These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / arch / x86 / kernel / cpu / perf_event_intel_bts.c

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 7795f3f..2cad71d 100644 (file)
--- 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);