Commit e950631e authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Remove the get_thread_info() function 



This function was introduced by previous commits implementing UAO.
However, it can be replaced with task_thread_info() in
uao_thread_switch() or get_fs() in do_page_fault() (the latter being
called only on the current context, so no need for using the saved
pt_regs).

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 70544196

arch/arm64/include/asm/thread_info.h

+0 −6
Original line number Diff line number Diff line
@@ -85,12 +85,6 @@ static inline struct thread_info *current_thread_info(void) 
	return (struct thread_info *)sp_el0;

}



/* Access struct thread_info of another thread */

static inline struct thread_info *get_thread_info(unsigned long thread_stack)

{

	return (struct thread_info *)(thread_stack & ~(THREAD_SIZE - 1));

}



#define thread_saved_pc(tsk)	\

	((unsigned long)(tsk->thread.cpu_context.pc))

#define thread_saved_sp(tsk)	\

arch/arm64/kernel/process.c

+6 −9
Original line number Diff line number Diff line
@@ -315,15 +315,12 @@ static void tls_thread_switch(struct task_struct *next) 
/* Restore the UAO state depending on next's addr_limit */

static void uao_thread_switch(struct task_struct *next)

{

	unsigned long next_sp = next->thread.cpu_context.sp;



	if (IS_ENABLED(CONFIG_ARM64_UAO) &&

	    get_thread_info(next_sp)->addr_limit == KERNEL_DS)

		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO,

			        CONFIG_ARM64_UAO));

	if (IS_ENABLED(CONFIG_ARM64_UAO)) {

		if (task_thread_info(next)->addr_limit == KERNEL_DS)

			asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));

		else

		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,

				CONFIG_ARM64_UAO));

			asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO));

	}

}



/*

arch/arm64/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, 
	}



	if (permission_fault(esr) && (addr < USER_DS)) {

		if (get_thread_info(regs->sp)->addr_limit == KERNEL_DS)

		if (get_fs() == KERNEL_DS)

			panic("Accessing user space memory with fs=KERNEL_DS");



		if (!search_exception_tables(regs->pc))

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