From: Balbir Singh <balbirs@nvidia.com>
To: Dave Hansen <dave.hansen@intel.com>, x86@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
apopple@nvidia.com, jhubbard@nvidia.com, jgg@nvidia.com,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>, Kees Cook <kees@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH v2] x86/kaslr: Revisit entropy when CONFIG_PCI_P2PDMA is enabled
Date: Fri, 7 Feb 2025 12:39:40 +1100 [thread overview]
Message-ID: <0b7945c5-d776-4313-a15f-d54cfb27aa32@nvidia.com> (raw)
In-Reply-To: <76d970d7-e183-4c7b-addd-3b00fa39f9b6@intel.com>
On 2/7/25 11:27, Dave Hansen wrote:
> On 2/6/25 15:42, Balbir Singh wrote:
>> Fix this by not shrinking the size of direct map when CONFIG_PCI_P2PDMA
>> is enabled. This reduces the total available entropy, but it's
>> better than the current work around of having to disable KASLR
>> completely.
>
> Is the size of these P2PDMA mappings known up front? Or do you just need
> them to be as large as possible?
The size is not known upfront, it depends on the system configuration.
Yes, we need them to be as large as possible.
Balbir
next prev parent reply other threads:[~2025-02-07 1:39 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-06 23:42 [PATCH v2] x86/kaslr: Revisit entropy when CONFIG_PCI_P2PDMA is enabled Balbir Singh
2025-02-07 0:27 ` Dave Hansen
2025-02-07 1:39 ` Balbir Singh [this message]
2025-02-07 1:00 ` Kees Cook
2025-02-19 1:11 ` Balbir Singh
2025-02-21 22:43 ` Bjorn Helgaas
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