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2014-04-29KVM: x86: expose invariant tsc cpuid bit (v2)Marcelo Tosatti
Invariant TSC is a property of TSC, no additional support code necessary. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-04-28genirq: x86: Ensure that dynamic irq allocation does not conflictThomas Gleixner
On x86 the allocation of irq descriptors may allocate interrupts which are in the range of the GSI interrupts. That's wrong as those interrupts are hardwired and we don't have the irq domain translation like PPC. So one of these interrupts can be hooked up later to one of the devices which are hard wired to it and the io_apic init code for that particular interrupt line happily reuses that descriptor with a completely different configuration so hell breaks lose. Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs, except for a few usage sites which have not yet blown up in our face for whatever reason. But for drivers which need an irq range, like the GPIO drivers, we have no limit in place and we don't want to expose such a detail to a driver. To cure this introduce a function which an architecture can implement to impose a lower bound on the dynamic interrupt allocations. Implement it for x86 and set the lower bound to nr_gsi_irqs, which is the end of the hardwired interrupt space, so all dynamic allocations happen above. That not only allows the GPIO driver to work sanely, it also protects the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and htirq code. They need to be cleaned up as well, but that's a separate issue. Reported-by: Jin Yao <yao.jin@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Krogerus Heikki <heikki.krogerus@intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-28KVM: x86: Check for host supported fields in shadow vmcsBandan Das
We track shadow vmcs fields through two static lists, one for read only and another for r/w fields. However, with addition of new vmcs fields, not all fields may be supported on all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on unsupported hosts will result in a vmwrite error. For example, commit 36be0b9deb23161 introduced GUEST_BNDCFGS, which is not supported by all processors. Filter out host unsupported fields before letting guests use shadow vmcs Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-04-28x86/vsmp: Fix irq routingOren Twaig
Correct IRQ routing in case a vSMP box is detected but the Interrupt Routing Comply (IRC) value is set to "comply", which leads to incorrect IRQ routing. Before the patch: When a vSMP box was detected and IRC was set to "comply", users (and the kernel) couldn't effectively set the destination of the IRQs. This is because the hook inside vsmp_64.c always setup all CPUs as the IRQ destination using cpumask_setall() as the return value for IRQ allocation mask. Later, this "overrided" mask caused the kernel to set the IRQ destination to the lowest online CPU in the mask (CPU0 usually). After the patch: When the IRC is set to "comply", users (and the kernel) can control the destination of the IRQs as we will not be changing the default "apic->vector_allocation_domain". Signed-off-by: Oren Twaig <oren@scalemp.com> Acked-by: Shai Fultheim <shai@scalemp.com> Link: http://lkml.kernel.org/r/1398669697-2123-1-git-send-email-oren@scalemp.com [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-27Merge 3.15-rc3 into tty-nextGreg Kroah-Hartman
2014-04-25x86/PCI: Mark ATI SBx00 HPET BAR as IORESOURCE_PCI_FIXEDBjorn Helgaas
Bodo reported that on the Asrock M3A UCC, v3.12.6 hangs during boot unless he uses "pci=nocrs". This regression was caused by 7bc5e3f2be32 ("x86/PCI: use host bridge _CRS info by default on 2008 and newer machines"), which appeared in v2.6.34. The reason is that the HPET address appears in a PCI device BAR, and this address is not contained in any of the host bridge windows. Linux moves the PCI BAR into a window, but the original address was published via the HPET table and an ACPI device, so changing the BAR is a bad idea. Here's the dmesg info: ACPI: HPET id: 0x43538301 base: 0xfed00000 pci_root PNP0A03:00: host bridge window [mem 0xd0000000-0xdfffffff] pci_root PNP0A03:00: host bridge window [mem 0xf0000000-0xfebfffff] pci 0000:00:14.0: [1002:4385] type 0 class 0x000c05 pci 0000:00:14.0: reg 14: [mem 0xfed00000-0xfed003ff] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0 pnp 00:06: Plug and Play ACPI device, IDs PNP0103 (active) pnp 00:06: [mem 0xfed00000-0xfed003ff] When we notice the BAR is not in a host bridge window, we try to move it, but that causes a hang shortly thereafter: pci 0000:00:14.0: no compatible bridge window for [mem 0xfed00000-0xfed003ff] pci 0000:00:14.0: BAR 1: assigned [mem 0xf0000000-0xf00003ff] This patch marks the BAR as IORESOURCE_PCI_FIXED to prevent Linux from moving it. This depends on a previous patch ("x86/PCI: Don't try to move IORESOURCE_PCI_FIXED resources") to check for this flag when pci_claim_resource() fails. Link: https://bugzilla.kernel.org/show_bug.cgi?id=68591 Reported-and-tested-by: Bodo Eggert <7eggert@gmx.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-04-25x86/PCI: Don't try to move IORESOURCE_PCI_FIXED resourcesBjorn Helgaas
