- 06 Jan, 2017 1 commit
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Jens Axboe authored
commit 0cbc72a1 upstream. aoeblk contains some mysterious code, that wants to elevate the bio vec page counts while it's under IO. That is not needed, it's fragile, and it's causing kernel oopses for some. Reported-by:
Tested-by: Don Koch <kochd@us.ibm.com> Tested-by:
Jens Axboe <axboe@fb.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 15 Dec, 2016 34 commits
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Greg Kroah-Hartman authored
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David Michael authored
commit 57891633 upstream. Both asn1 headers are included by rsa_helper.c, so rsa_helper.o should explicitly depend on them. Signed-off-by:
David Michael <david.michael@coreos.com> Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Cc: Tuomas Tynkkynen <tuomas@tuxera.com> Signed-off-by:
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Michal Hocko authored
commit 777c6e0d upstream. Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its notifiers when HOTPLUG_CPU=y while the registration might succeed even when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap might keep a stale notifier on the list on the manual clean up during the pool tear down and thus corrupt the list. Resulting in the following [ 144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78 [ 144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40 <snipped> [ 145.122628] Call Trace: [ 145.125086] [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20 [ 145.131350] [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400 [ 145.137268] [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300 [ 145.143188] [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10 [ 145.149018] [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30 [ 145.154940] [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0 [ 145.160511] [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20 [ 145.167035] [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0 [ 145.172694] [<ffffffffa290848d>] module_attr_store+0x1d/0x30 [ 145.178443] [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70 [ 145.183925] [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180 [ 145.189761] [<ffffffffa2a99248>] __vfs_write+0x18/0x40 [ 145.194982] [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0 [ 145.200122] [<ffffffffa2a9a732>] SyS_write+0x52/0xa0 [ 145.205177] [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17 This can be even triggered manually by changing /sys/module/zswap/parameters/compressor multiple times. Fix this issue by making unregister APIs symmetric to the register so there are no surprises. Fixes: 47e627bc ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU") Reported-and-tested-by:
Yu Zhao <yuzhao@google.com> Signed-off-by:
Michal Hocko <mhocko@suse.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.orgSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Sven Eckelmann authored
commit c2d0f48a upstream. batadv_tt_prepare_tvlv_local_data can fail to allocate the memory for the new TVLV block. The caller is informed about this problem with the returned length of 0. Not checking this value results in an invalid memory access when either tt_data or tt_change is accessed. Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Fixes: 7ea7b4a1 ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by:
Sven Eckelmann <sven@narfation.org> Signed-off-by:
Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by:
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Boris Brezillon authored
commit 7e251bb2 upstream. The current ndelay() macro definition has an extra semi-colon at the end of the line thus leading to a compilation error when ndelay is used in a conditional block without curly braces like this one: if (cond) ndelay(t); else ... which, after the preprocessor pass gives: if (cond) m68k_ndelay(t);; else ... thus leading to the following gcc error: error: 'else' without a previous 'if' Remove this extra semi-colon. Signed-off-by:
Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: c8ee038b ("m68k: Implement ndelay() based on the existing udelay() logic") Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by:
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Jeff Layton authored
