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* perf/x86/intel/pt: Fix kernel address filter's offset validationAlexander Shishkin2016-09-161-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel_ip() filter is used mostly by the DS/LBR code to look at the branch addresses, but Intel PT also uses it to validate the address filter offsets for kernel addresses, for which it is not sufficient: supplying something in bits 64:48 that's not a sign extension of the lower address bits (like 0xf00d000000000000) throws a #GP. This patch adds address validation for the user supplied kernel filters. Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org # v4.7 Cc: stable@vger.kernel.org#v4.7 Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160915151352.21306-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf/x86/intel/pt: Fix an off-by-one in address filter configurationAlexander Shishkin2016-09-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | PT address filter configuration requires that a range is specified by its first and last address, but at the moment we're obtaining the end of the range by adding user specified size to its start, which is off by one from what it actually needs to be. Fix this and make sure that zero-sized filters don't pass the filter validation. Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org # v4.7 Cc: stable@vger.kernel.org#v4.7 Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160915151352.21306-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* perf/x86/intel: Don't disable "intel_bts" around "intel" event batchingAlexander Shishkin2016-09-151-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | At the moment, intel_bts events get disabled from intel PMU's disable callback, which includes event scheduling transactions of said PMU, which have nothing to do with intel_bts events. We do want to keep intel_bts events off inside the PMI handler to avoid filling up their buffer too soon. This patch moves intel_bts enabling/disabling directly to the PMI handler. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160915082233.11065-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'pci-v4.8-fixes-2' of ↵Linus Torvalds2016-09-142-9/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI fixes from Bjorn Helgaas: "Here are two changes for v4.8. The first fixes a "[Firmware Bug]: reg 0x10: invalid BAR (can't size)" warning on Haswell, and the second fixes a problem in some new runtime suspend functionality we merged for v4.8. Summary: Enumeration: Mark Haswell Power Control Unit as having non-compliant BARs (Bjorn Helgaas) Power management: Fix bridge_d3 update on device removal (Lukas Wunner)" * tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Fix bridge_d3 update on device removal PCI: Mark Haswell Power Control Unit as having non-compliant BARs
| * PCI: Fix bridge_d3 update on device removalLukas Wunner2016-09-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Starting with v4.8, we allow a PCIe port to runtime suspend to D3hot if the port itself and its children satisfy a number of conditions. Once a child is removed, we recheck those conditions in case the removed device was blocking the port from suspending. The rechecking needs to happen *after* the device has been removed from the bus it resides on. Otherwise when walking the port's subordinate bus in pci_bridge_d3_update(), the device being removed would erroneously still be taken into account. However the device is removed from the bus_list in pci_destroy_dev() and we currently recheck *before* that. Fix it. Fixes: 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <mika.westerberg@linux.intel.com>
| * PCI: Mark Haswell Power Control Unit as having non-compliant BARsBjorn Helgaas2016-09-011-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Haswell Power Control Unit has a non-PCI register (CONFIG_TDP_NOMINAL) where BAR 0 is supposed to be. This is erratum HSE43 in the spec update referenced below: The PCIe* Base Specification indicates that Configuration Space Headers have a base address register at offset 0x10. Due to this erratum, the Power Control Unit's CONFIG_TDP_NOMINAL CSR (Bus 1; Device 30; Function 3; Offset 0x10) is located where a base register is expected. Mark the PCU as having non-compliant BARs so we don't try to probe any of them. There are no other BARs on this device. Rename the quirk so it's not Broadwell-specific. Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v3-spec-update.html Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v3-datasheet-vol-2.html (section 5.4, Device 30 Function 3) Link: https://bugzilla.kernel.org/show_bug.cgi?id=153881 Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Tested-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Myron Stowe <myron.stowe@redhat.com>
* | Merge branch 'uaccess-fixes' of ↵Linus Torvalds2016-09-1426-170/+179
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uaccess fixes from Al Viro: "Fixes for broken uaccess primitives - mostly lack of proper zeroing in copy_from_user()/get_user()/__get_user(), but for several architectures there's more (broken clear_user() on frv and strncpy_from_user() on hexagon)" * 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) avr32: fix copy_from_user() microblaze: fix __get_user() microblaze: fix copy_from_user() m32r: fix __get_user() blackfin: fix copy_from_user() sparc32: fix copy_from_user() sh: fix copy_from_user() sh64: failing __get_user() should zero score: fix copy_from_user() and friends score: fix __get_user/get_user s390: get_user() should zero on failure ppc32: fix copy_from_user() parisc: fix copy_from_user() openrisc: fix copy_from_user() nios2: fix __get_user() nios2: copy_from_user() should zero the tail of destination mn10300: copy_from_user() should zero on access_ok() failure... mn10300: failing __get_user() and get_user() should zero mips: copy_from_user() must zero the destination on access_ok() failure ARC: uaccess: get_user to zero out dest in cause of fault ...
