3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Weinberger <richard@xxxxxx> commit f911d731054ab3d82ee72a16b889e17ca3a2332a upstream. 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 <miklos@xxxxxxxxxx> Suggested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Richard Weinberger <richard@xxxxxx> Tested-by: Daniel Walter <d.walter@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/um/Kconfig.common | 1 + 1 file changed, 1 insertion(+) --- 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html