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 83 #define to_jalr_t0(offset) \ 84 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) 85 86 #define to_auipc_t0(offset) \ 87 ((offset & JALR_SIGN_MASK) ? \ 88 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ 89 ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) 90 91 #define make_call_t0(caller, callee, call) \ 92 do { \ 93 unsigned int offset = \ 94 (unsigned long) (callee) - (unsigned long) (caller); \ 95 call[0] = to_auipc_t0(offset); \ 96 call[1] = to_jalr_t0(offset); \ 97 } while (0) 98 99 #define to_jalr_ra(offset) \ 100 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) 101 102 #define to_auipc_ra(offset) \ 103 ((offset & JALR_SIGN_MASK) ? \ 104 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ 105 ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) 106 107 #define make_call_ra(caller, callee, call) \ 108 do { \ 109 unsigned int offset = \ 110 (unsigned long) (callee) - (unsigned long) (caller); \ 111 call[0] = to_auipc_ra(offset); \ 112 call[1] = to_jalr_ra(offset); \ 113 } while (0) 114 115 /* 116 * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. 117 */ 118 #define MCOUNT_INSN_SIZE 8 119 120 #ifndef __ASSEMBLY__ 121 struct dyn_ftrace; 122 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 123 #define ftrace_init_nop ftrace_init_nop 124 125 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS 126 #define arch_ftrace_get_regs(regs) NULL 127 #define HAVE_ARCH_FTRACE_REGS 128 struct ftrace_ops; 129 struct ftrace_regs; 130 #define arch_ftrace_regs(fregs) ((struct __arch_ftrace_regs *)(fregs)) 131 132 struct __arch_ftrace_regs { 133 unsigned long epc; 134 unsigned long ra; 135 unsigned long sp; 136 unsigned long s0; 137 unsigned long t1; 138 union { 139 unsigned long args[8]; 140 struct { 141 unsigned long a0; 142 unsigned long a1; 143 unsigned long a2; 144 unsigned long a3; 145 unsigned long a4; 146 unsigned long a5; 147 unsigned long a6; 148 unsigned long a7; 149 }; 150 }; 151 }; 152 153 static __always_inline unsigned long ftrace_regs_get_instruction_pointer(const struct ftrace_regs 154 *fregs) 155 { 156 return arch_ftrace_regs(fregs)->epc; 157 } 158 159 static __always_inline void ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, 160 unsigned long pc) 161 { 162 arch_ftrace_regs(fregs)->epc = pc; 163 } 164 165 static __always_inline unsigned long ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs) 166 { 167 return arch_ftrace_regs(fregs)->sp; 168 } 169 170 static __always_inline unsigned long ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) 171 { 172 return arch_ftrace_regs(fregs)->s0; 173 } 174 175 static __always_inline unsigned long ftrace_regs_get_argument(struct ftrace_regs *fregs, 176 unsigned int n) 177 { 178 if (n < 8) 179 return arch_ftrace_regs(fregs)->args[n]; 180 return 0; 181 } 182 183 static __always_inline unsigned long ftrace_regs_get_return_value(const struct ftrace_regs *fregs) 184 { 185 return arch_ftrace_regs(fregs)->a0; 186 } 187 188 static __always_inline unsigned long ftrace_regs_get_return_address(const struct ftrace_regs *fregs) 189 { 190 return arch_ftrace_regs(fregs)->ra; 191 } 192 193 static __always_inline void ftrace_regs_set_return_value(struct ftrace_regs *fregs, 194 unsigned long ret) 195 { 196 arch_ftrace_regs(fregs)->a0 = ret; 197 } 198 199 static __always_inline void ftrace_override_function_with_return(struct ftrace_regs *fregs) 200 { 201 arch_ftrace_regs(fregs)->epc = arch_ftrace_regs(fregs)->ra; 202 } 203 204 static __always_inline struct pt_regs * 205 ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) 206 { 207 struct __arch_ftrace_regs *afregs = arch_ftrace_regs(fregs); 208 209 memcpy(®s->a_regs, afregs->args, sizeof(afregs->args)); 210 regs->epc = afregs->epc; 211 regs->ra = afregs->ra; 212 regs->sp = afregs->sp; 213 regs->s0 = afregs->s0; 214 regs->t1 = afregs->t1; 215 return regs; 216 } 217 218 int ftrace_regs_query_register_offset(const char *name); 219 220 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, 221 struct ftrace_ops *op, struct ftrace_regs *fregs); 222 #define ftrace_graph_func ftrace_graph_func 223 224 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr) 225 { 226 arch_ftrace_regs(fregs)->t1 = addr; 227 } 228 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ 229 230 #endif /* __ASSEMBLY__ */ 231 232 #endif /* CONFIG_DYNAMIC_FTRACE */ 233 234 #endif /* _ASM_RISCV_FTRACE_H */ 235