On Thu, Mar 7, 2019 at 1:15 AM Arnd Bergmann <a...@arndb.de> wrote:
>
> On 32-bit ARM, I got a link failure in futex_init() when building
> with clang in some random configurations:
>
> kernel/futex.o:(.text.fixup+0x5c): relocation truncated to fit: R_ARM_JUMP24
> against `.init.text'
Do we know what function from the fixup text section is calling
futex_detect_cmpxchg? I'm curious if this is maybe another case of
-Wsection where some function may be in the wrong section?
>
> As far as I can tell, the problem is that a branch is over 16MB
> apart in those configurations, but only if it branches back to
> the init text.
>
> Marking the futex_detect_cmpxchg() function as noinline and
> not __init avoids the problem for me.
>
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
> ---
> kernel/futex.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index c3b73b0311bc..dda77ed9f445 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -3849,7 +3849,7 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int,
> op, u32, val,
> }
> #endif /* CONFIG_COMPAT_32BIT_TIME */
>
> -static void __init futex_detect_cmpxchg(void)
> +static noinline void futex_detect_cmpxchg(void)
> {
> #ifndef CONFIG_HAVE_FUTEX_CMPXCHG
> u32 curval;
> --
> 2.20.0
>
--
Thanks,
~Nick Desaulniers
