On 05/11/2025 14.03, Daniel Gomez wrote:
> On 10/10/2025 05.06, Kees Cook wrote:
>> v2:
>> - use static_assert instead of _Static_assert
>> - add Hans's Reviewed-by's
>> v1: https://lore.kernel.org/lkml/[email protected]/
>>
>> Hi!
>>
>> A long time ago we had an issue with embedded NUL bytes in MODULE_INFO
>> strings[1]. While this stands out pretty strongly when you look at the
>> code, and we can't do anything about a binary module that just plain lies,
>> we never actually implemented the trivial compile-time check needed to
>> detect it.
>>
>> Add this check (and fix 2 instances of needless trailing semicolons that
>> this change exposed).
>>
>> Note that these patches were produced as part of another LLM exercise.
>> This time I wanted to try "what happens if I ask an LLM to go read
>> a specific LWN article and write a patch based on a discussion?" It
>> pretty effortlessly chose and implemented a suggested solution, tested
>> the change, and fixed new build warnings in the process.
>>
>> Since this was a relatively short session, here's an overview of the
>> prompts involved as I guided it through a clean change and tried to see
>> how it would reason about static_assert vs _Static_assert. (It wanted
>> to use what was most common, not what was the current style -- we may
>> want to update the comment above the static_assert macro to suggest
>> using _Static_assert directly these days...)
>>
>> I want to fix a weakness in the module info strings. Read about it
>> here: https://lwn.net/Articles/82305/
>>
>> Since it's only "info" that we need to check, can you reduce the checks
>> to just that instead of all the other stuff?
>>
>> I think the change to the comment is redundent, and that should be
>> in a commit log instead. Let's just keep the change to the static assert.
>>
>> Is "static_assert" the idiomatic way to use a static assert in this
>> code base? I've seen _Static_assert used sometimes.
>>
>> What's the difference between the two?
>>
>> Does Linux use C11 by default now?
>>
>> Then let's not use the wrapper any more.
>>
>> Do an "allmodconfig all -s" build to verify this works for all modules
>> in the kernel.
>>
>>
>> Thanks!
>>
>> -Kees
>>
>> [1] https://lwn.net/Articles/82305/
>>
>> Kees Cook (3):
>> media: dvb-usb-v2: lmedm04: Fix firmware macro definitions
>> media: radio: si470x: Fix DRIVER_AUTHOR macro definition
>> module: Add compile-time check for embedded NUL characters
>>
>> include/linux/moduleparam.h | 3 +++
>> drivers/media/radio/si470x/radio-si470x-i2c.c | 2 +-
>> drivers/media/usb/dvb-usb-v2/lmedm04.c | 12 ++++++------
>> 3 files changed, 10 insertions(+), 7 deletions(-)
>>
>
> Reviewed-by: Daniel Gomez <[email protected]>
>
> I have also tested a build of v6.18-rc3 + patches using allmodconfig:
>
> Tested-by: Daniel Gomez <[email protected]>
>
I forgot to mention it required the following patch for the build to succeed:
dmaengine: mmp_pdma: fix DMA mask handling
https://lore.kernel.org/all/[email protected]/
