- 31 Jul, 2014 6 commits
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Naoya Horiguchi authored
commit 0253d634 upstream. Commit 4a705fef ("hugetlb: fix copy_hugetlb_page_range() to handle migration/hwpoisoned entry") changed the order of huge_ptep_set_wrprotect() and huge_ptep_get(), which leads to breakage in some workloads like hugepage-backed heap allocation via libhugetlbfs. This patch fixes it. The test program for the problem is shown below: $ cat heap.c #include <unistd.h> #include <stdlib.h> #include <string.h> #define HPS 0x200000 int main() { int i; char *p = malloc(HPS); memset(p, '1', HPS); for (i = 0; i < 5; i++) { if (!fork()) { memset(p, '2', HPS); p = malloc(HPS); memset(p, '3', HPS); free(p); return 0; } } sleep(1); free(p); return 0; } $ export HUGETLB_MORECORE=yes ; export HUGETLB_NO_PREFAULT= ; hugectl --heap ./heap Fixes 4a705fef ("hugetlb: fix copy_hugetlb_page_range() to handle migration/hwpoisoned entry"), so is applicable to -stable kernels which include it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Guillaume Morin <guillaume@morinfr.org> Suggested-by: Guillaume Morin <guillaume@morinfr.org> Acked-by: 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@linuxfoundation.org>
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Sven Wegener authored
commit 8142b215 upstream. Commit 554086d8 ("x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)") introduced a regression in the x86_32 syscall entry code, resulting in syscall() not returning proper errors for undefined syscalls on CPUs supporting the sysenter feature. The following code: > int result = syscall(666); > printf("result=%d errno=%d error=%s\n", result, errno, strerror(errno)); results in: > result=666 errno=0 error=Success Obviously, the syscall return value is the called syscall number, but it should have been an ENOSYS error. When run under ptrace it behaves correctly, which makes it hard to debug in the wild: > result=-1 errno=38 error=Function not implemented The %eax register is the return value register. For debugging via ptrace the syscall entry code stores the complete register context on the stack. The badsys handlers only store the ENOSYS error code in the ptrace register set and do not set %eax like a regular syscall handler would. The old resume_userspace call chain contains code that clobbers %eax and it restores %eax from the ptrace registers afterwards. The same goes for the ptrace-enabled call chain. When ptrace is not used, the syscall return value is the passed-in syscall number from the untouched %eax register. Use %eax as the return value register in syscall_badsys and sysenter_badsys, like a real syscall handler does, and have the caller push the value onto the stack for ptrace access. Signed-off-by: Sven Wegener <sven.wegener@stealer.net> Link: http://lkml.kernel.org/r/alpine.LNX.2.11.1407221022380.31021@titan.int.lan.stealer.netReviewed-and-tested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Romain Degez authored
commit b32bfc06 upstream. Add support of the Promise FastTrak TX8660 SATA HBA in ahci mode by registering the board in the ahci_pci_tbl[]. Note: this HBA also provide a hardware RAID mode when activated in BIOS but specific drivers from the manufacturer are required in this case. Signed-off-by: Romain Degez <romain.degez@gmail.com> Tested-by: Romain Degez <romain.degez@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Tejun Heo authored
commit 1a112d10 upstream. 1871ee13 ("libata: support the ata host which implements a queue depth less than 32") directly used ata_port->scsi_host->can_queue from ata_qc_new() to determine the number of tags supported by the host; unfortunately, SAS controllers doing SATA don't initialize ->scsi_host leading to the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 IP: [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0 PGD 0 Oops: 0002 [#1] SMP Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000 RIP: 0010:[<ffffffff814e0618>] [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0 RSP: 0018:ffff88061a003ae8 EFLAGS: 00010012 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000 FS: 00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0 Stack: ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200 ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68 ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80 Call Trace: [<ffffffff814e96e1>] ata_sas_queuecmd+0xa1/0x430 [<ffffffffa0056ce1>] sas_queuecommand+0x191/0x220 [libsas] [<ffffffff8149afee>] scsi_dispatch_cmd+0x10e/0x300 [<ffffffff814a3bc5>] scsi_request_fn+0x2f5/0x550 [<ffffffff81317613>] __blk_run_queue+0x33/0x40 [<ffffffff8131781a>] queue_unplugged+0x2a/0x90 [<ffffffff8131ceb4>] blk_flush_plug_list+0x1b4/0x210 [<ffffffff8131d274>] blk_finish_plug+0x14/0x50 [<ffffffff8117eaa8>] __do_page_cache_readahead+0x198/0x1f0 [<ffffffff8117ee21>] force_page_cache_readahead+0x31/0x50 [<ffffffff8117ee7e>] page_cache_sync_readahead+0x3e/0x50 [<ffffffff81172ac6>] generic_file_read_iter+0x496/0x5a0 [<ffffffff81219897>] blkdev_read_iter+0x37/0x40 [<ffffffff811e307e>] new_sync_read+0x7e/0xb0 [<ffffffff811e3734>] vfs_read+0x94/0x170 [<ffffffff811e43c6>] SyS_read+0x46/0xb0 [<ffffffff811e33d1>] ? SyS_lseek+0x91/0xb0 [<ffffffff8171ee29>] system_call_fastpath+0x16/0x1b Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00 Fix it by introducing ata_host->n_tags which is initialized to ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to scsi_host_template->can_queue in ata_host_register() for !SAS ones. As SAS hosts are never registered, this will give them the same ATA_MAX_QUEUE - 1 as before. Note that we can't use scsi_host->can_queue directly for SAS hosts anyway as they can go higher than the libata maximum. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Reported-by: Jesse Brandeburg <jesse.brandeburg@gmail.com> Reported-by: Peter Hurley <peter@hurleysoftware.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Fixes: 1871ee13 ("libata: support the ata host which implements a queue depth less than 32") Cc: Kevin Hao <haokexin@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Kevin Hao authored
