From ac23f9da757e8e47a6bdcfd619c54e9b4c2b906c Mon Sep 17 00:00:00 2001 From: Paul Menzel Date: Sun, 2 Oct 2022 20:17:04 +0200 Subject: [PATCH] Makefile.inc: Decrease minimal pagesize from 4 kB to 1 kB MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GCC 12 incorrectly warns about an array out of bounds issue: ``` $ make V=1 # emulation/qemu-i440fx […] CC ramstage/arch/x86/ebda.o x86_64-linux-gnu-gcc-12 -MMD -Isrc -Isrc/include -Isrc/commonlib/include -Isrc/commonlib/bsd/include -Ibuild -I3rdparty/vboot/firmware/include -include src/include/kconfig.h -include src/include/rules.h -include src/commonlib/bsd/include/commonlib/bsd/compiler.h -I3rdparty -D__BUILD_DIR__=\"build\" -Isrc/arch/x86/include -D__ARCH_x86_32__ -pipe -g -nostdinc -std=gnu11 -nostdlib -Wall -Wundef -Wstrict-prototypes -Wmissing-prototypes -Wwrite-strings -Wredundant-decls -Wno-trigraphs -Wimplicit-fallthrough -Wshadow -Wdate-time -Wtype-limits -Wvla -Wdangling-else -fno-common -ffreestanding -fno-builtin -fomit-frame-pointer -fstrict-aliasing -ffunction-sections -fdata-sections -fno-pie -Wno-packed-not-aligned -fconserve-stack -Wnull-dereference -Wreturn-type -Wlogical-op -Wduplicated-cond -Wno-unused-but-set-variable -Werror -Os -Wno-address-of-packed-member -m32 -Wl,-b,elf32-i386 -Wl,-melf_i386 -m32 -fuse-ld=bfd -fno-stack-protector -Wl,--build-id=none -fno-delete-null-pointer-checks -Wlogical-op -march=i686 -mno-mmx -MT build/ramstage/arch/x86/ebda.o -D__RAMSTAGE__ -c -o build/ramstage/arch/x86/ebda.o src/arch/x86/ebda.c In file included from src/arch/x86/ebda.c:6: In function 'write_ble8', inlined from 'write_le8' at src/commonlib/include/commonlib/endian.h:155:2, inlined from 'write_le16' at src/commonlib/include/commonlib/endian.h:178:2, inlined from 'setup_ebda' at src/arch/x86/ebda.c:35:2, inlined from 'setup_default_ebda' at src/arch/x86/ebda.c:48:2: src/commonlib/include/commonlib/endian.h:27:26: error: array subscript 0 is outside array bounds of 'void[0]' [-Werror=array-bounds] 27 | *(uint8_t *)dest = val; | ~~~~~~~~~~~~~~~~~^~~~~ […] ``` [In GCC 12 the new parameter `min-pagesize` is added and defaults 4 kB.][1] It treats INTEGER_CST addresses smaller than that as assumed results of pointer arithmetics from NULL while addresses equal or larger than that as expected user constant addresses. For GCC 13 we can represent results from pointer arithmetics on NULL using &MEM[(void*)0 + offset] instead of (void*)offset INTEGER_CSTs. [1]: https://web.archive.org/web/20220711061810/https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578 TEST=No compile error with gcc (Debian 12.2.0-3) 12.2.0 Change-Id: I6e36633f42cb4dc5af53212c10c919a86e451ee0 Signed-off-by: Paul Menzel Reviewed-on: https://review.coreboot.org/c/coreboot/+/62830 Tested-by: build bot (Jenkins) Reviewed-by: Angel Pons --- util/xcompile/xcompile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/util/xcompile/xcompile b/util/xcompile/xcompile index e6d312327b..7fba665121 100755 --- a/util/xcompile/xcompile +++ b/util/xcompile/xcompile @@ -192,6 +192,8 @@ detect_special_flags() { testcc "$GCC" "$CFLAGS_GCC -Wno-address-of-packed-member $FLAGS_GCC" && CFLAGS_GCC="$CFLAGS_GCC -Wno-address-of-packed-member" + testcc "$GCC" "$CFLAGS_GCC --param=min-pagesize=1024 $FLAGS_GCC" && + CFLAGS_GCC="$CFLAGS_GCC --param=min-pagesize=1024" case "$architecture" in x86) ;;