Re: [PATCH -next] arm: patch: FUNCTION_GRAPH_TRACER depends on CPU_ENDIAN_BE8 or !CPU_ENDIAN_BE32

[Steven Rostedt]

On Tue, 6 Apr 2021 18:23:51 +0800
Zhang Jianhua <zhangjianhua18@xxxxxxxxxx> wrote:

> If CONFIG_FUNCTION_GRAPH_TRACER=y, the following errors will be seen
> while compiling patch.c
> 
> arch/arm/kernel/patch.c: In function ‘__patch_text_real’:
> arch/arm/kernel/patch.c:94:11: error: implicit declaration of function
> ‘__opcode_to_mem_thumb32’; did you mean ‘__opcode_to_mem_thumb16’?
> [-Werror=implicit-function-declaration]
>     insn = __opcode_to_mem_thumb32(insn);
>            ^~~~~~~~~~~~~~~~~~~~~~~
>            __opcode_to_mem_thumb16
> 
> Signed-off-by: Zhang Jianhua <zhangjianhua18@xxxxxxxxxx>
> ---
>  kernel/trace/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index 7fa82778c3e6..fbf5fd80f105 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -177,6 +177,7 @@ config FUNCTION_GRAPH_TRACER
>  	depends on HAVE_FUNCTION_GRAPH_TRACER
>  	depends on FUNCTION_TRACER
>  	depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
> +	depends on CPU_ENDIAN_BE8 || !CPU_ENDIAN_BE32

Doesn't this break 32 bit big endian powerpc?

Not to mention, my config doesn't have either of those.

NACK

-- Steve

>  	default y
>  	help
>  	  Enable the kernel to trace a function at both its return