Re: [PATCH bpf-next 9/9] selftests/bpf: Test uprobes and fork() with busy mmap_lock

[Alexei Starovoitov]

On Wed, Oct 21, 2026 at 07:10 PM sashiko-...@kernel.org 
<sashiko-...@kernel.org> wrote:
>> +#define AREA_MAX    (64UL << 30)
>
> [ ... ]
>
>> +    area = mmap(NULL, AREA_MAX, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | 
>> MAP_NORESERVE, -1, 0);
>> +    if (area == MAP_FAILED)
>> +            goto err;
>
> [Severity: Medium]
> In tools/testing/selftests/bpf/prog_tests/uprobe_busy_mm.c, does AREA_MAX
> overflow on 32-bit architectures when passed to mmap() in hold_mmap_lock()?
>
> Should AREA_MAX be sized appropriately for 32-bit architectures as well?

No. uprobe_multi link is 64-bit only.
bpf_uprobe_multi_link_attach() returns -EOPNOTSUPP on 32-bit and
three of four subtests attach with it.