| * | avr32: fix copy_from_user()Al Viro2016-09-133-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | really ugly, but apparently avr32 compilers turns access_ok() into something so bad that they want it in assembler. Left that way, zeroing added in inline wrapper. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | microblaze: fix __get_user()Al Viro2016-09-131-1/+1
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | microblaze: fix copy_from_user()Al Viro2016-09-131-3/+6
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | m32r: fix __get_user()Al Viro2016-09-131-1/+1
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | blackfin: fix copy_from_user()Al Viro2016-09-131-4/+5
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | sparc32: fix copy_from_user()Al Viro2016-09-131-1/+3
| | | | | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | sh: fix copy_from_user()Al Viro2016-09-131-1/+4
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | sh64: failing __get_user() should zeroAl Viro2016-09-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | It could be done in exception-handling bits in __get_user_b() et.al., but the surgery involved would take more knowledge of sh64 details than I have or _want_ to have. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | score: fix copy_from_user() and friendsAl Viro2016-09-131-21/+20
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | score: fix __get_user/get_userAl Viro2016-09-131-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | * should zero on any failure * __get_user() should use __copy_from_user(), not copy_from_user() Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | s390: get_user() should zero on failureAl Viro2016-09-131-4/+4
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | ppc32: fix copy_from_user()Al Viro2016-09-131-23/+2
| | | | | | | | | | | | | | | | | | | | | | | | should clear on access_ok() failures. Also remove the useless range truncation logics. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | parisc: fix copy_from_user()Al Viro2016-09-131-2/+4
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | openrisc: fix copy_from_user()Al Viro2016-09-131-24/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... that should zero on faults. Also remove the <censored> helpful logics wrt range truncation copied from ppc32. Where it had ever been needed only in case of copy_from_user() *and* had not been merged into the mainline until a month after the need had disappeared. A decade before openrisc went into mainline, I might add... Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | nios2: fix __get_user()Al Viro2016-09-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | a) should not leave crap on fault b) should _not_ require access_ok() in any cases. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | nios2: copy_from_user() should zero the tail of destinationAl Viro2016-09-131-3/+6
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | mn10300: copy_from_user() should zero on access_ok() failure...Al Viro2016-09-131-1/+3
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | mn10300: failing __get_user() and get_user() should zeroAl Viro2016-09-131-0/+1
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | mips: copy_from_user() must zero the destination on access_ok() failureAl Viro2016-09-131-0/+3
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | ARC: uaccess: get_user to zero out dest in cause of faultVineet Gupta2016-09-131-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | metag: copy_from_user() should zero the destination on access_ok() failureAl Viro2016-09-131-1/+2
| | | | | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | ia64: copy_from_user() should zero the destination on access_ok() failureAl Viro2016-09-131-14/+11
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | hexagon: fix strncpy_from_user() error returnAl Viro2016-09-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | It's -EFAULT, not -1 (and contrary to the comment in there, __strnlen_user() can return 0 - on faults). Cc: stable@vger.kernel.org Acked-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | frv: fix clear_user()Al Viro2016-09-131-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | It should check access_ok(). Otherwise a bunch of places turn into trivially exploitable rootholes. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | cris: buggered copy_from_user/copy_to_user/clear_userAl Viro2016-09-131-39/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * copy_from_user() on access_ok() failure ought to zero the destination * none of those primitives should skip the access_ok() check in case of small constant size. Cc: stable@vger.kernel.org Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | asm-generic: make get_user() clear the destination on errorsAl Viro2016-09-131-3/+7
