the vmlist *after* it is fully initialized. So, it can avoid accessing the pages field with unallocated page when show_numa_info() is called. Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * io-mapping: ensure io_mapping_map_atomic _is_ atomicDaniel Vetter2011-11-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 24dd85ff723f142093f44244764b9b5c152235b8 upstream. For the !HAVE_ATOMIC_IOMAP case the stub functions did not call pagefault_disable/_enable. The i915 driver relies on the map actually being atomic, otherwise it can deadlock with it's own pagefault handler in the gtt pwrite fastpath. This is exercised by gem_mmap_gtt from the intel-gpu-toosl gem testsuite. v2: Chris Wilson noted the lack of an include. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38115 Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
generated by cgit v1.1 at 2025-01-25 08:41:32 +0000