commit c3f4688a upstream. This function sets req->r_locked_dir which is supposed to indicate to ceph_fill_trace that the parent's i_rwsem is locked for write. Unfortunately, there is no guarantee that the dir will be locked when d_revalidate is called, so we really don't want ceph_fill_trace to do any dcache manipulation from this context. Clear req->r_locked_dir since it's clearly not safe to do that. What we really want to know with d_revalidate is whether the dentry still points to the same inode. ceph_fill_trace installs a pointer to the inode in req->r_target_inode, so we can just compare that to d_inode(dentry) to see if it's the same one after the lookup. Also, since we aren't generally interested in the parent here, we can switch to using a GETATTR to hint that to the MDS, which also means that we only need to reserve one cap. Finally, just remove the d_unhashed check. That's really outside the purview of a filesystem's d_revalidate. If the thing became unhashed while we're checking it, then that's up to the VFS to handle anyway. Fixes: 200fd27c ("ceph: use lookup request to revalidate dentry") Link: http://tracker.ceph.com/issues/18041Reported-by:
Donatas Abraitis <donatas.abraitis@gmail.com> Signed-off-by:
Jeff Layton <jlayton@redhat.com> Reviewed-by:
"Yan, Zheng" <zyan@redhat.com> Signed-off-by:
Ilya Dryomov <idryomov@gmail.com> Signed-off-by:
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Stefan Agner authored
commit 4b707fa0 upstream. The eLCDIF IP of the i.MX 7 SoC knows multiple clocks and lists them separately: Clock Clock Root Description apb_clk MAIN_AXI_CLK_ROOT AXI clock pix_clk LCDIF_PIXEL_CLK_ROOT Pixel clock ipg_clk_s MAIN_AXI_CLK_ROOT Peripheral access clock All of them are switched by a single gate, which is part of the IMX7D_LCDIF_PIXEL_ROOT_CLK clock. Hence using that clock also for the AXI bus clock (clock-name "axi") makes sure the gate gets enabled when accessing registers. There seem to be no separate AXI display clock, and the clock is optional. Hence remove the dummy clock. This fixes kernel freezes when starting the X-Server (which disables/re-enables the display controller). Fixes: e8ed73f6 ("ARM: dts: imx7d: add lcdif support") Signed-off-by:
Stefan Agner <stefan@agner.ch> Reviewed-by:
Fabio Estevam <fabio.estevam@nxp.com> Acked-by:
Shawn Guo <shawnguo@kernel.org> Signed-off-by:
Olof Johansson <olof@lixom.net> Signed-off-by:
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Roger Shimizu authored
commit 038ccb3e upstream. Bug report from Debian [0] shows there's minor changed model of Linkstation LS-GL that uses the 2nd SATA port of the SoC. So it's necessary to enable two SATA ports, though for that specific model only the 2nd one is used. [0] https://bugs.debian.org/845611 Fixes: b1742ffa ("ARM: dts: orion5x: add device tree for buffalo linkstation ls-gl") Reported-by:
Ryan Tandy <ryan@nardis.ca> Tested-by:
Roger Shimizu <rogershimizu@gmail.com> Signed-off-by:
Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by:
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Rafael J. Wysocki authored
commit 9713adc2 upstream. Revert commit 2c85025c (ACPI: Execute _PTS before system reboot) as it is reported to cause poweroff and reboot to hang on Dell Latitude E7250. Link: https://bugzilla.kernel.org/show_bug.cgi?id=187061Reported-by:
Gianpaolo <gianpaoloc@gmail.com> Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by:
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추지호 authored
commit b67d0dd7 upstream. Fix for bad memory access while disconnecting. netdev is freed before private data free, and dev is accessed after freeing netdev. This makes a slub problem, and it raise kernel oops with slub debugger config. Signed-off-by:
Jiho Chu <jiho.chu@samsung.com> Signed-off-by:
Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by:
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Marc Kleine-Budde authored
commit 332b05ca upstream. This patch adds a check to limit the number of can_filters that can be set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER are not prevented resulting in a warning. Reference: https://lkml.org/lkml/2016/12/2/230Reported-by:
Andrey Konovalov <andreyknvl@google.com> Tested-by:
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Romain Perier authored
commit 9e5f7a14 upstream. mv_cesa_hash_std_step() copies the creq->state into the SRAM at each step, but this is only required on the first one. By doing that, we overwrite the engine state, and get erroneous results when the crypto request is split in several chunks to fit in the internal SRAM. This commit changes the function to copy the state only on the first step. Fixes: commit 2786cee8 ("crypto: marvell - Move SRAM I/O op...") Signed-off-by:
Romain Perier <romain.perier@free-electrons.com> Signed-off-by:
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tim authored
