Messages in this thread | | | Subject | Re: [PATCH v3 2/2] powerpc/64: add stack protector support | From | Christophe LEROY <> | Date | Tue, 25 Sep 2018 17:56:09 +0200 |
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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 ?
Otherwise, can you retry the build to see if it's happen again ?
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.leroy@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 >
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