v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c
new file mode 100644
index 0000000..684b84c
--- /dev/null
+++ b/arch/sparc/kernel/ftrace.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+#include <linux/ftrace.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <trace/syscall.h>
+
+#include <asm/ftrace.h>
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static const u32 ftrace_nop = 0x01000000;
+
+static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
+{
+ u32 call;
+ s32 off;
+
+ off = ((s32)addr - (s32)ip);
+ call = 0x40000000 | ((u32)off >> 2);
+
+ return call;
+}
+
+static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
+{
+ u32 replaced;
+ int faulted;
+
+ __asm__ __volatile__(
+ "1: cas [%[ip]], %[old], %[new]\n"
+ " flush %[ip]\n"
+ " mov 0, %[faulted]\n"
+ "2:\n"
+ " .section .fixup,#alloc,#execinstr\n"
+ " .align 4\n"
+ "3: sethi %%hi(2b), %[faulted]\n"
+ " jmpl %[faulted] + %%lo(2b), %%g0\n"
+ " mov 1, %[faulted]\n"
+ " .previous\n"
+ " .section __ex_table,\"a\"\n"
+ " .align 4\n"
+ " .word 1b, 3b\n"
+ " .previous\n"
+ : "=r" (replaced), [faulted] "=r" (faulted)
+ : [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
+ : "memory");
+
+ if (replaced != old && replaced != new)
+ faulted = 2;
+
+ return faulted;
+}
+
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ u32 old, new;
+
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop;
+ return ftrace_modify_code(ip, old, new);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ u32 old, new;
+
+ old = ftrace_nop;
+ new = ftrace_call_replace(ip, addr);
+ return ftrace_modify_code(ip, old, new);
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+ unsigned long ip = (unsigned long)(&ftrace_call);
+ u32 old, new;
+
+ old = *(u32 *) &ftrace_call;
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ return ftrace_modify_code(ip, old, new);
+}
+
+int __init ftrace_dyn_arch_init(void)
+{
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ u32 old, new;
+
+ old = *(u32 *) &ftrace_graph_call;
+ new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller);
+ return ftrace_modify_code(ip, old, new);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ u32 old, new;
+
+ old = *(u32 *) &ftrace_graph_call;
+ new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub);
+
+ return ftrace_modify_code(ip, old, new);
+}
+
+#endif /* !CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+unsigned long prepare_ftrace_return(unsigned long parent,
+ unsigned long self_addr,
+ unsigned long frame_pointer)
+{
+ unsigned long return_hooker = (unsigned long) &return_to_handler;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return parent + 8UL;
+
+ if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
+ return parent + 8UL;
+
+ return return_hooker;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */