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Diffstat (limited to 'arch/riscv/include/asm/ftrace.h')
| -rw-r--r-- | arch/riscv/include/asm/ftrace.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h new file mode 100644 index 000000000..2b2f5df7e --- /dev/null +++ b/arch/riscv/include/asm/ftrace.h @@ -0,0 +1,156 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2017 Andes Technology Corporation */ + +#ifndef _ASM_RISCV_FTRACE_H +#define _ASM_RISCV_FTRACE_H + +/* + * 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 +#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR + +/* + * Clang prior to 13 had "mcount" instead of "_mcount": + * https://reviews.llvm.org/D98881 + */ +#if defined(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 130000 +#define MCOUNT_NAME _mcount +#else +#define MCOUNT_NAME mcount +#endif + +#define ARCH_SUPPORTS_FTRACE_OPS 1 +#ifndef __ASSEMBLY__ +void MCOUNT_NAME(void); +static inline unsigned long ftrace_call_adjust(unsigned long addr) +{ + return addr; +} + +/* + * Let's do like x86/arm64 and ignore the compat syscalls. + */ +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) +{ + return is_compat_task(); +} + +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME +static inline bool arch_syscall_match_sym_name(const char *sym, + const char *name) +{ + /* + * Since all syscall functions have __riscv_ prefix, we must skip it. + * However, as we described above, we decided to ignore compat + * syscalls, so we don't care about __riscv_compat_ prefix here. + */ + return !strcmp(sym + 8, name); +} + +struct dyn_arch_ftrace { +}; +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE +/* + * A general call in RISC-V is a pair of insts: + * 1) auipc: setting high-20 pc-related bits to ra register + * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to + * return address (original pc + 4) + * + *<ftrace enable>: + * 0: auipc t0/ra, 0x? + * 4: jalr t0/ra, ?(t0/ra) + * + *<ftrace disable>: + * 0: nop + * 4: nop + * + * Dynamic ftrace generates probes to call sites, so we must deal with + * both auipc and jalr at the same time. + */ + +#define MCOUNT_ADDR ((unsigned long)MCOUNT_NAME) +#define JALR_SIGN_MASK (0x00000800) +#define JALR_OFFSET_MASK (0x00000fff) +#define AUIPC_OFFSET_MASK (0xfffff000) +#define AUIPC_PAD (0x00001000) +#define JALR_SHIFT 20 +#define JALR_RA (0x000080e7) +#define AUIPC_RA (0x00000097) +#define JALR_T0 (0x000282e7) +#define AUIPC_T0 (0x00000297) +#define NOP4 (0x00000013) + +#define to_jalr_t0(offset) \ + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) + +#define to_auipc_t0(offset) \ + ((offset & JALR_SIGN_MASK) ? \ + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ + ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) + +#define make_call_t0(caller, callee, call) \ +do { \ + unsigned int offset = \ + (unsigned long) callee - (unsigned long) caller; \ + call[0] = to_auipc_t0(offset); \ + call[1] = to_jalr_t0(offset); \ +} while (0) + +#define to_jalr_ra(offset) \ + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) + +#define to_auipc_ra(offset) \ + ((offset & JALR_SIGN_MASK) ? \ + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ + ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) + +#define make_call_ra(caller, callee, call) \ +do { \ + unsigned int offset = \ + (unsigned long) callee - (unsigned long) caller; \ + call[0] = to_auipc_ra(offset); \ + call[1] = to_jalr_ra(offset); \ +} while (0) + +/* + * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. + */ +#define MCOUNT_INSN_SIZE 8 + +#ifndef __ASSEMBLY__ +struct dyn_ftrace; +int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); +#define ftrace_init_nop ftrace_init_nop +#endif + +#endif /* CONFIG_DYNAMIC_FTRACE */ + +#ifndef __ASSEMBLY__ +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +struct fgraph_ret_regs { + unsigned long a1; + unsigned long a0; + unsigned long s0; + unsigned long ra; +}; + +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->a0; +} + +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->s0; +} +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ +#endif + +#endif /* _ASM_RISCV_FTRACE_H */ |