From: Guo Ren <[email protected]> When gcc with -pg, it'll add _mcount stub in every function. We need implement the _mcount in kernel and ftrace depends on stackstrace.
To do: call-graph, dynamic ftrace Signed-off-by: Guo Ren <[email protected]> --- arch/csky/Kconfig | 1 + arch/csky/abiv2/Makefile | 1 + arch/csky/abiv2/mcount.S | 24 ++++++++++++++++++++++++ arch/csky/include/asm/ftrace.h | 9 +++++++++ arch/csky/kernel/Makefile | 5 +++++ arch/csky/kernel/ftrace.c | 24 ++++++++++++++++++++++++ 6 files changed, 64 insertions(+) create mode 100644 arch/csky/abiv2/mcount.S create mode 100644 arch/csky/include/asm/ftrace.h create mode 100644 arch/csky/kernel/ftrace.c diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 65804d1..0b9a290 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -29,6 +29,7 @@ config CSKY select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select HAVE_ARCH_TRACEHOOK + select HAVE_FUNCTION_TRACER select HAVE_GENERIC_DMA_COHERENT select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZO diff --git a/arch/csky/abiv2/Makefile b/arch/csky/abiv2/Makefile index 069ca72..b1d44f6 100644 --- a/arch/csky/abiv2/Makefile +++ b/arch/csky/abiv2/Makefile @@ -8,3 +8,4 @@ obj-y += strcmp.o obj-y += strcpy.o obj-y += strlen.o obj-y += strksyms.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o diff --git a/arch/csky/abiv2/mcount.S b/arch/csky/abiv2/mcount.S new file mode 100644 index 0000000..73377d5 --- /dev/null +++ b/arch/csky/abiv2/mcount.S @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. + +#include <linux/linkage.h> + +ENTRY (_mcount) + subi sp, 20 + stw a0, (sp, 0) + stw a1, (sp, 4) + stw a2, (sp, 8) + stw a3, (sp, 12) + stw lr, (sp, 16) + mov a1, lr + ldw a0, (sp, 20) + jsri csky_mcount + ldw a0, (sp, 0) + ldw a1, (sp, 4) + ldw a2, (sp, 8) + ldw a3, (sp, 12) + ldw t1, (sp, 16) + ldw lr, (sp, 20) + addi sp, 24 + jmp t1 +END (_mcount) diff --git a/arch/csky/include/asm/ftrace.h b/arch/csky/include/asm/ftrace.h new file mode 100644 index 0000000..1d22a17 --- /dev/null +++ b/arch/csky/include/asm/ftrace.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. + +#ifndef __ASM_CSKY_FTRACE_H +#define __ASM_CSKY_FTRACE_H + +extern void _mcount(unsigned long from_pc); + +#endif /* __ASM_CSKY_FTRACE_H */ diff --git a/arch/csky/kernel/Makefile b/arch/csky/kernel/Makefile index ba5ca48..3c0e2d1 100644 --- a/arch/csky/kernel/Makefile +++ b/arch/csky/kernel/Makefile @@ -6,4 +6,9 @@ obj-y += process.o cpu-probe.o ptrace.o dumpstack.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o obj-$(CONFIG_STACKTRACE) += stacktrace.o + +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) +endif diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c new file mode 100644 index 0000000..ad054f719 --- /dev/null +++ b/arch/csky/kernel/ftrace.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. + +#include <linux/ftrace.h> +#include <linux/uaccess.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 volatile ("\n"); +} + +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); +} + +/* _mcount is defined in abi's mcount.S */ +EXPORT_SYMBOL(_mcount); -- 2.7.4
