Re: [PATCH v2 1/3] Doc: deprecated.rst: add strlcat()

[Randy Dunlap <rdunlap@infradead.org>]

On 5/14/26 9:31 AM, Kees Cook wrote:
> On Thu, May 14, 2026 at 06:26:53PM +0200, Manuel Ebner wrote:
>> add strlcat and alternatives
>>
>> Signed-off-by: Manuel Ebner <manuelebner@mailbox.org>
>> ---
>>  Documentation/process/deprecated.rst | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
>> index fed56864d036..06e802f4bbfd 100644
>> --- a/Documentation/process/deprecated.rst
>> +++ b/Documentation/process/deprecated.rst
>> @@ -153,6 +153,13 @@ used, and the destinations should be marked with the `__nonstring
>>  attribute to avoid future compiler warnings. For cases still needing
>>  NUL-padding, strtomem_pad() can be used.
>>  
>> +strlcat()
>> +---------
>> +strlcat() must re-scan the destination string from the beginning on each
>> +call (O(n^2) behavior). Alternatives are seq_buf_puts() and seq_buf_printf().
>> +snprintf(), scnprintf() and sysfs_emit() are possible aswell, but the adoption
>> +of the arguments needs to be taken care off.
>> +
> 
> How about just:
> 
> strlcat() must re-scan the destination string from the beginning on each
> call (O(n^2) behavior). Use the seq_buf API or similar instead.
> 

Yeah, that avoids the "aswell" (should be "as well").

> 
>>  strlcpy()
>>  ---------
>>  strlcpy() reads the entire source buffer first (since the return value
>> -- 
>> 2.54.0
>>
> 

-- 
~Randy