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-rw-r--r--arch/s390/kernel/mcount64.S63
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/s390/kernel/mcount64.S b/arch/s390/kernel/mcount64.S
new file mode 100644
index 00000000000..f70cadec68f
--- /dev/null
+++ b/arch/s390/kernel/mcount64.S
@@ -0,0 +1,63 @@
+/*
+ * Copyright IBM Corp. 2008,2009
+ *
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+
+ .section .kprobes.text, "ax"
+
+ENTRY(ftrace_stub)
+ br %r14
+
+ENTRY(_mcount)
+#ifdef CONFIG_DYNAMIC_FTRACE
+ br %r14
+
+ENTRY(ftrace_caller)
+#endif
+ larl %r1,function_trace_stop
+ icm %r1,0xf,0(%r1)
+ bnzr %r14
+ stmg %r2,%r5,32(%r15)
+ stg %r14,112(%r15)
+ lgr %r1,%r15
+ aghi %r15,-160
+ stg %r1,__SF_BACKCHAIN(%r15)
+ lgr %r2,%r14
+ lg %r3,168(%r15)
+ larl %r14,ftrace_trace_function
+ lg %r14,0(%r14)
+ basr %r14,%r14
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ lg %r2,168(%r15)
+ lg %r3,272(%r15)
+ENTRY(ftrace_graph_caller)
+# The bras instruction gets runtime patched to call prepare_ftrace_return.
+# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
+# bras %r14,prepare_ftrace_return
+ bras %r14,0f
+0: stg %r2,168(%r15)
+#endif
+ aghi %r15,160
+ lmg %r2,%r5,32(%r15)
+ lg %r14,112(%r15)
+ br %r14
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+ENTRY(return_to_handler)
+ stmg %r2,%r5,32(%r15)
+ lgr %r1,%r15
+ aghi %r15,-160
+ stg %r1,__SF_BACKCHAIN(%r15)
+ brasl %r14,ftrace_return_to_handler
+ aghi %r15,160
+ lgr %r14,%r2
+ lmg %r2,%r5,32(%r15)
+ br %r14
+
+#endif