From beb56b614b8904890498ff8eb41d294afff1ff69 Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey@neuling.org>
Date: Mon, 13 May 2013 18:44:58 +0000
Subject: [PATCH] --- yaml --- r: 375574 b: refs/heads/master c:
 691231846cebfe1fbbcf898c8af17a569dbb5463 h: refs/heads/master v: v3

---
 [refs]                                |  2 +-
 trunk/arch/powerpc/perf/core-book3s.c | 31 ++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 9563b5307c71..9e3f0bd68b87 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 506e70d13236dfdb0bc15e0914298ab0a7b7f4df
+refs/heads/master: 691231846cebfe1fbbcf898c8af17a569dbb5463
diff --git a/trunk/arch/powerpc/perf/core-book3s.c b/trunk/arch/powerpc/perf/core-book3s.c
index 3fdfe4575b8f..426180b84978 100644
--- a/trunk/arch/powerpc/perf/core-book3s.c
+++ b/trunk/arch/powerpc/perf/core-book3s.c
@@ -13,11 +13,13 @@
 #include <linux/perf_event.h>
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/uaccess.h>
 #include <asm/reg.h>
 #include <asm/pmc.h>
 #include <asm/machdep.h>
 #include <asm/firmware.h>
 #include <asm/ptrace.h>
+#include <asm/code-patching.h>
 
 #define BHRB_MAX_ENTRIES	32
 #define BHRB_TARGET		0x0000000000000002
@@ -362,6 +364,32 @@ void power_pmu_flush_branch_stack(void)
 	if (ppmu->bhrb_nr)
 		power_pmu_bhrb_reset();
 }
+/* Calculate the to address for a branch */
+static __u64 power_pmu_bhrb_to(u64 addr)
+{
+	unsigned int instr;
+	int ret;
+	__u64 target;
+
+	if (is_kernel_addr(addr))
+		return branch_target((unsigned int *)addr);
+
+	/* Userspace: need copy instruction here then translate it */
+	pagefault_disable();
+	ret = __get_user_inatomic(instr, (unsigned int __user *)addr);
+	if (ret) {
+		pagefault_enable();
+		return 0;
+	}
+	pagefault_enable();
+
+	target = branch_target(&instr);
+	if ((!target) || (instr & BRANCH_ABSOLUTE))
+		return target;
+
+	/* Translate relative branch target from kernel to user address */
+	return target - (unsigned long)&instr + addr;
+}
 
 /* Processing BHRB entries */
 void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
@@ -426,7 +454,8 @@ void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
 				/* Branches to immediate field 
 				   (ie I or B form) */
 				cpuhw->bhrb_entries[u_index].from = addr;
-				cpuhw->bhrb_entries[u_index].to = 0;
+				cpuhw->bhrb_entries[u_index].to =
+					power_pmu_bhrb_to(addr);
 				cpuhw->bhrb_entries[u_index].mispred = pred;
 				cpuhw->bhrb_entries[u_index].predicted = ~pred;
 			}