On Wed, Jun 22, 2016 at 09:11:27PM +0000, Brooks Davis wrote: > Author: brooks > Date: Wed Jun 22 21:11:27 2016 > New Revision: 302092 > URL: https://svnweb.freebsd.org/changeset/base/302092
> Log: > Replace use of the pipe(2) system call with pipe2(2) with a zero flags > value. > This eliminates the need for machine dependant assembly wrappers for > pipe(2). I like it. > It also make passing an invalid address to pipe(2) return EFAULT rather > than triggering a segfault. Document this behavior (which was already > true for pipe2(2), but undocumented). It is valid to promise [EFAULT] in this specific case since the kernel undoes the call's effects when the copyout fails (by closing the descriptors) and it seems unlikely that we will need a userland wrapper around pipe() or pipe2() that needs to access the created file descriptors. However, POSIX does not require it: passing invalid pointers to functions specified by the standard is undefined behaviour. See r241001 for some man pages where I removed the [EFAULT] condition because it is wrong for both reasons mentioned above (something changes even after copyout failure and userland wrappers dereference pointers). -- Jilles Tjoelker _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