Don't attempt to move resource marked IORESOURCE_PCI_FIXED, even if pci_claim_resource() fails. In some cases, these are legacy resources that cannot be moved. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-04-25x86/PCI: Fix Broadcom CNB20LE unintended sign extensionBjorn Helgaas
In the expression "word1 << 16", word1 starts as u16, but is promoted to a signed int, then sign-extended to resource_size_t, which is probably not what was intended. Cast to resource_size_t to avoid the sign extension. Found by Coverity (CID 138749, 138750). Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-04-25Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24x86: move FIX_EARLYCON_MEM kconfig into x86Rob Herring
In preparation to support FIX_EARLYCON_MEM on other arches, make the option per arch. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24arm: xen: implement multicall hypercall support.Ian Campbell
As part of this make the usual change to xen_ulong_t in place of unsigned long. This change has no impact on x86. The Linux definition of struct multicall_entry.result differs from the Xen definition, I think for good reasons, and used a long rather than an unsigned long. Therefore introduce a xen_long_t, which is a long on x86 architectures and a signed 64-bit integer on ARM. Use uint32_t nr_calls on x86 for consistency with the ARM definition. Build tested on amd64 and i386 builds. Runtime tested on ARM. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-04-24kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotationMasami Hiramatsu
Use NOKPROBE_SYMBOL macro for protecting functions from kprobes instead of __kprobes annotation under arch/x86. This applies nokprobe_inline annotation for some cases, because NOKPROBE_SYMBOL() will inhibit inlining by referring the symbol address. This just folds a bunch of previous NOKPROBE_SYMBOL() cleanup patches for x86 to one patch. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20140417081814.26341.51656.stgit@ltc230.yrl.intra.hitachi.co.jp Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fernando Luis Vázquez Cao <fernando_b1@lab.ntt.co.jp> Cc: Gleb Natapov <gleb@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Lebon <jlebon@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes, x86: Allow kprobes on text_poke/hw_breakpointMasami Hiramatsu
Allow kprobes on text_poke/hw_breakpoint because those are not related to the critical int3-debug recursive path of kprobes at this moment. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Link: http://lkml.kernel.org/r/20140417081807.26341.73219.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes/x86: Allow probe on some kprobe preparation functionsMasami Hiramatsu
There is no need to prohibit probing on the functions used in preparation phase. Those are safely probed because those are not invoked from breakpoint/fault/debug handlers, there is no chance to cause recursive exceptions. Following functions are now removed from the kprobes blacklist: can_boost can_probe can_optimize is_IF_modifier __copy_instruction copy_optimized_instructions arch_copy_kprobe arch_prepare_kprobe arch_arm_kprobe arch_disarm_kprobe arch_remove_kprobe arch_trampoline_kprobe arch_prepare_kprobe_ftrace arch_prepare_optimized_kprobe arch_check_optimized_kprobe arch_within_optimized_kprobe __arch_remove_optimized_kprobe arch_remove_optimized_kprobe arch_optimize_kprobes arch_unoptimize_kprobe I tested those functions by putting kprobes on all instructions in the functions with the bash script I sent to LKML. See: https://lkml.org/lkml/2014/3/27/33 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Lebon <jlebon@redhat.com> Link: http://lkml.kernel.org/r/20140417081747.26341.36065.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes, x86: Call exception_enter after kprobes handledMasami Hiramatsu
Move exception_enter() call after kprobes handler is done. Since the exception_enter() involves many other functions (like printk), it can cause recursive int3/break loop when kprobes probe such functions. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Kees Cook <keescook@chromium.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081740.26341.10894.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes/x86: Call exception handlers directly from do_int3/do_debugMasami Hiramatsu
