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H A D | Makefile | 44720996e2d79e47d508b0abe99b931a726a3197 Sat May 09 16:52:44 CDT 2020 Linus Torvalds <torvalds@linux-foundation.org> gcc-10: disable 'array-bounds' warning for now
This is another fine warning, related to the 'zero-length-bounds' one, but hitting the same historical code in the kernel.
Because C didn't historically support flexible array members, we have code that instead uses a one-sized array, the same way we have cases of zero-sized arrays.
The one-sized arrays come from either not wanting to use the gcc zero-sized array extension, or from a slight convenience-feature, where particularly for strings, the size of the structure now includes the allocation for the final NUL character.
So with a "char name[1];" at the end of a structure, you can do things like
v = my_malloc(sizeof(struct vendor) + strlen(name));
and avoid the "+1" for the terminator.
Yes, the modern way to do that is with a flexible array, and using 'offsetof()' instead of 'sizeof()', and adding the "+1" by hand. That also technically gets the size "more correct" in that it avoids any alignment (and thus padding) issues, but this is another long-term cleanup thing that will not happen for 5.7.
So disable the warning for now, even though it's potentially quite useful. Having a slew of warnings that then hide more urgent new issues is not an improvement.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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