From f911d731054ab3d82ee72a16b889e17ca3a2332a Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Wed, 10 Dec 2014 13:53:51 +0100 Subject: [PATCH] um: Skip futex_atomic_cmpxchg_inatomic() test futex_atomic_cmpxchg_inatomic() does not work on UML because it triggers a copy_from_user() in kernel context. On UML copy_from_user() can only be used if the kernel was called by a real user space process such that UML can use ptrace() to fetch the value. Reported-by: Miklos Szeredi Suggested-by: Geert Uytterhoeven Signed-off-by: Richard Weinberger Tested-by: Daniel Walter --- arch/um/Kconfig.common | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 87bc86821bc9..d195a87ca542 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -3,6 +3,7 @@ config UML default y select HAVE_ARCH_AUDITSYSCALL select HAVE_UID16 + select HAVE_FUTEX_CMPXCHG if FUTEX select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select GENERIC_IO -- 2.20.1