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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-05-09 23:52:44 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-05-09 23:52:44 +0200 |
commit | 44720996e2d79e47d508b0abe99b931a726a3197 (patch) | |
tree | 731517d0e160daa835abc1735d0e9fc31cd2b1fe /Makefile | |
parent | gcc-10: disable 'zero-length-bounds' warning for now (diff) | |
download | linux-44720996e2d79e47d508b0abe99b931a726a3197.tar.xz linux-44720996e2d79e47d508b0abe99b931a726a3197.zip |
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>
Diffstat (limited to 'Makefile')
-rw-r--r-- | Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
@@ -879,6 +879,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) +KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) # Enabled with W=2, disabled by default as noisy KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized) |