Bug#1056357: general: Command line of any program invocation is limited to less than 3544 bytes

[Bruno Haible <bruno@clisp.org>]

Package: general
Severity: important
X-Debbugs-Cc: bruno@clisp.org

I'm using Debian GNU/Linux on hppa, in a virtual machine emulated by QEMU
8.0.2.
$ uname -srm
Linux 6.3.0-2-parisc parisc

In this machine, for the invocation of any program, the length of the command
line (= all arguments together) is limited to less than 3544 bytes.

How to reproduce:

In bash:
$ /bin/echo `seq 913`
-bash: /bin/echo: Argument list too long

In dash:
$ /bin/echo `seq 913`
dash: 1: /bin/echo: Argument list too long

I also see this while doing "make check" of packages that have more than 1000
tests. So, it appears to be a general problem.

The values returned by getconf don't match the reality:
$ getconf ARG_MAX
2097152
$ getconf _POSIX_ARG_MAX
2097152

I have looked at the values of several files in /sys/kernel and
/proc/sys/kernel, without finding the cause.

For comparison, in a different VM, running "Linux 6.3.7-t2 parisc" (from the
T2-SDE distribution), I don't observe this bug. Both machines have the same
amount of "physical" RAM: 256 MiB.

The ulimit values don't appear to be the cause, because they are similar in
the two machines:
In the Debian VM (with the bug):
$ ulimit -a
real-time non-blocking time  (microseconds, -R) unlimited
core file size              (blocks, -c) 0
data seg size               (kbytes, -d) unlimited
scheduling priority                 (-e) 0
file size                   (blocks, -f) unlimited
pending signals                     (-i) 849
max locked memory           (kbytes, -l) 65536
max memory size             (kbytes, -m) unlimited
open files                          (-n) 1024
pipe size                (512 bytes, -p) 8
POSIX message queues         (bytes, -q) 819200
real-time priority                  (-r) 0
stack size                  (kbytes, -s) 8192
cpu time                   (seconds, -t) unlimited
max user processes                  (-u) 849
virtual memory              (kbytes, -v) unlimited
file locks                          (-x) unlimited
In the T2-SDE machine, with no bug:
$ ulimit -a
real-time non-blocking time  (microseconds, -R) unlimited
core file size              (blocks, -c) 1048575
data seg size               (kbytes, -d) unlimited
scheduling priority                 (-e) 0
file size                   (blocks, -f) unlimited
pending signals                     (-i) 909
max locked memory           (kbytes, -l) 8192
max memory size             (kbytes, -m) unlimited
open files                          (-n) 1024
pipe size                (512 bytes, -p) 8
POSIX message queues         (bytes, -q) 819200
real-time priority                  (-r) 0
stack size                  (kbytes, -s) 8192
cpu time                   (seconds, -t) unlimited
max user processes                  (-u) 909
virtual memory              (kbytes, -v) unlimited
file locks                          (-x) unlimited