To avoid a kernel crash by probing on lockdep code, call kprobe_int3_handler() and kprobe_debug_handler()(which was formerly called post_kprobe_handler()) directly from do_int3 and do_debug. Currently kprobes uses notify_die() to hook the int3/debug exceptoins. Since there is a locking code in notify_die, the lockdep code can be invoked. And because the lockdep involves printk() related things, theoretically, we need to prohibit probing on such code, which means much longer blacklist we'll have. Instead, hooking the int3/debug for kprobes before notify_die() can avoid this problem. Anyway, most of the int3 handlers in the kernel are already called from do_int3 directly, e.g. ftrace_int3_handler, poke_int3_handler, kgdb_ll_trap. Actually only kprobe_exceptions_notify is on the notifier_call_chain. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Lebon <jlebon@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081733.26341.24423.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes, x86: Prohibit probing on thunk functions and restoreMasami Hiramatsu
thunk/restore functions are also used for tracing irqoff etc. and those are involved in kprobe's exception handling. Prohibit probing on them to avoid kernel crash. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20140417081726.26341.3872.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes, x86: Prohibit probing on native_set_debugreg()/load_idt()Masami Hiramatsu
Since the kprobes uses do_debug for single stepping, functions called from do_debug() before notify_die() must not be probed. And also native_load_idt() is called from paranoid_exit when returning int3, this also must not be probed. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Alok Kataria <akataria@vmware.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: virtualization@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20140417081719.26341.65542.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes, x86: Prohibit probing on debug_stack_*()Masami Hiramatsu
Prohibit probing on debug_stack_reset and debug_stack_set_zero. Since the both functions are called from TRACE_IRQS_ON/OFF_DEBUG macros which run in int3 ist entry, probing it may cause a soft lockup. This happens when the kernel built with CONFIG_DYNAMIC_FTRACE=y and CONFIG_TRACE_IRQFLAGS=y. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Beulich <JBeulich@suse.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081712.26341.32994.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklistMasami Hiramatsu
Introduce NOKPROBE_SYMBOL() macro which builds a kprobes blacklist at kernel build time. The usage of this macro is similar to EXPORT_SYMBOL(), placed after the function definition: NOKPROBE_SYMBOL(function); Since this macro will inhibit inlining of static/inline functions, this patch also introduces a nokprobe_inline macro for static/inline functions. In this case, we must use NOKPROBE_SYMBOL() for the inline function caller. When CONFIG_KPROBES=y, the macro stores the given function address in the "_kprobe_blacklist" section. Since the data structures are not fully initialized by the macro (because there is no "size" information), those are re-initialized at boot time by using kallsyms. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20140417081705.26341.96719.stgit@ltc230.yrl.intra.hitachi.co.jp Cc: Alok Kataria <akataria@vmware.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christopher Li <sparse@chrisli.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: David S. Miller <davem@davemloft.net> Cc: Jan-Simon Möller <dl9pf@gmx.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-sparse@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes: Prohibit probing on .entry.text codeMasami Hiramatsu
.entry.text is a code area which is used for interrupt/syscall entries, which includes many sensitive code. Thus, it is better to prohibit probing on all of such code instead of a part of that. Since some symbols are already registered on kprobe blacklist, this also removes them from the blacklist. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Lebon <jlebon@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081658.26341.57354.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24kprobes/x86: Allow to handle reentered kprobe on single-steppingMasami Hiramatsu
Since the NMI handlers(e.g. perf) can interrupt in the single stepping (or preparing the single stepping, do_debug etc.), we should consider a kprobe is hit in the NMI handler. Even in that case, the kprobe is allowed to be reentered as same as the kprobes hit in kprobe handlers (KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE). The real issue will happen when a kprobe hit while another reentered kprobe is processing (KPROBE_REENTER), because we already consumed a saved-area for the previous kprobe. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Lebon <jlebon@redhat.com> Link: http://lkml.kernel.org/r/20140417081651.26341.10593.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24perf/x86: Fix RAPL rdmsrl_safe() usageStephane Eranian
