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 06/10] powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
Date: Fri, 19 Jan 2018 00:34:06 +1100 [thread overview]
Message-ID: <20180118133410.18716-6-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180118133410.18716-1-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>
---
arch/powerpc/kernel/exceptions-64s.S | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 85795d41f6ca..845291357f0b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -596,6 +596,9 @@ EXC_COMMON_BEGIN(slb_miss_common)
stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */
std r10,PACA_EXSLB+EX_LR(r13) /* save LR */
+ andi. r9,r11,MSR_PR // Check for exception from userspace
+ cmpdi cr4,r9,MSR_PR // And save the result in CR4 for later
+
/*
* Test MSR_RI before calling slb_allocate_realmode, because the
* MSR in r11 gets clobbered. However we still want to allocate
@@ -622,9 +625,32 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
/* All done -- return from exception. */
+ bne cr4,1f /* returning to kernel */
+
+.machine push
+.machine "power4"
+ mtcrf 0x80,r9
+ mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */
+ mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */
+ mtcrf 0x02,r9 /* I/D indication is in cr6 */
+ mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
+.machine pop
+
+ RESTORE_CTR(r9, PACA_EXSLB)
+ RESTORE_PPR_PACA(PACA_EXSLB, r9)
+ mr r3,r12
+ 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 */
+1:
.machine push
.machine "power4"
mtcrf 0x80,r9
+ mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */
mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */
mtcrf 0x02,r9 /* I/D indication is in cr6 */
mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
@@ -638,9 +664,10 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
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 */
+
2: std r3,PACA_EXSLB+EX_DAR(r13)
mr r3,r12
mfspr r11,SPRN_SRR0
--
2.14.3
next prev 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 ` [PATCH v4.14 backport 05/10] powerpc/64: Convert fast_exception_return " Michael Ellerman
2018-01-18 13:34 ` Michael Ellerman [this message]
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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