Radjin

If you're going to try models from cpdn, you need to be aware that they are 32 bit, and sometimes needed libraries aren't installed by default.
This is the usual culprit:
libstdc++.so.6

If it's not there, the models will crash at about 6 seconds.

What does

cat /usr/src/linux-headers-$(uname -r)/.config | grep VSYSCALL

tell me? I have seen this suggested in a number of posts where they received a reply of

cat /usr/src/linux-headers-$(uname -r)/.config | grep VSYSCALL 
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_X86_VSYSCALL_EMULATION=y
CONFIG_LEGACY_VSYSCALL_EMULATE=y
# CONFIG_LEGACY_VSYSCALL_NONE is not set

If you installed the kernel headers for your currently running kernel - $(uname -r) is the version string - this shows you how the kernel is configured regarding VSYSCALL. This is purely informational. In this example the vsyscall emulation is built in and enabled by default (VSYSCALL_EMULATE=y). For your kernel, it is built in and disabled by default (VSYSCALL_NONE=y). I suspect that's what the Seti application can't cope with, so you override it with the vsyscall=emulate boot parameter and then it's time for a test to see if we're on the right path.

cat /usr/src/linux-headers-$(uname -r)/.config | grep

cat: /usr/src/linux-headers-4.19.0-6-amd64/.config: No such file or directory

GRUB_CMDLINE_LINUX_DEFAULT="vsyscall=emulate"

sudo update-grub

Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.19.0-6-amd64
Found initrd image: /boot/initrd.img-4.19.0-6-amd64
Found linux image: /boot/vmlinuz-4.19.0-5-amd64
Found initrd image: /boot/initrd.img-4.19.0-5-amd64
Found memtest86+ image: /boot/memtest86+.bin
Found memtest86+ multiboot image: /boot/memtest86+_multiboot.bin
done

sudo reboot

OTHER SETTINGS
Run Linux app versions built with LIBC 2.15:
YESNO
This ensures compatibility with new Linux systems that have virtual syscalls disabled, but breaks compatibility with older systems with (G)LIBC prior to 2.15

I added to grub: GRUB_CMDLINE_LINUX_DEFAULT="VSYSCALL=EMULATE"

Better make that "vsyscall=emulate". I wouldn't be surprised to see that the upper case version doesn't work.

Replaced with lower case.

The grub update seemed to go ok.

So it seems. Of course you rebooted after that?

Yes

For some reason I don’t get the confirmation of the emulation mode.

I'm not aware of a way to query the current mode. You could look at /proc/cmdline. And of course the best confirmation would be if your application didn't segfault any longer.

What does

cat /usr/src/linux-headers-$(uname -r)/.config | grep VSYSCALL

tell me? I have seen this suggested in a number of posts where they received a reply of

cat /usr/src/linux-headers-$(uname -r)/.config | grep VSYSCALL 
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_X86_VSYSCALL_EMULATION=y
CONFIG_LEGACY_VSYSCALL_EMULATE=y
# CONFIG_LEGACY_VSYSCALL_NONE is not set

Be aware that vsyscall is just a run time parameter, it overrides the kernel default but doesn't change it permanently.

With CPDN, it stopped I think after a newer version of the particular model type so not a lot you can do at the user end. I can't comment on the Seti@home because I have never seen it with them.

What I am asking is since this is a known issue, how does one diagnose the cause of the error, memory, OS, BOINC? How did others resolve the issue? I can find dozens of references to the issue, all with a BOINC project, but only two resolutions, where vsyscall was put into emulate mode.

So you have identified a possible (and IMO very likely) cause, and you know a workaround. But you don't mention that you have tried it, or an outcome. What about that?

sudo update-grub

Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.19.0-6-amd64
Found initrd image: /boot/initrd.img-4.19.0-6-amd64
Found linux image: /boot/vmlinuz-4.19.0-5-amd64
Found initrd image: /boot/initrd.img-4.19.0-5-amd64
Found memtest86+ image: /boot/memtest86+.bin
Found memtest86+ multiboot image: /boot/memtest86+_multiboot.bin
done

cat /usr/src/linux-headers-$(uname -r)/.config | grep 

cat: /usr/src/linux-headers-4.19.0-6-amd64/.config: No such file or directory