arch/arm64/include/asm/pointer_auth.h

Source file repositories/reference/linux-study-clean/arch/arm64/include/asm/pointer_auth.h

File Facts

System
Linux kernel
Corpus path
arch/arm64/include/asm/pointer_auth.h
Extension
.h
Size
4789 bytes
Lines
154
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct ptrauth_key {
	unsigned long lo, hi;
};

/*
 * We give each process its own keys, which are shared by all threads. The keys
 * are inherited upon fork(), and reinitialised upon exec*().
 */
struct ptrauth_keys_user {
	struct ptrauth_key apia;
	struct ptrauth_key apib;
	struct ptrauth_key apda;
	struct ptrauth_key apdb;
	struct ptrauth_key apga;
};

#define __ptrauth_key_install_nosync(k, v)			\
do {								\
	struct ptrauth_key __pki_v = (v);			\
	write_sysreg_s(__pki_v.lo, SYS_ ## k ## KEYLO_EL1);	\
	write_sysreg_s(__pki_v.hi, SYS_ ## k ## KEYHI_EL1);	\
} while (0)

#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL

struct ptrauth_keys_kernel {
	struct ptrauth_key apia;
};

static __always_inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel *keys)
{
	if (system_supports_address_auth())
		get_random_bytes(&keys->apia, sizeof(keys->apia));
}

static __always_inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys)
{
	if (!system_supports_address_auth())
		return;

	__ptrauth_key_install_nosync(APIA, keys->apia);
	isb();
}

#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */

static inline void ptrauth_keys_install_user(struct ptrauth_keys_user *keys)
{
	if (system_supports_address_auth()) {
		__ptrauth_key_install_nosync(APIB, keys->apib);
		__ptrauth_key_install_nosync(APDA, keys->apda);
		__ptrauth_key_install_nosync(APDB, keys->apdb);
	}

	if (system_supports_generic_auth())
		__ptrauth_key_install_nosync(APGA, keys->apga);
}

static inline void ptrauth_keys_init_user(struct ptrauth_keys_user *keys)
{
	if (system_supports_address_auth()) {
		get_random_bytes(&keys->apia, sizeof(keys->apia));
		get_random_bytes(&keys->apib, sizeof(keys->apib));
		get_random_bytes(&keys->apda, sizeof(keys->apda));
		get_random_bytes(&keys->apdb, sizeof(keys->apdb));
	}

	if (system_supports_generic_auth())
		get_random_bytes(&keys->apga, sizeof(keys->apga));

	ptrauth_keys_install_user(keys);
}

extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg);

extern int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys,
				    unsigned long enabled);
extern int ptrauth_get_enabled_keys(struct task_struct *tsk);

static __always_inline void ptrauth_enable(void)
{
	if (!system_supports_address_auth())
		return;
	sysreg_clear_set(sctlr_el1, 0, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB |
					SCTLR_ELx_ENDA | SCTLR_ELx_ENDB));
	isb();
}

#define ptrauth_suspend_exit()                                                 \
	ptrauth_keys_install_user(&current->thread.keys_user)

Annotation

Implementation Notes