Re: new snapshot available: grep-3.4-almost.26-5419

[Paul Eggert <eggert@cs.ucla.edu>]

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In <https://lists.gnu.org/r/grep-devel/2020-09/msg00052.html> on 9/18/20 2:00 
PM, Bruce Dubbs wrote:
> ... if I run ./configure --prefix=/usr --bindir=/bin grep wants to link with 
> /usr/lib/libsigsegv.so /usr/lib/libc.a instead of just -lsigsegv
> In this later case, grep segfaults early.
> 
> If I remove /usr/lib/libc.a, everything is fine.  I do not know why configure 
> wants to use a static libc if the destination libraries are specified.
> 
> Is this possibly a gnulib issue?

Yes, most likely it's induced by grep's use of Gnulib's libsigsegv module. I'll 
cc. this email to the Gnulib mailing list.

To help narrow this down, let's try to reproduce the problem in Gnulib, without 
having grep be involved. I created the attached tarball from Gnulib master with 
the commands:

./gnulib-tool --create-testdir --dir c-stack-test c-stack
tar czf c-stack-test.tgz c-stack-test

Please run the following commands on your end and see whether they cause a 
similar failure:

tar xf c-stack-test.tgz
cd c-stack-test
./configure --prefix=/usr --bindir=/bin
make check

I ran that on my Ubuntu 18.04.5 x86-64 platform and got output that contained this:

...
checking for working C stack overflow detection... yes
checking for correct stack_t interpretation... yes
checking for precise C stack overflow detection... no
checking for ld used by gcc... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for shared library run path origin... done
checking 32-bit host C ABI... no
checking for ELF binary format... yes
checking for the common suffixes of directories in the library search path... 
lib,lib,lib
checking for libsigsegv... yes
checking how to link with libsigsegv... -lsigsegv
...

and all 93 tests succeeded.  Here are a few more things I tried and where I got 
the expected results; please compare them to your platform too.

$ ldd gltests/test-c-stack
	linux-vdso.so.1 (0x00007ffcf55e9000)
	libsigsegv.so.2 => /usr/lib/x86_64-linux-gnu/libsigsegv.so.2 (0x00007f28136f9000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f2813308000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f2813b04000)
$ gltests/test-c-stack
test-c-stack: stack overflow
$ gltests/test-c-stack 1
test-c-stack: program error
Aborted (core dumped)

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