The perf fuzzer caused Skylake machine to crash: [ 9680.085831] Call Trace: [ 9680.088301] <IRQ> [ 9680.090363] perf_output_sample_regs+0x43/0xa0 [ 9680.094928] perf_output_sample+0x3aa/0x7a0 [ 9680.099181] perf_event_output_forward+0x53/0x80 [ 9680.103917] __perf_event_overflow+0x52/0xf0 [ 9680.108266] ? perf_trace_run_bpf_submit+0xc0/0xc0 [ 9680.113108] perf_swevent_hrtimer+0xe2/0x150 [ 9680.117475] ? check_preempt_wakeup+0x181/0x230 [ 9680.122091] ? check_preempt_curr+0x62/0x90 [ 9680.126361] ? ttwu_do_wakeup+0x19/0x140 [ 9680.130355] ? try_to_wake_up+0x54/0x460 [ 9680.134366] ? reweight_entity+0x15b/0x1a0 [ 9680.138559] ? __queue_work+0x103/0x3f0 [ 9680.142472] ? update_dl_rq_load_avg+0x1cd/0x270 [ 9680.147194] ? timerqueue_del+0x1e/0x40 [ 9680.151092] ? __remove_hrtimer+0x35/0x70 [ 9680.155191] __hrtimer_run_queues+0x100/0x280 [ 9680.159658] hrtimer_interrupt+0x100/0x220 [ 9680.163835] smp_apic_timer_interrupt+0x6a/0x140 [ 9680.168555] apic_timer_interrupt+0xf/0x20 [ 9680.172756] </IRQ> The XMM registers can only be collected by PEBS hardware events on the platforms with PEBS baseline support, e.g. Icelake, not software/probe events. Add capabilities flag PERF_PMU_CAP_EXTENDED_REGS to indicate the PMU which support extended registers. For X86, the extended registers are XMM registers. Add has_extended_regs() to check if extended registers are applied. The generic code define the mask of extended registers as 0 if arch headers haven't overridden it.
Showing the changes to include/linux (2 of 5 files). Show all
Unified · Split
| @@ -241,6 +241,7 @@ struct perf_event; · 240 unmodified lines | ||
| 241 | 241 | #define PERF_PMU_CAP_NO_INTERRUPT 0x01 |
| 242 | 242 | #define PERF_PMU_CAP_NO_NMI 0x02 |
| 243 | 243 | #define PERF_PMU_CAP_AUX_NO_SG 0x04 |
| 244 | +#define PERF_PMU_CAP_EXTENDED_REGS 0x08 | |
| 244 | 245 | #define PERF_PMU_CAP_EXCLUSIVE 0x10 |
| 245 | 246 | #define PERF_PMU_CAP_ITRACE 0x20 |
| 246 | 247 | #define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40 |
| @@ -11,6 +11,11 @@ struct perf_regs { · 10 unmodified lines | ||
| 11 | 11 | |
| 12 | 12 | #ifdef CONFIG_HAVE_PERF_REGS |
| 13 | 13 | #include <asm/perf_regs.h> |
| 14 | + | |
| 15 | +#ifndef PERF_REG_EXTENDED_MASK | |
| 16 | +#define PERF_REG_EXTENDED_MASK 0 | |
| 17 | +#endif | |
| 18 | + | |
| 14 | 19 | u64 perf_reg_value(struct pt_regs *regs, int idx); |
| 15 | 20 | int perf_reg_validate(u64 mask); |
| 16 | 21 | u64 perf_reg_abi(struct task_struct *task); |
| @@ -18,6 +23,9 @@ void perf_get_regs_user(struct perf_regs *regs_user, · 1 unmodified line | ||
| 18 | 23 | struct pt_regs *regs, |
| 19 | 24 | struct pt_regs *regs_user_copy); |
| 20 | 25 | #else |
| 26 | + | |
| 27 | +#define PERF_REG_EXTENDED_MASK 0 | |
| 28 | + | |
| 21 | 29 | static inline u64 perf_reg_value(struct pt_regs *regs, int idx) |
| 22 | 30 | { |
| 23 | 31 | return 0; |