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 05/15] powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
Date: Fri, 2 Mar 2018 15:45:39 +1100 [thread overview]
Message-ID: <20180302044549.14930-6-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180302044549.14930-1-mpe@ellerman.id.au>
From: Nicholas Piggin <npiggin@gmail.com>
commit b8e90cb7bc04a509e821e82ab6ed7a8ef11ba333 upstream.
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: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/entry_64.S | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index f7421248cbd8..36a8bf3d053b 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -223,13 +223,23 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
ACCOUNT_CPU_USER_EXIT(r11, r12)
HMT_MEDIUM_LOW_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 */
syscall_error:
--
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 ` Michael Ellerman [this message]
2018-03-02 4:45 ` [PATCH v4.1 backport 06/15] powerpc/64s: Convert slb_miss_common " Michael Ellerman
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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