commit 1871ee13 upstream. The sata on fsl mpc8315e is broken after the commit 8a4aeec8 ("libata/ahci: accommodate tag ordered controllers"). The reason is that the ata controller on this SoC only implement a queue depth of 16. When issuing the commands in tag order, all the commands in tag 16 ~ 31 are mapped to tag 0 unconditionally and then causes the sata malfunction. It makes no senses to use a 32 queue in software while the hardware has less queue depth. So consider the queue depth implemented by the hardware when requesting a command tag. Fixes: 8a4aeec8 ("libata/ahci: accommodate tag ordered controllers") Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Christoph Hellwig authored
commit d45b3279 upstream. There is no inherent reason why the last put of a tag structure must be the one for the Scsi_Host, as device model objects can be held for arbitrary periods. Merge blk_free_tags and __blk_free_tags into a single funtion that just release a references and get rid of the BUG() when the host reference wasn't the last. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 28 Jul, 2014 24 commits
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Greg Kroah-Hartman authored
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Takao Indoh authored
commit 3a93c841 upstream. This patch disables translation(dma-remapping) before its initialization if it is already enabled. This is needed for kexec/kdump boot. If dma-remapping is enabled in the first kernel, it need to be disabled before initializing its page table during second kernel boot. Wei Hu also reported that this is needed when second kernel boots with intel_iommu=off. Basically iommu->gcmd is used to know whether translation is enabled or disabled, but it is always zero at boot time even when translation is enabled since iommu->gcmd is initialized without considering such a case. Therefor this patch synchronizes iommu->gcmd value with global command register when iommu structure is allocated. Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Signed-off-by: Joerg Roedel <joro@8bytes.org> [wyj: Backported to 3.4: adjust context] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Takashi Iwai authored
commit 4320f6b1 upstream. The commit [247bc037: PM / Sleep: Mitigate race between the freezer and request_firmware()] introduced the finer state control, but it also leads to a new bug; for example, a bug report regarding the firmware loading of intel BT device at suspend/resume: https://bugzilla.novell.com/show_bug.cgi?id=873790 The root cause seems to be a small window between the process resume and the clear of usermodehelper lock. The request_firmware() function checks the UMH lock and gives up when it's in UMH_DISABLE state. This is for avoiding the invalid f/w loading during suspend/resume phase. The problem is, however, that usermodehelper_enable() is called at the end of thaw_processes(). Thus, a thawed process in between can kick off the f/w loader code path (in this case, via btusb_setup_intel()) even before the call of usermodehelper_enable(). Then usermodehelper_read_trylock() returns an error and request_firmware() spews WARN_ON() in the end. This oneliner patch fixes the issue just by setting to UMH_FREEZING state again before restarting tasks, so that the call of request_firmware() will be blocked until the end of this function instead of returning an error. Fixes: 247bc037 (PM / Sleep: Mitigate race between the freezer and request_firmware()) Link: https://bugzilla.novell.com/show_bug.cgi?id=873790Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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John Stultz authored
commit 16927776 upstream. Sharvil noticed with the posix timer_settime interface, using the CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users tried to specify a relative time timer, it would incorrectly be treated as absolute regardless of the state of the flags argument. This patch corrects this, properly checking the absolute/relative flag, as well as adds further error checking that no invalid flag bits are set. Reported-by: Sharvil Nanavati <sharvil@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Alex Deucher authored
commit 0ac66eff upstream. In some cases we fetch the edid in the detect() callback in order to determine what sort of monitor is connected. If that happens, don't fetch the edid again in the get_modes() callback or we will leak the edid. Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Amitkumar Karwar authored
commit d76744a9 upstream. https://bugzilla.kernel.org/show_bug.cgi?id=70191 https://bugzilla.kernel.org/show_bug.cgi?id=77581 It is observed that sometimes Tx packet is downloaded without adding driver's txpd header. This results in firmware parsing garbage data as packet length. Sometimes firmware is unable to read the packet if length comes out as invalid. This stops further traffic and timeout occurs. The root cause is uninitialized fields in tx_info(skb->cb) of packet used to get garbage values. In this case if MWIFIEX_BUF_FLAG_REQUEUED_PKT flag is mistakenly set, txpd header was skipped. This patch makes sure that tx_info is correctly initialized to fix the problem. Reported-by: Andrew Wiley <wiley.andrew.j@gmail.com> Reported-by: Linus Gasser <list@markas-al-nour.org> Reported-by: Michael Hirsch <hirsch@teufel.de> Tested-by: Xinming Hu <huxm@marvell.com> Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Maithili Hinge <maithili@marvell.com> Signed-off-by: Avinash Patil <patila@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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HATAYAMA Daisuke authored