This patch fixes a bug introduced by: 24223657806a ("perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU") The rdmsrl_safe() function returns 0 on success. The current code was failing to detect the RAPL PMU on real hardware (missing /sys/devices/power) because the return value of rdmsrl_safe() was misinterpreted. Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Venkatesh Srinivas <venkateshs@google.com> Cc: peterz@infradead.org Cc: zheng.z.yan@intel.com Link: http://lkml.kernel.org/r/20140423170418.GA12767@quad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-23KVM: MMU: flush tlb out of mmu lock when write-protect the sptesXiao Guangrong
Now we can flush all the TLBs out of the mmu lock without TLB corruption when write-proect the sptes, it is because: - we have marked large sptes readonly instead of dropping them that means we just change the spte from writable to readonly so that we only need to care the case of changing spte from present to present (changing the spte from present to nonpresent will flush all the TLBs immediately), in other words, the only case we need to care is mmu_spte_update() - in mmu_spte_update(), we haved checked SPTE_HOST_WRITEABLE | PTE_MMU_WRITEABLE instead of PT_WRITABLE_MASK, that means it does not depend on PT_WRITABLE_MASK anymore Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: MMU: flush tlb if the spte can be locklessly modifiedXiao Guangrong
Relax the tlb flush condition since we will write-protect the spte out of mmu lock. Note lockless write-protection only marks the writable spte to readonly and the spte can be writable only if both SPTE_HOST_WRITEABLE and SPTE_MMU_WRITEABLE are set (that are tested by spte_is_locklessly_modifiable) This patch is used to avoid this kind of race: VCPU 0 VCPU 1 lockless wirte protection: set spte.w = 0 lock mmu-lock write protection the spte to sync shadow page, see spte.w = 0, then without flush tlb unlock mmu-lock !!! At this point, the shadow page can still be writable due to the corrupt tlb entry Flush all TLB Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: MMU: lazily drop large spteXiao Guangrong
Currently, kvm zaps the large spte if write-protected is needed, the later read can fault on that spte. Actually, we can make the large spte readonly instead of making them un-present, the page fault caused by read access can be avoided The idea is from Avi: | As I mentioned before, write-protecting a large spte is a good idea, | since it moves some work from protect-time to fault-time, so it reduces | jitter. This removes the need for the return value. This version has fixed the issue reported in 6b73a9606, the reason of that issue is that fast_page_fault() directly sets the readonly large spte to writable but only dirty the first page into the dirty-bitmap that means other pages are missed. Fixed it by only the normal sptes (on the PT_PAGE_TABLE_LEVEL level) can be fast fixed Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: MMU: properly check last spte in fast_page_fault()Xiao Guangrong
Using sp->role.level instead of @level since @level is not got from the page table hierarchy There is no issue in current code since the fast page fault currently only fixes the fault caused by dirty-log that is always on the last level (level = 1) This patch makes the code more readable and avoids potential issue in the further development Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23Revert "KVM: Simplify kvm->tlbs_dirty handling"Xiao Guangrong
This reverts commit 5befdc385ddb2d5ae8995ad89004529a3acf58fc. Since we will allow flush tlb out of mmu-lock in the later patch Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: x86: Processor mode may be determined incorrectlyNadav Amit
If EFER.LMA is off, cs.l does not determine execution mode. Currently, the emulation engine assumes differently. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: x86: IN instruction emulation should ignore REP-prefixNadav Amit
The IN instruction is not be affected by REP-prefix as INS is. Therefore, the emulation should ignore the REP prefix as well. The current emulator implementation tries to perform writeback when IN instruction with REP-prefix is emulated. This causes it to perform wrong memory write or spurious #GP exception to be injected to the guest. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: x86: Fix CR3 reserved bitsNadav Amit
