LWN: Comments on "Stable kernel 5.10.1 released"

Stable kernel 5.10.1 released

dskoll — Tue, 22 Dec 2020 23:42:20 +0000

I use bash; I don't think anything changed with the shell. I think something changed in Firefox 84; either it's printing to stderr where it never did before, or it now cares about errors from write() that it never used to care about. Anyway, the problem is all fixed by the redirection to /dev/null.

Stable kernel 5.10.1 released

mathstuf — Tue, 22 Dec 2020 17:01:00 +0000

Usually I need to do `detach` before exiting a shell with a backgrounded job. zsh, at least, warns about this and asks to confirm the exit (nb. this may be a setting I've toggled). Maybe something changed in the shell you're using?

Stable kernel 5.10.1 released

dskoll — Tue, 22 Dec 2020 04:38:07 +0000

No, I started Firefox from a shell, in the background, and then closed the terminal.

Here's a little test program; if you run ./test > /tmp/foo & exit in a terminal, then /tmp/foo ends up containing r = -1; errno = 5 where 5 is EIO.

#include <unistd.h>
#include <stdio.h>
#include <errno.h>

int
main(int argc, char **argv)
{
    int r;
    sleep(5);

    r = write(2, "Hello!\n", 7);
    printf("r = %d; errno = %d\n", r, errno);
}

Stable kernel 5.10.1 released

zlynx — Mon, 21 Dec 2020 23:38:08 +0000

I just did a quick look at EIO from the write system call and I'm worried for your system. It seems to indicate that you were writing to a disk file and the disk had an error. Or you were writing to a file on a network filesystem and had some kind of unrecoverable error.

I mean, are you writing stderr to $HOME/.xsession-errors on a USB thumb drive or something?

Stable kernel 5.10.1 released

dskoll — Mon, 21 Dec 2020 22:40:19 +0000

It wasn't the kernel; it crashed on 5.9.14 also. Firefox was getting -EIO when writing to stderr, so I just modified the startup to redirect stdin, stdout and stderr to /dev/null.

Stable kernel 5.10.1 released

dskoll — Mon, 21 Dec 2020 15:23:02 +0000

I know this comment will receive the "Most Useless Bug Report" award, but...

Firefox 84.0 runs fine on 5.9.14, but reliably crashes on 5.10.1. Unfortunately, the crash happens only after a fairly long while, so usually overnight while I'm asleep. For now, I've reverted to 5.9.14, but I'll try to get it to happen again and get Firefox to send an automated bug report back to Mozilla.