linux-kernel - [PATCH v5.1 15/19] mm/mmap: Use PHYS_PFN in mmap

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]

Message-ID: <20240816111405.11793-16-spasswolf@web.de>
Date: Fri, 16 Aug 2024 13:13:56 +0200
From: Bert Karwatzki <spasswolf@....de>
To: "Liam R . Howlett" <Liam.Howlett@...cle.com>
Cc: Bert Karwatzki <spasswolf@....de>,
	Suren Baghdasaryan <surenb@...gle.com>,
	Vlastimil Babka <vbabka@...e.cz>,
	Lorenzo Stoakes <lstoakes@...il.com>,
	Matthew Wilcox <willy@...radead.org>,
	sidhartha.kumar@...cle.com,
	"Paul E . McKenney" <paulmck@...nel.org>,
	Jiri Olsa <olsajiri@...il.com>,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Kees Cook <kees@...nel.org>,
	Jeff Xu <jeffxu@...omium.org>,
	"Liam R . Howlett" <Liam.Howlett@...cle.com>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Subject: [PATCH v5.1 15/19] mm/mmap: Use PHYS_PFN in mmap_region()

Instead of shifting the length by PAGE_SIZE, use PHYS_PFN.  Also use the
existing local variable everywhere instead of some of the time.

Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Reviewed-by: Suren Baghdasaryan <surenb@...gle.com>
---
 mm/mmap.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index e152b6caaf9c..57fb1c82a852 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1364,7 +1364,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma = NULL;
 	struct vm_area_struct *next, *prev, *merge;
-	pgoff_t pglen = len >> PAGE_SHIFT;
+	pgoff_t pglen = PHYS_PFN(len);
 	unsigned long charged = 0;
 	struct vma_munmap_struct vms;
 	struct ma_state mas_detach;
@@ -1384,7 +1384,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	 * MAP_FIXED may remove pages of mappings that intersects with requested
 	 * mapping. Account for the pages it would unmap.
 	 */
-	if (!may_expand_vm(mm, vm_flags, (len >> PAGE_SHIFT) - nr_pages))
+	if (!may_expand_vm(mm, vm_flags, pglen - nr_pages))
 		return -ENOMEM;

 	if (unlikely(!can_modify_mm(mm, addr, end)))
@@ -1415,7 +1415,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	 * Private writable mapping: check memory availability
 	 */
 	if (accountable_mapping(file, vm_flags)) {
-		charged = len >> PAGE_SHIFT;
+		charged = pglen;
 		charged -= nr_accounted;
 		if (security_vm_enough_memory_mm(mm, charged))
 			goto abort_munmap;
@@ -1575,14 +1575,14 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	if (vms.nr_pages)
 		vms_complete_munmap_vmas(&vms, &mas_detach);

-	vm_stat_account(mm, vm_flags, len >> PAGE_SHIFT);
+	vm_stat_account(mm, vm_flags, pglen);
 	if (vm_flags & VM_LOCKED) {
 		if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) ||
 					is_vm_hugetlb_page(vma) ||
 					vma == get_gate_vma(current->mm))
 			vm_flags_clear(vma, VM_LOCKED_MASK);
 		else
-			mm->locked_vm += (len >> PAGE_SHIFT);
+			mm->locked_vm += pglen;
 	}

 	if (file)
--
2.45.2