From: Michael Ellerman <mpe@ellerman.id.au>
To: linuxppc-dev@ozlabs.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
peterz@infradead.org, npiggin@gmail.com, anton@samba.org,
mikey@neuling.org, oohall@gmail.com, paulus@samba.org
Subject: [PATCH 04/11] powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
Date: Tue, 9 Jan 2018 03:54:46 +1100 [thread overview]
Message-ID: <20180108165453.26066-4-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180108165453.26066-1-mpe@ellerman.id.au>
From: Nicholas Piggin <npiggin@gmail.com>
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>
---
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 567d8f487f2f..b20c6cb0fa7f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -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:
--
2.14.3
next prev parent reply other threads:[~2018-01-08 16:55 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 16:54 [PATCH 01/11] powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper Michael Ellerman
2018-01-08 16:54 ` [PATCH 02/11] powerpc/64: Add macros for annotating the destination of rfid/hrfid Michael Ellerman
2018-01-08 16:54 ` [PATCH 03/11] powerpc/64s: Simple RFI macro conversions Michael Ellerman
2018-01-08 17:09 ` Peter Zijlstra
2018-01-08 21:01 ` Paul Mackerras
2018-01-08 22:04 ` Michael Ellerman
2018-01-08 16:54 ` Michael Ellerman [this message]
2018-01-08 16:54 ` [PATCH 05/11] powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL Michael Ellerman
2018-01-08 16:54 ` [PATCH 06/11] powerpc/64s: Convert slb_miss_common " Michael Ellerman
2018-01-08 16:54 ` [PATCH 07/11] powerpc/64s: Add support for RFI flush of L1-D cache Michael Ellerman
2018-01-09 7:02 ` Joel Stanley
2018-01-09 16:05 ` Michael Ellerman
2018-01-25 9:10 ` Christian Zigotzky
2018-01-30 2:11 ` Michael Ellerman
2018-01-08 16:54 ` [PATCH 08/11] powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti Michael Ellerman
2018-01-08 16:54 ` [PATCH 09/11] powerpc/64s: Allow control of RFI flush via sysfs Michael Ellerman
2018-01-08 17:20 ` Thomas Gleixner
2018-01-08 22:09 ` Michael Ellerman
2018-01-09 6:06 ` Jon Masters
2018-01-09 8:05 ` Greg KH
2018-01-09 8:11 ` Jon Masters
2018-01-09 8:03 ` Greg KH
2018-01-08 16:54 ` [PATCH 10/11] powerpc/pseries: Query hypervisor for RFI flush settings Michael Ellerman
2018-01-08 16:54 ` [PATCH 11/11] powerpc/powernv: Check device-tree " Michael Ellerman
2018-01-08 21:57 ` Tyrel Datwyler
2018-01-11 2:25 ` [01/11] powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper Michael Ellerman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180108165453.26066-4-mpe@ellerman.id.au \
--to=mpe@ellerman.id.au \
--cc=anton@samba.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=mikey@neuling.org \
--cc=npiggin@gmail.com \
--cc=oohall@gmail.com \
--cc=paulus@samba.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).