Re: [musl] Segmentation fault musl 1.2.4

[Szabolcs Nagy <nsz@port70.net>]

* Cody Wetzel <codyawetzel@gmail.com> [2024-01-12 17:10:24 -0600]:
> I did actually find that stackoverflow post and tried spinning up a new
> container but the results don't provide any useful information...
> 
> / # /tmp/ld-musl-armhf.so.1 /usr/bin/gdb --args ls -l /tmp
> > GNU gdb (GDB) 12.1
> > Copyright (C) 2022 Free Software Foundation, Inc.
> > License GPLv3+: GNU GPL version 3 or later <
> > http://gnu.org/licenses/gpl.html>
> > This is free software: you are free to change and redistribute it.
> > There is NO WARRANTY, to the extent permitted by law.
> > Type "show copying" and "show warranty" for details.
> > This GDB was configured as "armv7-alpine-linux-musleabihf".
> > Type "show configuration" for configuration details.
> > For bug reporting instructions, please see:
> > <https://www.gnu.org/software/gdb/bugs/>.
> > Find the GDB manual and other documentation resources online at:
> >     <http://www.gnu.org/software/gdb/documentation/>.
> >
> > For help, type "help".
> > Type "apropos word" to search for commands related to "word"...
> > Reading symbols from ls...
> > (No debugging symbols found in ls)
> > (gdb) run
> > Starting program: /bin/ls -l /tmp
> > During startup program terminated with signal SIGSEGV, Segmentation fault.
> >

so i looked at alpine armv7 binaries and they seem to be built with
4k page size.

since the elf files are not possible to map with 32k pages, it is
expected that they crash on exec in the kernel and thus you get no
backtrace.

i'm not sure why gdb works, unless it's an old gdb binary that's built
with large pagesize support.

an easy way to verify is to compare proram headers of old and new
binaries like

readelf -lW /tmp/ld-musl-armhf.so.1