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 29 extern void *return_address(unsigned int level); 30 31 #define ftrace_return_address(n) return_address(n) 32 33 void MCOUNT_NAME(void); 34 static inline unsigned long ftrace_call_adjust(unsigned long addr) 35 { 36 return addr; 37 } 38 39 /* 40 * Let's do like x86/arm64 and ignore the compat syscalls. 41 */ 42 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 43 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 44 { 45 return is_compat_task(); 46 } 47 48 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 49 static inline bool arch_syscall_match_sym_name(const char *sym, 50 const char *name) 51 { 52 /* 53 * Since all syscall functions have __riscv_ prefix, we must skip it. 54 * However, as we described above, we decided to ignore compat 55 * syscalls, so we don't care about __riscv_compat_ prefix here. 56 */ 57 return !strcmp(sym + 8, name); 58 } 59 60 struct dyn_arch_ftrace { 61 }; 62 #endif 63 64 #ifdef CONFIG_DYNAMIC_FTRACE 65 /* 66 * A general call in RISC-V is a pair of insts: 67 * 1) auipc: setting high-20 pc-related bits to ra register 68 * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to 69 * return address (original pc + 4) 70 * 71 *<ftrace enable>: 72 * 0: auipc t0/ra, 0x? 73 * 4: jalr t0/ra, ?(t0/ra) 74 * 75 *<ftrace disable>: 76 * 0: nop 77 * 4: nop 78 * 79 * Dynamic ftrace generates probes to call sites, so we must deal with 80 * both auipc and jalr at the same time. 81 */ 82 83 #define MCOUNT_ADDR ((unsigned long)MCOUNT_NAME) 84 #define JALR_SIGN_MASK (0x00000800) 85 #define JALR_OFFSET_MASK (0x00000fff) 86 #define AUIPC_OFFSET_MASK (0xfffff000) 87 #define AUIPC_PAD (0x00001000) 88 #define JALR_SHIFT 20 89 #define JALR_RA (0x000080e7) 90 #define AUIPC_RA (0x00000097) 91 #define JALR_T0 (0x000282e7) 92 #define AUIPC_T0 (0x00000297) 93 #define NOP4 (0x00000013) 94 95 #define to_jalr_t0(offset) \ 96 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) 97 98 #define to_auipc_t0(offset) \ 99 ((offset & JALR_SIGN_MASK) ? \ 100 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ 101 ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) 102 103 #define make_call_t0(caller, callee, call) \ 104 do { \ 105 unsigned int offset = \ 106 (unsigned long) callee - (unsigned long) caller; \ 107 call[0] = to_auipc_t0(offset); \ 108 call[1] = to_jalr_t0(offset); \ 109 } while (0) 110 111 #define to_jalr_ra(offset) \ 112 (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) 113 114 #define to_auipc_ra(offset) \ 115 ((offset & JALR_SIGN_MASK) ? \ 116 (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ 117 ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) 118 119 #define make_call_ra(caller, callee, call) \ 120 do { \ 121 unsigned int offset = \ 122 (unsigned long) callee - (unsigned long) caller; \ 123 call[0] = to_auipc_ra(offset); \ 124 call[1] = to_jalr_ra(offset); \ 125 } while (0) 126 127 /* 128 * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. 129 */ 130 #define MCOUNT_INSN_SIZE 8 131 132 #ifndef __ASSEMBLY__ 133 struct dyn_ftrace; 134 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 135 #define ftrace_init_nop ftrace_init_nop 136 #endif 137 138 #endif /* CONFIG_DYNAMIC_FTRACE */ 139 140 #ifndef __ASSEMBLY__ 141 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 142 struct fgraph_ret_regs { 143 unsigned long a1; 144 unsigned long a0; 145 unsigned long s0; 146 unsigned long ra; 147 }; 148 149 static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) 150 { 151 return ret_regs->a0; 152 } 153 154 static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) 155 { 156 return ret_regs->s0; 157 } 158 #endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ 159 #endif 160 161 #endif /* _ASM_RISCV_FTRACE_H */ 162