commit b292d7a1 upstream. Currently, any NMI is falsely handled by a NMI handler of NMI watchdog if CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR is set. For example, we use external NMI to make system panic to get crash dump, but in this case, the external NMI is falsely handled do to the issue. This commit deals with the issue simply by ignoring CondChgd bit. Here is explanation in detail. On x86 NMI watchdog uses performance monitoring feature to periodically signal NMI each time performance counter gets overflowed. intel_pmu_handle_irq() is called as a NMI_LOCAL handler from a NMI handler of NMI watchdog, perf_event_nmi_handler(). It identifies an owner of a given NMI by looking at overflow status bits in MSR_CORE_PERF_GLOBAL_STATUS MSR. If some of the bits are set, then it handles the given NMI as its own NMI. The problem is that the intel_pmu_handle_irq() doesn't distinguish CondChgd bit from other bits. Unlike the other status bits, CondChgd bit doesn't represent overflow status for performance counters. Thus, CondChgd bit cannot be thought of as a mark indicating a given NMI is NMI watchdog's. As a result, if CondChgd bit is set, any NMI is falsely handled by the NMI handler of NMI watchdog. Also, if type of the falsely handled NMI is either NMI_UNKNOWN, NMI_SERR or NMI_IO_CHECK, the corresponding action is never performed until CondChgd bit is cleared. I noticed this behavior on systems with Ivy Bridge processors: Intel Xeon CPU E5-2630 v2 and Intel Xeon CPU E7-8890 v2. On both systems, CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR has already been set in the beginning at boot. Then the CondChgd bit is immediately cleared by next wrmsr to MSR_CORE_PERF_GLOBAL_CTRL MSR and appears to remain 0. On the other hand, on older processors such as Nehalem, Xeon E7540, CondChgd bit is not set in the beginning at boot. I'm not sure about exact behavior of CondChgd bit, in particular when this bit is set. Although I read Intel System Programmer's Manual to figure out that, the descriptions I found are: In 18.9.1: "The MSR_PERF_GLOBAL_STATUS MSR also provides a ¡sticky bit¢ to indicate changes to the state of performancmonitoring hardware" In Table 35-2 IA-32 Architectural MSRs 63 CondChg: status bits of this register has changed. These are different from the bahviour I see on the actual system as I explained above. At least, I think ignoring CondChgd bit should be enough for NMI watchdog perspective. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140625.103503.409316067.d.hatayama@jp.fujitsu.comSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Eric Dumazet authored
[ Upstream commit 10ec9472 ] There is a benign buffer overflow in ip_options_compile spotted by AddressSanitizer[1] : Its benign because we always can access one extra byte in skb->head (because header is followed by struct skb_shared_info), and in this case this byte is not even used. [28504.910798] ================================================================== [28504.912046] AddressSanitizer: heap-buffer-overflow in ip_options_compile [28504.913170] Read of size 1 by thread T15843: [28504.914026] [<ffffffff81802f91>] ip_options_compile+0x121/0x9c0 [28504.915394] [<ffffffff81804a0d>] ip_options_get_from_user+0xad/0x120 [28504.916843] [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630 [28504.918175] [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0 [28504.919490] [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90 [28504.920835] [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70 [28504.922208] [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140 [28504.923459] [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b [28504.924722] [28504.925106] Allocated by thread T15843: [28504.925815] [<ffffffff81804995>] ip_options_get_from_user+0x35/0x120 [28504.926884] [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630 [28504.927975] [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0 [28504.929175] [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90 [28504.930400] [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70 [28504.931677] [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140 [28504.932851] [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b [28504.934018] [28504.934377] The buggy address ffff880026382828 is located 0 bytes to the right [28504.934377] of 40-byte region [ffff880026382800, ffff880026382828) [28504.937144] [28504.937474] Memory state around the buggy address: [28504.938430] ffff880026382300: ........ rrrrrrrr rrrrrrrr rrrrrrrr [28504.939884] ffff880026382400: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.941294] ffff880026382500: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr [28504.942504] ffff880026382600: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.943483] ffff880026382700: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.944511] >ffff880026382800: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr [28504.945573] ^ [28504.946277] ffff880026382900: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.094949] ffff880026382a00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.096114] ffff880026382b00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.097116] ffff880026382c00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.098472] ffff880026382d00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.099804] Legend: [28505.100269] f - 8 freed bytes [28505.100884] r - 8 redzone bytes [28505.101649] . - 8 allocated bytes [28505.102406] x=1..7 - x allocated bytes + (8-x) redzone bytes [28505.103637] ================================================================== [1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernelSigned-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ben Hutchings authored
