[ARM] Fix kernel mode preemption (28fab1a2) · Commits · 戴 / test

arch/arm/kernel/entry-armv.S

+5 −19

Original line number	Diff line number	Diff line
		@@ -209,14 +209,12 @@ __irq_svc:

		irq_handler
		#ifdef CONFIG_PREEMPT
		str r8, [tsk, #TI_PREEMPT] @ restore preempt count
		ldr r0, [tsk, #TI_FLAGS] @ get flags
		teq r8, #0 @ if preempt count != 0
		movne r0, #0 @ force flags to 0
		tst r0, #_TIF_NEED_RESCHED
		blne svc_preempt
		preempt_return:
		ldr r0, [tsk, #TI_PREEMPT] @ read preempt value
		str r8, [tsk, #TI_PREEMPT] @ restore preempt count
		teq r0, r7
		strne r0, [r0, -r0] @ bug()
		#endif
		ldr r0, [sp, #S_PSR] @ irqs are already disabled
		msr spsr_cxsf, r0
		@@ -230,19 +228,11 @@ preempt_return:

		#ifdef CONFIG_PREEMPT
		svc_preempt:
		teq r8, #0 @ was preempt count = 0
		ldreq r6, .LCirq_stat
		movne pc, lr @ no
		ldr r0, [r6, #4] @ local_irq_count
		ldr r1, [r6, #8] @ local_bh_count
		adds r0, r0, r1
		movne pc, lr
		mov r7, #0 @ preempt_schedule_irq
		str r7, [tsk, #TI_PREEMPT] @ expects preempt_count == 0
		mov r8, lr
		1: bl preempt_schedule_irq @ irq en/disable is done inside
		ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
		tst r0, #_TIF_NEED_RESCHED
		beq preempt_return @ go again
		moveq pc, r8 @ go again
		b 1b
		#endif

		@@ -326,10 +316,6 @@ __pabt_svc:
		#endif
		.LCfp:
		.word fp_enter
		#ifdef CONFIG_PREEMPT
		.LCirq_stat:
		.word irq_stat
		#endif

		/*
		* User mode handlers