[Linaro-mm-sig] sharing across process of ion/dma_buf created after fork

How do we share ion buffers from user-space with other processes if they are exported/shared after fork? The ION_IOC_SHARE ioctl creates an fd for process-1. In 3.0 kernel, the ION_ION_IMPORT ioctl from process-2 calls ion_import_fd which calls fget(fd) which fails to find the file for the fd shared by process-1. In 3.4 kernel, dma_buf_get does the fget(fd) to get struct file which also fails for the same reason - fget searches in current->files.

- Nishanth Peethambaran