From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21607 invoked by alias); 18 Dec 2014 19:15:20 -0000 Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: X-Seq: 34005 Received: (qmail 10476 invoked from network); 18 Dec 2014 19:15:14 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 X-Originating-IP: [86.6.25.230] X-Spam: 0 X-Authority: v=2.1 cv=Ku/D2AmN c=1 sm=1 tr=0 a=c0CwWhpM9oUd/BnC3z6Gzg==:117 a=c0CwWhpM9oUd/BnC3z6Gzg==:17 a=NLZqzBF-AAAA:8 a=kj9zAlcOel0A:10 a=q2GGsy2AAAAA:8 a=JfdBF1Ui_yOGiV_F8o8A:9 a=CjuIK1q_8ugA:10 Date: Thu, 18 Dec 2014 19:09:24 +0000 From: Peter Stephenson To: zsh-workers@zsh.org Subject: Re: Complex config triggering Segfault in pattern matching code. Message-ID: <20141218190924.0f08548b@pws-pc.ntlworld.com> In-Reply-To: <141217221400.ZM13648@torch.brasslantern.com> References: <141213152840.ZM16632@torch.brasslantern.com> <141213204032.ZM16766@torch.brasslantern.com> <20141214182021.1944bbcd@pws-pc.ntlworld.com> <141215153936.ZM17826@torch.brasslantern.com> <141217221400.ZM13648@torch.brasslantern.com> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 17 Dec 2014 22:14:00 -0800 Bart Schaefer wrote: > This is the one that repeats a lot: > > ==1705== Uninitialised value was created by a heap allocation > ==1705== at 0x4C2C29E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) > ==1705== by 0x45C798: zrealloc (mem.c:938) > ==1705== by 0x65B0D18: set_region_highlight (zle_refresh.c:454) > > It would appear that the loop at zle_refresh.c:461 needs to assign > values to rhp->start_meta and rhp->end_meta at the same time that it > calculates rhp->start and rhp->end. However, I'm not familiar enough > with the region_highlight algorithm to be sure how to initialize those. Zeroing at the realloc should stop this. Watch carefully in case I've got the sums wrong. > It's possible that fixing this will fix the next one as a side-effect. > > Finally this one repeats a few times: > > ==1705== Conditional jump or move depends on uninitialised value(s) > ==1705== at 0x5A04253: vfprintf (in /usr/lib/libc-2.20.so) > ==1705== by 0x5A278FA: vsprintf (in /usr/lib/libc-2.20.so) > ==1705== by 0x5A0ACD6: sprintf (in /usr/lib/libc-2.20.so) > ==1705== by 0x65B0B66: get_region_highlight (zle_refresh.c:410) > > That's this: > > sprintf(digbuf1, "%d", rhp->start); > sprintf(digbuf2, "%d", rhp->end); > > I'm confused about that one because I can't see where rhp->start might > be coming from without getting initialized. It LOOKS like the loop in > set_region_highlight() always either initializes those, or truncates > the array to be no more than N_SPECIAL_HIGHLIGHTS elements long. In > the latter case the loop containing those sprintf's should never make > a circuit. There is a potential problem in that the loop test is just > (arrsize--) which could go on infinitely if arrsize is negative when > the loop begins, but there isn't enough log output for this to be an > infinite loop. I don't see how arrsize could be negative, but here's a debug test. diff --git a/Src/Zle/zle_refresh.c b/Src/Zle/zle_refresh.c index 9f80753..d63f9b8 100644 --- a/Src/Zle/zle_refresh.c +++ b/Src/Zle/zle_refresh.c @@ -399,6 +399,7 @@ get_region_highlight(UNUSED(Param pm)) if (!arrsize) return hmkarray(NULL); arrsize -= N_SPECIAL_HIGHLIGHTS; + DPUTS(arrsize < 0, "arrsize is negative from n_region_highlights"); arrp = retarr = (char **)zhalloc((arrsize+1)*sizeof(char *)); /* ignore special highlighting */ @@ -450,10 +451,15 @@ set_region_highlight(UNUSED(Param pm), char **aval) len = aval ? arrlen(aval) : 0; if (n_region_highlights != len + N_SPECIAL_HIGHLIGHTS) { /* no null termination, but include special highlighting at start */ - n_region_highlights = len + N_SPECIAL_HIGHLIGHTS; + int newsize = len + N_SPECIAL_HIGHLIGHTS + int diffsize = newsize - n_region_highlights; region_highlights = (struct region_highlight *) zrealloc(region_highlights, - sizeof(struct region_highlight) * n_region_highlights); + sizeof(struct region_highlight) * newsize); + if (diffsize > 0) + memset(region_highlights + newsize, 0, + sizeof(struct region_highlight) * diffsize); + n_region_highlights = newsize; } if (!aval) -- Peter Stephenson Web page now at http://homepage.ntlworld.com/p.w.stephenson/