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From: Miles Chen <miles.chen@mediatek.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-mediatek@lists.infradead.org>, <wsd_upstream@mediatek.com>,
	Miles Chen <miles.chen@mediatek.com>
Subject: [PATCH] proc: use untagged_addr() for pagemap_read addresses
Date: Mon, 3 Aug 2020 23:39:53 +0800	[thread overview]
Message-ID: <20200803153953.20364-1-miles.chen@mediatek.com> (raw)

When we try to visit the pagemap of a tagged userspace pointer, we find
that the start_vaddr is not correct because of the tag.
To fix it, we should untag the usespace pointers in pagemap_read().

Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
 fs/proc/task_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dbda4499a859..d0c6e8e0cf37 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1541,11 +1541,11 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
 	src = *ppos;
 	svpfn = src / PM_ENTRY_BYTES;
-	start_vaddr = svpfn << PAGE_SHIFT;
+	start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
 	end_vaddr = mm->task_size;
 
 	/* watch out for wraparound */
-	if (svpfn > mm->task_size >> PAGE_SHIFT)
+	if (start_vaddr > mm->task_size)
 		start_vaddr = end_vaddr;
 
 	/*
-- 
2.18.0

WARNING: multiple messages have this Message-ID (diff)
From: Miles Chen <miles.chen@mediatek.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org,
	Miles Chen <miles.chen@mediatek.com>,
	linux-mediatek@lists.infradead.org,
	linux-fsdevel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH] proc: use untagged_addr() for pagemap_read addresses
Date: Mon, 3 Aug 2020 23:39:53 +0800	[thread overview]
Message-ID: <20200803153953.20364-1-miles.chen@mediatek.com> (raw)

When we try to visit the pagemap of a tagged userspace pointer, we find
that the start_vaddr is not correct because of the tag.
To fix it, we should untag the usespace pointers in pagemap_read().

Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
 fs/proc/task_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dbda4499a859..d0c6e8e0cf37 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1541,11 +1541,11 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
 	src = *ppos;
 	svpfn = src / PM_ENTRY_BYTES;
-	start_vaddr = svpfn << PAGE_SHIFT;
+	start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
 	end_vaddr = mm->task_size;
 
 	/* watch out for wraparound */
-	if (svpfn > mm->task_size >> PAGE_SHIFT)
+	if (start_vaddr > mm->task_size)
 		start_vaddr = end_vaddr;
 
 	/*
-- 
2.18.0
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID (diff)
From: Miles Chen <miles.chen@mediatek.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org,
	Miles Chen <miles.chen@mediatek.com>,
	linux-mediatek@lists.infradead.org,
	linux-fsdevel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH] proc: use untagged_addr() for pagemap_read addresses
Date: Mon, 3 Aug 2020 23:39:53 +0800	[thread overview]
Message-ID: <20200803153953.20364-1-miles.chen@mediatek.com> (raw)

When we try to visit the pagemap of a tagged userspace pointer, we find
that the start_vaddr is not correct because of the tag.
To fix it, we should untag the usespace pointers in pagemap_read().

Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
 fs/proc/task_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dbda4499a859..d0c6e8e0cf37 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1541,11 +1541,11 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
 	src = *ppos;
 	svpfn = src / PM_ENTRY_BYTES;
-	start_vaddr = svpfn << PAGE_SHIFT;
+	start_vaddr = untagged_addr(svpfn << PAGE_SHIFT);
 	end_vaddr = mm->task_size;
 
 	/* watch out for wraparound */
-	if (svpfn > mm->task_size >> PAGE_SHIFT)
+	if (start_vaddr > mm->task_size)
 		start_vaddr = end_vaddr;
 
 	/*
-- 
2.18.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2020-08-03 15:40 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-03 15:39 Miles Chen [this message]
2020-08-03 15:39 ` [PATCH] proc: use untagged_addr() for pagemap_read addresses Miles Chen
2020-08-03 15:39 ` Miles Chen

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