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csky/ftrace: Add dynamic function tracer (include graph tracer)

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Support dynamic ftrace including dynamic graph tracer. Gcc-csky with -pg
will produce call site in every function prologue and we can use these
call site to hook trace function.

gcc with -pg origin call site:
	push	lr
	jbsr	_mcount
	nop32
	nop32

If the (callee - caller)'s offset is in range of bsr instruction, we'll
modify code with:
	push	lr
	bsr	_mcount
	nop32
	nop32
Else if the (callee - caller)'s offset is out of bsr instrunction, we'll
modify code with:
	push	lr
	movih	r26, ...
	ori	r26, ...
	jsr	r26

(r26 is reserved for jsr link reg in csky abiv2 spec.)

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
This commit is contained in:
Guo Ren
2019-03-01 08:50:36 +08:00
parent 3dfc242f11
commit 28bb030f93
5 changed files with 205 additions and 6 deletions
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18
arch/csky/include/asm/ftrace.h
View File

@@ -4,10 +4,26 @@
#ifndef __ASM_CSKY_FTRACE_H
#define __ASM_CSKY_FTRACE_H
#define MCOUNT_INSN_SIZE 4
#define MCOUNT_INSN_SIZE 14
#define HAVE_FUNCTION_GRAPH_FP_TEST
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define MCOUNT_ADDR ((unsigned long)_mcount)
#ifndef __ASSEMBLY__
extern void _mcount(unsigned long);
extern void ftrace_graph_call(void);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
struct dyn_arch_ftrace {
};
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_CSKY_FTRACE_H */