xref: /OK3568_Linux_fs/kernel/arch/powerpc/include/asm/stackprotector.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * GCC stack protector support.
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #ifndef _ASM_STACKPROTECTOR_H
8*4882a593Smuzhiyun #define _ASM_STACKPROTECTOR_H
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #include <linux/random.h>
11*4882a593Smuzhiyun #include <linux/version.h>
12*4882a593Smuzhiyun #include <asm/reg.h>
13*4882a593Smuzhiyun #include <asm/current.h>
14*4882a593Smuzhiyun #include <asm/paca.h>
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun  * Initialize the stackprotector canary value.
18*4882a593Smuzhiyun  *
19*4882a593Smuzhiyun  * NOTE: this must only be called from functions that never return,
20*4882a593Smuzhiyun  * and it must always be inlined.
21*4882a593Smuzhiyun  */
boot_init_stack_canary(void)22*4882a593Smuzhiyun static __always_inline void boot_init_stack_canary(void)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	unsigned long canary;
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 	/* Try to get a semi random initial value. */
27*4882a593Smuzhiyun 	canary = get_random_canary();
28*4882a593Smuzhiyun 	canary ^= mftb();
29*4882a593Smuzhiyun 	canary ^= LINUX_VERSION_CODE;
30*4882a593Smuzhiyun 	canary &= CANARY_MASK;
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun 	current->stack_canary = canary;
33*4882a593Smuzhiyun #ifdef CONFIG_PPC64
34*4882a593Smuzhiyun 	get_paca()->canary = canary;
35*4882a593Smuzhiyun #endif
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun #endif	/* _ASM_STACKPROTECTOR_H */
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