On Tue, 2017-01-03 at 07:25 -0800, Christian Kujau wrote: > Hi, > > when compiling v4.10-rc2 with CONFIG_CC_STACKPROTECTOR_STRONG=y, the > linker fails with:
The way gcc implements the stack protector has some serious incompatibilities with the way the Linux kernel uses r13, I wouldn't even try until we sort that out... Cheers, Ben. > > ================================ > + ld -EB -m elf32ppc -Bstatic --build-id -X -o .tmp_vmlinux1 -T > ./arch/powerpc/kernel/vmlinux.lds arch/powerpc/kernel/head_32.o > arch/powerpc/kernel/fpu.o arch/powerpc/kernel/vector.o > arch/powerpc/kernel/prom_init.o init/built-in.o --start-group > usr/built-in.o arch/powerpc/kernel/built-in.o arch/powerpc/mm/built- > in.o > arch/powerpc/lib/built-in.o arch/powerpc/sysdev/built-in.o > arch/powerpc/platforms/built-in.o arch/powerpc/math-emu/built-in.o > arch/powerpc/crypto/built-in.o arch/powerpc/net/built-in.o > kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o > ipc/built-in.o security/built-in.o crypto/built-in.o block/built- > in.o > lib/lib.a lib/built-in.o drivers/built-in.o sound/built-in.o > firmware/built-in.o net/built-in.o virt/built-in.o --end-group > arch/powerpc/platforms/built-in.o: In function `bootx_printf': > /usr/local/src/linux- > git/arch/powerpc/platforms/powermac/bootx_init.c:88: undefined > reference to `__stack_chk_fail_local' > arch/powerpc/platforms/built-in.o: In function > `bootx_add_display_props': > /usr/local/src/linux- > git/arch/powerpc/platforms/powermac/bootx_init.c:211: undefined > reference to `__stack_chk_fail_local' > arch/powerpc/platforms/built-in.o: In function > `bootx_scan_dt_build_struct': > /usr/local/src/linux- > git/arch/powerpc/platforms/powermac/bootx_init.c:350: undefined > reference to `__stack_chk_fail_local' > arch/powerpc/platforms/built-in.o: In function `bootx_init': > /usr/local/src/linux- > git/arch/powerpc/platforms/powermac/bootx_init.c:596: undefined > reference to `__stack_chk_fail_local' > /usr/bin/ld.bfd.real: .tmp_vmlinux1: hidden symbol > `__stack_chk_fail_local' isn't defined > /usr/bin/ld.bfd.real: final link failed: Bad value > ================================ > > > $ ld --version | head -1 > GNU ld (GNU Binutils for Debian) 2.25 > > $ gcc --version | head -1 > gcc-4.9.real (Debian 4.9.2-10) 4.9.2 > > > I'm regularly compiling userspace programs with -fstack-protector > w/o > problems. I suspect it's either > 6533b7c16ee5712041b4e324100550e02a9a5dda > ("powerpc: Initial stack protector (-fstack-protector) support") or > 902e06eb86cd62753974c249bd1dedae2825b430 ("powerpc/32: Change the > stack > protector canary value per task") or both but I haven't started the > bisection yet. > > Any other ideas? > > Thanks, > Christian.