[ Upstream commit 640d7efe ] *_result[len] is parsed as *(_result[len]) which is not at all what we want to touch here. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Fixes: 84a7c0b1 ("dns_resolver: assure that dns_query() result is null-terminated") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Manuel Schölling authored
[ Upstream commit 84a7c0b1 ] dns_query() credulously assumes that keys are null-terminated and returns a copy of a memory block that is off by one. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Sowmini Varadhan authored
[ Upstream commit a4b70a07 ] Nothing cleans up the objects created by vnet_new(), they are completely leaked. vnet_exit(), after doing the vio_unregister_driver() to clean up ports, should call a helper function that iterates over vnet_list and cleans up those objects. This includes unregister_netdevice() as well as free_netdev(). Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Karl Volz <karl.volz@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Christoph Schulz authored
[ Upstream commit a8a3e41c ] The PPP channel MTU is used with Multilink PPP when ppp_mp_explode() (see ppp_generic module) tries to determine how big a fragment might be. According to RFC 1661, the MTU excludes the 2-byte PPP protocol field, see the corresponding comment and code in ppp_mp_explode(): /* * hdrlen includes the 2-byte PPP protocol field, but the * MTU counts only the payload excluding the protocol field. * (RFC1661 Section 2) */ mtu = pch->chan->mtu - (hdrlen - 2); However, the pppoe module *does* include the PPP protocol field in the channel MTU, which is wrong as it causes the PPP payload to be 1-2 bytes too big under certain circumstances (one byte if PPP protocol compression is used, two otherwise), causing the generated Ethernet packets to be dropped. So the pppoe module has to subtract two bytes from the channel MTU. This error only manifests itself when using Multilink PPP, as otherwise the channel MTU is not used anywhere. In the following, I will describe how to reproduce this bug. We configure two pppd instances for multilink PPP over two PPPoE links, say eth2 and eth3, with a MTU of 1492 bytes for each link and a MRRU of 2976 bytes. (This MRRU is computed by adding the two link MTUs and subtracting the MP header twice, which is 4 bytes long.) The necessary pppd statements on both sides are "multilink mtu 1492 mru 1492 mrru 2976". On the client side, we additionally need "plugin rp-pppoe.so eth2" and "plugin rp-pppoe.so eth3", respectively; on the server side, we additionally need to start two pppoe-server instances to be able to establish two PPPoE sessions, one over eth2 and one over eth3. We set the MTU of the PPP network interface to the MRRU (2976) on both sides of the connection in order to make use of the higher bandwidth. (If we didn't do that, IP fragmentation would kick in, which we want to avoid.) Now we send a ICMPv4 echo request with a payload of 2948 bytes from client to server over the PPP link. This results in the following network packet: 2948 (echo payload) + 8 (ICMPv4 header) + 20 (IPv4 header) --------------------- 2976 (PPP payload) These 2976 bytes do not exceed the MTU of the PPP network interface, so the IP packet is not fragmented. Now the multilink PPP code in ppp_mp_explode() prepends one protocol byte (0x21 for IPv4), making the packet one byte bigger than the negotiated MRRU. So this packet would have to be divided in three fragments. But this does not happen as each link MTU is assumed to be two bytes larger. So this packet is diveded into two fragments only, one of size 1489 and one of size 1488. Now we have for that bigger fragment: 1489 (PPP payload) + 4 (MP header) + 2 (PPP protocol field for the MP payload (0x3d)) + 6 (PPPoE header) -------------------------- 1501 (Ethernet payload) This packet exceeds the link MTU and is discarded. If one configures the link MTU on the client side to 1501, one can see the discarded Ethernet frames with tcpdump running on the client. A ping -s 2948 -c 1 192.168.15.254 leads to the smaller fragment that is correctly received on the server side: (tcpdump -vvvne -i eth3 pppoes and ppp proto 0x3d) 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x3] MLPPP (0x003d), length 1494: seq 0x000, Flags [end], length 1492 and to the bigger fragment that is not received on the server side: (tcpdump -vvvne -i eth2 pppoes and ppp proto 0x3d) 52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864), length 1515: PPPoE [ses 0x5] MLPPP (0x003d), length 1495: seq 0x000, Flags [begin], length 1493 With the patch below, we correctly obtain three fragments: 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000, Flags [begin], length 1492 52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864), length 1514: PPPoE [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000, Flags [none], length 1492 52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864), length 27: PPPoE [ses 0x1] MLPPP (0x003d), length 7: seq 0x000, Flags [end], length 5 And the ICMPv4 echo request is successfully received at the server side: IP (tos 0x0, ttl 64, id 21925, offset 0, flags [DF], proto ICMP (1), length 2976) 192.168.222.2 > 192.168.15.254: ICMP echo request, id 30530, seq 0, length 2956 The bug was introduced in commit c9aa6895 ("[PPPOE]: Advertise PPPoE MTU") from the very beginning. This patch applies to 3.10 upwards but the fix can be applied (with minor modifications) to kernels as old as 2.6.32. Signed-off-by: Christoph Schulz <develop@kristov.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Daniel Borkmann authored
