| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * arch/arm64/include/asm/ftrace.h |
| * |
| * Copyright (C) 2013 Linaro Limited |
| * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> |
| */ |
| #ifndef __ASM_FTRACE_H |
| #define __ASM_FTRACE_H |
| |
| #include <asm/insn.h> |
| |
| #define HAVE_FUNCTION_GRAPH_FP_TEST |
| |
| /* |
| * HAVE_FUNCTION_GRAPH_RET_ADDR_PTR means that the architecture can provide a |
| * "return address pointer" which can be used to uniquely identify a return |
| * address which has been overwritten. |
| * |
| * On arm64 we use the address of the caller's frame record, which remains the |
| * same for the lifetime of the instrumented function, unlike the return |
| * address in the LR. |
| */ |
| #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS |
| #define ARCH_SUPPORTS_FTRACE_OPS 1 |
| #else |
| #define MCOUNT_ADDR ((unsigned long)_mcount) |
| #endif |
| |
| /* The BL at the callsite's adjusted rec->ip */ |
| #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE |
| |
| #define FTRACE_PLT_IDX 0 |
| #define NR_FTRACE_PLTS 1 |
| |
| /* |
| * Currently, gcc tends to save the link register after the local variables |
| * on the stack. This causes the max stack tracer to report the function |
| * frame sizes for the wrong functions. By defining |
| * ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect |
| * to find the return address on the stack after the local variables have |
| * been set up. |
| * |
| * Note, this may change in the future, and we will need to deal with that |
| * if it were to happen. |
| */ |
| #define ARCH_FTRACE_SHIFT_STACK_TRACER 1 |
| |
| #ifndef __ASSEMBLY__ |
| #include <linux/compat.h> |
| |
| extern void _mcount(unsigned long); |
| extern void *return_address(unsigned int); |
| |
| struct dyn_arch_ftrace { |
| /* No extra data needed for arm64 */ |
| }; |
| |
| extern unsigned long ftrace_graph_call; |
| |
| extern void return_to_handler(void); |
| |
| static inline unsigned long ftrace_call_adjust(unsigned long addr) |
| { |
| /* |
| * Adjust addr to point at the BL in the callsite. |
| * See ftrace_init_nop() for the callsite sequence. |
| */ |
| if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) |
| return addr + AARCH64_INSN_SIZE; |
| /* |
| * addr is the address of the mcount call instruction. |
| * recordmcount does the necessary offset calculation. |
| */ |
| return addr; |
| } |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS |
| struct dyn_ftrace; |
| struct ftrace_ops; |
| |
| #define arch_ftrace_get_regs(regs) NULL |
| |
| struct ftrace_regs { |
| /* x0 - x8 */ |
| unsigned long regs[9]; |
| unsigned long __unused; |
| |
| unsigned long fp; |
| unsigned long lr; |
| |
| unsigned long sp; |
| unsigned long pc; |
| }; |
| |
| static __always_inline unsigned long |
| ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs) |
| { |
| return fregs->pc; |
| } |
| |
| static __always_inline void |
| ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, |
| unsigned long pc) |
| { |
| fregs->pc = pc; |
| } |
| |
| static __always_inline unsigned long |
| ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs) |
| { |
| return fregs->sp; |
| } |
| |
| static __always_inline unsigned long |
| ftrace_regs_get_argument(struct ftrace_regs *fregs, unsigned int n) |
| { |
| if (n < 8) |
| return fregs->regs[n]; |
| return 0; |
| } |
| |
| static __always_inline unsigned long |
| ftrace_regs_get_return_value(const struct ftrace_regs *fregs) |
| { |
| return fregs->regs[0]; |
| } |
| |
| static __always_inline void |
| ftrace_regs_set_return_value(struct ftrace_regs *fregs, |
| unsigned long ret) |
| { |
| fregs->regs[0] = ret; |
| } |
| |
| static __always_inline void |
| ftrace_override_function_with_return(struct ftrace_regs *fregs) |
| { |
| fregs->pc = fregs->lr; |
| } |
| |
| int ftrace_regs_query_register_offset(const char *name); |
| |
| int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); |
| #define ftrace_init_nop ftrace_init_nop |
| |
| void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct ftrace_regs *fregs); |
| #define ftrace_graph_func ftrace_graph_func |
| #endif |
| |
| #define ftrace_return_address(n) return_address(n) |
| |
| /* |
| * Because AArch32 mode does not share the same syscall table with AArch64, |
| * tracing compat syscalls may result in reporting bogus syscalls or even |
| * hang-up, so just do not trace them. |
| * See kernel/trace/trace_syscalls.c |
| * |
| * x86 code says: |
| * If the user really wants these, then they should use the |
| * raw syscall tracepoints with filtering. |
| */ |
| #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS |
| static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) |
| { |
| return is_compat_task(); |
| } |
| |
| #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME |
| |
| static inline bool arch_syscall_match_sym_name(const char *sym, |
| const char *name) |
| { |
| /* |
| * Since all syscall functions have __arm64_ prefix, we must skip it. |
| * However, as we described above, we decided to ignore compat |
| * syscalls, so we don't care about __arm64_compat_ prefix here. |
| */ |
| return !strcmp(sym + 8, name); |
| } |
| #endif /* ifndef __ASSEMBLY__ */ |
| |
| #endif /* __ASM_FTRACE_H */ |