6.12-stable review patch. If anyone has any objections, please let me know.
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commit 9d7a0577c9db35c4cc52db90bc415ea248446472 upstream.
From: Linus Torvalds torvalds@linux-foundation.org
I had left the warning around but as a non-fatal error to get my gcc-15 builds going, but fixed up some of the most annoying warning cases so that it wouldn't be *too* verbose.
Because I like the _concept_ of the warning, even if I detested the implementation to shut it up.
It turns out the implementation to shut it up is even more broken than I thought, and my "shut up most of the warnings" patch just caused fatal errors on gcc-14 instead.
I had tested with clang, but when I upgrade my development environment, I try to do it on all machines because I hate having different systems to maintain, and hadn't realized that gcc-14 now had issues.
The ACPI case is literally why I wanted to have a *type* that doesn't trigger the warning (see commit d5d45a7f2619: "gcc-15: make 'unterminated string initialization' just a warning"), instead of marking individual places as "__nonstring".
But gcc-14 doesn't like that __nonstring location that shut gcc-15 up, because it's on an array of char arrays, not on one single array:
drivers/acpi/tables.c:399:1: error: 'nonstring' attribute ignored on objects of type 'const char[][4]' [-Werror=attributes] 399 | static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst __nonstring = { | ^~~~~~
and my attempts to nest it properly with a type had failed, because of how gcc doesn't like marking the types as having attributes, only symbols.
There may be some trick to it, but I was already annoyed by the bad attribute design, now I'm just entirely fed up with it.
I wish gcc had a proper way to say "this type is a *byte* array, not a string".
The obvious thing would be to distinguish between "char []" and an explicitly signed "unsigned char []" (as opposed to an implicitly unsigned char, which is typically an architecture-specific default, but for the kernel is universal thanks to '-funsigned-char').
But any "we can typedef a 8-bit type to not become a string just because it's an array" model would be fine.
But "__attribute__((nonstring))" is sadly not that sane model.
Reported-by: Chris Clayton chris2553@googlemail.com Fixes: 4b4bd8c50f48 ("gcc-15: acpi: sprinkle random '__nonstring' crumbles around") Fixes: d5d45a7f2619 ("gcc-15: make 'unterminated string initialization' just a warning") Signed-off-by: Linus Torvalds torvalds@linux-foundation.org [nathan: drivers/acpi diff dropped due to lack of 4b4bd8c50f48 in stable] Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/Makefile +++ b/Makefile @@ -1001,8 +1001,8 @@ KBUILD_CFLAGS += $(call cc-option, -fstr KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow) KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
-#Currently, disable -Wunterminated-string-initialization as an error -KBUILD_CFLAGS += $(call cc-option, -Wno-error=unterminated-string-initialization) +#Currently, disable -Wunterminated-string-initialization as broken +KBUILD_CFLAGS += $(call cc-option, -Wno-unterminated-string-initialization)
# disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += -fno-strict-overflow