1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* Copyright (C) 2017 Andes Technology Corporation */ 3 4 #ifndef _ASM_RISCV_FTRACE_H 5 #define _ASM_RISCV_FTRACE_H 6 7 /* 8 * The graph frame test is not possible if CONFIG_FRAME_POINTER is not enabled. 9 * Check arch/riscv/kernel/mcount.S for detail. 10 */ 11 #if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER) 12 #define HAVE_FUNCTION_GRAPH_FP_TEST 13 #endif 14 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 15 16 /* 17 * Clang prior to 13 had "mcount" instead of "_mcount": 18 * https://reviews.llvm.org/D98881 19 */ 20 #if defined(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 130000 21 #define MCOUNT_NAME _mcount 22 #else 23 #define MCOUNT_NAME mcount 24 #endif 25 26 #define ARCH_SUPPORTS_FTRACE_OPS 1 27 #ifndef __ASSEMBLY__ 28 void MCOUNT_NAME(void); 29 static inline unsigned long ftrace_call_adjust(unsigned long addr) 30 { 31 return addr; 32 } 33 34 /* 35 * Let's do like x86/arm64 and ignore the compat syscalls. 36 */ 37 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 38 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 39 { 40 return is_compat_task(); 41 } 42 43 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 44 static inline bool arch_syscall_match_sym_name(const char *sym, 45 const char *name) 46 { 47 /* 48 * Since all syscall functions have __riscv_ prefix, we must skip it. 49 * However, as we described above, we decided to ignore compat 50 * syscalls, so we don't care about __riscv_compat_ prefix here. 51 */ 52 return !strcmp(sym + 8, name); 53 } 54 55 struct dyn_arch_ftrace { 56 }; 57 #endif 58 59 #ifdef CONFIG_DYNAMIC_FTRACE 60 /* 61 * A general call in RISC-V is a pair of insts: 62 * 1) auipc: setting high-20 pc-related bits to ra register 63 * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to 64 * return address (original pc + 4) 65 * 66 *<ftrace enable>: 67 * 0: auipc t0/ra, 0x? 68 * 4: jalr t0/ra, ?(t0/ra) 69 * 70 *<ftrace disable>: 71 * 0: nop 72 * 4: nop 73 * 74 * Dynamic ftrace generates probes to call sites, so we must deal with 75 * both auipc and jalr at the same time. 76 */ 77 78 #define MCOUNT_ADDR ((unsigned long)MCOUNT_NAME) 79 #define JALR_SIGN_MASK (0x00000800) 80 #define JALR_OFFSET_MASK (0x00000fff) 81 #define AUIPC_OFFSET_MASK (0xfffff000) 82 #define AUIPC_PAD (0x00001000) 83 #define JALR_SHIFT 20 84 #define JALR_RA (0x000080e7) 85 #define AUIPC_RA (0x00000097) 86 #define JALR_T0 (0x000282e7) 87 #define AUIPC_T0 (0x00000297) 88 #define NOP4 (0x00000013) 89 90 #define to_jalr_t0(offset) \ 91 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) 92 93 #define to_auipc_t0(offset) \ 94 ((offset & JALR_SIGN_MASK) ? \ 95 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ 96 ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) 97 98 #define make_call_t0(caller, callee, call) \ 99 do { \ 100 unsigned int offset = \ 101 (unsigned long) callee - (unsigned long) caller; \ 102 call[0] = to_auipc_t0(offset); \ 103 call[1] = to_jalr_t0(offset); \ 104 } while (0) 105 106 #define to_jalr_ra(offset) \ 107 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) 108 109 #define to_auipc_ra(offset) \ 110 ((offset & JALR_SIGN_MASK) ? \ 111 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ 112 ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) 113 114 #define make_call_ra(caller, callee, call) \ 115 do { \ 116 unsigned int offset = \ 117 (unsigned long) callee - (unsigned long) caller; \ 118 call[0] = to_auipc_ra(offset); \ 119 call[1] = to_jalr_ra(offset); \ 120 } while (0) 121 122 /* 123 * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. 124 */ 125 #define MCOUNT_INSN_SIZE 8 126 127 #ifndef __ASSEMBLY__ 128 struct dyn_ftrace; 129 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 130 #define ftrace_init_nop ftrace_init_nop 131 #endif 132 133 #endif /* CONFIG_DYNAMIC_FTRACE */ 134 135 #ifndef __ASSEMBLY__ 136 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 137 struct fgraph_ret_regs { 138 unsigned long a1; 139 unsigned long a0; 140 unsigned long s0; 141 unsigned long ra; 142 }; 143 144 static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) 145 { 146 return ret_regs->a0; 147 } 148 149 static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) 150 { 151 return ret_regs->s0; 152 } 153 #endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ 154 #endif 155 156 #endif /* _ASM_RISCV_FTRACE_H */ 157