forked from mirrors/linux
06ec27aea9
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>
38 lines
788 B
C
38 lines
788 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* GCC stack protector support.
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*
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*/
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#ifndef _ASM_STACKPROTECTOR_H
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#define _ASM_STACKPROTECTOR_H
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#include <linux/random.h>
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#include <linux/version.h>
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#include <asm/reg.h>
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#include <asm/current.h>
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#include <asm/paca.h>
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/*
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* Initialize the stackprotector canary value.
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*
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* NOTE: this must only be called from functions that never return,
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* and it must always be inlined.
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*/
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static __always_inline void boot_init_stack_canary(void)
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{
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unsigned long canary;
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/* Try to get a semi random initial value. */
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canary = get_random_canary();
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canary ^= mftb();
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canary ^= LINUX_VERSION_CODE;
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canary &= CANARY_MASK;
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current->stack_canary = canary;
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#ifdef CONFIG_PPC64
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get_paca()->canary = canary;
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#endif
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}
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#endif /* _ASM_STACKPROTECTOR_H */
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