[ Upstream commit 8f2e5ae4 ] While working on some other SCTP code, I noticed that some structures shared with user space are leaking uninitialized stack or heap buffer. In particular, struct sctp_sndrcvinfo has a 2 bytes hole between .sinfo_flags and .sinfo_ppid that remains unfilled by us in sctp_ulpevent_read_sndrcvinfo() when putting this into cmsg. But also struct sctp_remote_error contains a 2 bytes hole that we don't fill but place into a skb through skb_copy_expand() via sctp_ulpevent_make_remote_error(). Both structures are defined by the IETF in RFC6458: * Section 5.3.2. SCTP Header Information Structure: The sctp_sndrcvinfo structure is defined below: struct sctp_sndrcvinfo { uint16_t sinfo_stream; uint16_t sinfo_ssn; uint16_t sinfo_flags; <-- 2 bytes hole --> uint32_t sinfo_ppid; uint32_t sinfo_context; uint32_t sinfo_timetolive; uint32_t sinfo_tsn; uint32_t sinfo_cumtsn; sctp_assoc_t sinfo_assoc_id; }; * 6.1.3. SCTP_REMOTE_ERROR: A remote peer may send an Operation Error message to its peer. This message indicates a variety of error conditions on an association. The entire ERROR chunk as it appears on the wire is included in an SCTP_REMOTE_ERROR event. Please refer to the SCTP specification [RFC4960] and any extensions for a list of possible error formats. An SCTP error notification has the following format: struct sctp_remote_error { uint16_t sre_type; uint16_t sre_flags; uint32_t sre_length; uint16_t sre_error; <-- 2 bytes hole --> sctp_assoc_t sre_assoc_id; uint8_t sre_data[]; }; Fix this by setting both to 0 before filling them out. We also have other structures shared between user and kernel space in SCTP that contains holes (e.g. struct sctp_paddrthlds), but we copy that buffer over from user space first and thus don't need to care about it in that cases. While at it, we can also remove lengthy comments copied from the draft, instead, we update the comment with the correct RFC number where one can look it up. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jon Paul Maloy authored
[ Upstream commit 99941754 ] If the 'next' pointer of the last fragment buffer in a message is not zeroed before reassembly, we risk ending up with a corrupt message, since the reassembly function itself isn't doing this. Currently, when a buffer is retrieved from the deferred queue of the broadcast link, the next pointer is not cleared, with the result as described above. This commit corrects this, and thereby fixes a bug that may occur when long broadcast messages are transmitted across dual interfaces. The bug has been present since 40ba3cdf ("tipc: message reassembly using fragment chain") This commit should be applied to both net and net-next. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Suresh Reddy authored
[ Upstream commit 4cad9f3b ] On BE3, if the clear-interrupt bit of the EQ doorbell is not set the first time it is armed, ocassionally we have observed that the EQ doesn't raise anymore interrupts even if it is in armed state. This patch fixes this by setting the clear-interrupt bit when EQs are armed for the first time in be_open(). Signed-off-by: Suresh Reddy <Suresh.Reddy@emulex.com> Signed-off-by: Sathya Perla <sathya.perla@emulex.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andrey Utkin authored
[ Upstream commit 36beddc2 ] Setting just skb->sk without taking its reference and setting a destructor is invalid. However, in the places where this was done, skb is used in a way not requiring skb->sk setting. So dropping the setting of skb->sk. Thanks to Eric Dumazet <eric.dumazet@gmail.com> for correct solution. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79441Reported-by: Ed Martin <edman007@edman007.com> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Yuchung Cheng authored
[ Upstream commit 6e08d5e3 ] The undo code assumes that, upon entering loss recovery, TCP 1) always retransmit something 2) the retransmission never fails locally (e.g., qdisc drop) so undo_marker is set in tcp_enter_recovery() and undo_retrans is incremented only when tcp_retransmit_skb() is successful. When the assumption is broken because TCP's cwnd is too small to retransmit or the retransmit fails locally. The next (DUP)ACK would incorrectly revert the cwnd and the congestion state in tcp_try_undo_dsack() or tcp_may_undo(). Subsequent (DUP)ACKs may enter the recovery state. The sender repeatedly enter and (incorrectly) exit recovery states if the retransmits continue to fail locally while receiving (DUP)ACKs. The fix is to initialize undo_retrans to -1 and start counting on the first retransmission. Always increment undo_retrans even if the retransmissions fail locally because they couldn't cause DSACKs to undo the cwnd reduction. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dingtianhong authored
