[PATCH] arm64: ftrace: fix building without CONFIG_MODULES

On Fri, Jun 9, 2017 at 1:38 PM, Will Deacon [off-list ref] wrote:

Hi Arnd,

On Fri, Jun 09, 2017 at 12:27:06PM +0200, Arnd Bergmann wrote:

quoted

When CONFIG_MODULES is disabled, we cannot dereference a module pointer:

arch/arm64/kernel/ftrace.c: In function 'ftrace_make_call':
arch/arm64/kernel/ftrace.c:107:36: error: dereferencing pointer to incomplete type 'struct module'
   trampoline = (unsigned long *)mod->arch.ftrace_trampoline;

Also, the within_module() function is not defined:

arch/arm64/kernel/ftrace.c: In function 'ftrace_make_nop':
arch/arm64/kernel/ftrace.c:171:8: error: implicit declaration of function 'within_module'; did you mean 'init_module'? [-Werror=implicit-function-declaration]

This addresses both by adding the appropriate stubs.

Fixes: e71a4e1bebaf ("arm64: ftrace: add support for far branches to dynamic ftrace")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/include/asm/module.h | 6 ++++++
 arch/arm64/kernel/ftrace.c      | 2 +-
 include/linux/module.h          | 5 +++++
 3 files changed, 12 insertions(+), 1 deletion(-)

I can't seem to reproduce this simply by disabling MODULES in defconfig.
Could you share your .config, please?

This is the randconfig I used: https://pastebin.com/SfKBY7f8

      Arnd