From 1cb61759d40716643281b8e0f8c7afebc8699249 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Fri, 21 May 2021 09:26:10 +0200 Subject: [PATCH] init: verify that function is initcall_t at compile-time In the spirit of making it hard to misuse an interface, add a compile-time assertion in the CONFIG_HAVE_ARCH_PREL32_RELOCATIONS case to verify the initcall function matches initcall_t, because the inline asm bypasses any type-checking the compiler would otherwise do. This will help developers catch incorrect API use in all configurations. A recent example of this is: https://lkml.kernel.org/r/20210514140015.2944744-1-arnd@kernel.org Signed-off-by: Marco Elver Reviewed-by: Miguel Ojeda Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Sami Tolvanen Tested-by: Paul E. McKenney Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210521072610.2880286-1-elver@google.com --- include/linux/init.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/init.h b/include/linux/init.h index 045ad16..d82b4b2e 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -242,7 +242,8 @@ extern bool initcall_debug; asm(".section \"" __sec "\", \"a\" \n" \ __stringify(__name) ": \n" \ ".long " __stringify(__stub) " - . \n" \ - ".previous \n"); + ".previous \n"); \ + static_assert(__same_type(initcall_t, &fn)); #else #define ____define_initcall(fn, __unused, __name, __sec) \ static initcall_t __name __used \ -- 2.7.4