linux-kernel - [PATCH 08/11] KVM: guest_memfd: extract __kvm_gmem_punch

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

Date: Thu,  4 Apr 2024 14:50:30 -0400
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Cc: seanjc@...gle.com,
	michael.roth@....com,
	isaku.yamahata@...el.com
Subject: [PATCH 08/11] KVM: guest_memfd: extract __kvm_gmem_punch_hole()

Extract a version of kvm_gmem_punch_hole() that expects the
caller to take the filemap invalidate_lock.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 virt/kvm/guest_memfd.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index a537a7e63ab5..51c99667690a 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -152,19 +152,12 @@ static void kvm_gmem_invalidate_end(struct kvm_gmem *gmem, pgoff_t start,
 	}
 }
 
-static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
+static long __kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 {
 	struct list_head *gmem_list = &inode->i_mapping->i_private_list;
 	pgoff_t start = offset >> PAGE_SHIFT;
 	pgoff_t end = (offset + len) >> PAGE_SHIFT;
 	struct kvm_gmem *gmem;
-
-	/*
-	 * Bindings must be stable across invalidation to ensure the start+end
-	 * are balanced.
-	 */
-	filemap_invalidate_lock(inode->i_mapping);
-
 	list_for_each_entry(gmem, gmem_list, entry)
 		kvm_gmem_invalidate_begin(gmem, start, end);
 
@@ -173,11 +166,23 @@ static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 	list_for_each_entry(gmem, gmem_list, entry)
 		kvm_gmem_invalidate_end(gmem, start, end);
 
-	filemap_invalidate_unlock(inode->i_mapping);
-
 	return 0;
 }
 
+static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
+{
+	int r;
+
+	/*
+	 * Bindings must be stable across invalidation to ensure the start+end
+	 * are balanced.
+	 */
+	filemap_invalidate_lock(inode->i_mapping);
+	r = __kvm_gmem_punch_hole(inode, offset, len);
+	filemap_invalidate_unlock(inode->i_mapping);
+	return r;
+}
+
 static long kvm_gmem_allocate(struct inode *inode, loff_t offset, loff_t len)
 {
 	struct address_space *mapping = inode->i_mapping;
-- 
2.43.0