| | | | | | | | | | | | | | | | | | | | | both for access_ok() failures and for faults halfway through Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | asm-generic: make copy_from_user() zero the destination properlyAl Viro2016-09-101-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... in all cases, including the failing access_ok() Note that some architectures using asm-generic/uaccess.h have __copy_from_user() not zeroing the tail on failure halfway through. This variant works either way. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | alpha: fix copy_from_user()Al Viro2016-09-101-11/+8
| | | | | | | | | | | | | | | | | | | | | it should clear the destination even when access_ok() fails. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge tag 'for-linus-4.8b-rc6-tag' of ↵Linus Torvalds2016-09-141-4/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen regression fix from David Vrabel: "Fix SMP boot in arm guests" * tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: arm/xen: fix SMP guests boot
| * | | arm/xen: fix SMP guests bootVitaly Kuznetsov2016-09-141-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 88e957d6e47f ("xen: introduce xen_vcpu_id mapping") broke SMP ARM guests on Xen. When FIFO-based event channels are in use (this is the default), evtchn_fifo_alloc_control_block() is called on CPU_UP_PREPARE event and this happens before we set up xen_vcpu_id mapping in xen_starting_cpu. Temporary fix the issue by setting direct Linux CPU id <-> Xen vCPU id mapping for all possible CPUs at boot. We don't currently support kexec/kdump on Xen/ARM so these ids always match. In future, we have several ways to solve the issue, e.g.: - Eliminate all hypercalls from CPU_UP_PREPARE, do them from the starting CPU. This can probably be done for both x86 and ARM and, if done, will allow us to get Xen's idea of vCPU id from CPUID/MPIDR on the starting CPU directly, no messing with ACPI/device tree required. - Save vCPU id information from ACPI/device tree on ARM and use it to initialize xen_vcpu_id mapping. This is the same trick we currently do on x86. Reported-by: Julien Grall <julien.grall@arm.com> Tested-by: Wei Chen <Wei.Chen@arm.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* | | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-09-133-7/+16
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Three fixes: - AMD microcode loading fix with randomization - an lguest tooling fix - and an APIC enumeration boundary condition fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Fix num_processors value in case of failure tools/lguest: Don't bork the terminal in case of wrong args x86/microcode/AMD: Fix load of builtin microcode with randomized memory
| * | | | x86/apic: Fix num_processors value in case of failureDou Liyang2016-09-081-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the topology package map check of the APIC ID and the CPU is a failure, we don't generate the processor info for that APIC ID yet we increase disabled_cpus by one - which is buggy. Only increase num_processors once we are sure we don't fail. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1473214893-16481-1-git-send-email-douly.fnst@cn.fujitsu.com [ Rewrote the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | tools/lguest: Don't bork the terminal in case of wrong argsDaniel Baluta2016-09-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Running lguest without arguments or with a wrong argument name borks the terminal, because the cleanup handler is set up too late in the initialization process. Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/microcode/AMD: Fix load of builtin microcode with randomized memoryBorislav Petkov2016-09-051-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We do not need to add the randomization offset when the microcode is built in. Reported-and-tested-by: Emanuel Czirai <icanrealizeum@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20160904093736.GA11939@pd.tnic Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2016-09-131-0/+22
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "A try_to_wake_up() memory ordering race fix causing a busy-loop in ttwu()" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix a race between try_to_wake_up() and a woken up task
| * | | | | sched/core: Fix a race between try_to_wake_up() and a woken up taskBalbir Singh2016-09-051-0/+22
