[PATCH 1/2] futex: mark futex_detect_cmpxchg() as 'noinline'

From: Arnd Bergmann
Date: Thu Mar 07 2019 - 04:15:48 EST


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'

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 <arnd@xxxxxxxx>
---
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