[ Upstream commit 52ad353a ] The problem was triggered by these steps: 1) create socket, bind and then setsockopt for add mc group. mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37"); mreq.imr_interface.s_addr = inet_addr("192.168.1.2"); setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)); 2) drop the mc group for this socket. mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37"); mreq.imr_interface.s_addr = inet_addr("0.0.0.0"); setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); 3) and then drop the socket, I found the mc group was still used by the dev: netstat -g Interface RefCnt Group --------------- ------ --------------------- eth2 1 255.0.0.37 Normally even though the IP_DROP_MEMBERSHIP return error, the mc group still need to be released for the netdev when drop the socket, but this process was broken when route default is NULL, the reason is that: The ip_mc_leave_group() will choose the in_dev by the imr_interface.s_addr, if input addr is NULL, the default route dev will be chosen, then the ifindex is got from the dev, then polling the inet->mc_list and return -ENODEV, but if the default route dev is NULL, the in_dev and ifIndex is both NULL, when polling the inet->mc_list, the mc group will be released from the mc_list, but the dev didn't dec the refcnt for this mc group, so when dropping the socket, the mc_list is NULL and the dev still keep this group. v1->v2: According Hideaki's suggestion, we should align with IPv6 (RFC3493) and BSDs, so I add the checking for the in_dev before polling the mc_list, make sure when we remove the mc group, dec the refcnt to the real dev which was using the mc address. The problem would never happened again. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Li RongQing authored
[ Upstream commit 916c1689 ] skb_cow called in vlan_reorder_header does not free the skb when it failed, and vlan_reorder_header returns NULL to reset original skb when it is called in vlan_untag, lead to a memory leak. Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Neal Cardwell authored
[ Upstream commit 2cd0d743 ] If there is an MSS change (or misbehaving receiver) that causes a SACK to arrive that covers the end of an skb but is less than one MSS, then tcp_match_skb_to_sack() was rounding up pkt_len to the full length of the skb ("Round if necessary..."), then chopping all bytes off the skb and creating a zero-byte skb in the write queue. This was visible now because the recently simplified TLP logic in bef1909e ("tcp: fixing TLP's FIN recovery") could find that 0-byte skb at the end of the write queue, and now that we do not check that skb's length we could send it as a TLP probe. Consider the following example scenario: mss: 1000 skb: seq: 0 end_seq: 4000 len: 4000 SACK: start_seq: 3999 end_seq: 4000 The tcp_match_skb_to_sack() code will compute: in_sack = false pkt_len = start_seq - TCP_SKB_CB(skb)->seq = 3999 - 0 = 3999 new_len = (pkt_len / mss) * mss = (3999/1000)*1000 = 3000 new_len += mss = 4000 Previously we would find the new_len > skb->len check failing, so we would fall through and set pkt_len = new_len = 4000 and chop off pkt_len of 4000 from the 4000-byte skb, leaving a 0-byte segment afterward in the write queue. With this new commit, we notice that the new new_len >= skb->len check succeeds, so that we return without trying to fragment. Fixes: adb92db8 ("tcp: Make SACK code to split only at mss boundaries") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Ilpo Jarvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Hugh Dickins authored
commit b1a36650 upstream. shmem_fault() is the actual culprit in trinity's hole-punch starvation, and the most significant cause of such problems: since a page faulted is one that then appears page_mapped(), needing unmap_mapping_range() and i_mmap_mutex to be unmapped again. But it is not the only way in which a page can be brought into a hole in the radix_tree while that hole is being punched; and Vlastimil's testing implies that if enough other processors are busy filling in the hole, then shmem_undo_range() can be kept from completing indefinitely. shmem_file_splice_read() is the main other user of SGP_CACHE, which can instantiate shmem pagecache pages in the read-only case (without holding i_mutex, so perhaps concurrently with a hole-punch). Probably it's silly not to use SGP_READ already (using the ZERO_PAGE for holes): which ought to be safe, but might bring surprises - not a change to be rushed. shmem_read_mapping_page_gfp() is an internal interface used by drivers/gpu/drm GEM (and next by uprobes): it should be okay. And shmem_file_read_iter() uses the SGP_DIRTY variant of SGP_CACHE, when called internally by the kernel (perhaps for a stacking filesystem, which might rely on holes to be reserved): it's unclear whether it could be provoked to keep hole-punch busy or not. We could apply the same umbrella as now used in shmem_fault() to shmem_file_splice_read() and the others; but it looks ugly, and use over a range raises questions - should it actually be per page? can these get starved themselves? The origin of this part of the problem is my v3.1 commit d0823576 ("mm: pincer in truncate_inode_pages_range"), once it was duplicated into shmem.c. It seemed like a nice idea at the time, to ensure (barring RCU lookup fuzziness) that there's an instant when the entire hole is empty; but the indefinitely repeated scans to ensure that make it vulnerable. Revert that "enhancement" to hole-punch from shmem_undo_range(), but retain the unproblematic rescanning when it's truncating; add a couple of comments there. Remove the "indices[0] >= end" test: that is now handled satisfactorily by the inner loop, and mem_cgroup_uncharge_start()/end() are too light to be worth avoiding here. But if we do not always loop indefinitely, we do need to handle the case of swap swizzled back to page before shmem_free_swap() gets it: add a retry for that case, as suggested by Konstantin Khlebnikov; and for the case of page swizzled back to swap, as suggested by Johannes Weiner. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@redhat.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@linuxfoundation.org>
