From: Richard Weinberger <richard@xxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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: Jiri Slaby <jslaby@xxxxxxx> --- arch/um/Kconfig.common | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 8ddea1f8006a..0228a6ab9b18 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -7,6 +7,7 @@ config UML bool default y select HAVE_UID16 + select HAVE_FUTEX_CMPXCHG if FUTEX select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select GENERIC_IO -- 2.2.2 -- 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