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 15 #define ARCH_SUPPORTS_FTRACE_OPS 1 16 #ifndef __ASSEMBLY__ 17 18 extern void *return_address(unsigned int level); 19 20 #define ftrace_return_address(n) return_address(n) 21 22 void _mcount(void); 23 static inline unsigned long ftrace_call_adjust(unsigned long addr) 24 { 25 return addr; 26 } 27 28 /* 29 * Let's do like x86/arm64 and ignore the compat syscalls. 30 */ 31 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 32 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 33 { 34 return is_compat_task(); 35 } 36 37 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 38 static inline bool arch_syscall_match_sym_name(const char *sym, 39 const char *name) 40 { 41 /* 42 * Since all syscall functions have __riscv_ prefix, we must skip it. 43 * However, as we described above, we decided to ignore compat 44 * syscalls, so we don't care about __riscv_compat_ prefix here. 45 */ 46 return !strcmp(sym + 8, name); 47 } 48 49 struct dyn_arch_ftrace { 50 }; 51 #endif 52 53 #ifdef CONFIG_DYNAMIC_FTRACE 54 /* 55 * A general call in RISC-V is a pair of insts: 56 * 1) auipc: setting high-20 pc-related bits to ra register 57 * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to 58 * return address (original pc + 4) 59 * 60 *<ftrace enable>: 61 * 0: auipc t0/ra, 0x? 62 * 4: jalr t0/ra, ?(t0/ra) 63 * 64 *<ftrace disable>: 65 * 0: nop 66 * 4: nop 67 * 68 * Dynamic ftrace generates probes to call sites, so we must deal with 69 * both auipc and jalr at the same time. 70 */ 71 72 #define MCOUNT_ADDR ((unsigned long)_mcount) 73 #define JALR_SIGN_MASK (0x00000800) 74 #define JALR_OFFSET_MASK (0x00000fff) 75 #define AUIPC_OFFSET_MASK (0xfffff000) 76 #define AUIPC_PAD (0x00001000) 77 #define JALR_SHIFT 20 78 #define JALR_RA (0x000080e7) 79 #define AUIPC_RA (0x00000097) 80 #define JALR_T0 (0x000282e7) 81 #define AUIPC_T0 (0x00000297) 82 #define NOP4 (0x00000013) 83 84 #define to_jalr_t0(offset) \ 85 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) 86 87 #define to_auipc_t0(offset) \ 88 ((offset & JALR_SIGN_MASK) ? \ 89 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ 90 ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) 91 92 #define make_call_t0(caller, callee, call) \ 93 do { \ 94 unsigned int offset = \ 95 (unsigned long) callee - (unsigned long) caller; \ 96 call[0] = to_auipc_t0(offset); \ 97 call[1] = to_jalr_t0(offset); \ 98 } while (0) 99 100 #define to_jalr_ra(offset) \ 101 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) 102 103 #define to_auipc_ra(offset) \ 104 ((offset & JALR_SIGN_MASK) ? \ 105 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ 106 ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) 107 108 #define make_call_ra(caller, callee, call) \ 109 do { \ 110 unsigned int offset = \ 111 (unsigned long) callee - (unsigned long) caller; \ 112 call[0] = to_auipc_ra(offset); \ 113 call[1] = to_jalr_ra(offset); \ 114 } while (0) 115 116 /* 117 * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. 118 */ 119 #define MCOUNT_INSN_SIZE 8 120 121 #ifndef __ASSEMBLY__ 122 struct dyn_ftrace; 123 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 124 #define ftrace_init_nop ftrace_init_nop 125 126 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS 127 #define arch_ftrace_get_regs(regs) NULL 128 struct ftrace_ops; 129 struct ftrace_regs { 130 unsigned long epc; 131 unsigned long ra; 132 unsigned long sp; 133 unsigned long s0; 134 unsigned long t1; 135 union { 136 unsigned long args[8]; 137 struct { 138 unsigned long a0; 139 unsigned long a1; 140 unsigned long a2; 141 unsigned long a3; 142 unsigned long a4; 143 unsigned long a5; 144 unsigned long a6; 145 unsigned long a7; 146 }; 147 }; 148 }; 149 150 static __always_inline unsigned long ftrace_regs_get_instruction_pointer(const struct ftrace_regs 151 *fregs) 152 { 153 return fregs->epc; 154 } 155 156 static __always_inline void ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, 157 unsigned long pc) 158 { 159 fregs->epc = pc; 160 } 161 162 static __always_inline unsigned long ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs) 163 { 164 return fregs->sp; 165 } 166 167 static __always_inline unsigned long ftrace_regs_get_argument(struct ftrace_regs *fregs, 168 unsigned int n) 169 { 170 if (n < 8) 171 return fregs->args[n]; 172 return 0; 173 } 174 175 static __always_inline unsigned long ftrace_regs_get_return_value(const struct ftrace_regs *fregs) 176 { 177 return fregs->a0; 178 } 179 180 static __always_inline void ftrace_regs_set_return_value(struct ftrace_regs *fregs, 181 unsigned long ret) 182 { 183 fregs->a0 = ret; 184 } 185 186 static __always_inline void ftrace_override_function_with_return(struct ftrace_regs *fregs) 187 { 188 fregs->epc = fregs->ra; 189 } 190 191 int ftrace_regs_query_register_offset(const char *name); 192 193 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, 194 struct ftrace_ops *op, struct ftrace_regs *fregs); 195 #define ftrace_graph_func ftrace_graph_func 196 197 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr) 198 { 199 fregs->t1 = addr; 200 } 201 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ 202 203 #endif /* __ASSEMBLY__ */ 204 205 #endif /* CONFIG_DYNAMIC_FTRACE */ 206 207 #ifndef __ASSEMBLY__ 208 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 209 struct fgraph_ret_regs { 210 unsigned long a1; 211 unsigned long a0; 212 unsigned long s0; 213 unsigned long ra; 214 }; 215 216 static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) 217 { 218 return ret_regs->a0; 219 } 220 221 static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) 222 { 223 return ret_regs->s0; 224 } 225 #endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ 226 #endif 227 228 #endif /* _ASM_RISCV_FTRACE_H */ 229