On 06. 01. 2023. 11:39, Alexey Dobriyan wrote:

On Wed, Jan 04, 2023 at 07:27:40PM +0100, Mirsad Goran Todorovac wrote:

...

Dear all,

Trying to complete `make kselftest` for the first time, so maybe I'm doing something wrong?

Or we are having a regression in 6.2-rc2 release candidate ...

However, the output of selftest run is:

make[2]: Entering directory '.../linux_torvalds/tools/testing/selftests/proc' TAP version 13 1..21 # selftests: proc: fd-001-lookup ok 1 selftests: proc: fd-001-lookup # selftests: proc: fd-002-posix-eq ok 2 selftests: proc: fd-002-posix-eq # selftests: proc: fd-003-kthread ok 3 selftests: proc: fd-003-kthread # selftests: proc: proc-loadavg-001 ok 4 selftests: proc: proc-loadavg-001 # selftests: proc: proc-empty-vm # proc-empty-vm: proc-empty-vm.c:184: test_proc_pid_maps: Assertion `rv == 0' failed. # /usr/bin/timeout: the monitored command dumped core # Aborted not ok 5 selftests: proc: proc-empty-vm # exit=134 # selftests: proc: proc-pid-vm # proc-pid-vm: proc-pid-vm.c:365: main: Assertion `rv == len' failed. # /usr/bin/timeout: the monitored command dumped core # Aborted

Please find attached lshw output, dmesg, config and lsmod.

I am available for further diagnostics.

The platform is Ubuntu 22.10 kinetic kudu on a Lenovo Ideapad 3 15ITL6 laptop.

The "bug" is that "call rel32" instruction testing for executable vsyscall page which should be relocated to "call 0xffffffffff600000" is messed up. Ubuntu 22.10 ships with "vsyscall=xonly" so there should not be any faults when executing from it. But segfault happens with normal randomised userspace address.

I'll change it to "call *rax" which should be more robust (and works) and free from relocations.

If you will need to test the patch in the same environment where the problem initially occurred, I am ready at your disposal.

Thanks, Mirsad

-- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu