Re: [PATCH] arm: ftrace: fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTER

[Rabin Vincent]

On Wed, Mar 15, 2017 at 06:07:39PM +0000, Abel Vesa wrote:
> The support for dynamic ftrace with CONFIG_DEBUG_RODATA involves
> overriding the weak arch_ftrace_update_code() with a variant which makes
> the kernel text writable around the patching.
> 
> This override was however added under the CONFIG_OLD_MCOUNT ifdef, and
> CONFIG_OLD_MCOUNT is only enabled if frame pointers are enabled.
> 
> This leads to non-functional dynamic ftrace (ftrace triggers a
> WARN_ON()) when CONFIG_DEBUG_RODATA is enabled and CONFIG_FRAME_POINTER
> is not.
> 
> Move the override out of that ifdef and into the CONFIG_DYNAMIC_FTRACE
> ifdef where it belongs.
> 
> Fixes: 80d6b0c2eed2a ("ARM: mm: allow text and rodata sections to be read-only")
> 
> Suggested-by: Nicolai Stange <nicstange@xxxxxxxxx>
> Suggested-by: Rabin Vincent <rabin@xxxxxx>
> Signed-off-by: Abel Vesa <abelvesa@xxxxxxxxx>

Acked-by: Rabin Vincent <rabin@xxxxxx>