From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc/8xx: Fix clearing of bits 20-23 in ITLB miss
Date: Sun, 9 Feb 2020 18:14:42 +0000 (UTC) [thread overview]
Message-ID: <4f70c2778163affce8508a210f65d140e84524b4.1581272050.git.christophe.leroy@c-s.fr> (raw)
In ITLB miss handled the line supposed to clear bits 20-23 on the
L2 ITLB entry is buggy and does indeed nothing, leading to undefined
value which could allow execution when it shouldn't.
Properly do the clearing with the relevant instruction.
Fixes: 74fabcadfd43 ("powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/head_8xx.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 9922306ae512..073a651787df 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -256,7 +256,7 @@ InstructionTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
- rlwimi r10, r10, 0, 0x0f00 /* Clear bits 20-23 */
+ rlwinm r10, r10, 0, ~0x0f00 /* Clear bits 20-23 */
rlwimi r10, r10, 4, 0x0400 /* Copy _PAGE_EXEC into bit 21 */
ori r10, r10, RPN_PATTERN | 0x200 /* Set 22 and 24-27 */
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
--
2.25.0
next reply other threads:[~2020-02-09 18:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-09 18:14 Christophe Leroy [this message]
2020-02-15 6:28 ` [PATCH] powerpc/8xx: Fix clearing of bits 20-23 in ITLB miss Leonardo Bras
2020-02-15 10:17 ` Christophe Leroy
2020-02-17 14:10 ` Leonardo Bras
2020-02-19 12:39 ` Michael Ellerman
2020-02-11 4:28 Leonardo Bras
2020-02-20 21:53 ` Leonardo Bras
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=4f70c2778163affce8508a210f65d140e84524b4.1581272050.git.christophe.leroy@c-s.fr \
--to=christophe.leroy@c-s.fr \
--cc=benh@kernel.crashing.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
/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).