| |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The origin of the issue I've seen is related to a missing memory barrier between check for task->state and the check for task->on_rq. The task being woken up is already awake from a schedule() and is doing the following: do { schedule() set_current_state(TASK_(UN)INTERRUPTIBLE); } while (!cond); The waker, actually gets stuck doing the following in try_to_wake_up(): while (p->on_cpu) cpu_relax(); Analysis: The instance I've seen involves the following race: CPU1 CPU2 while () { if (cond) break; do { schedule(); set_current_state(TASK_UN..) } while (!cond); wakeup_routine() spin_lock_irqsave(wait_lock) raw_spin_lock_irqsave(wait_lock) wake_up_process() } try_to_wake_up() set_current_state(TASK_RUNNING); .. list_del(&waiter.list); CPU2 wakes up CPU1, but before it can get the wait_lock and set current state to TASK_RUNNING the following occurs: CPU3 wakeup_routine() raw_spin_lock_irqsave(wait_lock) if (!list_empty) wake_up_process() try_to_wake_up() raw_spin_lock_irqsave(p->pi_lock) .. if (p->on_rq && ttwu_wakeup()) .. while (p->on_cpu) cpu_relax() .. CPU3 tries to wake up the task on CPU1 again since it finds it on the wait_queue, CPU1 is spinning on wait_lock, but immediately after CPU2, CPU3 got it. CPU3 checks the state of p on CPU1, it is TASK_UNINTERRUPTIBLE and the task is spinning on the wait_lock. Interestingly since p->on_rq is checked under pi_lock, I've noticed that try_to_wake_up() finds p->on_rq to be 0. This was the most confusing bit of the analysis, but p->on_rq is changed under runqueue lock, rq_lock, the p->on_rq check is not reliable without this fix IMHO. The race is visible (based on the analysis) only when ttwu_queue() does a remote wakeup via ttwu_queue_remote. In which case the p->on_rq change is not done uder the pi_lock. The result is that after a while the entire system locks up on the raw_spin_irqlock_save(wait_lock) and the holder spins infintely Reproduction of the issue: The issue can be reproduced after a long run on my system with 80 threads and having to tweak available memory to very low and running memory stress-ng mmapfork test. It usually takes a long time to reproduce. I am trying to work on a test case that can reproduce the issue faster, but thats work in progress. I am still testing the changes on my still in a loop and the tests seem OK thus far. Big thanks to Benjamin and Nick for helping debug this as well. Ben helped catch the missing barrier, Nick caught every missing bit in my theory. Signed-off-by: Balbir Singh <bsingharora@gmail.com> [ Updated comment to clarify matching barriers. Many architectures do not have a full barrier in switch_to() so that cannot be relied upon. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <nicholas.piggin@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/e02cce7b-d9ca-1ad0-7a61-ea97c7582b37@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-09-136-55/+180
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This contains: - a set of fixes found by directed-random perf fuzzing efforts by Vince Weaver, Alexander Shishkin and Peter Zijlstra - a cqm driver crash fix - an AMD uncore driver use after free fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Fix PEBSv3 record drain perf/x86/intel/bts: Kill a silly warning perf/x86/intel/bts: Fix BTS PMI detection perf/x86/intel/bts: Fix confused ordering of PMU callbacks perf/core: Fix aux_mmap_count vs aux_refcount order perf/core: Fix a race between mmap_close() and set_output() of AUX events perf/x86/amd/uncore: Prevent use after free perf/x86/intel/cqm: Check cqm/mbm enabled state in event init perf/core: Remove WARN from perf_event_read()
| * | | | | perf/x86/intel: Fix PEBSv3 record drainPeter Zijlstra2016-09-101-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexander hit the WARN_ON_ONCE(!event) on his Skylake while running the perf fuzzer. This means the PEBSv3 record included a status bit for an inactive event, something that _should_ not happen. Move the code that filters the status bits against our known PEBS events up a spot to guarantee we only deal with events we know about. Further add "continue" statements to the WARN_ON_ONCE()s such that we'll not die nor generate silly events in case we ever do hit them again. Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.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 <vince@deater.net> Cc: stable@vger.kernel.org Fixes: a3d86542de88 ("perf/x86/intel/pebs: Add PEBSv3 decoding") Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | perf/x86/intel/bts: Kill a silly warningAlexander Shishkin2016-09-101-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment, intel_bts will WARN() out if there is more than one event writing to the same ring buffer, via SET_OUTPUT, and will only send data from one event to a buffer. There is no reason to have this warning in, so kill it. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-6-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | perf/x86/intel/bts: Fix BTS PMI detectionAlexander Shishkin2016-09-101-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since BTS doesn't have a dedicated PMI status bit, the driver needs to take extra care to check for the condition that triggers it to avoid spurious NMI warnings. Regardless of the local BTS context state, the only way of knowing that the NMI is ours is to compare the write pointer against the interrupt threshold. