diff options
| author | Richard Weinberger <richard@nod.at> | 2025-08-20 09:12:46 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2025-10-02 08:44:51 +0100 |
| commit | 9aa791c8d7bfc46d8e155cfd812674e8ffedf6b9 (patch) | |
| tree | 4fc3f4b32fd48dc2a2bf46cf3b594a2e952accf1 | |
| parent | fb0e5f266ebc86eb97e061ce5e3a74370c16de53 (diff) | |
ARM: 9457/1: ftrace: Implement HAVE_FUNCTION_GRAPH_FREGSfor-linus
Enable support for ftrace's funcgraph-retval feature by capturing r0-r3
and fp.
Since ARM does not provide its own __arch_ftrace_regs structure,
we instead populate pt_regs with the registers required by ftrace.
Cc: Donglin Peng <pengdonglin@sangfor.com.cn>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-ftrace.S | 18 |
2 files changed, 15 insertions, 4 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b1f3df39ed40..ba84c6f7f5f7 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -108,6 +108,7 @@ config ARM select HAVE_GUP_FAST if ARM_LPAE select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER + select HAVE_FUNCTION_GRAPH_FREGS select HAVE_FUNCTION_TRACER if !XIP_KERNEL select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index bc598e3d8dd2..e24ee559af81 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -257,11 +257,21 @@ 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 + sub sp, #PT_REGS_SIZE + str r0, [sp, #S_R0] + str r1, [sp, #S_R1] + str r2, [sp, #S_R2] + str r3, [sp, #S_R3] + str ip, [sp, #S_FP] + 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 + ldr r3, [sp, #S_R3] + ldr r2, [sp, #S_R2] + ldr r1, [sp, #S_R1] + ldr r0, [sp, #S_R0] + add sp, sp, #PT_REGS_SIZE @ restore stack pointer ret lr ENDPROC(return_to_handler) #endif |