diff options
| -rw-r--r-- | arch/riscv/Kconfig | 5 | ||||
| -rw-r--r-- | arch/riscv/include/asm/Kbuild | 1 | ||||
| -rw-r--r-- | arch/riscv/include/asm/ftrace.h | 10 | ||||
| -rw-r--r-- | arch/riscv/kernel/Makefile | 7 | ||||
| -rw-r--r-- | arch/riscv/kernel/ftrace.c | 41 | ||||
| -rw-r--r-- | arch/riscv/kernel/mcount.S | 126 |
6 files changed, 189 insertions, 1 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 2c6adf12713a..504ba386b22e 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -55,6 +55,9 @@ config PAGE_OFFSET config STACKTRACE_SUPPORT def_bool y +config TRACE_IRQFLAGS_SUPPORT + def_bool y + config RWSEM_GENERIC_SPINLOCK def_bool y @@ -107,6 +110,8 @@ config ARCH_RV64I bool "RV64I" select CPU_SUPPORTS_64BIT_KERNEL select 64BIT + select HAVE_FUNCTION_TRACER + select HAVE_FUNCTION_GRAPH_TRACER endchoice diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild index 970460a0b492..b44a42499860 100644 --- a/arch/riscv/include/asm/Kbuild +++ b/arch/riscv/include/asm/Kbuild @@ -12,7 +12,6 @@ generic-y += errno.h generic-y += exec.h generic-y += fb.h generic-y += fcntl.h -generic-y += ftrace.h generic-y += futex.h generic-y += hardirq.h generic-y += hash.h diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h new file mode 100644 index 000000000000..66d4175eb13e --- /dev/null +++ b/arch/riscv/include/asm/ftrace.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2017 Andes Technology Corporation */ + +/* + * The graph frame test is not possible if CONFIG_FRAME_POINTER is not enabled. + * Check arch/riscv/kernel/mcount.S for detail. + */ +#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER) +#define HAVE_FUNCTION_GRAPH_FP_TEST +#endif diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index ab8baf7bd142..196f62ffc428 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -2,6 +2,11 @@ # Makefile for the RISC-V Linux kernel # +ifdef CONFIG_FTRACE +CFLAGS_REMOVE_ftrace.o = -pg +CFLAGS_REMOVE_setup.o = -pg +endif + extra-y += head.o extra-y += vmlinux.lds @@ -29,5 +34,7 @@ CFLAGS_setup.o := -mcmodel=medany obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_MODULES) += module.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o +obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o clean: diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c new file mode 100644 index 000000000000..d0de68d144cb --- /dev/null +++ b/arch/riscv/kernel/ftrace.c @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2013 Linaro Limited + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> + * Copyright (C) 2017 Andes Technology Corporation + */ + +#include <linux/ftrace.h> + +/* + * Most of this file is copied from arm64. + */ +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; + struct ftrace_graph_ent trace; + int err; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + /* + * We don't suffer access faults, so no extra fault-recovery assembly + * is needed here. + */ + old = *parent; + + trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; + + if (!ftrace_graph_entry(&trace)) + return; + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer, NULL); + if (err == -EBUSY) + return; + *parent = return_hooker; +} diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S new file mode 100644 index 000000000000..c46a778627be --- /dev/null +++ b/arch/riscv/kernel/mcount.S @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2017 Andes Technology Corporation */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/asm.h> +#include <asm/csr.h> +#include <asm/unistd.h> +#include <asm/thread_info.h> +#include <asm/asm-offsets.h> +#include <asm-generic/export.h> +#include <asm/ftrace.h> + + .text + + .macro SAVE_ABI_STATE + addi sp, sp, -16 + sd s0, 0(sp) + sd ra, 8(sp) + addi s0, sp, 16 + .endm + + /* + * The call to ftrace_return_to_handler would overwrite the return + * register if a0 was not saved. + */ + .macro SAVE_RET_ABI_STATE + addi sp, sp, -32 + sd s0, 16(sp) + sd ra, 24(sp) + sd a0, 8(sp) + addi s0, sp, 32 + .endm + + .macro STORE_ABI_STATE + ld ra, 8(sp) + ld s0, 0(sp) + addi sp, sp, 16 + .endm + + .macro STORE_RET_ABI_STATE + ld ra, 24(sp) + ld s0, 16(sp) + ld a0, 8(sp) + addi sp, sp, 32 + .endm + +ENTRY(ftrace_stub) + ret +ENDPROC(ftrace_stub) + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +ENTRY(return_to_handler) +/* + * On implementing the frame point test, the ideal way is to compare the + * s0 (frame pointer, if enabled) on entry and the sp (stack pointer) on return. + * However, the psABI of variable-length-argument functions does not allow this. + * + * So alternatively we check the *old* frame pointer position, that is, the + * value stored in -16(s0) on entry, and the s0 on return. + */ +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + mv t6, s0 +#endif + SAVE_RET_ABI_STATE +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + mv a0, t6 +#endif + la t0, ftrace_return_to_handler + jalr t0 + mv a1, a0 + STORE_RET_ABI_STATE + jalr a1 +ENDPROC(return_to_handler) +EXPORT_SYMBOL(return_to_handler) +#endif + +ENTRY(_mcount) + la t4, ftrace_stub +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + la t0, ftrace_graph_return + ld t1, 0(t0) + bne t1, t4, do_ftrace_graph_caller + + la t3, ftrace_graph_entry + ld t2, 0(t3) + la t6, ftrace_graph_entry_stub + bne t2, t6, do_ftrace_graph_caller +#endif + la t3, ftrace_trace_function + ld t5, 0(t3) + bne t5, t4, do_trace + ret + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +/* + * A pseudo representation for the function graph tracer: + * prepare_to_return(&ra_to_caller_of_caller, ra_to_caller) + */ +do_ftrace_graph_caller: + addi a0, s0, -8 + mv a1, ra +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + ld a2, -16(s0) +#endif + SAVE_ABI_STATE + la t0, prepare_ftrace_return + jalr t0 + STORE_ABI_STATE + ret +#endif + +/* + * A pseudo representation for the function tracer: + * (*ftrace_trace_function)(ra_to_caller, ra_to_caller_of_caller) + */ +do_trace: + ld a1, -8(s0) + mv a0, ra + + SAVE_ABI_STATE + jalr t5 + STORE_ABI_STATE + ret +ENDPROC(_mcount) +EXPORT_SYMBOL(_mcount) |