1 files changed, 50 insertions, 0 deletions

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index f8908ea4ea73..3f66fcf8ad99 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -198,6 +198,10 @@ static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp)
 
 	if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
 		*addrp = mfspr(SPRN_SDAR);
+
+	if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) &&
+		is_kernel_addr(mfspr(SPRN_SDAR)))
+		*addrp = 0;
 }
 
 static bool regs_sihv(struct pt_regs *regs)
@@ -457,6 +461,16 @@ static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
 				/* invalid entry */
 				continue;
 
+			/*
+			 * BHRB rolling buffer could very much contain the kernel
+			 * addresses at this point. Check the privileges before
+			 * exporting it to userspace (avoid exposure of regions
+			 * where we could have speculative execution)
+			 */
+			if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) &&
+				is_kernel_addr(addr))
+				continue;
+
 			/* Branches are read most recent first (ie. mfbhrb 0 is
 			 * the most recent branch).
 			 * There are two types of valid entries:
@@ -1226,6 +1240,7 @@ static void power_pmu_disable(struct pmu *pmu)
 		 */
 		write_mmcr0(cpuhw, val);
 		mb();
+		isync();
 
 		/*
 		 * Disable instruction sampling if it was enabled
@@ -1234,12 +1249,26 @@ static void power_pmu_disable(struct pmu *pmu)
 			mtspr(SPRN_MMCRA,
 			      cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
 			mb();
+			isync();
 		}
 
 		cpuhw->disabled = 1;
 		cpuhw->n_added = 0;
 
 		ebb_switch_out(mmcr0);
+
+#ifdef CONFIG_PPC64
+		/*
+		 * These are readable by userspace, may contain kernel
+		 * addresses and are not switched by context switch, so clear
+		 * them now to avoid leaking anything to userspace in general
+		 * including to another process.
+		 */
+		if (ppmu->flags & PPMU_ARCH_207S) {
+			mtspr(SPRN_SDAR, 0);
+			mtspr(SPRN_SIAR, 0);
+		}
+#endif
 	}
 
 	local_irq_restore(flags);
@@ -1810,6 +1839,18 @@ static int hw_perf_cache_event(u64 config, u64 *eventp)
 	return 0;
 }
 
+static bool is_event_blacklisted(u64 ev)
+{
+	int i;
+
+	for (i=0; i < ppmu->n_blacklist_ev; i++) {
+		if (ppmu->blacklist_ev[i] == ev)
+			return true;
+	}
+
+	return false;
+}
+
 static int power_pmu_event_init(struct perf_event *event)
 {
 	u64 ev;
@@ -1835,15 +1876,24 @@ static int power_pmu_event_init(struct perf_event *event)
 		ev = event->attr.config;
 		if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0)
 			return -EOPNOTSUPP;
+
+		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
+			return -EINVAL;
 		ev = ppmu->generic_events[ev];
 		break;
 	case PERF_TYPE_HW_CACHE:
 		err = hw_perf_cache_event(event->attr.config, &ev);
 		if (err)
 			return err;
+
+		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
+			return -EINVAL;
 		break;
 	case PERF_TYPE_RAW:
 		ev = event->attr.config;
+
+		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
+			return -EINVAL;
 		break;
 	default:
 		return -ENOENT;