Re: [PATCH] crash_dump: Remove redundant less-than-zero check

Andrew Morton
2026-02-28T19:02:58Z

On Sat, 28 Feb 2026 09:51:36 +0100 Thorsten Blum <thorsten.blum@linux.dev> wrote:

> 'key_count' is an 'unsigned int' and cannot be less than zero. Remove
> the redundant condition.
>

umm. OK.

> --- a/kernel/crash_dump_dm_crypt.c
> +++ b/kernel/crash_dump_dm_crypt.c
> @@ -115,7 +115,7 @@ static int restore_dm_crypt_keys_to_thread_keyring(void)
>
> addr = dm_crypt_keys_addr;
> dm_crypt_keys_read((char *)&key_count, sizeof(key_count), &addr);
> - if (key_count < 0 || key_count > KEY_NUM_MAX) {
> + if (key_count > KEY_NUM_MAX) {
> kexec_dprintk("Failed to read the number of dm-crypt keys\n");
> return -1;
> }

iirc Linus has said "this is OK". The compiler will eliminate it and
the code still works if the type is later changed to signed.