Considering code such as the following (drivers/acpi/osl.c): struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work); if (!dpc) { printk(KERN_ERR PREFIX "Invalid (NULL) context\n"); return; } Is it very likely that container_of can return NULL? Container_of computes an offset from a pointer, so I have the impression that if given a NULL value it would normally return a negative number (or a very large positive one, depending on how it is interpreted). thanks, julia -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html