Messages in this thread Patch in this message | | | From | Donglin Peng <> | Subject | [PATCH v10 3/8] ARM: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL | Date | Fri, 31 Mar 2023 05:47:39 -0700 |
| |
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 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> --- v10: - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition
v9: - Fix stack pointer align issues - Update the commit message
v8: - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL --- arch/arm/Kconfig | 1 + arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++ arch/arm/kernel/asm-offsets.c | 8 +++++++- arch/arm/kernel/entry-ftrace.S | 10 ++++++---- 4 files changed, 36 insertions(+), 5 deletions(-)
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..3c457902b355 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -77,4 +77,26 @@ 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 { + /* r0 - r3 */ + unsigned long regs[4]; + + 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_ARM_FTRACE */ diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 38121c59cbc2..18bb85115b21 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -23,6 +23,7 @@ #include <asm/suspend.h> #include <asm/vdso_datapage.h> #include <asm/hardware/cache-l2x0.h> +#include <asm/ftrace.h> #include <linux/kbuild.h> #include <linux/arm-smccc.h> #include "signal.h" @@ -170,5 +171,10 @@ int main(void) DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page)); DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type)); DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2)); - return 0; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + BLANK(); + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); + BLANK(); +#endif + return 0; } diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index 3e7bcaca5e07..d41a1676608c 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller) #ifdef CONFIG_FUNCTION_GRAPH_TRACER ENTRY(return_to_handler) - stmdb sp!, {r0-r3} - add r0, sp, #16 @ sp at exit of instrumented routine + mov ip, sp @ sp at exit of instrumented routine + stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs + mov r0, sp bl ftrace_return_to_handler - mov lr, r0 @ r0 has real ret addr - ldmia sp!, {r0-r3} + mov lr, r0 @ r0 has real ret addr + ldmia sp, {r0-r3} + add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer ret lr ENDPROC(return_to_handler) #endif -- 2.25.1
| |