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-rw-r--r--arch/powerpc/perf/core-book3s.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 3fdfe4575b8f..426180b84978 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/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;
}