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Diffstat (limited to 'arch/arm64/include/asm/ftrace.h')
| -rw-r--r-- | arch/arm64/include/asm/ftrace.h | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h new file mode 100644 index 000000000..ab1581964 --- /dev/null +++ b/arch/arm64/include/asm/ftrace.h @@ -0,0 +1,221 @@ +/* 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); + +unsigned long ftrace_call_adjust(unsigned long addr); + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS +struct dyn_ftrace; +struct ftrace_ops; + +#define arch_ftrace_get_regs(regs) NULL + +/* + * Note: sizeof(struct ftrace_regs) must be a multiple of 16 to ensure correct + * stack alignment + */ +struct ftrace_regs { + /* x0 - x8 */ + unsigned long regs[9]; + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + unsigned long direct_tramp; +#else + unsigned long __unused; +#endif + + 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 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, + unsigned long addr) +{ + /* + * The ftrace trampoline will return to this address instead of the + * instrumented function. + */ + fregs->direct_tramp = addr; +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + +#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__ */ + +#ifndef __ASSEMBLY__ +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +struct fgraph_ret_regs { + /* x0 - x7 */ + unsigned long regs[8]; + + unsigned long fp; + unsigned long __unused; +}; + +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->regs[0]; +} + +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->fp; +} + +void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, + unsigned long frame_pointer); + +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ +#endif + +#endif /* __ASM_FTRACE_H */ |