Re: linux-next: WARNING: at kernel/panic.c:375 __stack_chk_test+0x50/0x54()

From: Kevin Winchester
Date: Tue May 06 2008 - 19:36:26 EST


Arjan van de Ven wrote:
Kevin Winchester wrote:
David Miller wrote:
From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Date: Tue, 06 May 2008 12:49:33 -0700

this is weird; something is adding ANOTHER -fstack-protector to the (effective) gcc
flags.. which might be overriding the -fstack-protector-all setting.

I wonder if this is a distro special ;(
Ubuntu adds -fstack-protector to the GCC command line.

But I've been able to override it trivially when, for example, doing
GCC builds, by simply adding -fno-stack-protector.
I assume adding -fno-stack-protector would not really be an option in this case (since if I understand correctly it would be appended to the end of the flags which would turn the option off).

I guess I'll be figuring out how to build my own gcc...

one question (since I don't have an ubuntu system on my desk right now)

if you do

make V=1 kernel/panic.o

(after deleting that file if needed), can you check that -fstack-protector-all is the last
stack protector option we explicitly give to gcc ?
(anything else is distro special which we unfortunately cannot fix.. but maybe we can detect)



kevin@alekhine:~/linux/linux-2.6$ make V=1 kernel/panic.o
rm -f include/config/kernel.release
echo 2.6.25-next-20080430 > include/config/kernel.release
set -e; :; mkdir -p include/linux/; (echo \#define LINUX_VERSION_CODE 132633; echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';) < /home/kevin/linux/linux-2.6/Makefile > include/linux/version.h.tmp; if [ -r include/linux/version.h ] && cmp -s include/linux/version.h include/linux/version.h.tmp; then rm -f include/linux/version.h.tmp; else :; mv -f include/linux/version.h.tmp include/linux/version.h; fi
set -e; :; mkdir -p include/linux/; if [ `echo -n "2.6.25-next-20080430" | wc -c ` -gt 64 ]; then echo '"2.6.25-next-20080430" exceeds 64 characters' >&2; exit 1; fi; (echo \#define UTS_RELEASE \"2.6.25-next-20080430\";) < include/config/kernel.release > include/linux/utsrelease.h.tmp; if [ -r include/linux/utsrelease.h ] && cmp -s include/linux/utsrelease.h include/linux/utsrelease.h.tmp; then rm -f include/linux/utsrelease.h.tmp; else :; mv -f include/linux/utsrelease.h.tmp include/linux/utsrelease.h; fi
set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`; \
if [ -L include/asm ]; then \
if [ "$asmlink" != "x86" ]; then \
echo "ERROR: the symlink include/asm points to asm-$asmlink but asm-x86 was expected"; \
echo " set ARCH or save .config and run 'make mrproper' to fix it"; \
exit 1; \
fi; \
else \
echo ' SYMLINK include/asm -> include/asm-x86'; \
if [ ! -d include ]; then \
mkdir -p include; \
fi; \
ln -fsn asm-x86 include/asm; \
fi
mkdir -p .tmp_versions
make -f scripts/Makefile.build obj=scripts/basic
make -f scripts/Makefile.build obj=.
mkdir -p kernel/
mkdir -p arch/x86/kernel/
make -f scripts/Makefile.build obj=. missing-syscalls
/bin/bash scripts/checksyscalls.sh gcc -Wp,-MD,./.missing-syscalls.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/4.2.3/include -D__KERNEL__ -Iinclude -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Os -fno-stack-protector -m64 -march=k8 -mno-red-zone -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -fstack-protector -DGCC_HAS_SP -fstack-protector-all -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Iinclude/asm-x86/mach-default -fno-omit-frame-pointer -fno-optimize-sibling-calls -g -pg -Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(missing_syscalls)" -D"KBUILD_MODNAME=KBUILD_STR(missing_syscalls)"
make -f scripts/Makefile.build obj=scripts
make -f scripts/Makefile.build obj=scripts/mod
make -f scripts/Makefile.build obj=kernel kernel/panic.o
gcc -Wp,-MD,kernel/.panic.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/4.2.3/include -D__KERNEL__ -Iinclude -include include/linux/autoconf.h -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Os -fno-stack-protector -m64 -march=k8 -mno-red-zone -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -fstack-protector -DGCC_HAS_SP -fstack-protector-all -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Iinclude/asm-x86/mach-default -fno-omit-frame-pointer -fno-optimize-sibling-calls -g -pg -Wdeclaration-after-statement -Wno-pointer-sign -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(panic)" -D"KBUILD_MODNAME=KBUILD_STR(panic)" -c -o kernel/panic.o kernel/panic.c
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