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authorGuo Ren <ren_guo@c-sky.com>2018-12-15 21:04:27 +0800
committerGuo Ren <ren_guo@c-sky.com>2018-12-31 23:17:23 +0800
commitd7950be145c84ca5094c52bc1ad1e7f1893d0f19 (patch)
treec69b59c597f07f36159112ad3afc251feb32455e /arch/csky/kernel/ftrace.c
parent230c77a5e92a29bf21e98ee35e22b0537f61c55b (diff)
downloadlinux-sh-d7950be145c84ca5094c52bc1ad1e7f1893d0f19.tar.gz
csky: ftrace call graph supported.
With csky-gcc -pg -mbacktrace, ftrace call graph supported. Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Diffstat (limited to 'arch/csky/kernel/ftrace.c')
-rw-r--r--arch/csky/kernel/ftrace.c48
1 files changed, 37 insertions, 11 deletions
diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c
index ad054f7190f9..274c431f1810 100644
--- a/arch/csky/kernel/ftrace.c
+++ b/arch/csky/kernel/ftrace.c
@@ -4,21 +4,47 @@
#include <linux/ftrace.h>
#include <linux/uaccess.h>
-extern void (*ftrace_trace_function)(unsigned long, unsigned long,
- struct ftrace_ops*, struct pt_regs*);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+ unsigned long frame_pointer)
+{
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+ unsigned long old;
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ return;
-noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
-{
- asm volatile ("\n");
-}
+ old = *parent;
-noinline void csky_mcount(unsigned long from_pc, unsigned long self_pc)
-{
- if (ftrace_trace_function != ftrace_stub)
- ftrace_trace_function(self_pc, from_pc, NULL, NULL);
+ if (!function_graph_enter(old, self_addr,
+ *(unsigned long *)frame_pointer, parent)) {
+ /*
+ * For csky-gcc function has sub-call:
+ * subi sp, sp, 8
+ * stw r8, (sp, 0)
+ * mov r8, sp
+ * st.w r15, (sp, 0x4)
+ * push r15
+ * jl _mcount
+ * We only need set *parent for resume
+ *
+ * For csky-gcc function has no sub-call:
+ * subi sp, sp, 4
+ * stw r8, (sp, 0)
+ * mov r8, sp
+ * push r15
+ * jl _mcount
+ * We need set *parent and *(frame_pointer + 4) for resume,
+ * because lr is resumed twice.
+ */
+ *parent = return_hooker;
+ frame_pointer += 4;
+ if (*(unsigned long *)frame_pointer == old)
+ *(unsigned long *)frame_pointer = return_hooker;
+ }
}
+#endif
/* _mcount is defined in abi's mcount.S */
+extern void _mcount(void);
EXPORT_SYMBOL(_mcount);