powerpc: Clear RI and EE at the same time in system call exit (ac1dc365) · Commits · 戴 / test

arch/powerpc/kernel/entry_64.S

+13 −12

Original line number	Diff line number	Diff line
		@@ -197,7 +197,16 @@ syscall_exit:
		wrteei 0
		#else
		ld r10,PACAKMSR(r13)
		mtmsrd r10,1
		/*
		* For performance reasons we clear RI the same time that we
		* clear EE. We only need to clear RI just before we restore r13
		* below, but batching it with EE saves us one expensive mtmsrd call.
		* We have to be careful to restore RI if we branch anywhere from
		* here (eg syscall_exit_work).
		*/
		li r9,MSR_RI
		andc r11,r10,r9
		mtmsrd r11,1
		#endif /* CONFIG_PPC_BOOK3E */

		ld r9,TI_FLAGS(r12)
		@@ -214,17 +223,6 @@ BEGIN_FTR_SECTION
		END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
		andi. r6,r8,MSR_PR
		ld r4,_LINK(r1)
		/*
		* Clear RI before restoring r13. If we are returning to
		* userspace and we take an exception after restoring r13,
		* we end up corrupting the userspace r13 value.
		*/
		#ifdef CONFIG_PPC_BOOK3S
		/* No MSR:RI on BookE */
		li r12,MSR_RI
		andc r11,r10,r12
		mtmsrd r11,1 /* clear MSR.RI */
		#endif /* CONFIG_PPC_BOOK3S */

		beq- 1f
		ACCOUNT_CPU_USER_EXIT(r11, r12)
		@@ -271,6 +269,9 @@ syscall_enosys:
		b syscall_exit

		syscall_exit_work:
		#ifdef CONFIG_PPC_BOOK3S
		mtmsrd r10,1 /* Restore RI */
		#endif
		/* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
		If TIF_NOERROR is set, just save r3 as it is. */