linux-kernel - [PATCH v2 2/2] device-dax: implement ->pagesize() for smaps to report MMUPageSize

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] [day] [month] [year] [list]

Date:   Fri, 09 Feb 2018 17:38:32 -0700
From:   Dave Jiang <dave.jiang@...el.com>
To:     akpm@...ux-foundation.org
Cc:     Jane Chu <jane.chu@...cle.com>, linux-nvdimm@...ts.01.org,
        linux-kernel@...r.kernel.org, mhocko@...nel.org,
        linux-mm@...ck.org, dan.j.williams@...el.com
Subject: [PATCH v2 2/2] device-dax: implement ->pagesize() for smaps to
 report MMUPageSize

From: Dan Williams <dan.j.williams@...el.com>

Given that device-dax is making similar page mapping size guarantees as
hugetlbfs, emit the size in smaps and any other kernel path that
requests the mapping size of a vma.

Reported-by: Jane Chu <jane.chu@...cle.com>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
 drivers/dax/device.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 7b0bf825c4e7..b57cd5a7b0bd 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -439,10 +439,20 @@ static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr)
 	return 0;
 }
 
+static unsigned long dev_dax_pagesize(struct vm_area_struct *vma)
+{
+	struct file *filp = vma->vm_file;
+	struct dev_dax *dev_dax = filp->private_data;
+	struct dax_region *dax_region = dev_dax->region;
+
+	return dax_region->align;
+}
+
 static const struct vm_operations_struct dax_vm_ops = {
 	.fault = dev_dax_fault,
 	.huge_fault = dev_dax_huge_fault,
 	.split = dev_dax_split,
+	.pagesize = dev_dax_pagesize,
 };
 
 static int dax_mmap(struct file *filp, struct vm_area_struct *vma)