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linux-next/arch/powerpc/include/asm/stackprotector.h
Christophe Leroy 06ec27aea9 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>
2018-10-03 15:40:03 +10:00

39 lines
788 B
C

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