From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/sparc/kernel/ftrace.c | 133 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 arch/sparc/kernel/ftrace.c

(limited to 'arch/sparc/kernel/ftrace.c')

diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c
new file mode 100644
index 000000000..eaead3da8
--- /dev/null
+++ b/arch/sparc/kernel/ftrace.c
@@ -0,0 +1,133 @@
+// 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);
+}
+#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(&current->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 */
-- 
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