From d938ba17683effd95b44400d30df16fe541f40fd Mon Sep 17 00:00:00 2001 From: Donglin Peng Date: Sat, 8 Apr 2023 05:42:20 -0700 Subject: [PATCH] x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL The previous patch ("function_graph: Support recording and printing the return value of function") has laid the groundwork for the for the funcgraph-retval, and this modification makes it available on the x86 platform. We introduce a new structure called fgraph_ret_regs for the x86 platform to hold return registers and the frame pointer. We then fill its content in the return_to_handler and pass its address to the function ftrace_return_to_handler to record the return value. Link: https://lkml.kernel.org/r/53a506f0f18ff4b7aeb0feb762f1c9a5e9b83ee9.1680954589.git.pengdonglin@sangfor.com.cn Signed-off-by: Donglin Peng Signed-off-by: Steven Rostedt (Google) --- arch/x86/Kconfig | 1 + arch/x86/include/asm/ftrace.h | 20 ++++++++++++++++++++ arch/x86/kernel/ftrace_32.S | 8 +++++--- arch/x86/kernel/ftrace_64.S | 7 ++++--- 4 files changed, 30 insertions(+), 6 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 53bab123a8ee..da5c081d64a5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -216,6 +216,7 @@ config X86 select HAVE_FAST_GUP select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) select HAVE_FUNCTION_TRACER select HAVE_GCC_PLUGINS diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index 5061ac98ffa1..38d1df9aed37 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -147,4 +147,24 @@ static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) #endif /* !COMPILE_OFFSETS */ #endif /* !__ASSEMBLY__ */ +#ifndef __ASSEMBLY__ +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +struct fgraph_ret_regs { + unsigned long ax; + unsigned long dx; + unsigned long bp; +}; + +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->ax; +} + +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) +{ + return ret_regs->bp; +} +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ +#endif + #endif /* _ASM_X86_FTRACE_H */ diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index 0d9a14528176..24c1175a47e2 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -187,12 +187,14 @@ SYM_CODE_END(ftrace_graph_caller) .globl return_to_handler return_to_handler: - pushl %eax + pushl $0 pushl %edx - movl $0, %eax + pushl %eax + movl %esp, %eax call ftrace_return_to_handler movl %eax, %ecx - popl %edx popl %eax + popl %edx + addl $4, %esp # skip ebp JMP_NOSPEC ecx #endif diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index b8c720b5dab2..945cfa5f7239 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -348,12 +348,13 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__) SYM_CODE_START(return_to_handler) UNWIND_HINT_UNDEFINED ANNOTATE_NOENDBR - subq $16, %rsp + subq $24, %rsp /* Save the return values */ movq %rax, (%rsp) movq %rdx, 8(%rsp) - movq %rbp, %rdi + movq %rbp, 16(%rsp) + movq %rsp, %rdi call ftrace_return_to_handler @@ -361,7 +362,7 @@ SYM_CODE_START(return_to_handler) movq 8(%rsp), %rdx movq (%rsp), %rax - addq $16, %rsp + addq $24, %rsp /* * Jump back to the old return address. This cannot be JMP_NOSPEC rdi * since IBT would demand that contain ENDBR, which simply isn't so for -- 2.11.0