commit 48a99272 upstream. Algorithms not compatible with mcryptd could be spawned by mcryptd with a direct crypto_alloc_tfm invocation using a "mcryptd(alg)" name construct. This causes mcryptd to crash the kernel if an arbitrary "alg" is incompatible and not intended to be used with mcryptd. It is an issue if AF_ALG tries to spawn mcryptd(alg) to expose it externally. But such algorithms must be used internally and not be exposed. We added a check to enforce that only internal algorithms are allowed with mcryptd at the time mcryptd is spawning an algorithm. Link: http://marc.info/?l=linux-crypto-vger&m=148063683310477&w=2Reported-by:
Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:
Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by:
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Horia Geantă authored
commit 39eaf759 upstream. Start with a clean slate before dealing with bit 16 (pointer size) of Master Configuration Register. This fixes the case of AArch64 boot loader + AArch32 kernel, when the boot loader might set MCFGR[PS] and kernel would fail to clear it. Reported-by:
Alison Wang <alison.wang@nxp.com> Signed-off-by:
Horia Geantă <horia.geanta@nxp.com> Reviewed-By:
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Romain Perier authored
commit 68c7f8c1 upstream. No need to copy the template of an hash operation twice into the SRAM from the step function. Fixes: commit 85030c51 ("crypto: marvell - Add support for chai...") Signed-off-by:
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Dan Williams authored
commit d6eb270c upstream. Given dimms and bus commands share the same command number space we need to be careful that we are translating status in the correct context. Otherwise we can, for example, fail an ND_CMD_GET_CONFIG_SIZE command because max_xfer is zero. It fails because that condition erroneously correlates with the 'cleared == 0' failure of ND_CMD_CLEAR_ERROR. Fixes: aef25338 ("libnvdimm, nfit: centralize command status translation") Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Dan Williams authored
commit 82aa37cf upstream. If an ARS Status command returns truncated output, do not process partial records or otherwise consume non-status fields. Fixes: 0caeef63 ("libnvdimm: Add a poison list and export badblocks") Signed-off-by:
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Dan Williams authored
commit efda1b5d upstream. Given ambiguities in the ACPI 6.1 definition of the "Output (Size)" field of the ARS (Address Range Scrub) Status command, a firmware implementation may in practice return 0, 4, or 8 to indicate that there is no output payload to process. The specification states "Size of Output Buffer in bytes, including this field.". However, 'Output Buffer' is also the name of the entire payload, and earlier in the specification it states "Max Query ARS Status Output Buffer Size: Maximum size of buffer (including the Status and Extended Status fields)". Without this fix if the BIOS happens to return 0 it causes memory corruption as evidenced by this result from the acpi_nfit_ctl() unit test. ars_status00000000: 00020000 00000000 ........ BUG: stack guard page was hit at ffffc90001750000 (stack is ffffc9000174c000..ffffc9000174ffff) kernel stack overflow (page fault): 0000 [#1] SMP DEBUG_PAGEALLOC task: ffff8803332d2ec0 task.stack: ffffc9000174c000 RIP: 0010:[<ffffffff814cfe72>] [<ffffffff814cfe72>] __memcpy+0x12/0x20 RSP: 0018:ffffc9000174f9a8 EFLAGS: 00010246 RAX: ffffc9000174fab8 RBX: 0000000000000000 RCX: 000000001fffff56 RDX: 0000000000000000 RSI: ffff8803231f5a08 RDI: ffffc90001750000 RBP: ffffc9000174fa88 R08: ffffc9000174fab0 R09: ffff8803231f54b8 R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: ffff8803231f54a0 FS: 00007f3a611af640(0000) GS:ffff88033ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc90001750000 CR3: 0000000325b20000 CR4: 00000000000406e0 Stack: ffffffffa00bc60d 0000000000000008 ffffc90000000001 ffffc9000174faac 0000000000000292 ffffffffa00c24e4 ffffffffa00c2914 0000000000000000 0000000000000000 ffffffff00000003 ffff880331ae8ad0 0000000800000246 Call Trace: [<ffffffffa00bc60d>] ? acpi_nfit_ctl+0x49d/0x750 [nfit] [<ffffffffa01f4fe0>] nfit_test_probe+0x670/0xb1b [nfit_test] Fixes: 747ffe11 ("libnvdimm, tools/testing/nvdimm: fix 'ars_status' output buffer sizing") Signed-off-by:
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Vishal Verma authored
commit 9a901f54 upstream. ACPI DSMs can have an 'extended' status which can be non-zero to convey additional information about the command. In the xlat_status routine, where we translate the command statuses, we were returning an error for a non-zero extended status, even if the primary status indicated success. Return from each command's 'case' once we have verified both its status and extend status are good. Fixes: 11294d63 ("nfit: fail DSMs that return non-zero status by default") Signed-off-by:
