ftrace.h (3608B)
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)function_nocfi(_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 55extern void _mcount(unsigned long); 56extern void *return_address(unsigned int); 57 58struct dyn_arch_ftrace { 59 /* No extra data needed for arm64 */ 60}; 61 62extern unsigned long ftrace_graph_call; 63 64extern void return_to_handler(void); 65 66static 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 82struct dyn_ftrace; 83struct ftrace_ops; 84struct ftrace_regs; 85 86int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); 87#define ftrace_init_nop ftrace_init_nop 88 89void 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 107static 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 114static 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 */