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Date: Thu, 10 Dec 2015 14:11:56 -0700 From: Jeff Merkey <linux.mdb@...il.com> To: Thomas Gleixner <tglx@...utronix.de> Cc: Andy Lutomirski <luto@...capital.net>, LKML <linux-kernel@...r.kernel.org>, Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>, X86 ML <x86@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Andy Lutomirski <luto@...nel.org>, Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>, Steven Rostedt <rostedt@...dmis.org>, Borislav Petkov <bp@...en8.de>, Jiri Olsa <jolsa@...nel.org> Subject: Re: [PATCH 1/1] Fix int1 recursion when no perf_bp_event is registeredy There's no output to send when the bug occurs, the system locks up. Here is the CPU info in any event for the affected system. processor : 0 vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9850 Quad-Core Processor stepping : 3 microcode : 0x1000095 cpu MHz : 1250.000 cache size : 512 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs hw_pstate npt lbrv svm_lock vmmcall bugs : tlb_mmatch fxsave_leak sysret_ss_attrs bogomips : 5022.82 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm stc 100mhzsteps hwpstate processor : 1 vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9850 Quad-Core Processor stepping : 3 microcode : 0x1000095 cpu MHz : 1250.000 cache size : 512 KB physical id : 0 siblings : 4 core id : 1 cpu cores : 4 apicid : 1 initial apicid : 1 fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs hw_pstate npt lbrv svm_lock vmmcall bugs : tlb_mmatch fxsave_leak sysret_ss_attrs bogomips : 5022.82 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm stc 100mhzsteps hwpstate processor : 2 vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9850 Quad-Core Processor stepping : 3 microcode : 0x1000095 cpu MHz : 1250.000 cache size : 512 KB physical id : 0 siblings : 4 core id : 2 cpu cores : 4 apicid : 2 initial apicid : 2 fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs hw_pstate npt lbrv svm_lock vmmcall bugs : tlb_mmatch fxsave_leak sysret_ss_attrs bogomips : 5022.82 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm stc 100mhzsteps hwpstate processor : 3 vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9850 Quad-Core Processor stepping : 3 microcode : 0x1000095 cpu MHz : 1250.000 cache size : 512 KB physical id : 0 siblings : 4 core id : 3 cpu cores : 4 apicid : 3 initial apicid : 3 fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs hw_pstate npt lbrv svm_lock vmmcall bugs : tlb_mmatch fxsave_leak sysret_ss_attrs bogomips : 5022.82 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm stc 100mhzsteps hwpstate On 12/10/15, Thomas Gleixner <tglx@...utronix.de> wrote: > On Thu, 10 Dec 2015, Andy Lutomirski wrote: >> On brief inspection, this smells like a microcode bug. Can you send >> /proc/cpuinfo output? >> >> If this is the issue, I'm not sure we want to be in the business of >> working around localized microcode bugs and, if we do, then I think we >> should explicitly detect the bug and log about it. > > I think we should handle such stuff gracefully. Yes, we should log it > and we also should check what the contents of the debug registers are. > > If dr7 has a break point enabled w/o perf having one installed then we > know that someone did a horrible hackery .... > > Thanks, > > tglx > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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