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Commit 84931327 authored by Will Deacon's avatar Will Deacon
Browse files

arm64: ptr auth: Move per-thread keys from thread_info to thread_struct 



We don't need to get at the per-thread keys from assembly at all, so
they can live alongside the rest of the per-thread register state in
thread_struct instead of thread_info.

This will also allow straighforward whitelisting of the keys for
hardened usercopy should we expose them via a ptrace request later on.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 04ca3204

arch/arm64/include/asm/pointer_auth.h

+3 −3
Original line number Diff line number Diff line
@@ -80,12 +80,12 @@ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr) 
#define ptrauth_thread_init_user(tsk)					\

do {									\

	struct task_struct *__ptiu_tsk = (tsk);				\

	ptrauth_keys_init(&__ptiu_tsk->thread_info.keys_user);		\

	ptrauth_keys_switch(&__ptiu_tsk->thread_info.keys_user);	\

	ptrauth_keys_init(&__ptiu_tsk->thread.keys_user);		\

	ptrauth_keys_switch(&__ptiu_tsk->thread.keys_user);		\

} while (0)



#define ptrauth_thread_switch(tsk)	\

	ptrauth_keys_switch(&(tsk)->thread_info.keys_user)

	ptrauth_keys_switch(&(tsk)->thread.keys_user)



#else /* CONFIG_ARM64_PTR_AUTH */

#define ptrauth_prctl_reset_keys(tsk, arg)	(-EINVAL)

arch/arm64/include/asm/processor.h

+3 −0
Original line number Diff line number Diff line
@@ -147,6 +147,9 @@ struct thread_struct { 
	unsigned long		fault_address;	/* fault info */

	unsigned long		fault_code;	/* ESR_EL1 value */

	struct debug_info	debug;		/* debugging */

#ifdef CONFIG_ARM64_PTR_AUTH

	struct ptrauth_keys	keys_user;

#endif

};



static inline void arch_thread_struct_whitelist(unsigned long *offset,

arch/arm64/include/asm/thread_info.h

+0 −4
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 
struct task_struct;



#include <asm/memory.h>

#include <asm/pointer_auth.h>

#include <asm/stack_pointer.h>

#include <asm/types.h>
@@ -55,9 +54,6 @@ struct thread_info { 
#endif

		} preempt;

	};

#ifdef CONFIG_ARM64_PTR_AUTH

	struct ptrauth_keys	keys_user;

#endif

};



#define thread_saved_pc(tsk)	\

arch/arm64/kernel/pointer_auth.c

+1 −1
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 


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

{

	struct ptrauth_keys *keys = &tsk->thread_info.keys_user;

	struct ptrauth_keys *keys = &tsk->thread.keys_user;

	unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |

				      PR_PAC_APDAKEY | PR_PAC_APDBKEY;

	unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY;