All of lore.kernel.org
 help / color / mirror / Atom feed
From: Adrian Hunter <adrian.hunter@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Borislav Petkov <bp@alien8.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ard Biesheuvel <ardb@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Mike Rapoport <rppt@linux.ibm.com>,
	Lorenzo Stoakes <lstoakes@gmail.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
	Dave Young <dyoung@redhat.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, linux-coco@lists.linux.dev,
	linux-efi@vger.kernel.org, kexec@lists.infradead.org
Subject: [PATCH V2 2/2] proc/kcore: Do not try to access unaccepted memory
Date: Mon, 11 Sep 2023 14:21:14 +0300	[thread overview]
Message-ID: <20230911112114.91323-3-adrian.hunter@intel.com> (raw)
In-Reply-To: <20230911112114.91323-1-adrian.hunter@intel.com>

Support for unaccepted memory was added recently, refer commit
dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual
machine may need to accept memory before it can be used.

Do not try to access unaccepted memory because it can cause the guest to
fail.

For /proc/kcore, which is read-only and does not support mmap, this means a
read of unaccepted memory will return zeros.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 fs/proc/kcore.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


Changes in V2:

          Change patch subject and commit message
          Do not open code pfn_is_unaccepted_memory()


diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 23fc24d16b31..6422e569b080 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -546,7 +546,8 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
 			 * and explicitly excluded physical ranges.
 			 */
 			if (!page || PageOffline(page) ||
-			    is_page_hwpoison(page) || !pfn_is_ram(pfn)) {
+			    is_page_hwpoison(page) || !pfn_is_ram(pfn) ||
+			    pfn_is_unaccepted_memory(pfn)) {
 				if (iov_iter_zero(tsz, iter) != tsz) {
 					ret = -EFAULT;
 					goto out;
-- 
2.34.1


WARNING: multiple messages have this Message-ID (diff)
From: Adrian Hunter <adrian.hunter@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Borislav Petkov <bp@alien8.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ard Biesheuvel <ardb@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Mike Rapoport <rppt@linux.ibm.com>,
	Lorenzo Stoakes <lstoakes@gmail.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
	Dave Young <dyoung@redhat.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, linux-coco@lists.linux.dev,
	linux-efi@vger.kernel.org, kexec@lists.infradead.org
Subject: [PATCH V2 2/2] proc/kcore: Do not try to access unaccepted memory
Date: Mon, 11 Sep 2023 14:21:14 +0300	[thread overview]
Message-ID: <20230911112114.91323-3-adrian.hunter@intel.com> (raw)
In-Reply-To: <20230911112114.91323-1-adrian.hunter@intel.com>

Support for unaccepted memory was added recently, refer commit
dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual
machine may need to accept memory before it can be used.

Do not try to access unaccepted memory because it can cause the guest to
fail.

For /proc/kcore, which is read-only and does not support mmap, this means a
read of unaccepted memory will return zeros.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 fs/proc/kcore.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


Changes in V2:

          Change patch subject and commit message
          Do not open code pfn_is_unaccepted_memory()


diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 23fc24d16b31..6422e569b080 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -546,7 +546,8 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
 			 * and explicitly excluded physical ranges.
 			 */
 			if (!page || PageOffline(page) ||
-			    is_page_hwpoison(page) || !pfn_is_ram(pfn)) {
+			    is_page_hwpoison(page) || !pfn_is_ram(pfn) ||
+			    pfn_is_unaccepted_memory(pfn)) {
 				if (iov_iter_zero(tsz, iter) != tsz) {
 					ret = -EFAULT;
 					goto out;
-- 
2.34.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

  parent reply	other threads:[~2023-09-11 11:21 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-11 11:21 [PATCH V2 0/2] Do not try to access unaccepted memory Adrian Hunter
2023-09-11 11:21 ` Adrian Hunter
2023-09-11 11:21 ` [PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore " Adrian Hunter
2023-09-11 11:21   ` Adrian Hunter
2023-09-12  7:18   ` David Hildenbrand
2023-09-12  7:18     ` David Hildenbrand
2023-09-12  7:19   ` David Hildenbrand
2023-09-12  7:19     ` David Hildenbrand
2023-09-12  7:47     ` Adrian Hunter
2023-09-12  7:47       ` Adrian Hunter
2023-09-12  7:50       ` David Hildenbrand
2023-09-12  7:50         ` David Hildenbrand
2023-09-11 11:21 ` Adrian Hunter [this message]
2023-09-11 11:21   ` [PATCH V2 2/2] proc/kcore: Do not " Adrian Hunter
2023-09-12  7:13   ` David Hildenbrand
2023-09-12  7:13     ` David Hildenbrand

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=20230911112114.91323-3-adrian.hunter@intel.com \
    --to=adrian.hunter@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=ardb@kernel.org \
    --cc=bhe@redhat.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@intel.com \
    --cc=dyoung@redhat.com \
    --cc=kexec@lists.infradead.org \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lstoakes@gmail.com \
    --cc=rppt@linux.ibm.com \
    --cc=thomas.lendacky@amd.com \
    --cc=vbabka@suse.cz \
    --cc=vgoyal@redhat.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.