On Sun, Aug 19, 2012 at 09:46:04AM +0100, Jan Beulich wrote: > >>> Andi Kleen <andi@xxxxxxxxxxxxxx> 08/19/12 5:05 AM >>> > >Work around a LTO gcc problem: when there is no reference to a variable > >in a module it will be moved to the end of the program. This causes > >reordering of initcalls which the kernel does not like. > >Add a dummy reference function to avoid this. The function is > >deleted by the linker. > > This is not even true on x86, not to speak of generally. Why is it not true ? __initcall is only defined for !MODULE and there __exit discards. > > >+#ifdef CONFIG_LTO > >+/* Work around a LTO gcc problem: when there is no reference to a variable > >+ * in a module it will be moved to the end of the program. This causes > >+ * reordering of initcalls which the kernel does not like. > >+ * Add a dummy reference function to avoid this. The function is > >+ * deleted by the linker. > >+ */ > >+#define LTO_REFERENCE_INITCALL(x) \ > >+ ; /* yes this is needed */ \ > >+ static __used __exit void *reference_##x(void) \ > > Why not put it into e.g. section .discard.text? That could be expected to be > discarded by the linker without being arch dependent, as long as all arches > use DISCARDS in their linker script. That's what __exit does, doesn't it? -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
