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From: Michael Ellerman <mpe@ellerman.id.au>
To: stable@vger.kernel.org
Cc: greg@kroah.com, linuxppc-dev@ozlabs.org
Subject: [PATCH v4.14 backport 05/10] powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
Date: Fri, 19 Jan 2018 00:34:05 +1100	[thread overview]
Message-ID: <20180118133410.18716-5-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180118133410.18716-1-mpe@ellerman.id.au>

From: Nicholas Piggin <npiggin@gmail.com>

commit a08f828cf47e6c605af21d2cdec68f84e799c318 upstream.

Similar to the syscall return path, in fast_exception_return 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: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/entry_64.S | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 150c402728d1..8a8a6d7ddcc6 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -892,7 +892,7 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ACCOUNT_CPU_USER_EXIT(r13, r2, r4)
 	REST_GPR(13, r1)
-1:
+
 	mtspr	SPRN_SRR1,r3
 
 	ld	r2,_CCR(r1)
@@ -905,8 +905,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ld	r3,GPR3(r1)
 	ld	r4,GPR4(r1)
 	ld	r1,GPR1(r1)
+	RFI_TO_USER
+	b	.	/* prevent speculative execution */
+
+1:	mtspr	SPRN_SRR1,r3
+
+	ld	r2,_CCR(r1)
+	mtcrf	0xFF,r2
+	ld	r2,_NIP(r1)
+	mtspr	SPRN_SRR0,r2
 
-	rfid
+	ld	r0,GPR0(r1)
+	ld	r2,GPR2(r1)
+	ld	r3,GPR3(r1)
+	ld	r4,GPR4(r1)
+	ld	r1,GPR1(r1)
+	RFI_TO_KERNEL
 	b	.	/* prevent speculative execution */
 
 #endif /* CONFIG_PPC_BOOK3E */
-- 
2.14.3

  parent reply	other threads:[~2018-01-18 13:34 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-18 13:34 [PATCH v4.14 backport 01/10] powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 02/10] powerpc/64: Add macros for annotating the destination of rfid/hrfid Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 03/10] powerpc/64s: Simple RFI macro conversions Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 04/10] powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL Michael Ellerman
2018-01-18 13:34 ` Michael Ellerman [this message]
2018-01-18 13:34 ` [PATCH v4.14 backport 06/10] powerpc/64s: Convert slb_miss_common " Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 07/10] powerpc/64s: Add support for RFI flush of L1-D cache Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 08/10] powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 09/10] powerpc/pseries: Query hypervisor for RFI flush settings Michael Ellerman
2018-01-18 13:34 ` [PATCH v4.14 backport 10/10] powerpc/powernv: Check device-tree " Michael Ellerman

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