According to Intel specifications, PAE and non-PAE does not have any reserved bits. In long-mode, regardless to PCIDE, only the high bits (above the physical address) are reserved. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23KVM: x86: Fix wrong/stuck PMU when guest does not use PMINadav Amit
If a guest enables a performance counter but does not enable PMI, the hypervisor currently does not reprogram the performance counter once it overflows. As a result the host performance counter is kept with the original sampling period which was configured according to the value of the guest's counter when the counter was enabled. Such behaviour can cause very bad consequences. The most distrubing one can cause the guest not to make any progress at all, and keep exiting due to host PMI before any guest instructions is exeucted. This situation occurs when the performance counter holds a very high value when the guest enables the performance counter. As a result the host's sampling period is configured to be very short. The host then never reconfigures the sampling period and get stuck at entry->PMI->exit loop. We encountered such a scenario in our experiments. The solution is to reprogram the counter even if the guest does not use PMI. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22KVM: nVMX: Advertise support for interrupt acknowledgementBandan Das
Some Type 1 hypervisors such as XEN won't enable VMX without it present Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22KVM: nVMX: Ack and write vector info to intr_info if L1 asks us toBandan Das
This feature emulates the "Acknowledge interrupt on exit" behavior. We can safely emulate it for L1 to run L2 even if L0 itself has it disabled (to run L1). Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22KVM: nVMX: Don't advertise single context invalidation for inveptBandan Das
For single context invalidation, we fall through to global invalidation in handle_invept() except for one case - when the operand supplied by L1 is different from what we have in vmcs12. However, typically hypervisors will only call invept for the currently loaded eptp, so the condition will never be true. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22KVM: VMX: Advance rip to after an ICEBP instructionHuw Davies
When entering an exception after an ICEBP, the saved instruction pointer should point to after the instruction. This fixes the bug here: https://bugs.launchpad.net/qemu/+bug/1119686 Signed-off-by: Huw Davies <huw@codeweavers.com> Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso fix from Peter Anvin: "This is a single build fix for building with gold as opposed to GNU ld. It got queued up separately and was expected to be pushed during the merge window, but it got left behind" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, vdso: Make the vdso linker script compatible with Gold
2014-04-22x86: LLVMLinux: Wrap -mno-80387 with cc-optionBehan Webster
Wrap -mno-80387 gcc options with cc-option so they don't break clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Cc: torvalds@linux-foundation.org Cc: dwmw2@infradead.org Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/1398145227-25053-1-git-send-email-behanw@converseincode.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-21KVM: x86: Fix CR3 and LDT sel should not be saved in TSSNadav Amit
According to Intel specifications, only general purpose registers and segment selectors should be saved in the old TSS during 32-bit task-switch. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-21ftrace/x86: Fix order of warning messages when ftrace modifies codePetr Mladek
The colon at the end of the printk message suggests that it should get printed before the details printed by ftrace_bug(). When touching the line, let's use the preferred pr_warn() macro as suggested by checkpatch.pl. Link: http://lkml.kernel.org/r/1392650573-3390-5-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-19Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Ingo Molnar: "This fixes the preemption-count imbalance crash reported by Owen Kibel" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Fix CMCI preemption bugs
2014-04-19Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two kernel side fixes: - an Intel uncore PMU driver potential crash fix - a kprobes/perf-call-graph interaction fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU kprobes/x86: Fix page-fault handling logic
2014-04-18arch,x86: Convert smp_mb__*()Peter Zijlstra
x86 is strongly ordered and all its atomic ops imply a full barrier. Implement the two new primitives as the old ones were. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-knswsr5mldkr0w1lrdxvc81w@git.kernel.org Cc: Dave Jones <davej@redhat.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michel Lespinasse <walken@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18perf/x86: Export perf_assign_events()Yan, Zheng
