x86/entry/traps: Refactor preemption and interrupt flag handling (d99e1bd1) · Commits · e / devices / android_kernel_fairphone_FP4

arch/x86/kernel/traps.c

+19 −28

Original line number	Original line	Diff line number	Diff line
	@@ -83,30 +83,16 @@ gate_desc idt_table[NR_VECTORS] __page_aligned_bss;
	DECLARE_BITMAP(used_vectors, NR_VECTORS);		DECLARE_BITMAP(used_vectors, NR_VECTORS);
	EXPORT_SYMBOL_GPL(used_vectors);		EXPORT_SYMBOL_GPL(used_vectors);

	static inline void conditional_sti(struct pt_regs *regs)		static inline void cond_local_irq_enable(struct pt_regs *regs)
	{		{
	if (regs->flags & X86_EFLAGS_IF)		if (regs->flags & X86_EFLAGS_IF)
	local_irq_enable();		local_irq_enable();
	}		}

	static inline void preempt_conditional_sti(struct pt_regs *regs)		static inline void cond_local_irq_disable(struct pt_regs *regs)
	{
	preempt_count_inc();
	if (regs->flags & X86_EFLAGS_IF)
	local_irq_enable();
	}

	static inline void conditional_cli(struct pt_regs *regs)
	{
	if (regs->flags & X86_EFLAGS_IF)
	local_irq_disable();
	}

	static inline void preempt_conditional_cli(struct pt_regs *regs)
	{		{
	if (regs->flags & X86_EFLAGS_IF)		if (regs->flags & X86_EFLAGS_IF)
	local_irq_disable();		local_irq_disable();
	preempt_count_dec();
	}		}

	void ist_enter(struct pt_regs *regs)		void ist_enter(struct pt_regs *regs)
	@@ -286,7 +272,7 @@ static void do_error_trap(struct pt_regs regs, long error_code, char str,

	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) !=		if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) !=
	NOTIFY_STOP) {		NOTIFY_STOP) {
	conditional_sti(regs);		cond_local_irq_enable(regs);
	do_trap(trapnr, signr, str, regs, error_code,		do_trap(trapnr, signr, str, regs, error_code,
	fill_trap_info(regs, signr, trapnr, &info));		fill_trap_info(regs, signr, trapnr, &info));
	}		}
	@@ -368,7 +354,7 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
	if (notify_die(DIE_TRAP, "bounds", regs, error_code,		if (notify_die(DIE_TRAP, "bounds", regs, error_code,
	X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP)		X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP)
	return;		return;
	conditional_sti(regs);		cond_local_irq_enable(regs);

	if (!user_mode(regs))		if (!user_mode(regs))
	die("bounds", regs, error_code);		die("bounds", regs, error_code);
	@@ -443,7 +429,7 @@ do_general_protection(struct pt_regs *regs, long error_code)
	struct task_struct *tsk;		struct task_struct *tsk;

	RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");		RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
	conditional_sti(regs);		cond_local_irq_enable(regs);

	if (v8086_mode(regs)) {		if (v8086_mode(regs)) {
	local_irq_enable();		local_irq_enable();
	@@ -517,9 +503,11 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
	* as we may switch to the interrupt stack.		* as we may switch to the interrupt stack.
	*/		*/
	debug_stack_usage_inc();		debug_stack_usage_inc();
	preempt_conditional_sti(regs);		preempt_disable();
			cond_local_irq_enable(regs);
	do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);		do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
	preempt_conditional_cli(regs);		cond_local_irq_disable(regs);
			preempt_enable_no_resched();
	debug_stack_usage_dec();		debug_stack_usage_dec();
	exit:		exit:
	ist_exit(regs);		ist_exit(regs);
	@@ -648,12 +636,14 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
	debug_stack_usage_inc();		debug_stack_usage_inc();

	/* It's safe to allow irq's after DR6 has been saved */		/* It's safe to allow irq's after DR6 has been saved */
	preempt_conditional_sti(regs);		preempt_disable();
			cond_local_irq_enable(regs);

	if (v8086_mode(regs)) {		if (v8086_mode(regs)) {
	handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,		handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
	X86_TRAP_DB);		X86_TRAP_DB);
	preempt_conditional_cli(regs);		cond_local_irq_disable(regs);
			preempt_enable_no_resched();
	debug_stack_usage_dec();		debug_stack_usage_dec();
	goto exit;		goto exit;
	}		}
	@@ -673,7 +663,8 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
	si_code = get_si_code(tsk->thread.debugreg6);		si_code = get_si_code(tsk->thread.debugreg6);
	if (tsk->thread.debugreg6 & (DR_STEP \| DR_TRAP_BITS) \|\| user_icebp)		if (tsk->thread.debugreg6 & (DR_STEP \| DR_TRAP_BITS) \|\| user_icebp)
	send_sigtrap(tsk, regs, error_code, si_code);		send_sigtrap(tsk, regs, error_code, si_code);
	preempt_conditional_cli(regs);		cond_local_irq_disable(regs);
			preempt_enable_no_resched();
	debug_stack_usage_dec();		debug_stack_usage_dec();

	exit:		exit:
	@@ -696,7 +687,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)

	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)		if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
	return;		return;
	conditional_sti(regs);		cond_local_irq_enable(regs);

	if (!user_mode(regs)) {		if (!user_mode(regs)) {
	if (!fixup_exception(regs)) {		if (!fixup_exception(regs)) {
	@@ -743,7 +734,7 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
	dotraplinkage void		dotraplinkage void
	do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)		do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
	{		{
	conditional_sti(regs);		cond_local_irq_enable(regs);
	}		}

	dotraplinkage void		dotraplinkage void
	@@ -756,7 +747,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
	if (read_cr0() & X86_CR0_EM) {		if (read_cr0() & X86_CR0_EM) {
	struct math_emu_info info = { };		struct math_emu_info info = { };

	conditional_sti(regs);		cond_local_irq_enable(regs);

	info.regs = regs;		info.regs = regs;
	math_emulate(&info);		math_emulate(&info);
	@@ -765,7 +756,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
	#endif		#endif
	fpu__restore(&current->thread.fpu); /* interrupts still off */		fpu__restore(&current->thread.fpu); /* interrupts still off */
	#ifdef CONFIG_X86_32		#ifdef CONFIG_X86_32
	conditional_sti(regs);		cond_local_irq_enable(regs);
	#endif		#endif
	}		}
	NOKPROBE_SYMBOL(do_device_not_available);		NOKPROBE_SYMBOL(do_device_not_available);