Vishal Verma <vishal.l.verma@intel.com> Signed-off-by:
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Peter Zijlstra (Intel) authored
commit 7f612a7f upstream. Lukasz reported that perf stat counters overflow handling is broken on KNL/SLM. Both these parts have full_width_write set, and that does indeed have a problem. In order to deal with counter wrap, we must sample the counter at at least half the counter period (see also the sampling theorem) such that we can unambiguously reconstruct the count. However commit: 069e0c3c ("perf/x86/intel: Support full width counting") sets the sampling interval to the full period, not half. Fixing that exposes another issue, in that we must not sign extend the delta value when we shift it right; the counter cannot have decremented after all. With both these issues fixed, counter overflow functions correctly again. Reported-by:
Lukasz Odzioba <lukasz.odzioba@intel.com> Tested-by:
Liang, Kan <kan.liang@intel.com> Tested-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 069e0c3c ("perf/x86/intel: Support full width counting") Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Peng Tao authored
commit c4587631 upstream. local_addr.svm_cid is host cid. We should check guest cid instead, which is remote_addr.svm_cid. Otherwise we end up resetting all connections to all guests. Reviewed-by:
Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by:
Peng Tao <bergwolf@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Mike Galbraith authored
commit 83929cce upstream. Michael Kerrisk reported: > Regarding the previous paragraph... My tests indicate > that writing *any* value to the autogroup [nice priority level] > file causes the task group to get a lower priority. Because autogroup didn't call the then meaningless scale_load()... Autogroup nice level adjustment has been broken ever since load resolution was increased for 64-bit kernels. Use scale_load() to scale group weight. Michael Kerrisk tested this patch to fix the problem: > Applied and tested against 4.9-rc6 on an Intel u7 (4 cores). > Test setup: > > Terminal window 1: running 40 CPU burner jobs > Terminal window 2: running 40 CPU burner jobs > Terminal window 1: running 1 CPU burner job > > Demonstrated that: > * Writing "0" to the autogroup file for TW1 now causes no change > to the rate at which the process on the terminal consume CPU. > * Writing -20 to the autogroup file for TW1 caused those processes > to get the lion's share of CPU while TW2 TW3 get a tiny amount. > * Writing -20 to the autogroup files for TW1 and TW3 allowed the > process on TW3 to get as much CPU as it was getting as when > the autogroup nice values for both terminals were 0. Reported-by:
Michael Kerrisk <mtk.manpages@gmail.com> Tested-by:
Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-man <linux-man@vger.kernel.org> Link: http://lkml.kernel.org/r/1479897217.4306.6.camel@gmx.deSigned-off-by:
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Mauricio Faria de Oliveira authored
commit 2319f847 upstream. The BUG_ON() recently introduced in lpfc_sli_ringtxcmpl_put() is hit in the lpfc_els_abort() > lpfc_sli_issue_abort_iotag() > lpfc_sli_abort_iotag_issue() function path [similar names], due to 'piocb->vport == NULL': BUG_ON(!piocb || !piocb->vport); This happens because lpfc_sli_abort_iotag_issue() doesn't set the 'abtsiocbp->vport' pointer -- but this is not the problem. Previously, lpfc_sli_ringtxcmpl_put() accessed 'piocb->vport' only if 'piocb->iocb.ulpCommand' is neither CMD_ABORT_XRI_CN nor CMD_CLOSE_XRI_CN, which are the only possible values for lpfc_sli_abort_iotag_issue(): lpfc_sli_ringtxcmpl_put(): if ((unlikely(pring->ringno == LPFC_ELS_RING)) && (piocb->iocb.ulpCommand != CMD_ABORT_XRI_CN) && (piocb->iocb.ulpCommand != CMD_CLOSE_XRI_CN) && (!(piocb->vport->load_flag & FC_UNLOADING))) lpfc_sli_abort_iotag_issue(): if (phba->link_state >= LPFC_LINK_UP) iabt->ulpCommand = CMD_ABORT_XRI_CN; else iabt->ulpCommand = CMD_CLOSE_XRI_CN; So, this function path would not have hit this possible NULL pointer dereference before. In order to fix this regression, move the second part of the BUG_ON() check prior to the pointer dereference that it does check for. For reference, this is the stack trace observed. The problem happened because an unsolicited event was received - a PLOGI was received after our PLOGI was issued but not yet complete, so the discovery state machine goes on to sw-abort our PLOGI. kernel BUG at drivers/scsi/lpfc/lpfc_sli.c:1326! Oops: Exception in kernel mode, sig: 5 [#1] <...