From a03ffcf873fe0f2565386ca8ef832144c42e67fa Mon Sep 17 00:00:00 2001 From: Markus Kötter Date: Sat, 17 Dec 2011 11:39:08 +0000 Subject: net: bpf_jit: fix an off-one bug in x86_64 cond jump target MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit x86 jump instruction size is 2 or 5 bytes (near/long jump), not 2 or 6 bytes. In case a conditional jump is followed by a long jump, conditional jump target is one byte past the start of target instruction. Signed-off-by: Markus Kötter Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- arch/x86/net/bpf_jit_comp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index bfab3fa10edc..7b65f752c5f8 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -568,8 +568,8 @@ cond_branch: f_offset = addrs[i + filter[i].jf] - addrs[i]; break; } if (filter[i].jt != 0) { - if (filter[i].jf) - t_offset += is_near(f_offset) ? 2 : 6; + if (filter[i].jf && f_offset) + t_offset += is_near(f_offset) ? 2 : 5; EMIT_COND_JMP(t_op, t_offset); if (filter[i].jf) EMIT_JMP(f_offset); -- cgit v1.2.3 From 13f541c10b30fc6529200d7f9a0073217709622f Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 19 Dec 2011 22:07:58 +0100 Subject: x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT When printing the code bytes in show_registers(), the markers around the byte at the fault address could make the printk() format string look like a valid log level and facility code. This would prevent this byte from being printed and result in a spurious newline: [ 7555.765589] Code: 8b 32 e9 94 00 00 00 81 7d 00 ff 00 00 00 0f 87 96 00 00 00 48 8b 83 c0 00 00 00 44 89 e2 44 89 e6 48 89 df 48 8b 80 d8 02 00 00 [ 7555.765683] 8b 48 28 48 89 d0 81 e2 ff 0f 00 00 48 c1 e8 0c 48 c1 e0 04 Add KERN_CONT where needed, and elsewhere in show_registers() for consistency. Signed-off-by: Clemens Ladisch Link: http://lkml.kernel.org/r/4EEFA7AE.9020407@ladisch.de Signed-off-by: H. Peter Anvin --- arch/x86/kernel/dumpstack_32.c | 8 ++++---- arch/x86/kernel/dumpstack_64.c | 8 ++++---- 2 files changed, 8 insertions(+), 8 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index 3b97a80ce329..c99f9ed013d5 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -116,16 +116,16 @@ void show_registers(struct pt_regs *regs) for (i = 0; i < code_len; i++, ip++) { if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { - printk(" Bad EIP value."); + printk(KERN_CONT " Bad EIP value."); break; } if (ip == (u8 *)regs->ip) - printk("<%02x> ", c); + printk(KERN_CONT "<%02x> ", c); else - printk("%02x ", c); + printk(KERN_CONT "%02x ", c); } } - printk("\n"); + printk(KERN_CONT "\n"); } int is_valid_bugaddr(unsigned long ip) diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 19853ad8afc5..6d728d9284bd 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -284,16 +284,16 @@ void show_registers(struct pt_regs *regs) for (i = 0; i < code_len; i++, ip++) { if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { - printk(" Bad RIP value."); + printk(KERN_CONT " Bad RIP value."); break; } if (ip == (u8 *)regs->ip) - printk("<%02x> ", c); + printk(KERN_CONT "<%02x> ", c); else - printk("%02x ", c); + printk(KERN_CONT "%02x ", c); } } - printk("\n"); + printk(KERN_CONT "\n"); } int is_valid_bugaddr(unsigned long ip) -- cgit v1.2.3 From 2e64694de21a812d637dcbea4471ad1f7897b049 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Fri, 23 Dec 2011 14:24:25 +0100 Subject: perf/x86: Fix raw_spin_unlock_irqrestore() usage Use raw_spin_unlock_irqrestore() as equivalent to raw_spin_lock_irqsave(). Signed-off-by: Robert Richter Cc: Stephane Eranian Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1324646665-13334-1-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 8d601b18bf9f..121f1be4da19 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1169,7 +1169,7 @@ again: */ c = &unconstrained; } else if (intel_try_alt_er(event, orig_idx)) { - raw_spin_unlock(&era->lock); + raw_spin_unlock_irqrestore(&era->lock, flags); goto again; } raw_spin_unlock_irqrestore(&era->lock, flags); -- cgit v1.2.3 From 0924ab2cfa98b1ece26c033d696651fd62896c69 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 14 Dec 2011 19:25:13 +0100 Subject: KVM: x86: Prevent starting PIT timers in the absence of irqchip support User space may create the PIT and forgets about setting up the irqchips. In that case, firing PIT IRQs will crash the host: BUG: unable to handle kernel NULL pointer dereference at 0000000000000128 IP: [] kvm_set_irq+0x30/0x170 [kvm] ... Call Trace: [] pit_do_work+0x51/0xd0 [kvm] [] process_one_work+0x111/0x4d0 [] worker_thread+0x152/0x340 [] kthread+0x7e/0x90 [] kernel_thread_helper+0x4/0x10 Prevent this by checking the irqchip mode before starting a timer. We can't deny creating the PIT if the irqchips aren't set up yet as current user land expects this order to work. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/i8254.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 76e3f1cd0369..405f2620392f 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -338,11 +338,15 @@ static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) return HRTIMER_NORESTART; } -static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period) +static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) { + struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; struct kvm_timer *pt = &ps->pit_timer; s64 interval; + if (!irqchip_in_kernel(kvm)) + return; + interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); pr_debug("create pit timer, interval is %llu nsec\n", interval); @@ -394,13 +398,13 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val) /* FIXME: enhance mode 4 precision */ case 4: if (!(ps->flags & KVM_PIT_FLAGS_HPET_LEGACY)) { - create_pit_timer(ps, val, 0); + create_pit_timer(kvm, val, 0); } break; case 2: case 3: if (!(ps->flags & KVM_PIT_FLAGS_HPET_LEGACY)){ - create_pit_timer(ps, val, 1); + create_pit_timer(kvm, val, 1); } break; default: -- cgit v1.2.3 From 4d25a066b69fb749a39d0d4c610689dd765a0b0e Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 21 Dec 2011 12:28:29 +0100 Subject: KVM: Don't automatically expose the TSC deadline timer in cpuid Unlike all of the other cpuid bits, the TSC deadline timer bit is set unconditionally, regardless of what userspace wants. This is broken in several ways: - if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC deadline timer feature, a guest that uses the feature will break - live migration to older host kernels that don't support the TSC deadline timer will cause the feature to be pulled from under the guest's feet; breaking it - guests that are broken wrt the feature will fail. Fix by not enabling the feature automatically; instead report it to userspace. Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not KVM_GET_SUPPORTED_CPUID. Fixes the Illumos guest kernel, which uses the TSC deadline timer feature. [avi: add the KVM_CAP + documentation] Reported-by: Alexey Zaytsev Tested-by: Alexey Zaytsev Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- Documentation/virtual/kvm/api.txt | 9 +++++++++ arch/x86/kvm/x86.c | 19 +++++++++---------- include/linux/kvm.h | 1 + 3 files changed, 19 insertions(+), 10 deletions(-) (limited to 'arch/x86') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 4df9af4f6132..e2a4b5287361 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1100,6 +1100,15 @@ emulate them efficiently. The fields in each entry are defined as follows: eax, ebx, ecx, edx: the values returned by the cpuid instruction for this function/index combination +The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned +as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC +support. Instead it is reported via + + ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) + +if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the +feature in userspace, then you can enable the feature for KVM_SET_CPUID2. + 4.47 KVM_PPC_GET_PVINFO Capability: KVM_CAP_PPC_GET_PVINFO diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c38efd7b792e..4c938da2ba00 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -602,7 +602,6 @@ static void update_cpuid(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; struct kvm_lapic *apic = vcpu->arch.apic; - u32 timer_mode_mask; best = kvm_find_cpuid_entry(vcpu, 1, 0); if (!best) @@ -615,15 +614,12 @@ static void update_cpuid(struct kvm_vcpu *vcpu) best->ecx |= bit(X86_FEATURE_OSXSAVE); } - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && - best->function == 0x1) { - best->ecx |= bit(X86_FEATURE_TSC_DEADLINE_TIMER); - timer_mode_mask = 3 << 17; - } else - timer_mode_mask = 1 << 17; - - if (apic) - apic->lapic_timer.timer_mode_mask = timer_mode_mask; + if (apic) { + if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER)) + apic->lapic_timer.timer_mode_mask = 3 << 17; + else + apic->lapic_timer.timer_mode_mask = 1 << 17; + } } int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) @@ -2135,6 +2131,9 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_TSC_CONTROL: r = kvm_has_tsc_control; break; + case KVM_CAP_TSC_DEADLINE_TIMER: + r = boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER); + break; default: r = 0; break; diff --git a/include/linux/kvm.h b/include/linux/kvm.h index c3892fc1d538..68e67e50d028 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -557,6 +557,7 @@ struct kvm_ppc_pvinfo { #define KVM_CAP_MAX_VCPUS 66 /* returns max vcpus per vm */ #define KVM_CAP_PPC_PAPR 68 #define KVM_CAP_S390_GMAP 71 +#define KVM_CAP_TSC_DEADLINE_TIMER 72 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3