LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL

The previous patch ("function_graph: Support recording and printing
the return value of function") has laid the groundwork for the for
the funcgraph-retval, and this modification makes it available on
the LoongArch platform.

We introduce a new structure called fgraph_ret_regs for the LoongArch
platform to hold return registers and the frame pointer. We then fill
its content in the return_to_handler and pass its address to the
function ftrace_return_to_handler to record the return value.

Link: https://lkml.kernel.org/r/c5462255e435fab363895c2d7433bc0f5a140411.1680954589.git.pengdonglin@sangfor.com.cn

Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Donglin Peng 2023-04-08 05:42:21 -07:00 committed by Steven Rostedt (Google)
parent d938ba1768
commit 5779e3c0f5
5 changed files with 53 additions and 14 deletions

View File

@ -103,6 +103,7 @@ config LOONGARCH
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GENERIC_VDSO

View File

@ -100,4 +100,26 @@ __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
#endif /* CONFIG_FUNCTION_TRACER */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
/* a0 - a1 */
unsigned long regs[2];
unsigned long fp;
unsigned long __unused;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->regs[0];
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_LOONGARCH_FTRACE_H */

View File

@ -12,6 +12,7 @@
#include <asm/cpu-info.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/ftrace.h>
void output_ptreg_defines(void)
{
@ -264,7 +265,7 @@ void output_smpboot_defines(void)
#ifdef CONFIG_HIBERNATION
void output_pbe_defines(void)
{
COMMENT(" Linux struct pbe offsets. ");
COMMENT("Linux struct pbe offsets.");
OFFSET(PBE_ADDRESS, pbe, address);
OFFSET(PBE_ORIG_ADDRESS, pbe, orig_address);
OFFSET(PBE_NEXT, pbe, next);
@ -272,3 +273,15 @@ void output_pbe_defines(void)
BLANK();
}
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
void output_fgraph_ret_regs_defines(void)
{
COMMENT("LoongArch fgraph_ret_regs offsets.");
OFFSET(FGRET_REGS_A0, fgraph_ret_regs, regs[0]);
OFFSET(FGRET_REGS_A1, fgraph_ret_regs, regs[1]);
OFFSET(FGRET_REGS_FP, fgraph_ret_regs, fp);
DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
BLANK();
}
#endif

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@ -79,18 +79,20 @@ SYM_FUNC_START(ftrace_graph_caller)
SYM_FUNC_END(ftrace_graph_caller)
SYM_FUNC_START(return_to_handler)
PTR_ADDI sp, sp, -2 * SZREG
PTR_S a0, sp, 0
PTR_S a1, sp, SZREG
PTR_ADDI sp, sp, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
PTR_S a1, sp, FGRET_REGS_A1
PTR_S zero, sp, FGRET_REGS_FP
move a0, sp
bl ftrace_return_to_handler
/* Restore the real parent address: a0 -> ra */
move ra, a0
PTR_L a0, sp, 0
PTR_L a1, sp, SZREG
PTR_ADDI sp, sp, 2 * SZREG
PTR_L a0, sp, FGRET_REGS_A0
PTR_L a1, sp, FGRET_REGS_A1
PTR_ADDI sp, sp, FGRET_REGS_SIZE
jr ra
SYM_FUNC_END(return_to_handler)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

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@ -136,18 +136,19 @@ SYM_CODE_END(ftrace_graph_caller)
SYM_CODE_START(return_to_handler)
/* Save return value regs */
PTR_ADDI sp, sp, -2 * SZREG
PTR_S a0, sp, 0
PTR_S a1, sp, SZREG
PTR_ADDI sp, sp, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
PTR_S a1, sp, FGRET_REGS_A1
PTR_S zero, sp, FGRET_REGS_FP
move a0, zero
move a0, sp
bl ftrace_return_to_handler
move ra, a0
/* Restore return value regs */
PTR_L a0, sp, 0
PTR_L a1, sp, SZREG
PTR_ADDI sp, sp, 2 * SZREG
PTR_L a0, sp, FGRET_REGS_A0
PTR_L a1, sp, FGRET_REGS_A1
PTR_ADDI sp, sp, FGRET_REGS_SIZE
jr ra
SYM_CODE_END(return_to_handler)