1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * arch/arm64/include/asm/ftrace.h 4 * 5 * Copyright (C) 2013 Linaro Limited 6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> 7 */ 8 #ifndef __ASM_FTRACE_H 9 #define __ASM_FTRACE_H 10 11 #include <asm/insn.h> 12 13 #define HAVE_FUNCTION_GRAPH_FP_TEST 14 15 /* 16 * HAVE_FUNCTION_GRAPH_RET_ADDR_PTR means that the architecture can provide a 17 * "return address pointer" which can be used to uniquely identify a return 18 * address which has been overwritten. 19 * 20 * On arm64 we use the address of the caller's frame record, which remains the 21 * same for the lifetime of the instrumented function, unlike the return 22 * address in the LR. 23 */ 24 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 25 26 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 27 #define ARCH_SUPPORTS_FTRACE_OPS 1 28 #else 29 #define MCOUNT_ADDR ((unsigned long)_mcount) 30 #endif 31 32 /* The BL at the callsite's adjusted rec->ip */ 33 #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE 34 35 #define FTRACE_PLT_IDX 0 36 #define FTRACE_REGS_PLT_IDX 1 37 #define NR_FTRACE_PLTS 2 38 39 /* 40 * Currently, gcc tends to save the link register after the local variables 41 * on the stack. This causes the max stack tracer to report the function 42 * frame sizes for the wrong functions. By defining 43 * ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect 44 * to find the return address on the stack after the local variables have 45 * been set up. 46 * 47 * Note, this may change in the future, and we will need to deal with that 48 * if it were to happen. 49 */ 50 #define ARCH_FTRACE_SHIFT_STACK_TRACER 1 51 52 #ifndef __ASSEMBLY__ 53 #include <linux/compat.h> 54 55 extern void _mcount(unsigned long); 56 extern void *return_address(unsigned int); 57 58 struct dyn_arch_ftrace { 59 /* No extra data needed for arm64 */ 60 }; 61 62 extern unsigned long ftrace_graph_call; 63 64 extern void return_to_handler(void); 65 66 static inline unsigned long ftrace_call_adjust(unsigned long addr) 67 { 68 /* 69 * Adjust addr to point at the BL in the callsite. 70 * See ftrace_init_nop() for the callsite sequence. 71 */ 72 if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) 73 return addr + AARCH64_INSN_SIZE; 74 /* 75 * addr is the address of the mcount call instruction. 76 * recordmcount does the necessary offset calculation. 77 */ 78 return addr; 79 } 80 81 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 82 struct dyn_ftrace; 83 struct ftrace_ops; 84 struct ftrace_regs; 85 86 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 87 #define ftrace_init_nop ftrace_init_nop 88 89 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, 90 struct ftrace_ops *op, struct ftrace_regs *fregs); 91 #define ftrace_graph_func ftrace_graph_func 92 #endif 93 94 #define ftrace_return_address(n) return_address(n) 95 96 /* 97 * Because AArch32 mode does not share the same syscall table with AArch64, 98 * tracing compat syscalls may result in reporting bogus syscalls or even 99 * hang-up, so just do not trace them. 100 * See kernel/trace/trace_syscalls.c 101 * 102 * x86 code says: 103 * If the user really wants these, then they should use the 104 * raw syscall tracepoints with filtering. 105 */ 106 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 107 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 108 { 109 return is_compat_task(); 110 } 111 112 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 113 114 static inline bool arch_syscall_match_sym_name(const char *sym, 115 const char *name) 116 { 117 /* 118 * Since all syscall functions have __arm64_ prefix, we must skip it. 119 * However, as we described above, we decided to ignore compat 120 * syscalls, so we don't care about __arm64_compat_ prefix here. 121 */ 122 return !strcmp(sym + 8, name); 123 } 124 #endif /* ifndef __ASSEMBLY__ */ 125 126 #endif /* __ASM_FTRACE_H */ 127