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-5-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | perf/x86/intel/bts: Fix confused ordering of PMU callbacksAlexander Shishkin2016-09-101-24/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The intel_bts driver is using a CPU-local 'started' variable to order callbacks and PMIs and make sure that AUX transactions don't get messed up. However, the ordering rules in regard to this variable is a complete mess, which recently resulted in perf_fuzzer-triggered warnings and panics. The general ordering rule that is patch is enforcing is that this cpu-local variable be set only when the cpu-local AUX transaction is active; consequently, this variable is to be checked before the AUX related bits can be touched. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-4-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | perf/core: Fix aux_mmap_count vs aux_refcount orderAlexander Shishkin2016-09-101-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The order of accesses to ring buffer's aux_mmap_count and aux_refcount has to be preserved across the users, namely perf_mmap_close() and perf_aux_output_begin(), otherwise the inversion can result in the latter holding the last reference to the aux buffer and subsequently free'ing it in atomic context, triggering a warning. > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 257 at kernel/events/ring_buffer.c:541 __rb_free_aux+0x11a/0x130 > CPU: 0 PID: 257 Comm: stopbug Not tainted 4.8.0-rc1+ #2596 > Call Trace: > [<ffffffff810f3e0b>] __warn+0xcb/0xf0 > [<ffffffff810f3f3d>] warn_slowpath_null+0x1d/0x20 > [<ffffffff8121182a>] __rb_free_aux+0x11a/0x130 > [<ffffffff812127a8>] rb_free_aux+0x18/0x20 > [<ffffffff81212913>] perf_aux_output_begin+0x163/0x1e0 > [<ffffffff8100c33a>] bts_event_start+0x3a/0xd0 > [<ffffffff8100c42d>] bts_event_add+0x5d/0x80 > [<ffffffff81203646>] event_sched_in.isra.104+0xf6/0x2f0 > [<ffffffff8120652e>] group_sched_in+0x6e/0x190 > [<ffffffff8120694e>] ctx_sched_in+0x2fe/0x5f0 > [<ffffffff81206ca0>] perf_event_sched_in+0x60/0x80 > [<ffffffff81206d1b>] ctx_resched+0x5b/0x90 > [<ffffffff81207281>] __perf_event_enable+0x1e1/0x240 > [<ffffffff81200639>] event_function+0xa9/0x180 > [<ffffffff81202000>] ? perf_cgroup_attach+0x70/0x70 > [<ffffffff8120203f>] remote_function+0x3f/0x50 > [<ffffffff811971f3>] flush_smp_call_function_queue+0x83/0x150 > [<ffffffff81197bd3>] generic_smp_call_function_single_interrupt+0x13/0x60 > [<ffffffff810a6477>] smp_call_function_single_interrupt+0x27/0x40 > [<ffffffff81a26ea9>] call_function_single_interrupt+0x89/0x90 > [<ffffffff81120056>] finish_task_switch+0xa6/0x210 > [<ffffffff81120017>] ? finish_task_switch+0x67/0x210 > [<ffffffff81a1e83d>] __schedule+0x3dd/0xb50 > [<ffffffff81a1efe5>] schedule+0x35/0x80 > [<ffffffff81128031>] sys_sched_yield+0x61/0x70 > [<ffffffff81a25be5>] entry_SYSCALL_64_fastpath+0x18/0xa8 > ---[ end trace 6235f556f5ea83a9 ]--- This patch puts the checks in perf_aux_output_begin() in the same order as that of perf_mmap_close(). Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | perf/core: Fix a race between mmap_close() and set_output() of AUX eventsAlexander Shishkin2016-09-101-6/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the mmap_close() path we need to stop all the AUX events that are writing data to the AUX area that we are unmapping, before we can safely free the pages. To determine if an event needs to be stopped, we're comparing its ->rb against the one that's getting unmapped. However, a SET_OUTPUT ioctl may turn up inside an AUX transaction and swizzle event::rb to some other ring buffer, but the transaction will keep writing data to the old ring buffer until the event gets scheduled out. At this point, mmap_close() will skip over such an event and will proceed to free the AUX area, while it's still being used by this event, which will set off a warning in the mmap_close() path and cause a memory corruption. To avoid this, always stop an AUX event before its ->rb is updated; this will release the (potentially) last reference on the AUX area of the buffer. If the event gets restarted, its new ring buffer will be used. If another SET_OUTPUT comes and switches it back to the old ring buffer that's getting unmapped, it's also fine: this ring buffer's aux_mmap_count will be zero and AUX transactions won't start any more. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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@deater.net Link: http://lkml.kernel.org/r/20160906132353.19887-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>