tree 6c2b7c71f648a80e6cd57fd85a7371ff7aa2555d
parent 7c709f2d4f9872d1b445f760b0e68da89e256b9e
author Rich Felker <dalias@aerifal.cx> 1517848271 -0500
committer Rich Felker <dalias@aerifal.cx> 1517848271 -0500

revert regression in faccessat AT_EACCESS robustness

commit f9fb20b42da0e755d93de229a5a737d79a0e8f60 switched from using a
pipe for the result to conveying it via the child process exit status.
Alexander Monakov pointed out that the latter could fail if the
application is not expecting faccessat to produce a child and performs
a wait operation with __WCLONE or __WALL, and that it is not clear
whether it's guaranteed to work when SIGCHLD's disposition has been
set to SIG_IGN.

in addition, that commit introduced a bug that caused EACCES to be
produced instead of EBUSY due to an exit path that was overlooked when
the error channel was changed, and introduced a spurious retry loop
around the wait operation.