1 files changed, 28 insertions, 55 deletions

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 745caa6c15a3..0c38a31d5fc7 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -20,6 +20,7 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/kdebug.h>
+#include <linux/kvm_types.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/clock.h>
 #include <linux/uaccess.h>
@@ -554,14 +555,22 @@ static inline int precise_br_compat(struct perf_event *event)
 	return m == b;
 }
 
-int x86_pmu_max_precise(void)
+int x86_pmu_max_precise(struct pmu *pmu)
 {
 	int precise = 0;
 
-	/* Support for constant skid */
 	if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
-		precise++;
+		/* arch PEBS */
+		if (x86_pmu.arch_pebs) {
+			precise = 2;
+			if (hybrid(pmu, arch_pebs_cap).pdists)
+				precise++;
+
+			return precise;
+		}
 
+		/* legacy PEBS - support for constant skid */
+		precise++;
 		/* Support for IP fixup */
 		if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
 			precise++;
@@ -569,13 +578,14 @@ int x86_pmu_max_precise(void)
 		if (x86_pmu.pebs_prec_dist)
 			precise++;
 	}
+
 	return precise;
 }
 
 int x86_pmu_hw_config(struct perf_event *event)
 {
 	if (event->attr.precise_ip) {
-		int precise = x86_pmu_max_precise();
+		int precise = x86_pmu_max_precise(event->pmu);
 
 		if (event->attr.precise_ip > precise)
 			return -EOPNOTSUPP;
@@ -714,7 +724,7 @@ struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
 {
 	return static_call(x86_pmu_guest_get_msrs)(nr, data);
 }
-EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
+EXPORT_SYMBOL_FOR_KVM(perf_guest_get_msrs);
 
 /*
  * There may be PMI landing after enabled=0. The PMI hitting could be before or
@@ -1344,6 +1354,7 @@ static void x86_pmu_enable(struct pmu *pmu)
 				hwc->state |= PERF_HES_ARCH;
 
 			x86_pmu_stop(event, PERF_EF_UPDATE);
+			cpuc->events[hwc->idx] = NULL;
 		}
 
 		/*
@@ -1365,6 +1376,7 @@ static void x86_pmu_enable(struct pmu *pmu)
 			 * if cpuc->enabled = 0, then no wrmsr as
 			 * per x86_pmu_enable_event()
 			 */
+			cpuc->events[hwc->idx] = event;
 			x86_pmu_start(event, PERF_EF_RELOAD);
 		}
 		cpuc->n_added = 0;
@@ -1531,7 +1543,6 @@ static void x86_pmu_start(struct perf_event *event, int flags)
 
 	event->hw.state = 0;
 
-	cpuc->events[idx] = event;
 	__set_bit(idx, cpuc->active_mask);
 	static_call(x86_pmu_enable)(event);
 	perf_event_update_userpage(event);
@@ -1610,7 +1621,6 @@ void x86_pmu_stop(struct perf_event *event, int flags)
 	if (test_bit(hwc->idx, cpuc->active_mask)) {
 		static_call(x86_pmu_disable)(event);
 		__clear_bit(hwc->idx, cpuc->active_mask);
-		cpuc->events[hwc->idx] = NULL;
 		WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
 		hwc->state |= PERF_HES_STOPPED;
 	}
@@ -1648,6 +1658,7 @@ static void x86_pmu_del(struct perf_event *event, int flags)
 	 * Not a TXN, therefore cleanup properly.
 	 */
 	x86_pmu_stop(event, PERF_EF_UPDATE);
+	cpuc->events[event->hw.idx] = NULL;
 
 	for (i = 0; i < cpuc->n_events; i++) {
 		if (event == cpuc->event_list[i])
@@ -2629,7 +2640,9 @@ static ssize_t max_precise_show(struct device *cdev,
 				  struct device_attribute *attr,
 				  char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
+	struct pmu *pmu = dev_get_drvdata(cdev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise(pmu));
 }
 
 static DEVICE_ATTR_RO(max_precise);
@@ -2789,13 +2802,13 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 		return;
 	}
 
-	if (perf_callchain_store(entry, regs->ip))
-		return;
-
-	if (perf_hw_regs(regs))
+	if (perf_hw_regs(regs)) {
+		if (perf_callchain_store(entry, regs->ip))
+			return;
 		unwind_start(&state, current, regs, NULL);
-	else
+	} else {
 		unwind_start(&state, current, NULL, (void *)regs->sp);
+	}
 
 	for (; !unwind_done(&state); unwind_next_frame(&state)) {
 		addr = unwind_get_return_address(&state);
@@ -2845,46 +2858,6 @@ static unsigned long get_segment_base(unsigned int segment)
 	return get_desc_base(desc);
 }
 
-#ifdef CONFIG_UPROBES
-/*
- * Heuristic-based check if uprobe is installed at the function entry.
- *
- * Under assumption of user code being compiled with frame pointers,
- * `push %rbp/%ebp` is a good indicator that we indeed are.
- *
- * Similarly, `endbr64` (assuming 64-bit mode) is also a common pattern.
- * If we get this wrong, captured stack trace might have one extra bogus
- * entry, but the rest of stack trace will still be meaningful.
- */
-static bool is_uprobe_at_func_entry(struct pt_regs *regs)
-{
-	struct arch_uprobe *auprobe;
-
-	if (!current->utask)
-		return false;
-
-	auprobe = current->utask->auprobe;
-	if (!auprobe)
-		return false;
-
-	/* push %rbp/%ebp */
-	if (auprobe->insn[0] == 0x55)
-		return true;
-
-	/* endbr64 (64-bit only) */
-	if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
-		return true;
-
-	return false;
-}
-
-#else
-static bool is_uprobe_at_func_entry(struct pt_regs *regs)
-{
-	return false;
-}
-#endif /* CONFIG_UPROBES */
-
 #ifdef CONFIG_IA32_EMULATION
 
 #include <linux/compat.h>
@@ -3106,7 +3079,7 @@ void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
 	cap->events_mask_len	= x86_pmu.events_mask_len;
 	cap->pebs_ept		= x86_pmu.pebs_ept;
 }
-EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);
+EXPORT_SYMBOL_FOR_KVM(perf_get_x86_pmu_capability);
 
 u64 perf_get_hw_event_config(int hw_event)
 {
@@ -3117,4 +3090,4 @@ u64 perf_get_hw_event_config(int hw_event)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(perf_get_hw_event_config);
+EXPORT_SYMBOL_FOR_KVM(perf_get_hw_event_config);