Change Details

In particular, CLONE_FS does not suggest the child process should share an fd table with the parent process. In Chrome, clone(2) is used with CLONE_FS, without CLONE_FILES, and expects independent fd tables. I'm not sure what, if anything, relies on the weird properties of CLONE_FS; this change might regress that functionality. This conflation was introduced in r163371 (2006) without clear justification.

The two flags are distinct and it is impossible to correctly handle clone(2) without the assistance of fork1(). I've added a fork_req flag, FR2_SHARE_PATHS, which indicates that p_pd should be treated the opposite way p_fd is (based on RFFDG flag). This is a little ugly, but the benefit is that existing RFFDG API is preserved. Holding FR2_SHARE_PATHS disabled, RFFDG indicates both p_fd and p_pd are copied, while !RFFDG indicates both should be cloned. In Chrome, clone(2) is used with CLONE_FS, without CLONE_FILES, and expects independent fd tables. The previous conflation of CLONE_FS and CLONE_FILES was introduced in r163371 (2006).

In particular, CLONE_FS does not suggest the child process should share anThe two flags are distinct and it is impossible to correctly handle clone(2) fd table with the parent process. In Chromewithout the assistance of fork1(). I've added a fork_req flag, FR2_SHARE_PATHS, clone(2) is used withwhich indicates that p_pd CLONE_FSshould be treated the opposite way p_fd is (based on RFFDG flag). This is a little ugly, but the benefit is that existing RFFDG API is preserved. Holding FR2_SHARE_PATHS disabled, without CLONE_FILESRFFDG indicates both p_fd and p_pd are copied, and expectswhile !RFFDG independent fd tablesicates both should be cloned. I'm not sure whatIn Chrome, clone(2) is used with CLONE_FS, if anythingwithout CLONE_FILES, relies on the weird properties of CLONE_FS;and expects this change might regress that functionality. This conflation wasindependent fd tables. The previous conflation of CLONE_FS and CLONE_FILES was introduced in introduced in r163371 (2006) without clear justification.