From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Helge Deller <deller@gmx.de>,
John David Anglin <dave.anglin@bell.net>,
Sasha Levin <sashal@kernel.org>,
James.Bottomley@HansenPartnership.com, svens@stackframe.org,
akpm@linux-foundation.org, mpe@ellerman.id.au,
rmk+kernel@armlinux.org.uk, wangkefeng.wang@huawei.com,
linux-parisc@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 20/26] parisc: Clear stale IIR value on instruction access rights trap
Date: Mon, 27 Dec 2021 14:03:21 -0500 [thread overview]
Message-ID: <20211227190327.1042326-20-sashal@kernel.org> (raw)
In-Reply-To: <20211227190327.1042326-1-sashal@kernel.org>
From: Helge Deller <deller@gmx.de>
[ Upstream commit 484730e5862f6b872dca13840bed40fd7c60fa26 ]
When a trap 7 (Instruction access rights) occurs, this means the CPU
couldn't execute an instruction due to missing execute permissions on
the memory region. In this case it seems the CPU didn't even fetched
the instruction from memory and thus did not store it in the cr19 (IIR)
register before calling the trap handler. So, the trap handler will find
some random old stale value in cr19.
This patch simply overwrites the stale IIR value with a constant magic
"bad food" value (0xbaadf00d), in the hope people don't start to try to
understand the various random IIR values in trap 7 dumps.
Noticed-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/parisc/kernel/traps.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 747c328fb8862..197cb8480350c 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -729,6 +729,8 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
}
mmap_read_unlock(current->mm);
}
+ /* CPU could not fetch instruction, so clear stale IIR value. */
+ regs->iir = 0xbaadf00d;
fallthrough;
case 27:
/* Data memory protection ID trap */
--
2.34.1
next prev parent reply other threads:[~2021-12-27 19:04 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-27 19:03 [PATCH AUTOSEL 5.15 01/26] pinctrl: mediatek: fix global-out-of-bounds issue Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 02/26] Input: i8042 - add deferred probe support Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 03/26] Input: iqs626a - prohibit inlining of channel parsing functions Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 04/26] ASoC: SOF: Intel: pci-tgl: add ADL-N support Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 05/26] ASoC: SOF: Intel: pci-tgl: add new ADL-P variant Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 06/26] Input: i8042 - enable deferred probe quirk for ASUS UM325UA Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 07/26] Input: goodix - add id->model mapping for the "9111" model Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 08/26] hwmon: (lm90) Do not report 'busy' status bit as alarm Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 09/26] ASoC: rt5682: fix the wrong jack type detected Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 10/26] ASoC: tas2770: Fix setting of high sample rates Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 11/26] Revert "x86/boot: Pull up cmdline preparation and early param parsing" Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 12/26] tomoyo: Check exceeded quota early in tomoyo_domain_quota_is_ok() Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 13/26] tomoyo: use hwight16() " Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 14/26] x86/boot: Move EFI range reservation after cmdline parsing Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 15/26] net/sched: Extend qdisc control block with tc control block Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 16/26] tun: avoid double free in tun_free_netdev Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 17/26] ax25: NPD bug when detaching AX25 device Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 18/26] Input: elants_i2c - do not check Remark ID on eKTH3900/eKTH5312 Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 19/26] phonet/pep: refuse to enable an unbound pipe Sasha Levin
2021-12-27 19:03 ` Sasha Levin [this message]
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 21/26] platform/mellanox: mlxbf-pmc: Fix an IS_ERR() vs NULL bug in mlxbf_pmc_map_counters Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 22/26] platform/x86: apple-gmux: use resource_size() with res Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 23/26] memblock: fix memblock_phys_alloc() section mismatch error Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 24/26] ALSA: hda: intel-sdw-acpi: harden detection of controller Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 25/26] ALSA: hda: intel-sdw-acpi: go through HDAS ACPI at max depth of 2 Sasha Levin
2021-12-27 19:03 ` [PATCH AUTOSEL 5.15 26/26] r8152: sync ocp base Sasha Levin
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=20211227190327.1042326-20-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=James.Bottomley@HansenPartnership.com \
--cc=akpm@linux-foundation.org \
--cc=dave.anglin@bell.net \
--cc=deller@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-parisc@vger.kernel.org \
--cc=mpe@ellerman.id.au \
--cc=rmk+kernel@armlinux.org.uk \
--cc=stable@vger.kernel.org \
--cc=svens@stackframe.org \
--cc=wangkefeng.wang@huawei.com \
/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
all inboxes | Powered by JetHome®