linux/arch/arm64/include/asm/pointer_auth.h
Srinivas Ramana 7f6240858c arm64: Defer enabling pointer authentication on boot core
Defer enabling pointer authentication on boot core until
after its required to be enabled by cpufeature framework.
This will help in controlling the feature dynamically
with a boot parameter.

Signed-off-by: Ajay Patil <pajay@qti.qualcomm.com>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1610152163-16554-2-git-send-email-sramana@codeaurora.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-22-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-02-09 13:50:57 +00:00

105 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_POINTER_AUTH_H
#define __ASM_POINTER_AUTH_H
#include <linux/bitops.h>
#include <linux/random.h>
#include <asm/cpufeature.h>
#include <asm/memory.h>
#include <asm/sysreg.h>
#ifdef CONFIG_ARM64_PTR_AUTH
/*
* Each key is a 128-bit quantity which is split across a pair of 64-bit
* registers (Lo and Hi).
*/
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;
};
struct ptrauth_keys_kernel {
struct ptrauth_key apia;
};
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));
}
#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)
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();
}
extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg);
static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr)
{
return ptrauth_clear_pac(ptr);
}
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_thread_init_user(tsk) \
ptrauth_keys_init_user(&(tsk)->thread.keys_user)
#define ptrauth_thread_init_kernel(tsk) \
ptrauth_keys_init_kernel(&(tsk)->thread.keys_kernel)
#define ptrauth_thread_switch_kernel(tsk) \
ptrauth_keys_switch_kernel(&(tsk)->thread.keys_kernel)
#else /* CONFIG_ARM64_PTR_AUTH */
#define ptrauth_enable()
#define ptrauth_prctl_reset_keys(tsk, arg) (-EINVAL)
#define ptrauth_strip_insn_pac(lr) (lr)
#define ptrauth_thread_init_user(tsk)
#define ptrauth_thread_init_kernel(tsk)
#define ptrauth_thread_switch_kernel(tsk)
#endif /* CONFIG_ARM64_PTR_AUTH */
#endif /* __ASM_POINTER_AUTH_H */