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Hugh Dickins authored
commit 8e205f77 upstream. Commit f00cdc6d ("shmem: fix faulting into a hole while it's punched") was buggy: Sasha sent a lockdep report to remind us that grabbing i_mutex in the fault path is a no-no (write syscall may already hold i_mutex while faulting user buffer). We tried a completely different approach (see following patch) but that proved inadequate: good enough for a rational workload, but not good enough against trinity - which forks off so many mappings of the object that contention on i_mmap_mutex while hole-puncher holds i_mutex builds into serious starvation when concurrent faults force the puncher to fall back to single-page unmap_mapping_range() searches of the i_mmap tree. So return to the original umbrella approach, but keep away from i_mutex this time. We really don't want to bloat every shmem inode with a new mutex or completion, just to protect this unlikely case from trinity. So extend the original with wait_queue_head on stack at the hole-punch end, and wait_queue item on the stack at the fault end. This involves further use of i_lock to guard against the races: lockdep has been happy so far, and I see fs/inode.c:unlock_new_inode() holds i_lock around wake_up_bit(), which is comparable to what we do here. i_lock is more convenient, but we could switch to shmem's info->lock. This issue has been tagged with CVE-2014-4171, which will require commit f00cdc6d and this and the following patch to be backported: we suggest to 3.1+, though in fact the trinity forkbomb effect might go back as far as 2.6.16, when madvise(,,MADV_REMOVE) came in - or might not, since much has changed, with i_mmap_mutex a spinlock before 3.0. Anyone running trinity on 3.0 and earlier? I don't think we need care. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@redhat.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@linuxfoundation.org>
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Hugh Dickins authored
commit f00cdc6d upstream. Trinity finds that mmap access to a hole while it's punched from shmem can prevent the madvise(MADV_REMOVE) or fallocate(FALLOC_FL_PUNCH_HOLE) from completing, until the reader chooses to stop; with the puncher's hold on i_mutex locking out all other writers until it can complete. It appears that the tmpfs fault path is too light in comparison with its hole-punching path, lacking an i_data_sem to obstruct it; but we don't want to slow down the common case. Extend shmem_fallocate()'s existing range notification mechanism, so shmem_fault() can refrain from faulting pages into the hole while it's punched, waiting instead on i_mutex (when safe to sleep; or repeatedly faulting when not). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Dave Jones <davej@redhat.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@linuxfoundation.org>
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Markus F.X.J. Oberhumer authored
commit 0ec73820 upstream. Update the LZO compression test vectors according to the latest compressor version. Signed-off-by: Markus F.X.J. Oberhumer <markus@oberhumer.com> Cc: Derrick Pallas <pallas@meraki.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 17 Jul, 2014 10 commits
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Greg Kroah-Hartman authored
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Lan Tianyu authored
commit 75646e75 upstream. Some machines (eg. Lenovo Z480) ECs are not stable during boot up and causes battery driver fails to be loaded due to failure of getting battery information from EC sometimes. After several retries, the operation will work. This patch is to retry to get battery information 5 times if the first try fails. [ backport to 3.14.5: removed second parameter in acpi_battery_update(), introduced by the commit 9e50bc14 (ACPI / battery: Accelerate battery resume callback)] [naszar <naszar@ya.ru>: backport to 3.14.5] Link: https://bugzilla.kernel.org/show_bug.cgi?id=75581Reported-and-tested-by: naszar <naszar@ya.ru> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Roland Dreier authored
commit c81c8a1e upstream. In __ioremap_caller() (the guts of ioremap), we loop over the range of pfns being remapped and checks each one individually with page_is_ram(). For large ioremaps, this can be very slow. For example, we have a device with a 256 GiB PCI BAR, and ioremapping this BAR can take 20+ seconds -- sometimes long enough to trigger the soft lockup detector! Internally, page_is_ram() calls walk_system_ram_range() on a single page. Instead, we can make a single call to walk_system_ram_range() from __ioremap_caller(), and do our further checks only for any RAM pages that we find. For the common case of MMIO, this saves an enormous amount of work, since the range being ioremapped doesn't intersect system RAM at all. With this change, ioremap on our 256 GiB BAR takes less than 1 second. Signed-off-by: Roland Dreier <roland@purestorage.com> Link: http://lkml.kernel.org/r/1399054721-1331-1-git-send-email-roland@kernel.orgSigned-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Thomas Gleixner authored
