<pre>include/linux/irq.h:441:8: 警告：variable 「gfp」 set but not used [-Wunused-but-set-variable]
  CC      arch/x86/vdso/vgetcpu.o
  CC      arch/x86/vdso/vvar.o
  VDSO    arch/x86/vdso/vdso.so.dbg
gcc: 錯誤：elf_x86_64: 沒有此一檔案或目錄
make[2]: *** [arch/x86/vdso/vdso.so.dbg] Error 1
make[1]: *** [arch/x86/vdso] Error 2
make: *** [arch/x86] Error 2</pre>

Google 好難找…終於找到

https://bugzilla.redhat.com/attachment.cgi?id=488326&action=diff

可能是 gcc 在加 -m 參數時的版本差異

要把

arch/x86/vdso/Makefile

裡面的

-m elf_x86_64 改成 -m64

-m elf_i386  改成 -m32

…

[Documentation/video4linux/v4lgrab] Error 1

+//#include <linux/videodev.h>
+#include <libv4l1-videodev.h>

http://git.kernel.org/?p=linux/hotplug/udev.git;a=commitdiff;h=4ace8a43ac2cbbd4d6f5c29fc461c3caa8f8545b