> NIP [...] lpfc_sli_ringtxcmpl_put+0x1c/0xf0 [lpfc] LR [...] __lpfc_sli_issue_iocb_s4+0x188/0x200 [lpfc] Call Trace: [...] [...] __lpfc_sli_issue_iocb_s4+0xb0/0x200 [lpfc] (unreliable) [...] [...] lpfc_sli_issue_abort_iotag+0x2b4/0x350 [lpfc] [...] [...] lpfc_els_abort+0x1a8/0x4a0 [lpfc] [...] [...] lpfc_rcv_plogi+0x6d4/0x700 [lpfc] [...] [...] lpfc_rcv_plogi_plogi_issue+0xd8/0x1d0 [lpfc] [...] [...] lpfc_disc_state_machine+0xc0/0x2b0 [lpfc] [...] [...] lpfc_els_unsol_buffer+0xcc0/0x26c0 [lpfc] [...] [...] lpfc_els_unsol_event+0xa8/0x220 [lpfc] [...] [...] lpfc_complete_unsol_iocb+0xb8/0x138 [lpfc] [...] [...] lpfc_sli4_handle_received_buffer+0x6a0/0xec0 [lpfc] [...] [...] lpfc_sli_handle_slow_ring_event_s4+0x1c4/0x240 [lpfc] [...] [...] lpfc_sli_handle_slow_ring_event+0x24/0x40 [lpfc] [...] [...] lpfc_do_work+0xd88/0x1970 [lpfc] [...] [...] kthread+0x108/0x130 [...] [...] ret_from_kernel_thread+0x5c/0xbc <...> Fixes: 22466da5 ("lpfc: Fix possible NULL pointer dereference") Reported-by:
Harsha Thyagaraja <hathyaga@in.ibm.com> Signed-off-by:
Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
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Dan Williams authored
commit 325896ff upstream. Hugh notes in response to commit 4cb19355 "device-dax: fail all private mapping attempts": "I think that is more restrictive than you intended: haven't tried, but I believe it rejects a PROT_READ, MAP_SHARED, O_RDONLY fd mmap, leaving no way to mmap /dev/dax without write permission to it." Indeed it does restrict read-only mappings, switch to checking VM_MAYSHARE, not VM_SHARED. Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Pawel Lebioda <pawel.lebioda@intel.com> Fixes: 4cb19355 ("device-dax: fail all private mapping attempts") Reported-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
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Thomas Gleixner authored
commit 1be5d4fa upstream. While debugging the rtmutex unlock vs. dequeue race Will suggested to use READ_ONCE() in rt_mutex_owner() as it might race against the cmpxchg_release() in unlock_rt_mutex_safe(). Will: "It's a minor thing which will most likely not matter in practice" Careful search did not unearth an actual problem in todays code, but it's better to be safe than surprised. Suggested-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
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Thomas Gleixner authored
commit dbb26055 upstream. David reported a futex/rtmutex state corruption. It's caused by the following problem: CPU0 CPU1 CPU2 l->owner=T1 rt_mutex_lock(l) lock(l->wait_lock) l->owner = T1 | HAS_WAITERS; enqueue(T2) boost() unlock(l->wait_lock) schedule() rt_mutex_lock(l) lock(l->wait_lock) l->owner = T1 | HAS_WAITERS; enqueue(T3) boost() unlock(l->wait_lock) schedule() signal(->T2) signal(->T3) lock(l->wait_lock) dequeue(T2) deboost() unlock(l->wait_lock) lock(l->wait_lock) dequeue(T3) ===> wait list is now empty deboost() unlock(l->wait_lock) lock(l->wait_lock) fixup_rt_mutex_waiters() if (wait_list_empty(l)) { owner = l->owner & ~HAS_WAITERS; l->owner = owner ==> l->owner = T1 } lock(l->wait_lock) rt_mutex_unlock(l) fixup_rt_mutex_waiters() if (wait_list_empty(l)) { owner = l->owner & ~HAS_WAITERS; cmpxchg(l->owner, T1, NULL) ===> Success (l->owner = NULL) l->owner = owner ==> l->owner = T1 } That means the problem is caused by fixup_rt_mutex_waiters() which does the RMW to clear the waiters bit unconditionally when there are no waiters in the rtmutexes rbtree. This can be fatal: A concurrent unlock can release the rtmutex in the fastpath because the waiters bit is not set. If the cmpxchg() gets in the middle of the RMW operation then the previous owner, which just unlocked the rtmutex is set as the owner again when the write takes place after the successfull cmpxchg(). The solution is rather trivial: verify that the owner member of the rtmutex has the waiters bit set before clearing it. This does not require a cmpxchg() or other atomic operations because the waiters bit can only be set and cleared with the rtmutex wait_lock held. It's also safe against the fast path unlock attempt. The unlock attempt via cmpxchg() will either see the bit set and take the slowpath or see the bit cleared and release it atomically in the fastpath. It's remarkable that the test program provided by David triggers on ARM64 and MIPS64 really quick, but it refuses to reproduce on x86-64, while the problem exists there as well. That refusal might explain that this got not discovered earlier despite the bug existing from day one of the rtmutex implementation more than 10 years ago. Thanks to David for meticulously instrumenting the code and providing the information which allowed to decode this subtle problem. Reported-by:
David Daney <ddaney@caviumnetworks.com> Tested-by:
David Daney <david.daney@cavium.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Acked-by:
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Sergey Senozhatsky authored
commit 5c7e9ccd upstream. zram hot_add sysfs attribute is a very 'special' attribute - reading from it creates a new uninitialized zram device. This file, by a mistake, can be read by a 'normal' user at the moment, while only root must be able to create a new zram device, therefore hot_add attribute must have S_IRUSR mode, not S_IRUGO. [akpm@linux-foundation.org: s/sence/sense/, reflow comment to use 80 cols] Fixes: 6566d1a3 ("zram: add dynamic device add/remove functionality") Link: http://lkml.kernel.org/r/20161205155845.20129-1-sergey.senozhatsky@gmail.comSigned-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by:
Steven Allen <steven@stebalien.com> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Helge Deller authored
commit 24d0492b upstream. At bootup we run measurements to calculate the best threshold for when we should be using full TLB flushes instead of just flushing a specific amount of TLB entries. This performance test is run over the kernel text segment. But running this TLB performance test on the kernel text segment turned out to crash some SMP machines when the kernel text pages were mapped as huge pages. To avoid those crashes this patch simply skips this test on some SMP machines and calculates an optimal threshold based on the maximum number of available TLB entries and number of online CPUs. On a technical side, this seems to happen: The TLB measurement code uses flush_tlb_kernel_range() to flush specific TLB entries with a page size of 4k (pdtlb 0(sr1,addr)). On UP systems this purge instruction seems to work without problems even if the pages were mapped as huge pages. But on SMP systems the TLB purge instruction is broadcasted to other CPUs. Those CPUs then crash the machine because the page size is not as expected. C8000 machines with PA8800/PA8900 CPUs were not affected by this problem, because the required cache coherency prohibits to use huge pages at all. Sadly I didn't found any documentation about this behaviour, so this finding is purely based on testing with phyiscal SMP machines (A500-44 and J5000, both were 2-way boxes). Signed-off-by:
Helge Deller <deller@gmx.de> Signed-off-by:
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John David Anglin authored
commit febe4296 upstream. We have four routines in pacache.S that use temporary alias pages: copy_user_page_asm(), clear_user_page_asm(), flush_dcache_page_asm() and flush_icache_page_asm(). copy_user_page_asm() and clear_user_page_asm() don't purge the TLB entry used for the operation. flush_dcache_page_asm() and flush_icache_page_asm do purge the entry. Presumably, this was thought to optimize TLB use. However, the operation is quite heavy weight on PA 1.X processors as we need to take the TLB lock and a TLB broadcast is sent to all processors. This patch removes the purges from flush_dcache_page_asm() and flush_icache_page_asm. Signed-off-by:
John David Anglin <dave.anglin@bell.net> Signed-off-by:
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John David Anglin authored
commit c78e710c upstream. The attached change interchanges the order of purging the TLB and setting the corresponding page table entry. TLB purges are strongly ordered. It occurred to me one night that setting the PTE first might have subtle ordering issues on SMP machines and cause random memory corruption. A TLB lock guards the insertion of user TLB entries. So after the TLB is purged, a new entry can't be inserted until the lock is released. This ensures that the new PTE value is used when the lock is released. Since making this change, no random segmentation faults have been observed on the Debian hppa buildd servers. Signed-off-by:
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Miklos Szeredi authored
commit c01638f5 upstream. Basically, the pjdfstests set the ownership of a file to 06555, and then chowns it (as root) to a new uid/gid. Prior to commit a09f99ed ("fuse: fix killing s[ug]id in setattr"), fuse would send down a setattr with both the uid/gid change and a new mode. Now, it just sends down the uid/gid change. Technically this is NOTABUG, since POSIX doesn't _require_ that we clear these bits for a privileged process, but Linux (wisely) has done that and I think we don't want to change that behavior here. This is caused by the use of should_remove_suid(), which will always return 0 when the process has CAP_FSETID. In fact we really don't need to be calling should_remove_suid() at all, since we've already been indicated that we should remove the suid, we just don't want to use a (very) stale mode for that. This patch should fix the above as well as simplify the logic. Reported-by:
