Extending the AT for upcoming kernel makes certain software segfault

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

Start by reproducing the failure with docker run clickhouse/clickhouse-server:latest on the UEK next 6.10 kernel. Read the AT_VA_RESERVATION definition in the linked kernel commit and ClickHouse's base/glibc-compatibility/musl/getauxval.c, especially its fixed 64-entry auxiliary-vector array. Done means the reported ClickHouse startup segfault is resolved when AT_VA_RESERVATION is present.