All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jacopo Mondi <jacopo+renesas@jmondi.org>
To: ysato@users.sourceforge.jp, dalias@libc.org,
	thomas.petazzoni@free-electrons.com, robin.murphy@arm.com
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
	geert@linux-m68k.org, linux-renesas-soc@vger.kernel.org,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] sh: mm: Fix unprotected access to struct device
Date: Tue, 17 Apr 2018 14:35:51 +0000	[thread overview]
Message-ID: <1523975751-12826-1-git-send-email-jacopo+renesas@jmondi.org> (raw)

With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping
operations observe dev->dma_pfn_offset") the generic DMA allocation
function on which the SH 'dma_alloc_coherent()' function relies on,
accesses the 'dma_pfn_offset' field of struct device.

Unfortunately the 'dma_generic_alloc_coherent()' function is called from
several places with a NULL struct device argument, halting the CPU
during the boot process.

This patch fixes the issue by protecting access to dev->dma_pfn_offset,
with a trivial check for validity. It also passes a valid 'struct device'
in the 'platform_resource_setup_memory' function which is the main user
of 'dma_alloc_coherent()', and inserts a WARN_ON() check to remind to future
(and existing) bogus users of this function to provide a valid 'struct device'
whenever possible.

Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset")
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 arch/sh/mm/consistent.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 8ce9869..ec177c0 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -59,7 +59,9 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,

 	split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);

-	*dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset);
+	*dma_handle = virt_to_phys(ret);
+	if (!WARN_ON(!dev))
+		*dma_handle -= PFN_PHYS(dev->dma_pfn_offset);

 	return ret_nocache;
 }
@@ -69,9 +71,12 @@ void dma_generic_free_coherent(struct device *dev, size_t size,
 			       unsigned long attrs)
 {
 	int order = get_order(size);
-	unsigned long pfn = (dma_handle >> PAGE_SHIFT) + dev->dma_pfn_offset;
+	unsigned long pfn = (dma_handle >> PAGE_SHIFT);
 	int k;

+	if (!WARN_ON(!dev))
+		pfn += dev->dma_pfn_offset;
+
 	for (k = 0; k < (1 << order); k++)
 		__free_pages(pfn_to_page(pfn + k), 0);

@@ -143,7 +148,7 @@ int __init platform_resource_setup_memory(struct platform_device *pdev,
 	if (!memsize)
 		return 0;

-	buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
+	buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL);
 	if (!buf) {
 		pr_warning("%s: unable to allocate memory\n", name);
 		return -ENOMEM;
--
2.7.4


WARNING: multiple messages have this Message-ID (diff)
From: Jacopo Mondi <jacopo+renesas@jmondi.org>
To: ysato@users.sourceforge.jp, dalias@libc.org,
	thomas.petazzoni@free-electrons.com, robin.murphy@arm.com
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
	geert@linux-m68k.org, linux-renesas-soc@vger.kernel.org,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] sh: mm: Fix unprotected access to struct device
Date: Tue, 17 Apr 2018 16:35:51 +0200	[thread overview]
Message-ID: <1523975751-12826-1-git-send-email-jacopo+renesas@jmondi.org> (raw)

With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping
operations observe dev->dma_pfn_offset") the generic DMA allocation
function on which the SH 'dma_alloc_coherent()' function relies on,
accesses the 'dma_pfn_offset' field of struct device.

Unfortunately the 'dma_generic_alloc_coherent()' function is called from
several places with a NULL struct device argument, halting the CPU
during the boot process.

This patch fixes the issue by protecting access to dev->dma_pfn_offset,
with a trivial check for validity. It also passes a valid 'struct device'
in the 'platform_resource_setup_memory' function which is the main user
of 'dma_alloc_coherent()', and inserts a WARN_ON() check to remind to future
(and existing) bogus users of this function to provide a valid 'struct device'
whenever possible.

Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset")
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 arch/sh/mm/consistent.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 8ce9869..ec177c0 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -59,7 +59,9 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,

 	split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);

-	*dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset);
+	*dma_handle = virt_to_phys(ret);
+	if (!WARN_ON(!dev))
+		*dma_handle -= PFN_PHYS(dev->dma_pfn_offset);

 	return ret_nocache;
 }
@@ -69,9 +71,12 @@ void dma_generic_free_coherent(struct device *dev, size_t size,
 			       unsigned long attrs)
 {
 	int order = get_order(size);
-	unsigned long pfn = (dma_handle >> PAGE_SHIFT) + dev->dma_pfn_offset;
+	unsigned long pfn = (dma_handle >> PAGE_SHIFT);
 	int k;

+	if (!WARN_ON(!dev))
+		pfn += dev->dma_pfn_offset;
+
 	for (k = 0; k < (1 << order); k++)
 		__free_pages(pfn_to_page(pfn + k), 0);

@@ -143,7 +148,7 @@ int __init platform_resource_setup_memory(struct platform_device *pdev,
 	if (!memsize)
 		return 0;

-	buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
+	buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL);
 	if (!buf) {
 		pr_warning("%s: unable to allocate memory\n", name);
 		return -ENOMEM;
--
2.7.4

             reply	other threads:[~2018-04-17 14:35 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-17 14:35 Jacopo Mondi [this message]
2018-04-17 14:35 ` [PATCH v2] sh: mm: Fix unprotected access to struct device Jacopo Mondi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1523975751-12826-1-git-send-email-jacopo+renesas@jmondi.org \
    --to=jacopo+renesas@jmondi.org \
    --cc=dalias@libc.org \
    --cc=geert@linux-m68k.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=thomas.petazzoni@free-electrons.com \
    --cc=ysato@users.sourceforge.jp \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.