redir: Retry open64 on EINTR

It is possible for open64 to block on named pipes, and therefore
it can be interrupted by signals and return EINTR.  We should only
let it fail with EINTR if real signals are pending (i.e., it should
not fail on SIGCHLD if SIGCHLD has not been trapped).

This patch adds a new helper sh_open to retry the open64 call if
necessary.  It also calls sh_error when appropriate.

Fixes: 3800d4934391 ("[JOBS] Fix dowait signal race")
Reported-by: Samuel Thibault <>
Signed-off-by: Herbert Xu <>
4 files changed