Messages in this thread Patch in this message | | | From | Donglin Peng <> | Subject | [PATCH v8 3/8] ARM: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL | Date | Tue, 28 Mar 2023 06:43:14 -0700 |
| |
The commit d4815c5d1bbd ("function_graph: Support recording and printing the return value of function") laid the groundwork for the for the funcgraph-retval, and this modification makes it available on the ARM platform.
We introduce a new structure called fgraph_ret_regs for the ARM 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.
Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn> --- v8: - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL --- arch/arm/Kconfig | 1 + arch/arm/include/asm/ftrace.h | 18 ++++++++++++++++++ arch/arm/kernel/entry-ftrace.S | 6 +++++- 3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e24a9820e12f..73061379855a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -98,6 +98,7 @@ config ARM select HAVE_FAST_GUP if ARM_LPAE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_ERROR_INJECTION + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER if !XIP_KERNEL select HAVE_GCC_PLUGINS diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 7e9251ca29fe..2ab4bee21d79 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -77,4 +77,22 @@ static inline bool arch_syscall_match_sym_name(const char *sym, #endif /* ifndef __ASSEMBLY__ */ + +#ifndef __ASSEMBLY__ +struct fgraph_ret_regs { + unsigned long regs[4]; + unsigned long fp; +}; + +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 + #endif /* _ASM_ARM_FTRACE */ diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index 3e7bcaca5e07..5f1e74555b25 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -257,11 +257,15 @@ ENDPROC(ftrace_graph_regs_caller) #ifdef CONFIG_FUNCTION_GRAPH_TRACER ENTRY(return_to_handler) + sub sp, sp, #4 stmdb sp!, {r0-r3} - add r0, sp, #16 @ sp at exit of instrumented routine + add r0, sp, #20 @ sp at exit of instrumented routine + str r0, [sp, #16] + mov r0, sp bl ftrace_return_to_handler mov lr, r0 @ r0 has real ret addr ldmia sp!, {r0-r3} + add sp, sp, #4 @ skip fp ret lr ENDPROC(return_to_handler) #endif -- 2.25.1
| |