On Tue, 2018-09-25 at 17:56 +0200, Christophe LEROY wrote: > Snowpatch reports failure on pmac32_defconfig, as follows: > > arch/powerpc/platforms/powermac/bootx_init.o: In function `bootx_printf': > /var/lib/jenkins-slave/workspace/snowpatch/snowpatch-linux- > sparse/linux/arch/powerpc/platforms/powermac/bootx_init.c:88: > undefined reference to `__stack_chk_fail_local' > arch/powerpc/platforms/powermac/bootx_init.o: In function > `bootx_add_display_props': > /var/lib/jenkins-slave/workspace/snowpatch/snowpatch-linux- > sparse/linux/arch/powerpc/platforms/powermac/bootx_init.c:211: > undefined reference to `__stack_chk_fail_local' > arch/powerpc/platforms/powermac/bootx_init.o: In function > `bootx_scan_dt_build_struct': > /var/lib/jenkins-slave/workspace/snowpatch/snowpatch-linux- > sparse/linux/arch/powerpc/platforms/powermac/bootx_init.c:350: > undefined reference to `__stack_chk_fail_local' > arch/powerpc/platforms/powermac/bootx_init.o: In function `bootx_init': > /var/lib/jenkins-slave/workspace/snowpatch/snowpatch-linux- > sparse/linux/arch/powerpc/platforms/powermac/bootx_init.c:598: > undefined reference to `__stack_chk_fail_local' > ld: .tmp_vmlinux1: hidden symbol `__stack_chk_fail_local' isn't defined > ld: final link failed: Bad value > Makefile:1040: recipe for target 'vmlinux' failed > make: *** [vmlinux] Error 1 > > I don't have this issue with GCC 8.1, bootx_init.o has references to > __stack_chk_fail, not to __stack_chk_fail_local > > Looking online, it may be due to an old build and a lack of 'make > clean', could it be the case here ?
We do make mrproper AND clean, just to be sure :) > > Otherwise, can you retry the build to see if it's happen again ? I've retried the build and the same thing happens. Our build environment is using GCC 7.3 on Ubuntu 18.04. Reproduced on a different machine too, running the same OS and compiler. You can see exactly what gets run here: https://github.com/ajdlinux/openpower.xyz-snowpatch/blob/master/kernel-build-sparse.sh - Russell > > Christophe > > Le 24/09/2018 à 17:15, Christophe Leroy a écrit : > > On PPC64, as register r13 points to the paca_struct at all time, > > this patch adds a copy of the canary there, which is copied at > > task_switch. > > That new canary is then used by using the following GCC options: > > -mstack-protector-guard=tls > > -mstack-protector-guard-reg=r13 > > -mstack-protector-guard-offset=offsetof(struct paca_struct, canary)) > > > > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > > --- > > arch/powerpc/Kconfig | 2 +- > > arch/powerpc/Makefile | 8 ++++++++ > > arch/powerpc/include/asm/paca.h | 3 +++ > > arch/powerpc/include/asm/stackprotector.h | 3 +++ > > arch/powerpc/kernel/asm-offsets.c | 3 +++ > > arch/powerpc/kernel/entry_64.S | 4 ++++ > > 6 files changed, 22 insertions(+), 1 deletion(-) > > > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > > index 3bcb05929931..602eea723624 100644 > > --- a/arch/powerpc/Kconfig > > +++ b/arch/powerpc/Kconfig > > @@ -180,7 +180,7 @@ config PPC > > select HAVE_ARCH_SECCOMP_FILTER > > select HAVE_ARCH_TRACEHOOK > > select HAVE_CBPF_JIT if !PPC64 > > - select HAVE_STACKPROTECTOR if > > $(cc-option,-mstack-protector- > > guard=tls) && PPC32 > > + select HAVE_STACKPROTECTOR if > > $(cc-option,-mstack-protector- > > guard=tls) > > select HAVE_CONTEXT_TRACKING