From: "Jürgen Groß" <jgross@suse.com>
To: "Kalra, Ashish" <ashish.kalra@amd.com>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"luto@kernel.org" <luto@kernel.org>,
"bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"tglx@linutronix.de" <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>,
"mhklinux@outlook.com" <mhklinux@outlook.com>,
"Rodel, Jorg" <jroedel@suse.de>, "hpa@zytor.com" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"thomas.lendacky@amd.com" <thomas.lendacky@amd.com>,
"kirill.shutemov@linux.intel.com"
<kirill.shutemov@linux.intel.com>,
"peterx@redhat.com" <peterx@redhat.com>,
"linux-coco@lists.linux.dev" <linux-coco@lists.linux.dev>
Subject: Re: [PATCH] x86/mm: fix lookup_address() to handle physical memory holes in direct mapping
Date: Tue, 2 Jul 2024 07:29:44 +0200 [thread overview]
Message-ID: <89aa51c4-20e1-4284-9ab4-bb505f261bea@suse.com> (raw)
In-Reply-To: <306a9358-a452-4595-b1d0-8e38a53d9084@amd.com>
On 01.07.24 21:39, Kalra, Ashish wrote:
>
> On 7/1/2024 2:13 PM, Edgecombe, Rick P wrote:
>> On Mon, 2024-07-01 at 13:59 -0500, Kalra, Ashish wrote:
>>> Then what is the caller supposed to do in this case ?
>>>
>>> As the return from lookup_address() is non-NULL in this case, accessing it
>>> causes a fatal #PF.
>>>
>>> Is the caller supposed to add the check for a valid PTE using pte_none(*pte) ?
>> I did a quick look at the callers, and some do their own check for pte_none().
>> But some don't. Some also assume the return can't be NULL.
>>
>> Can you elaborate on your goal for this change? Just a cleanup?
>
> Hit this issue while implementing and testing SNP guest kexec.
>
> So trying to understand if need a generic fix for this issue or do i need to add my own check for pte_none() ?
Please add a check for pte_none() after calling lookup_address().
Juergen
prev parent reply other threads:[~2024-07-02 5:29 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-28 20:52 [PATCH] x86/mm: fix lookup_address() to handle physical memory holes in direct mapping Ashish Kalra
2024-06-28 20:58 ` Edgecombe, Rick P
2024-06-28 21:22 ` Kalra, Ashish
2024-06-28 21:33 ` Edgecombe, Rick P
2024-06-28 21:36 ` Tom Lendacky
2024-06-28 21:31 ` Tom Lendacky
2024-06-29 10:20 ` Jürgen Groß
2024-06-29 15:16 ` Tom Lendacky
2024-06-29 16:50 ` Jürgen Groß
2024-07-01 17:57 ` Kalra, Ashish
2024-07-01 18:38 ` Jürgen Groß
2024-07-01 18:59 ` Kalra, Ashish
2024-07-01 19:13 ` Edgecombe, Rick P
2024-07-01 19:39 ` Kalra, Ashish
2024-07-02 5:29 ` Jürgen Groß [this message]
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