LXR linux/arch/arm64/include/asm/ftrace.h

   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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
  16#define ARCH_SUPPORTS_FTRACE_OPS 1
  17#else
  18#define MCOUNT_ADDR             ((unsigned long)_mcount)
  19#endif
  20
  21/* The BL at the callsite's adjusted rec->ip */
  22#define MCOUNT_INSN_SIZE        AARCH64_INSN_SIZE
  23
  24#define FTRACE_PLT_IDX          0
  25#define FTRACE_REGS_PLT_IDX     1
  26#define NR_FTRACE_PLTS          2
  27
  28/*
  29 * Currently, gcc tends to save the link register after the local variables
  30 * on the stack. This causes the max stack tracer to report the function
  31 * frame sizes for the wrong functions. By defining
  32 * ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect
  33 * to find the return address on the stack after the local variables have
  34 * been set up.
  35 *
  36 * Note, this may change in the future, and we will need to deal with that
  37 * if it were to happen.
  38 */
  39#define ARCH_FTRACE_SHIFT_STACK_TRACER 1
  40
  41#ifndef __ASSEMBLY__
  42#include <linux/compat.h>
  43
  44extern void _mcount(unsigned long);
  45extern void *return_address(unsigned int);
  46
  47struct dyn_arch_ftrace {
  48        /* No extra data needed for arm64 */
  49};
  50
  51extern unsigned long ftrace_graph_call;
  52
  53extern void return_to_handler(void);
  54
  55static inline unsigned long ftrace_call_adjust(unsigned long addr)
  56{
  57        /*
  58         * Adjust addr to point at the BL in the callsite.
  59         * See ftrace_init_nop() for the callsite sequence.
  60         */
  61        if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
  62                return addr + AARCH64_INSN_SIZE;
  63        /*
  64         * addr is the address of the mcount call instruction.
  65         * recordmcount does the necessary offset calculation.
  66         */
  67        return addr;
  68}
  69
  70#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
  71struct dyn_ftrace;
  72int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
  73#define ftrace_init_nop ftrace_init_nop
  74#endif
  75
  76#define ftrace_return_address(n) return_address(n)
  77
  78/*
  79 * Because AArch32 mode does not share the same syscall table with AArch64,
  80 * tracing compat syscalls may result in reporting bogus syscalls or even
  81 * hang-up, so just do not trace them.
  82 * See kernel/trace/trace_syscalls.c
  83 *
  84 * x86 code says:
  85 * If the user really wants these, then they should use the
  86 * raw syscall tracepoints with filtering.
  87 */
  88#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
  89static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
  90{
  91        return is_compat_task();
  92}
  93
  94#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
  95
  96static inline bool arch_syscall_match_sym_name(const char *sym,
  97                                               const char *name)
  98{
  99        /*
 100         * Since all syscall functions have __arm64_ prefix, we must skip it.
 101         * However, as we described above, we decided to ignore compat
 102         * syscalls, so we don't care about __arm64_compat_ prefix here.
 103         */
 104        return !strcmp(sym + 8, name);
 105}
 106#endif /* ifndef __ASSEMBLY__ */
 107
 108#endif /* __ASM_FTRACE_H */
 109