linux-kernel - Re: [PATCH v2] MIPS: mm: tlb-r4k: Uniquify TLB entries on init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aHfpszi6l_YRSOjY@alpha.franken.de>
Date: Wed, 16 Jul 2025 20:04:35 +0200
From: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
To: Jiaxun Yang <jiaxun.yang@...goat.com>
Cc: "Maciej W. Rozycki" <macro@...am.me.uk>, linux-mips@...r.kernel.org,
	linux-kernel@...r.kernel.org, stable@...nel.org
Subject: Re: [PATCH v2] MIPS: mm: tlb-r4k: Uniquify TLB entries on init

On Sat, Jun 07, 2025 at 01:43:56PM +0100, Jiaxun Yang wrote:
> Hardware or bootloader will initialize TLB entries to any value, which
> may collide with kernel's UNIQUE_ENTRYHI value. On MIPS microAptiv/M5150
> family of cores this will trigger machine check exception and cause boot
> failure. On M5150 simulation this could happen 7 times out of 1000 boots.
> 
> Replace local_flush_tlb_all() with r4k_tlb_uniquify() which probes each
> TLB ENTRIHI unique value for collisions before it's written, and in case
> of collision try a different ASID.
> 
> Cc: stable@...nel.org
> Signed-off-by: Jiaxun Yang <jiaxun.yang@...goat.com>
> ---
> Changes in v2:
> - Cycle ASID instead of ENTRYHI index in case of collison.
> - Avoid int over flow UB (Maciej)
> - Link to v1: https://lore.kernel.org/r/20250605-tlb-fix-v1-1-4af496f17b2f@flygoat.com
> ---
>  arch/mips/mm/tlb-r4k.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 55 insertions(+), 1 deletion(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]