summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/perf_event.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/perf_event.c')
-rw-r--r--arch/s390/kernel/perf_event.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index c27321cb09..dfa77da2fd 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -15,7 +15,10 @@
#include <linux/export.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/compat.h>
#include <linux/sysfs.h>
+#include <asm/stacktrace.h>
#include <asm/irq.h>
#include <asm/cpu_mf.h>
#include <asm/lowcore.h>
@@ -212,6 +215,44 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
}
}
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
+ struct pt_regs *regs)
+{
+ struct stack_frame_user __user *sf;
+ unsigned long ip, sp;
+ bool first = true;
+
+ if (is_compat_task())
+ return;
+ perf_callchain_store(entry, instruction_pointer(regs));
+ sf = (void __user *)user_stack_pointer(regs);
+ pagefault_disable();
+ while (entry->nr < entry->max_stack) {
+ if (__get_user(sp, &sf->back_chain))
+ break;
+ if (__get_user(ip, &sf->gprs[8]))
+ break;
+ if (ip & 0x1) {
+ /*
+ * If the instruction address is invalid, and this
+ * is the first stack frame, assume r14 has not
+ * been written to the stack yet. Otherwise exit.
+ */
+ if (first && !(regs->gprs[14] & 0x1))
+ ip = regs->gprs[14];
+ else
+ break;
+ }
+ perf_callchain_store(entry, ip);
+ /* Sanity check: ABI requires SP to be aligned 8 bytes. */
+ if (!sp || sp & 0x7)
+ break;
+ sf = (void __user *)sp;
+ first = false;
+ }
+ pagefault_enable();
+}
+
/* Perf definitions for PMU event attributes in sysfs */
ssize_t cpumf_events_sysfs_show(struct device *dev,
struct device_attribute *attr, char *page)