Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Fri, 24 Sep 2021 10:48:57 -0300
From: √Črico Nogueira <ericonr@...root.org>
To: <musl@...ts.openwall.com>, "Rich Felker" <dalias@...c.org>
Subject: Re: Musl compiled gawk coredumps. How to find out where?

On Fri Sep 24, 2021 at 10:02 AM -03, Ivo Palli wrote:
> That helped!
>
> (gdb) backtrace
> #0 __restore_sigs (set=set@...ry=0x7fff62ee5de0) at
> ./arch/x86_64/syscall_arch.h:40
> #1 0x00000000004cf1c4 in raise (sig=sig@...ry=6) at
> src/signal/raise.c:11
> #2 0x00000000004c96ea in abort () at src/exit/abort.c:11
> #3 0x0000000000452f16 in catchsig (sig=<optimized out>) at main.c:1231
> #4 catchsig (sig=<optimized out>) at main.c:1217
> #5 <signal handler called>
> #6 get_meta (p=p@...ry=0x7f4d35d74f50 "\260\232\243\001") at
> src/malloc/mallocng/meta.h:141
> #7 0x00000000004ca62c in __libc_free (p=0x7f4d35d74f50) at
> src/malloc/mallocng/free.c:105
> #8 0x0000000000459d57 in r_unref (tmp=tmp@...ry=0x7f4d35f5c778) at
> node.c:492
> #9 0x00000000004456e5 in unref (r=0x7f4d35f5c778) at awk.h:1898
> #10 purge_record () at field.c:360
> #11 0x0000000000445f36 in set_record (
> buf=0x7f4d34f34cfe
> "SIZE\t1KB\t192758\t112698119\nSIZE\t4KB\t462090\t1122421206\nSIZE\t16KB\t355596\t3138948391\nSIZE\t64KB\t413028\t13558910172\nSIZE\t256KB\t1014012\t165385758947\nSIZE\t1MB\t2546508\t1346405498466\nSIZE\t10MB\t480844\t1602796961"...,
> cnt=25, fw=0x0) at field.c:269
> #12 0x000000000044e765 in inrec (iop=<optimized out>,
> errcode=errcode@...ry=0x7fff62ee6cb0) at io.c:608
> #13 0x00000000004414f8 in h_interpret (code=<optimized out>) at
> interpret.h:1289
> #14 0x0000000000402631 in main (argc=<optimized out>, argv=<optimized
> out>) at main.c:516
>
> Little unsure where gawk stops and musl begins. I guess #6 is where it
> goes wrong. Any musl developer want to work with me to figure this out?

You are correct that #6 is where it starts, above that it's just the
SIGSEGV signal handler.

Do you think you can share your script and input? That would help anyone
trying to reproduce the bug if they can't find the issue in the code via
inspection.

>
> Ivo Palli
>
> ________________________________
> From: Rich Felker <dalias@...c.org>
> Sent: Friday, September 24, 2021 14:37
> To: Ivo Palli <Ivo.Palli@...esnet.nl>
> Cc: musl@...ts.openwall.com <musl@...ts.openwall.com>
> Subject: Re: [musl] Musl compiled gawk coredumps. How to find out where?
>
> On Fri, Sep 24, 2021 at 10:41:24AM +0000, Ivo Palli wrote:
> > Hi there,
> >
> > I compiled gawk-4.2.1 (with gmp-6.2.1 and mpfr-4.1.0) using musl-1.2.2.
> >
> > Using it with I script I wrote I get
> >
> > gawk: /.../.../build_total.awk:25: (FILENAME=big.report FNR=6) fatal error: internal error
> > ../go: line 36: 14488 Aborted                 (core dumped)
> >
> > Loading it into gdb doesn't give much information:
> >
> > # gdb -q ./gawk core.gawk.0.51bcaa32ed144d2498e3a70ff28af961.14488.1632479605000000
> > Reading symbols from ./gawk...done.
> > [New LWP 14488]
> > Core was generated by `gawk -i functions.awk -v TEMPLATE=...
> > Program terminated with signal SIGABRT, Aborted.
> > #0  0x00000000004cf169 in __restore_sigs ()
> > (gdb) backtrace
> > #0  0x00000000004cf169 in __restore_sigs ()
> > #1  0x00000000004cf1c4 in raise ()
> > #2  0x0000000000000000 in ?? ()
> > (gdb) frame 0
> > #0  0x00000000004cf169 in __restore_sigs ()
> > (gdb) print
> > The history is empty.
> > (gdb)
> >
> > I compiled gawk the same with regular gcc (version 8.3.1 20190507 (Red Hat 8.3.1-4)) into a dynamic binary with the same libraries, and that did complete my script without crashing.
> >
> > Can anybody inform me how to find out exactly where the crash occurs and how I can help fix this bug?
>
> Try with musl and gawk built with debug info. If you're running with
> musl provided by your distro, it probably has a debug symbols package
> you can install. If you're building musl yourself, add --enable-debug
> to configure command line or -g to CFLAGS manually.
>
> Rich

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.