From 046814c2703b8fd0030ad026bf42e153bbe41db4 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 Original-Signed-off-by: Paul Menzel Original-Reviewed-on: https://review.coreboot.org/c/coreboot/+/62830 Original-Tested-by: build bot (Jenkins) Original-Reviewed-by: Angel Pons Reviewed-on: https://review.coreboot.org/c/coreboot/+/81785 Tested-by: Felix Singer Reviewed-by: Felix Singer Reviewed-by: Angel Pons --- util/xcompile/xcompile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/util/xcompile/xcompile b/util/xcompile/xcompile index 2d3da1e00e..13273240c5 100755 --- a/util/xcompile/xcompile +++ b/util/xcompile/xcompile @@ -184,7 +184,8 @@ detect_special_flags() { CFLAGS_GCC="$CFLAGS_GCC -fno-stack-protector" testcc "$GCC" "$CFLAGS_GCC -Wl,--build-id=none" && CFLAGS_GCC="$CFLAGS_GCC -Wl,--build-id=none" - + testcc "$GCC" "$CFLAGS_GCC --param=min-pagesize=1024 $FLAGS_GCC" && + CFLAGS_GCC="$CFLAGS_GCC --param=min-pagesize=1024" case "$architecture" in x86) ;;