From: Michael Ellerman <mpe@ellerman.id.au>
To: Alexander.Levin@microsoft.com
Cc: stable@vger.kernel.org, linuxppc-dev@ozlabs.org, npiggin@gmail.com
Subject: [PATCH v4.1 backport 06/15] powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
Date: Fri, 2 Mar 2018 15:45:40 +1100 [thread overview]
Message-ID: <20180302044549.14930-7-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180302044549.14930-1-mpe@ellerman.id.au>
From: Nicholas Piggin <npiggin@gmail.com>
commit c7305645eb0c1621351cfc104038831ae87c0053 upstream.
In the SLB miss handler we may be returning to user or kernel. We need
to add a check early on and save the result in the cr4 register, and
then we bifurcate the return path based on that.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Backport to 4.4 based on patch from Balbir]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/exceptions-64s.S | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 591efc03f80d..c7dfd67c14da 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1511,6 +1511,8 @@ slb_miss_realmode:
andi. r10,r12,MSR_RI /* check for unrecoverable exception */
beq- 2f
+ andi. r10,r12,MSR_PR /* check for user mode (PR != 0) */
+ bne 1f
.machine push
.machine "power4"
@@ -1524,7 +1526,23 @@ slb_miss_realmode:
ld r11,PACA_EXSLB+EX_R11(r13)
ld r12,PACA_EXSLB+EX_R12(r13)
ld r13,PACA_EXSLB+EX_R13(r13)
- rfid
+ RFI_TO_KERNEL
+ b . /* prevent speculative execution */
+
+1:
+.machine push
+.machine "power4"
+ mtcrf 0x80,r9
+ mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
+.machine pop
+
+ RESTORE_PPR_PACA(PACA_EXSLB, r9)
+ ld r9,PACA_EXSLB+EX_R9(r13)
+ ld r10,PACA_EXSLB+EX_R10(r13)
+ ld r11,PACA_EXSLB+EX_R11(r13)
+ ld r12,PACA_EXSLB+EX_R12(r13)
+ ld r13,PACA_EXSLB+EX_R13(r13)
+ RFI_TO_USER
b . /* prevent speculative execution */
2: mfspr r11,SPRN_SRR0
@@ -1533,7 +1551,7 @@ slb_miss_realmode:
mtspr SPRN_SRR0,r10
ld r10,PACAKMSR(r13)
mtspr SPRN_SRR1,r10
- rfid
+ RFI_TO_KERNEL
b .
unrecov_slb:
--
2.14.1
next prev parent reply other threads:[~2018-03-02 4:46 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-02 4:45 [PATCH v4.1 backport 00/15] powerpc stable backports for v4.1 Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 01/15] powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 02/15] powerpc/64: Add macros for annotating the destination of rfid/hrfid Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 03/15] powerpc/64s: Simple RFI macro conversions Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 04/15] powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 05/15] powerpc/64: Convert the syscall exit path " Michael Ellerman
2018-03-02 4:45 ` Michael Ellerman [this message]
2018-03-02 4:45 ` [PATCH v4.1 backport 07/15] powerpc/64s: Add support for RFI flush of L1-D cache Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 08/15] powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 09/15] powerpc/64s: Improve RFI L1-D cache flush fallback Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 10/15] powerpc/pseries: Query hypervisor for RFI flush settings Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 11/15] powerpc/powernv: Check device-tree " Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 12/15] powerpc/64s: Allow control of RFI flush via debugfs Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 13/15] powerpc/pseries: include linux/types.h in asm/hvcall.h Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 14/15] powerpc/ptrace: Fix out of bounds array access warning Michael Ellerman
2018-03-02 4:45 ` [PATCH v4.1 backport 15/15] powerpc/vdso64: Use double word compare on pointers Michael Ellerman
2018-03-03 22:17 ` [PATCH v4.1 backport 00/15] powerpc stable backports for v4.1 Sasha Levin
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