From 3646970322464c21e69dcb9a2e37d461c5834bf5 Mon Sep 17 00:00:00 2001 From: Donglin Peng Date: Sat, 8 Apr 2023 05:42:18 -0700 Subject: arm64: 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 ARM64 platform. We introduce a new structure called fgraph_ret_regs for the ARM64 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/c78366416ce93f704ae7000c4ee60eb4258c38f7.1680954589.git.pengdonglin@sangfor.com.cn Reviewed-by: Mark Rutland Tested-by: Mark Rutland Acked-by: Catalin Marinas Signed-off-by: Donglin Peng Signed-off-by: Steven Rostedt (Google) --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/ftrace.h | 22 ++++++++++++++++++++++ arch/arm64/kernel/asm-offsets.c | 13 +++++++++++++ arch/arm64/kernel/entry-ftrace.S | 27 ++++++++++++++------------- 4 files changed, 50 insertions(+), 13 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1201d25a8a4..f90b1780ea6c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -201,6 +201,7 @@ config ARM64 select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_ERROR_INJECTION + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_GRAPH_TRACER select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index b87d70b693c6..21ac1c5c71d3 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -192,4 +192,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym, } #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; +} +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ +#endif + #endif /* __ASM_FTRACE_H */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 0996094b0d22..757d01a68ffd 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -200,6 +200,19 @@ int main(void) #endif #ifdef CONFIG_FUNCTION_TRACER DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func)); +#endif + BLANK(); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + DEFINE(FGRET_REGS_X0, offsetof(struct fgraph_ret_regs, regs[0])); + DEFINE(FGRET_REGS_X1, offsetof(struct fgraph_ret_regs, regs[1])); + DEFINE(FGRET_REGS_X2, offsetof(struct fgraph_ret_regs, regs[2])); + DEFINE(FGRET_REGS_X3, offsetof(struct fgraph_ret_regs, regs[3])); + DEFINE(FGRET_REGS_X4, offsetof(struct fgraph_ret_regs, regs[4])); + DEFINE(FGRET_REGS_X5, offsetof(struct fgraph_ret_regs, regs[5])); + DEFINE(FGRET_REGS_X6, offsetof(struct fgraph_ret_regs, regs[6])); + DEFINE(FGRET_REGS_X7, offsetof(struct fgraph_ret_regs, regs[7])); + DEFINE(FGRET_REGS_FP, offsetof(struct fgraph_ret_regs, fp)); + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call)); #endif diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 1c38a60575aa..f0c16640ef21 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -330,22 +330,23 @@ SYM_FUNC_END(ftrace_stub_graph) */ SYM_CODE_START(return_to_handler) /* save return value regs */ - sub sp, sp, #64 - stp x0, x1, [sp] - stp x2, x3, [sp, #16] - stp x4, x5, [sp, #32] - stp x6, x7, [sp, #48] + sub sp, sp, #FGRET_REGS_SIZE + stp x0, x1, [sp, #FGRET_REGS_X0] + stp x2, x3, [sp, #FGRET_REGS_X2] + stp x4, x5, [sp, #FGRET_REGS_X4] + stp x6, x7, [sp, #FGRET_REGS_X6] + str x29, [sp, #FGRET_REGS_FP] // parent's fp - mov x0, x29 // parent's fp - bl ftrace_return_to_handler// addr = ftrace_return_to_hander(fp); - mov x30, x0 // restore the original return address + mov x0, sp + bl ftrace_return_to_handler // addr = ftrace_return_to_hander(regs); + mov x30, x0 // restore the original return address /* restore return value regs */ - ldp x0, x1, [sp] - ldp x2, x3, [sp, #16] - ldp x4, x5, [sp, #32] - ldp x6, x7, [sp, #48] - add sp, sp, #64 + ldp x0, x1, [sp, #FGRET_REGS_X0] + ldp x2, x3, [sp, #FGRET_REGS_X2] + ldp x4, x5, [sp, #FGRET_REGS_X4] + ldp x6, x7, [sp, #FGRET_REGS_X6] + add sp, sp, #FGRET_REGS_SIZE ret SYM_CODE_END(return_to_handler) -- cgit v1.2.3