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 <[email protected]> Suggested-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Richard Weinberger <[email protected]> --- arch/um/Kconfig.common | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 87bc868..d195a87 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 -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
