Extending the AT for upcoming kernel makes certain software segfault

[op]

We ran into a segfault when testing the UEK next 6.10 kernel and wanted to share this with you.

You can reproduce this by running this:

docker run clickhouse/clickhouse-server:latest
[..]
AT_* is out of range: 71 (maximum allowed is 64)
Aborted                 (core dumped)

The introduction of va reservation:

#define AT_VA_RESERVATION	71	/* VA reservation support */

Makes software like Clickhouse segfault which has code like this:

// We don't have libc struct available here.
// Compute aux vector manually (from /proc/self/auxv).
//
// Right now there is only 51 AT_* constants,
// so 64 should be enough until this implementation will be replaced with musl.
static unsigned long __auxv_procfs[64];

https://github.com/ClickHouse/ClickHouse/blob/master/base/glibc-compatibility/musl/getauxval.c#L30

[darrenkenny]

@op, thanks for your report, we will take a look into this.