[Bug target/44129] Building linux kernel with gcc-4.5.0 and CONFIG_CC_OPTIMIZE_FOR_SIZE segfaults

["bdubbs at linuxfromscratch dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #11 from bdubbs at linuxfromscratch dot org  2010-05-24 06:32 -------
Updated to gcc (GCC) 4.5.1 20100524 (prerelease) but still have the problem.

There is something about -Os that triggers the kernel panic in
arch/x86/kernel/tsc.c

I tried to disable all -O2 options after -Os and the kernel still fails.

gcc -Wp,-MD,arch/x86/kernel/.tsc.o.d  -nostdinc -isystem \
/usr/lib/gcc/x86_64-unknown-linux-gnu/4.5.1/include \
-I/sources/linux-2.6.33.4-gcc45/arch/x86/include -Iinclude  -include \
include/generated/autoconf.h -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes \
-Wno-trigraphs -fno-strict-aliasing -fno-common \
-Werror-implicit-function-declaration -Wno-format-security \
-fno-delete-null-pointer-checks -Os \
-fno-thread-jumps \
-fno-caller-saves \
-fno-crossjumping \
-fno-cse-follow-jumps  \
-fno-cse-skip-blocks \
-fno-delete-null-pointer-checks \
-fno-expensive-optimizations \
-fno-gcse  \
-fno-gcse-lm  \
-fno-inline-small-functions \
-fno-indirect-inlining \
-fno-ipa-sra \
-fno-optimize-sibling-calls \
-fno-peephole2 \
-fno-regmove \
-fno-rerun-cse-after-loop  \
-fno-sched-interblock  \
-fno-sched-spec \
-fno-schedule-insns  \
-fno-schedule-insns2 \
-fno-strict-overflow \
-fno-tree-switch-conversion \
-fno-tree-pre \
-fno-tree-vrp \
-fno-align-functions  \
-fno-align-jumps \
-fno-align-loops  \
-fno-align-labels \
-fno-reorder-blocks  \
-fno-strict-aliasing \
-fno-reorder-blocks \
-m64 -march=core2 -mno-red-zone \
-mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -DCONFIG_AS_CFI=1 \
-DCONFIG_AS_CFI_SIGNAL_FRAME=1 -pipe -Wno-sign-compare \
-fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow \
-Wframe-larger-than=2048 -fno-stack-protector -fno-omit-frame-pointer \
-fno-optimize-sibling-calls -Wdeclaration-after-statement -Wno-pointer-sign \
-fno-strict-overflow -fno-dwarf2-cfi-asm -fconserve-stack -fno-stack-protector
\
 -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(tsc)" \
 -D"KBUILD_MODNAME=KBUILD_STR(tsc)"  -c -o arch/x86/kernel/tsc.o \
 arch/x86/kernel/tsc.c

Changing -Os to -O2 does *not* fail, even with the -fno options in the single
column above removed.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44129