export perf_assign_events to allow building perf Intel uncore driver as module Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1395133004-23205-3-git-send-email-zheng.z.yan@intel.com Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: eranian@google.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18Merge branch 'perf/urgent' into perf/core, to pick up PMU driver fixes.Ingo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMUVenkatesh Srinivas
CPUs which should support the RAPL counters according to Family/Model/Stepping may still issue #GP when attempting to access the RAPL MSRs. This may happen when Linux is running under KVM and we are passing-through host F/M/S data, for example. Use rdmsrl_safe to first access the RAPL_POWER_UNIT MSR; if this fails, do not attempt to use this PMU. Signed-off-by: Venkatesh Srinivas <venkateshs@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com Cc: zheng.z.yan@intel.com Cc: eranian@google.com Cc: ak@linux.intel.com Cc: linux-kernel@vger.kernel.org [ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-17uprobes/x86: Emulate relative conditional "near" jmp'sOleg Nesterov
Change branch_setup_xol_ops() to simply use opc1 = OPCODE2(insn) - 0x10 if OPCODE1() == 0x0f; this matches the "short" jmp which checks the same condition. Thanks to lib/insn.c, it does the rest correctly. branch->ilen/offs are correct no matter if this jmp is "near" or "short". Reported-by: Jonathan Lebon <jlebon@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
2014-04-17uprobes/x86: Emulate relative conditional "short" jmp'sOleg Nesterov
Teach branch_emulate_op() to emulate the conditional "short" jmp's which check regs->flags. Note: this doesn't support jcxz/jcexz, loope/loopz, and loopne/loopnz. They all are rel8 and thus they can't trigger the problem, but perhaps we will add the support in future just for completeness. Reported-by: Jonathan Lebon <jlebon@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
2014-04-17uprobes/x86: Emulate relative call'sOleg Nesterov
See the previous "Emulate unconditional relative jmp's" which explains why we can not execute "jmp" out-of-line, the same applies to "call". Emulating of rip-relative call is trivial, we only need to additionally push the ret-address. If this fails, we execute this instruction out of line and this should trigger the trap, the probed application should die or the same insn will be restarted if a signal handler expands the stack. We do not even need ->post_xol() for this case. But there is a corner (and almost theoretical) case: another thread can expand the stack right before we execute this insn out of line. In this case it hit the same problem we are trying to solve. So we simply turn the probed insn into "call 1f; 1:" and add ->post_xol() which restores ->sp and restarts. Many thanks to Jonathan who finally found the standalone reproducer, otherwise I would never resolve the "random SIGSEGV's under systemtap" bug-report. Now that the problem is clear we can write the simplified test-case: void probe_func(void), callee(void); int failed = 1; asm ( ".text\n" ".align 4096\n" ".globl probe_func\n" "probe_func:\n" "call callee\n" "ret" ); /* * This assumes that: * * - &probe_func = 0x401000 + a_bit, aligned = 0x402000 * * - xol_vma->vm_start = TASK_SIZE_MAX - PAGE_SIZE = 0x7fffffffe000 * as xol_add_vma() asks; the 1st slot = 0x7fffffffe080 * * so we can target the non-canonical address from xol_vma using * the simple math below, 100 * 4096 is just the random offset */ asm (".org . + 0x800000000000 - 0x7fffffffe080 - 5 - 1 + 100 * 4096\n"); void callee(void) { failed = 0; } int main(void) { probe_func(); return failed; } It SIGSEGV's if you probe "probe_func" (although this is not very reliable, randomize_va_space/etc can change the placement of xol area). Note: as Denys Vlasenko pointed out, amd and intel treat "callw" (0x66 0xe8) differently. This patch relies on lib/insn.c and thus implements the intel's behaviour: 0x66 is simply ignored. Fortunately nothing sane should ever use this insn, so we postpone the fix until we decide what should we do; emulate or not, support or not, etc. Reported-by: Jonathan Lebon <jlebon@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
2014-04-17uprobes/x86: Emulate nop's using ops->emulate()Oleg Nesterov
Finally we can kill the ugly (and very limited) code in __skip_sstep(). Just change branch_setup_xol_ops() to treat "nop" as jmp to the next insn. Thanks to lib/insn.c, it is clever enough. OPCODE1() == 0x90 includes "(rep;)+ nop;" at least, and (afaics) much more. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>