Date: Fri, 16 Apr 1999 16:48:26 +1000 From: Bruce Evans <bde@zeta.org.au> To: phk@critter.freebsd.dk, robert+freebsd@cyrus.watson.org Cc: freebsd-security@FreeBSD.ORG Subject: Re: POSIX.1E auditing support, an initial pass and some questions Message-ID: <199904160648.QAA06234@godzilla.zeta.org.au>
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>>I had suspected (and observed) as much. What is the rational behind >>having the name lookup pull the pathname into the kernel as opposed to >>using a copyin in the syscall and passing it in as an argument? >>Presumably someone, somewhere has to allocate space on the stack, and if Space is allocated by zalloc(). Not long ago, space was allocated by malloc(). The kernel stack may be too small to hold a name of length MAXPATHLEN. >>it's done in the syscall function then more argument processing is done in >>one place? This would make at least a bit more available to an auditing >>layer in the syscall. > >I think it is an old thing, conserving kernel memory. Indeed it may >not make sense today where the vfs-name-cache is so much more efficient. >Changing it may be a PITA. I think it's just centralisation. The pathname is copied in in one place instead of in 100's of syscall functions. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message
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