Re: makewhatis(8) (from textproc/mandoc) fails with SIGSEGV

[Leonardo Taccari <leot%NetBSD.org@localhost>]

Hello Paul,

Paul Goyette writes:
> With a recently-rebuilt mandoc package, and a NetBSD-8.99.22 amd64 host, 
> I am seeing makewhatis(8) aborting with SIGSEGV.  I've tried to figure 
> out what's going on, but have not succeeded.  The stack backtrace in the 
> core file is unhelpful:
> [...]

Trying to recompile it with `env CFLAGS=-g INSTALL_UNSTRIPPED=yes
make install' and then:

 % /usr/pkg/sbin/makewhatis -n
 Segmentation fault (core dumped)
 Exit 139

...but according the .core the problem doesn't seem immediate!

 |  % gdb -core makewhatis.core /usr/pkg/sbin/makewhatis
 |  Reading symbols from /usr/pkg/sbin/makewhatis...done.
 |  [New process 1]
 |  Core was generated by `makewhatis'.
 |  Program terminated with signal SIGSEGV, Segmentation fault.
 |  #0  0x000000000041cc02 in manpath_add (dirs=dirs@entry=0x7f7ffffe1cd0, dir=0x7f7ffffe1c00 "/usr/share/man", complain=complain@entry=0)
 |      at manpath.c:147
 |  147             dirs->paths[dirs->sz++] = mandoc_strdup(cp);
 |  (gdb) bt
 |  #0  0x000000000041cc02 in manpath_add (dirs=dirs@entry=0x7f7ffffe1cd0, dir=0x7f7ffffe1c00 "/usr/share/man", complain=complain@entry=0)
 |      at manpath.c:147
 |  #1  0x000000000041cc45 in manpath_parseline (dirs=dirs@entry=0x7f7ffffe1cd0, path=path@entry=0x7f7ffffe1c00 "/usr/share/man",
 |      complain=complain@entry=0) at manpath.c:113
 |  #2  0x000000000041d33f in manconf_file (conf=conf@entry=0x7f7ffffe1c90, file=file@entry=0x4448c5 "/etc/man.conf") at manpath.c:228
 |  #3  0x000000000041d470 in manconf_parse (conf=conf@entry=0x7f7ffffe1c90, file=0x4448c5 "/etc/man.conf", file@entry=0x0,
 |      defp=<optimized out>, defp@entry=0x0, auxp=auxp@entry=0x0) at manpath.c:76
 |  #4  0x000000000041bea0 in mandocdb (argc=0, argc@entry=2, argv=<optimized out>, argv@entry=0x7f7ffffe1f80) at mandocdb.c:478
 |  #5  0x000000000043b8dd in main (argc=2, argv=0x7f7ffffe1f80) at main.c:157
 |  (gdb) l
 |  142             }
 |  143
 |  144             dirs->paths = mandoc_reallocarray(dirs->paths,
 |  145                 dirs->sz + 1, sizeof(char *));
 |  146
 |  147             dirs->paths[dirs->sz++] = mandoc_strdup(cp);
 |  148     }
 |  149
 |  150     void
 |  151     manconf_free(struct manconf *conf)
 |  (gdb) p dirs->paths
 |  $1 = (char **) 0xfffffffff210b4e8
 |  (gdb) p dirs->paths[0]
 |  Cannot access memory at address 0xfffffffff210b4e8
 |  (gdb) p dirs->sz
 |  $2 = 1
 |  (gdb) p dirs->paths[1]
 |  Cannot access memory at address 0xfffffffff210b4f0

It seems that mandoc_reallocarray() (if it calls reallocarray(3))
have not realloc-ated!

Giving a look at the compiler warnings seem to shed some light!:

 | mandoc_aux.c: In function 'mandoc_reallocarray':
 | mandoc_aux.c:83:8: warning: implicit declaration of function 'reallocarray' [-Wimplicit-function-declaration]
 |   ptr = reallocarray(ptr, num, size);
 |         ^~~~~~~~~~~~

Whoops!  This is why (IIRC) since NetBSD 8.0 programs that uses
reallocarray(3) needs to be compiled with -D_OPENBSD_SOURCE.

The attached patch seems to fix this problem and after running the
`test' target all tests are now passed.

Paul, can you please try it and let us know if it fixes the problem?


Thank you!

mandoc: Add -D_OPENBSD_SOURCE to CFLAGS on NetBSD

Uses both strtonum(3) and reallocarray(3).

Bump PKGREVISION

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/textproc/mandoc/Makefile,v
retrieving revision 1.8
diff -u -p -r1.8 Makefile
--- Makefile	22 Aug 2018 09:46:47 -0000	1.8
+++ Makefile	10 Oct 2018 23:14:51 -0000
@@ -1,7 +1,7 @@
 # $NetBSD: Makefile,v 1.8 2018/08/22 09:46:47 wiz Exp $
 
 DISTNAME=	mandoc-1.14.4
-PKGREVISION=	1
+PKGREVISION=	2
 CATEGORIES=	textproc devel
 MASTER_SITES=	http://mdocml.bsd.lv/snapshots/
 
@@ -18,6 +18,8 @@ SUBST_FILES.roff=	mandoc.1 mandoc.3
 SUBST_FILES.roff+=	eqn.7 man.7 mdoc.7 tbl.7
 SUBST_SED.roff=		-e 's,Xr roff,Xr mandoc-roff,g'
 
+CFLAGS.NetBSD+=	-D_OPENBSD_SOURCE
+
 # test needs perl
 USE_TOOLS+=	perl:build
 TEST_TARGET=	regress