C != Java Which is to say, a null pointer is not a valid argument to unlink, and the Hurd's use of a signal instead of an error is allowed by Posix.
Thomas On Jan 14, 2012 8:48 AM, "Steven McDonald" <steven.mcdon...@libremail.me> wrote: > Hi, > > I've been looking at the problems with visudo as tracked on alioth[1]. > I've applied Justus's fix to use flock instead of lockf, and created a > patch that solves the segfault issue (see attached). visudo now seems > to work correctly on Hurd. > > However, I'm uncertain whether the segfault should actually be > considered a bug in visudo, or whether it should rather be fixed in > Hurd's implementation of unlink (see backtrace[2]). As such, I'm asking > on the list for advice before I submit this as a bug report. (I'll be > submitting Justus's fix anyway, as it's really a separate problem.) > > As you can see in the attached patch, visudo already uses a void cast > on unlink, suggesting that it doesn't care if the unlink operation > fails. Presumably on Linux and kFreeBSD (I haven't verified this, as > I'm not sure where it's defined), unlink exits gracefully with failure > if it is passed a null pointer, whereas on Hurd it doesn't check this > and segfaults as a result. > > Is this something that should be fixed in Hurd (or perhaps eglibc), or > should I go ahead and submit the attached patch via the BTS? > > [1] > https://alioth.debian.org/tracker/index.php?func=detail&aid=303084&group_id=30628&atid=411594 > [2] http://ftp.steven-mcdonald.id.au/visudo_backtrace.txt > > Thanks, > Steven. >
