Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Received-SPF: None (esa5.hc3370-68.iphmx.com: no sender
  authenticity information available from domain of
  sergey.dyasli@citrix.com) identity=pra;
  client-ip=162.221.158.21; receiver=esa5.hc3370-68.iphmx.com;
  envelope-from="sergey.dyasli@citrix.com";
  x-sender="sergey.dyasli@citrix.com";
  x-conformance=sidf_compatible
Received-SPF: Pass (esa5.hc3370-68.iphmx.com: domain of
  sergey.dyasli@citrix.com designates 162.221.158.21 as
  permitted sender) identity=mailfrom;
  client-ip=162.221.158.21; receiver=esa5.hc3370-68.iphmx.com;
  envelope-from="sergey.dyasli@citrix.com";
  x-sender="sergey.dyasli@citrix.com";
  x-conformance=sidf_compatible; x-record-type="v=spf1";
  x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133
  ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4
  ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88
  ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83
  ip4:168.245.78.127 ~all"
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  authenticity information available from domain of
  postmaster@mail.citrix.com) identity=helo;
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  envelope-from="sergey.dyasli@citrix.com";
  x-sender="postmaster@mail.citrix.com";
  x-conformance=sidf_compatible
IronPort-SDR: TqQkzmi9JuPNn7Gy/JzerQopbW+J7Eg/HSvyodqgKwy6liyt49GclLM2WQADT6NXTl/kZ1p9du
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 iuU=
From:   Sergey Dyasli <sergey.dyasli@citrix.com>
To:     <xen-devel@lists.xen.org>, <kasan-dev@googlegroups.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
CC:     Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        "Stefano Stabellini" <sstabellini@kernel.org>,
        George Dunlap <george.dunlap@citrix.com>,
        Ross Lagerwall <ross.lagerwall@citrix.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Sergey Dyasli <sergey.dyasli@citrix.com>
Subject: [PATCH v1 3/4] xen: teach KASAN about grant tables
Date:   Wed, 8 Jan 2020 15:20:59 +0000
Message-ID: <20200108152100.7630-4-sergey.dyasli@citrix.com>
In-Reply-To: <20200108152100.7630-1-sergey.dyasli@citrix.com>
References: <20200108152100.7630-1-sergey.dyasli@citrix.com>
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Sender: linux-kernel-owner@vger.kernel.org
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From: Ross Lagerwall <ross.lagerwall@citrix.com>

Otherwise it produces lots of false positives when a guest starts using
PV I/O devices.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
---
RFC --> v1:
- Slightly clarified the commit message
---
 drivers/xen/grant-table.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 7b36b51cdb9f..ce95f7232de6 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -1048,6 +1048,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 			foreign = xen_page_foreign(pages[i]);
 			foreign->domid = map_ops[i].dom;
 			foreign->gref = map_ops[i].ref;
+			kasan_alloc_pages(pages[i], 0);
 			break;
 		}
 
@@ -1084,8 +1085,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 	if (ret)
 		return ret;
 
-	for (i = 0; i < count; i++)
+	for (i = 0; i < count; i++) {
 		ClearPageForeign(pages[i]);
+		kasan_free_pages(pages[i], 0);
+	}
 
 	return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
 }
-- 
2.17.1