Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b8e90cb7 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL 



In the syscall exit path we may be returning to user or kernel
context. We already have a test for that, because we conditionally
restore r13. So use that existing test and branch, and bifurcate the
return based on that.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 222f20f1

arch/powerpc/kernel/entry_64.S

+11 −1
Original line number Diff line number Diff line
@@ -267,13 +267,23 @@ BEGIN_FTR_SECTION 
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)



	ld	r13,GPR13(r1)	/* only restore r13 if returning to usermode */

	ld	r2,GPR2(r1)

	ld	r1,GPR1(r1)

	mtlr	r4

	mtcr	r5

	mtspr	SPRN_SRR0,r7

	mtspr	SPRN_SRR1,r8

	RFI_TO_USER

	b	.	/* prevent speculative execution */



	/* exit to kernel */

1:	ld	r2,GPR2(r1)

	ld	r1,GPR1(r1)

	mtlr	r4

	mtcr	r5

	mtspr	SPRN_SRR0,r7

	mtspr	SPRN_SRR1,r8

	RFI

	RFI_TO_KERNEL

	b	.	/* prevent speculative execution */



.Lsyscall_error: