Messages in this thread Patch in this message |  | | From | Zong Li <> | Subject | [PATCH 1/6] nds32/ftrace: Support static function tracer | Date | Wed, 15 Aug 2018 17:35:18 +0800 |
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This patch support the static function tracer. On nds32 ABI, we need to always push return address to stack for __builtin_return_address can work correctly, otherwise, it will get the wrong value of $lp at leaf function.
Signed-off-by: Zong Li <zong@andestech.com> --- arch/nds32/Kconfig | 1 + arch/nds32/Makefile | 4 ++++ arch/nds32/include/asm/ftrace.h | 20 ++++++++++++++++++++ arch/nds32/kernel/Makefile | 6 ++++++ arch/nds32/kernel/ftrace.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 59 insertions(+) create mode 100644 arch/nds32/include/asm/ftrace.h create mode 100644 arch/nds32/kernel/ftrace.c
diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig index 34f7222..af30e1a 100644 --- a/arch/nds32/Kconfig +++ b/arch/nds32/Kconfig @@ -40,6 +40,7 @@ config NDS32 select NO_IOPORT_MAP select RTC_LIB select THREAD_INFO_IN_TASK + select HAVE_FUNCTION_TRACER help Andes(nds32) Linux support. diff --git a/arch/nds32/Makefile b/arch/nds32/Makefile index 031c676..3ca8172 100644 --- a/arch/nds32/Makefile +++ b/arch/nds32/Makefile @@ -5,6 +5,10 @@ KBUILD_DEFCONFIG := defconfig comma = , +ifdef CONFIG_FUNCTION_TRACER +arch-y += -malways-save-lp -mno-relax +endif + KBUILD_CFLAGS += $(call cc-option, -mno-sched-prolog-epilog) KBUILD_CFLAGS += -mcmodel=large diff --git a/arch/nds32/include/asm/ftrace.h b/arch/nds32/include/asm/ftrace.h new file mode 100644 index 0000000..bac7657 --- /dev/null +++ b/arch/nds32/include/asm/ftrace.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_NDS32_FTRACE_H +#define __ASM_NDS32_FTRACE_H + +#ifdef CONFIG_FUNCTION_TRACER + +#define HAVE_FUNCTION_GRAPH_FP_TEST + +#define MCOUNT_ADDR ((unsigned long)(_mcount)) +/* mcount call is composed of three instructions: + * sethi + ori + jral + */ +#define MCOUNT_INSN_SIZE 12 + +extern void _mcount(unsigned long parent_ip); + +#endif /* CONFIG_FUNCTION_TRACER */ + +#endif /* __ASM_NDS32_FTRACE_H */ diff --git a/arch/nds32/kernel/Makefile b/arch/nds32/kernel/Makefile index 4279274..27cded3 100644 --- a/arch/nds32/kernel/Makefile +++ b/arch/nds32/kernel/Makefile @@ -21,3 +21,9 @@ extra-y := head.o vmlinux.lds obj-y += vdso/ + +obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o + +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) +endif diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c new file mode 100644 index 0000000..563f64c --- /dev/null +++ b/arch/nds32/kernel/ftrace.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/ftrace.h> +#include <linux/uaccess.h> +#include <asm/cacheflush.h> + +extern void (*ftrace_trace_function)(unsigned long, unsigned long, + struct ftrace_ops*, struct pt_regs*); + +noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct pt_regs *regs) +{ + __asm__ (""); /* avoid to optimize as pure function */ +} + +noinline void _mcount(unsigned long parent_ip) +{ + /* save all state by the compiler prologue */ + + unsigned long ip = (unsigned long)__builtin_return_address(0); + + if (ftrace_trace_function != ftrace_stub) + ftrace_trace_function(ip - MCOUNT_INSN_SIZE, parent_ip, + NULL, NULL); + + /* restore all state by the compiler epilogue */ +} +EXPORT_SYMBOL(_mcount); -- 2.7.4
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