From: Christoph Hellwig <hch@lst.de>
To: Andy Gross <agross@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konrad.dybcio@linaro.org>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>
Cc: linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
iommu@lists.linux.dev
Subject: [PATCH 1/2] Revert "remoteproc: qcom_q6v5_mss: map/unmap metadata region before/after use"
Date: Fri, 23 Dec 2022 10:27:02 +0100 [thread overview]
Message-ID: <20221223092703.61927-2-hch@lst.de> (raw)
In-Reply-To: <20221223092703.61927-1-hch@lst.de>
This reverts commit fc156629b23a21181e473e60341e3a78af25a1d4.
This commit manages to do three API violations at once:
- dereference the return value of dma_alloc_attrs with the
DMA_ATTR_NO_KERNEL_MAPPING mapping, which is clearly forbidden and
will do the wrong thing on various dma mapping implementations. The
fact that dma-direct uses a struct page as a cookie is an undocumented
implementation detail
- include dma-map-ops.h and use pgprot_dmacoherent despite a clear
comment documenting that this is not acceptable
- use of the VM_DMA_COHERENT for something that is not the dma-mapping
code
- use of VM_FLUSH_RESET_PERMS for vmap, while it is only supported for
vmalloc
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/remoteproc/qcom_q6v5_mss.c | 38 +++++-------------------------
1 file changed, 6 insertions(+), 32 deletions(-)
diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index fddb63cffee078..a8b141db4de63f 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c
@@ -10,7 +10,6 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/devcoredump.h>
-#include <linux/dma-map-ops.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
@@ -933,52 +932,27 @@ static void q6v5proc_halt_axi_port(struct q6v5 *qproc,
static int q6v5_mpss_init_image(struct q6v5 *qproc, const struct firmware *fw,
const char *fw_name)
{
- unsigned long dma_attrs = DMA_ATTR_FORCE_CONTIGUOUS | DMA_ATTR_NO_KERNEL_MAPPING;
- unsigned long flags = VM_DMA_COHERENT | VM_FLUSH_RESET_PERMS;
- struct page **pages;
- struct page *page;
+ unsigned long dma_attrs = DMA_ATTR_FORCE_CONTIGUOUS;
dma_addr_t phys;
void *metadata;
int mdata_perm;
int xferop_ret;
size_t size;
- void *vaddr;
- int count;
+ void *ptr;
int ret;
- int i;
metadata = qcom_mdt_read_metadata(fw, &size, fw_name, qproc->dev);
if (IS_ERR(metadata))
return PTR_ERR(metadata);
- page = dma_alloc_attrs(qproc->dev, size, &phys, GFP_KERNEL, dma_attrs);
- if (!page) {
+ ptr = dma_alloc_attrs(qproc->dev, size, &phys, GFP_KERNEL, dma_attrs);
+ if (!ptr) {
kfree(metadata);
dev_err(qproc->dev, "failed to allocate mdt buffer\n");
return -ENOMEM;
}
- count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
- if (!pages) {
- ret = -ENOMEM;
- goto free_dma_attrs;
- }
-
- for (i = 0; i < count; i++)
- pages[i] = nth_page(page, i);
-
- vaddr = vmap(pages, count, flags, pgprot_dmacoherent(PAGE_KERNEL));
- kfree(pages);
- if (!vaddr) {
- dev_err(qproc->dev, "unable to map memory region: %pa+%zx\n", &phys, size);
- ret = -EBUSY;
- goto free_dma_attrs;
- }
-
- memcpy(vaddr, metadata, size);
-
- vunmap(vaddr);
+ memcpy(ptr, metadata, size);
/* Hypervisor mapping to access metadata by modem */
mdata_perm = BIT(QCOM_SCM_VMID_HLOS);
@@ -1008,7 +982,7 @@ static int q6v5_mpss_init_image(struct q6v5 *qproc, const struct firmware *fw,
"mdt buffer not reclaimed system may become unstable\n");
free_dma_attrs:
- dma_free_attrs(qproc->dev, size, page, phys, dma_attrs);
+ dma_free_attrs(qproc->dev, size, ptr, phys, dma_attrs);
kfree(metadata);
return ret < 0 ? ret : 0;
--
2.35.1
next prev parent reply other threads:[~2022-12-23 9:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-23 9:27 revert dma-mapping and vmap API abuse in qcom_q6v5_mss Christoph Hellwig
2022-12-23 9:27 ` Christoph Hellwig [this message]
2022-12-23 14:47 ` [PATCH 1/2] Revert "remoteproc: qcom_q6v5_mss: map/unmap metadata region before/after use" Manivannan Sadhasivam
2022-12-23 14:57 ` Christoph Hellwig
2022-12-23 15:40 ` Manivannan Sadhasivam
2022-12-23 15:51 ` Christoph Hellwig
2022-12-23 9:27 ` [PATCH 2/2] vmalloc: reject vmap with VM_FLUSH_RESET_PERMS Christoph Hellwig
2022-12-23 10:24 ` Lorenzo Stoakes
2022-12-23 14:03 ` Christoph Hellwig
2022-12-23 14:10 ` Lorenzo Stoakes
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=20221223092703.61927-2-hch@lst.de \
--to=hch@lst.de \
--cc=agross@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=andersson@kernel.org \
--cc=iommu@lists.linux.dev \
--cc=konrad.dybcio@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-remoteproc@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=urezki@gmail.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).