linux-kernel - [PATCH v2 08/14] tools/testing/nvdimm: Allow a NULL-pfn to ->direct

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:   Mon, 16 Jul 2018 10:01:03 -0700
From:   Dan Williams <dan.j.williams@...el.com>
To:     akpm@...ux-foundation.org
Cc:     Huaisheng Ye <yehs1@...ovo.com>, Jan Kara <jack@...e.cz>,
        vishal.l.verma@...el.com, hch@....de, linux-mm@...ck.org,
        jack@...e.cz, linux-nvdimm@...ts.01.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 08/14] tools/testing/nvdimm: Allow a NULL-pfn to
 ->direct_access()

From: Huaisheng Ye <yehs1@...ovo.com>

The mock / test version of pmem_direct_access() needs to check the
validity of pointer pfn for NULL assignment. If pfn equals to NULL, it
doesn't need to calculate the value. This is in support of asynchronous
memmap init and avoid page lookups when possible.

Suggested-by: Dan Williams <dan.j.williams@...el.com>
Signed-off-by: Huaisheng Ye <yehs1@...ovo.com>
Reviewed-by: Jan Kara <jack@...e.cz>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
 tools/testing/nvdimm/pmem-dax.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/nvdimm/pmem-dax.c b/tools/testing/nvdimm/pmem-dax.c
index b53596ad601b..d4cb5281b30e 100644
--- a/tools/testing/nvdimm/pmem-dax.c
+++ b/tools/testing/nvdimm/pmem-dax.c
@@ -33,7 +33,8 @@ long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 
 		*kaddr = pmem->virt_addr + offset;
 		page = vmalloc_to_page(pmem->virt_addr + offset);
-		*pfn = page_to_pfn_t(page);
+		if (pfn)
+			*pfn = page_to_pfn_t(page);
 		pr_debug_ratelimited("%s: pmem: %p pgoff: %#lx pfn: %#lx\n",
 				__func__, pmem, pgoff, page_to_pfn(page));
 
@@ -41,7 +42,8 @@ long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 	}
 
 	*kaddr = pmem->virt_addr + offset;
-	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
+	if (pfn)
+		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 
 	/*
 	 * If badblocks are present, limit known good range to the