commit 27e35715 upstream. When the rtmutex fast path is enabled the slow unlock function can create the following situation: spin_lock(foo->m->wait_lock); foo->m->owner = NULL; rt_mutex_lock(foo->m); <-- fast path free = atomic_dec_and_test(foo->refcnt); rt_mutex_unlock(foo->m); <-- fast path if (free) kfree(foo); spin_unlock(foo->m->wait_lock); <--- Use after free. Plug the race by changing the slow unlock to the following scheme: while (!rt_mutex_has_waiters(m)) { /* Clear the waiters bit in m->owner */ clear_rt_mutex_waiters(m); owner = rt_mutex_owner(m); spin_unlock(m->wait_lock); if (cmpxchg(m->owner, owner, 0) == owner) return; spin_lock(m->wait_lock); } So in case of a new waiter incoming while the owner tries the slow path unlock we have two situations: unlock(wait_lock); lock(wait_lock); cmpxchg(p, owner, 0) == owner mark_rt_mutex_waiters(lock); acquire(lock); Or: unlock(wait_lock); lock(wait_lock); mark_rt_mutex_waiters(lock); cmpxchg(p, owner, 0) != owner enqueue_waiter(); unlock(wait_lock); lock(wait_lock); wakeup_next waiter(); unlock(wait_lock); lock(wait_lock); acquire(lock); If the fast path is disabled, then the simple m->owner = NULL; unlock(m->wait_lock); is sufficient as all access to m->owner is serialized via m->wait_lock; Also document and clarify the wakeup_next_waiter function as suggested by Oleg Nesterov. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140611183852.937945560@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Thomas Gleixner authored
commit 3d5c9340 upstream. Even in the case when deadlock detection is not requested by the caller, we can detect deadlocks. Right now the code stops the lock chain walk and keeps the waiter enqueued, even on itself. Silly not to yell when such a scenario is detected and to keep the waiter enqueued. Return -EDEADLK unconditionally and handle it at the call sites. The futex calls return -EDEADLK. The non futex ones dequeue the waiter, throw a warning and put the task into a schedule loop. Tagged for stable as it makes the code more robust. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brad Mouring <bmouring@ni.com> Link: http://lkml.kernel.org/r/20140605152801.836501969@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Thomas Gleixner authored
commit 82084984 upstream. When we walk the lock chain, we drop all locks after each step. So the lock chain can change under us before we reacquire the locks. That's harmless in principle as we just follow the wrong lock path. But it can lead to a false positive in the dead lock detection logic: T0 holds L0 T0 blocks on L1 held by T1 T1 blocks on L2 held by T2 T2 blocks on L3 held by T3 T4 blocks on L4 held by T4 Now we walk the chain lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> drop locks T2 times out and blocks on L0 Now we continue: lock T2 -> lock L0 -> deadlock detected, but it's not a deadlock at all. Brad tried to work around that in the deadlock detection logic itself, but the more I looked at it the less I liked it, because it's crystal ball magic after the fact. We actually can detect a chain change very simple: lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> next_lock = T2->pi_blocked_on->lock; drop locks T2 times out and blocks on L0 Now we continue: lock T2 -> if (next_lock != T2->pi_blocked_on->lock) return; So if we detect that T2 is now blocked on a different lock we stop the chain walk. That's also correct in the following scenario: lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> next_lock = T2->pi_blocked_on->lock; drop locks T3 times out and drops L3 T2 acquires L3 and blocks on L4 now Now we continue: lock T2 -> if (next_lock != T2->pi_blocked_on->lock) return; We don't have to follow up the chain at that point, because T2 propagated our priority up to T4 already. [ Folded a cleanup patch from peterz ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Brad Mouring <bmouring@ni.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140605152801.930031935@linutronix.deSigned-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Thomas Gleixner authored
commit 397335f0 upstream. The current deadlock detection logic does not work reliably due to the following early exit path: /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! */ if (top_waiter && (!task_has_pi_waiters(task) || top_waiter != task_top_pi_waiter(task))) goto out_unlock_pi; So this not only exits when the task has no waiters, it also exits unconditionally when the current waiter is not the top priority waiter of the task. So in a nested locking scenario, it might abort the lock chain walk and therefor miss a potential deadlock. Simple fix: Continue the chain walk, when deadlock detection is enabled. We also avoid the whole enqueue, if we detect the deadlock right away (A-A). It's an optimization, but also prevents that another waiter who comes in after the detection and before the task has undone the damage observes the situation and detects the deadlock and returns -EDEADLOCK, which is wrong as the other task is not in a deadlock situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Link: http://lkml.kernel.org/r/20140522031949.725272460@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Steven Rostedt (Red Hat) authored
commit 099ed151 upstream. Disabling reading and writing to the trace file should not be able to disable all function tracing callbacks. There's other users today (like kprobes and perf). Reading a trace file should not stop those from happening. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Christian König authored
commit 0986c1a5 upstream. When we set the valid bit on invalid GART entries they are loaded into the TLB when an adjacent entry is loaded. This poisons the TLB with invalid entries which are sometimes not correctly removed on TLB flush. For stable inclusion the patch probably needs to be modified a bit. Signed-off-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Theodore Ts'o authored
commit ae0f78de upstream. Make it clear that values printed are times, and that it is error since last fsck. Also add note about fsck version required. Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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