Miklos Szeredi <mszeredi@redhat.com> Fixes: a09f99ed ("fuse: fix killing s[ug]id in setattr") Reviewed-by:
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Ben Hutchings authored
commit 10c77dba upstream. OPAL is not callable from 32-bit mode and the assembly code for it may not even build (depending on how binutils was configured). References: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpcspe&ver=4.8.7-1&stamp=1479203712 Fixes: 656ad58e ("powerpc/boot: Add OPAL console to epapr wrappers") Signed-off-by:
Ben Hutchings <ben@decadent.org.uk> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Benjamin Herrenschmidt authored
commit dd7b2f03 upstream. On 64-bit CPUs with no-execute support and non-snooping icache, such as 970 or POWER4, we have a software mechanism to ensure coherency of the cache (using exec faults when needed). This was broken due to a logic error when the code was rewritten from assembly to C, previously the assembly code did: BEGIN_FTR_SECTION mr r4,r30 mr r5,r7 bl hash_page_do_lazy_icache END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE) Which tests that: (cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE Which says that the current cpu does have NOEXECUTE, but does not have COHERENT_ICACHE. Fixes: 91f1da99 ("powerpc/mm: Convert 4k hash insert to C") Fixes: 89ff7250 ("powerpc/mm: Convert __hash_page_64K to C") Fixes: a43c0eb8 ("powerpc/mm: Convert 4k insert from asm to C") Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Change log verbosification] Signed-off-by:
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Andrew Donnellan authored
commit 409bf7f8 upstream. In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after after we call eeh_reset_pe() to reset the PCI controller. We then call eeh_clear_pe_frozen_state(), which can return an error. In this case, we bail out of eeh_reset_device() without calling pci_unlock_rescan_remove(). Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state() error path so that we don't cause a deadlock later on. Reported-by:
Pradipta Ghosh <pradghos@in.ibm.com> Fixes: 78954700 ("powerpc/eeh: Avoid I/O access during PE reset") Signed-off-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by:
Russell Currey <ruscur@russell.cc> Signed-off-by:
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- 10 Dec, 2016 5 commits
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Greg Kroah-Hartman authored
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Tobias Brunner authored
commit a55e2386 upstream. When handling inbound packets, the two halves of the sequence number stored on the skb are already in network order. Fixes: 000ae7b2 ("esp6: Switch to new AEAD interface") Signed-off-by:
Tobias Brunner <tobias@strongswan.org> Acked-by:
Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by:
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Tobias Brunner authored
commit 7c7fedd5 upstream. When handling inbound packets, the two halves of the sequence number stored on the skb are already in network order. Fixes: 7021b2e1 ("esp4: Switch to new AEAD interface") Signed-off-by:
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Miroslav Urbanek authored
commit 6b226487 upstream. The threshold for OOM protection is too small for systems with large number of CPUs. Applications report ENOBUFs on connect() every 10 minutes. The problem is that the variable net->xfrm.flow_cache_gc_count is a global counter while the variable fc->high_watermark is a per-CPU constant. Take the number of CPUs into account as well. Fixes: 6ad3122a ("flowcache: Avoid OOM condition under preasure") Reported-by:
Lukáš Koldrt <lk@excello.cz> Tested-by:
Jan Hejl <jh@excello.cz> Signed-off-by:
Miroslav Urbanek <mu@miroslavurbanek.com> Signed-off-by:
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Eli Cooper authored
commit 80d1106a upstream. This reverts commit ae148b08 ("ip6_tunnel: Update skb->protocol to ETH_P_IPV6 in ip6_tnl_xmit()"). skb->protocol is now set in __ip_local_out() and __ip6_local_out() before dst_output() is called. It is no longer necessary to do it for each tunnel. Signed-off-by:
Eli Cooper <elicooper@gmx.com> Signed-off-by:
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