if PPC64 > > select HAVE_DEBUG_KMEMLEAK > > select HAVE_DEBUG_STACKOVERFLOW > > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > > index 45b8eb4d8fe7..81552c7b46eb 100644 > > --- a/arch/powerpc/Makefile > > +++ b/arch/powerpc/Makefile > > @@ -113,7 +113,11 @@ KBUILD_ARFLAGS += --target=elf$(BITS)-$(GNUTARGET) > > endif > > > > cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard=tls > > +ifdef CONFIG_PPC64 > > +cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r13 > > +else > > cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r2 > > +endif > > > > LDFLAGS_vmlinux-y := -Bstatic > > LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie > > @@ -411,8 +415,12 @@ ifdef CONFIG_STACKPROTECTOR > > prepare: stack_protector_prepare > > > > stack_protector_prepare: prepare0 > > +ifdef CONFIG_PPC64 > > + $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if > > ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) > > +else > > $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if > > ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) > > endif > > +endif > > > > # Use the file '.tmp_gas_check' for binutils tests, as gas won't output > > # to stdout and these checks are run even on install targets. > > diff --git a/arch/powerpc/include/asm/paca.h > > b/arch/powerpc/include/asm/paca.h > > index 6d6b3706232c..98d883e58945 100644 > > --- a/arch/powerpc/include/asm/paca.h > > +++ b/arch/powerpc/include/asm/paca.h > > @@ -246,6 +246,9 @@ struct paca_struct { > > struct slb_entry *mce_faulty_slbs; > > u16 slb_save_cache_ptr; > > #endif /* CONFIG_PPC_BOOK3S_64 */ > > +#ifdef CONFIG_STACKPROTECTOR > > + unsigned long canary; > > +#endif > > } ____cacheline_aligned; > > > > extern struct paca_struct **paca_ptrs; > > diff --git a/arch/powerpc/include/asm/stackprotector.h > > b/arch/powerpc/include/asm/stackprotector.h > > index 263e2aab1862..e81991955c0d 100644 > > --- a/arch/powerpc/include/asm/stackprotector.h > > +++ b/arch/powerpc/include/asm/stackprotector.h > > @@ -29,6 +29,9 @@ static __always_inline void boot_init_stack_canary(void) > > canary ^= LINUX_VERSION_CODE; > > > > current->stack_canary = canary; > > +#ifdef CONFIG_PPC64 > > + get_paca()->canary = canary; > > +#endif > > } > > > > #endif /* _ASM_STACKPROTECTOR_H */ > > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm- > > offsets.c > > index a992f7a53cf3..773dee55b3f6 100644 > > --- a/arch/powerpc/kernel/asm-offsets.c > > +++ b/arch/powerpc/kernel/asm-offsets.c > > @@ -81,6 +81,9 @@ int main(void) > > OFFSET(MM, task_struct, mm); > > #ifdef CONFIG_STACKPROTECTOR > > OFFSET(TASK_CANARY, task_struct, stack_canary); > > +#ifdef CONFIG_PPC64 > > + OFFSET(PACA_CANARY, paca_struct, canary); > > +#endif > > #endif > > OFFSET(MMCONTEXTID, mm_struct, context.id); > > #ifdef CONFIG_PPC64 > > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S > > index 77a888bfcb53..573fa879d785 100644 > > --- a/arch/powerpc/kernel/entry_64.S > > +++ b/arch/powerpc/kernel/entry_64.S > > @@ -624,6 +624,10 @@ _GLOBAL(_switch) > > > > addi r6,r4,-THREAD /* Convert THREAD to 'current' */ > > std r6,PACACURRENT(r13) /* Set new 'current' */ > > +#if defined(CONFIG_STACKPROTECTOR) > > + ld r6, TASK_CANARY(r6) > > + std r6, PACA_CANARY(r13) > > +#endif > > > > ld r8,KSP(r4) /* new stack pointer */ > > #ifdef CONFIG_PPC_BOOK3S_64 > >
