diff options
Diffstat (limited to 'kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c')
| -rw-r--r-- | kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c b/kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c index 7795f3f8b..2cad71d1b 100644 --- a/kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c +++ b/kernel/arch/x86/kernel/cpu/perf_event_intel_bts.c @@ -62,9 +62,6 @@ struct bts_buffer { struct pmu bts_pmu; -void intel_pmu_enable_bts(u64 config); -void intel_pmu_disable_bts(void); - static size_t buf_size(struct page *page) { return 1 << (PAGE_SHIFT + page_private(page)); @@ -225,6 +222,7 @@ static void __bts_event_start(struct perf_event *event) if (!buf || bts_buffer_is_full(buf, bts)) return; + event->hw.itrace_started = 1; event->hw.state = 0; if (!buf->snapshot) @@ -497,6 +495,19 @@ static int bts_event_init(struct perf_event *event) if (x86_add_exclusive(x86_lbr_exclusive_bts)) return -EBUSY; + /* + * BTS leaks kernel addresses even when CPL0 tracing is + * disabled, so disallow intel_bts driver for unprivileged + * users on paranoid systems since it provides trace data + * to the user in a zero-copy fashion. + * + * Note that the default paranoia setting permits unprivileged + * users to profile the kernel. + */ + if (event->attr.exclude_kernel && perf_paranoid_kernel() && + !capable(CAP_SYS_ADMIN)) + return -EACCES; + ret = x86_reserve_hardware(); if (ret) { x86_del_exclusive(x86_lbr_exclusive_bts); @@ -530,5 +541,4 @@ static __init int bts_init(void) return perf_pmu_register(&bts_pmu, "intel_bts", -1); } - -module_init(bts_init); +arch_initcall(bts_init); |