Messages in this thread | | | From | Sami Tolvanen <> | Date | Fri, 21 May 2021 09:36:11 -0700 | Subject | Re: [PATCH] init: verify that function is initcall_t at compile-time |
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Hi Marco,
On Fri, May 21, 2021 at 12:26 AM Marco Elver <elver@google.com> wrote: > > 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 <elver@google.com> > Reviewed-by: Miguel Ojeda <ojeda@kernel.org> > Reviewed-by: Nathan Chancellor <nathan@kernel.org> > Tested-by: Nathan Chancellor <nathan@kernel.org> > --- > 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 045ad1650ed1..d82b4b2e1d25 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 \
This looks like a nice improvement, thank you for sending the patch!
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Sami
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