我们可以看到unlocked_ioctl 和 compat_ioctl这2个函数的最后一个参数是 unsigned long类型的,long类型在不同的架构下面的长度是不同的,在32位平台下是4字节,64位平台下就是8个字节,当32位的应用程序使用ioctl系统调用时,传了4个字节的参数,到驱动中,应该是8个字节,这样就产生了不兼容,为了不影响64位的应用程...
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. media: v4l2-compat-ioctl32.c: refactor compat ioctl32 logic commita1dfb4cupstream. The 32-bit compat v4l2 ioctl handling is implemented based on its 64-bit equivalent. It con...