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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-09-27 07:05:55 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-03 15:40:03 +1000 |
| commit | 06ec27aea9fc84d9c6d879eb64b5bcf28a8a1eb7 (patch) | |
| tree | 74bcc3ec9f8ea5647aead31b19d287f720fd0ab5 /arch | |
| parent | c3ff2a5193fa61b1b284cfb1d79628814ed0e95a (diff) | |
| download | linux-06ec27aea9fc84d9c6d879eb64b5bcf28a8a1eb7.tar.gz linux-06ec27aea9fc84d9c6d879eb64b5bcf28a8a1eb7.tar.bz2 linux-06ec27aea9fc84d9c6d879eb64b5bcf28a8a1eb7.zip | |
powerpc/64: add stack protector support
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/powerpc/Makefile | 8 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/paca.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/stackprotector.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 4 |
6 files changed, 23 insertions, 1 deletions
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 7b6e23af3808..c6d01f0aa898 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -256,6 +256,9 @@ 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 void copy_mm_to_paca(struct mm_struct *mm); diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h index d05d969c98c2..1c8460e23583 100644 --- a/arch/powerpc/include/asm/stackprotector.h +++ b/arch/powerpc/include/asm/stackprotector.h @@ -11,6 +11,7 @@ #include <linux/version.h> #include <asm/reg.h> #include <asm/current.h> +#include <asm/paca.h> /* * Initialize the stackprotector canary value. @@ -29,6 +30,9 @@ static __always_inline void boot_init_stack_canary(void) canary &= CANARY_MASK; 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 9e9ee168e177..a6d70fd2e499 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 |