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Re: [patch] Error on setenv(..., NULL, ...)
- From: Rich Felker <dalias at libc dot org>
- To: Siddhesh Poyarekar <siddhesh at redhat dot com>, Szabolcs Nagy <szabolcs dot nagy at arm dot com>, Paul Pluzhnikov <ppluzhnikov at google dot com>, GLIBC Devel <libc-alpha at sourceware dot org>
- Date: Wed, 11 Mar 2015 14:42:16 -0400
- Subject: Re: [patch] Error on setenv(..., NULL, ...)
- Authentication-results: sourceware.org; auth=none
- References: <CALoOobNSbWUkd_i-L6U0ovbqPYnJY-h=ftX1K61yb19pmJj6aw at mail dot gmail dot com> <20150311163327 dot GV9714 at spoyarek dot pnq dot redhat dot com> <55006F71 dot 6000807 at arm dot com> <20150311164415 dot GW9714 at spoyarek dot pnq dot redhat dot com> <20150311172546 dot GA877 at vapier>
On Wed, Mar 11, 2015 at 01:25:46PM -0400, Mike Frysinger wrote:
> On 11 Mar 2015 22:14, Siddhesh Poyarekar wrote:
> > On Wed, Mar 11, 2015 at 04:38:09PM +0000, Szabolcs Nagy wrote:
> > > no, this just says that NULL argument is undefined behaviour
> > >
> > > this is not a bug in glibc and i don't think any change should be made
> >
> > Fair enough, but if we ever decide to protect ourselves against such
> > bad access, I'd be in favour of something more conservative like
> > returning a blank string than returning an error.
>
> if we agree it's undefined behavior, then can't we have fortification turn this
> into a build failure ?
Not a build failure but a runtime trap. UB can't be caught at build
time because it's only forbidden if the statement that results in UB
is reached, and reachability is equivalent to the halting problem.
Rich
- References:
- [patch] Error on setenv(..., NULL, ...)
- Re: [patch] Error on setenv(..., NULL, ...)
- Re: [patch] Error on setenv(..., NULL, ...)
- Re: [patch] Error on setenv(..., NULL, ...)
- Re: [patch] Error on setenv(..., NULL, ...)