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* [bug report] drm: remove usage of drm_pci_alloc/free
@ 2021-05-14 13:54 Dan Carpenter
  2021-05-14 15:13 ` Joseph Kogut
  2021-05-14 20:48 ` [PATCH 1/1] drm: drm_legacy_addbufs_pci(): fix return without cleanup Joseph Kogut
  0 siblings, 2 replies; 5+ messages in thread
From: Dan Carpenter @ 2021-05-14 13:54 UTC (permalink / raw)
  To: joseph.kogut; +Cc: dri-devel

Hello Joseph Kogut,

The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free"
from Apr 22, 2021, leads to the following static checker warning:

    drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
    warn: inconsistent returns '&dev->struct_mutex'.
      Locked on  : 988
      Unlocked on: 938,944,951,959,973,1005,1042,1060,1090

drivers/gpu/drm/drm_bufs.c
   965          temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
   966                                        sizeof(*dma->pagelist),
   967                                        GFP_KERNEL);
   968          if (!temp_pagelist) {
   969                  kfree(entry->buflist);
   970                  kfree(entry->seglist);
   971                  mutex_unlock(&dev->struct_mutex);
   972                  atomic_dec(&dev->buf_alloc);
   973                  return -ENOMEM;

There is a bunch of clean up happenning on the existing returns.

   974          }
   975          memcpy(temp_pagelist,
   976                 dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
   977          DRM_DEBUG("pagelist: %d entries\n",
   978                    dma->page_count + (count << page_order));
   979  
   980          entry->buf_size = size;
   981          entry->page_order = page_order;
   982          byte_count = 0;
   983          page_count = 0;
   984  
   985          while (entry->buf_count < count) {
   986                  dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
   987                  if (!dmah)
   988                          return -ENOMEM;

This new return has no clean up.  We a mutex_unlock(&dev->struct_mutex).

   989  
   990                  dmah->size = total;
   991                  dmah->vaddr = dma_alloc_coherent(dev->dev,
   992                                                   dmah->size,
   993                                                   &dmah->busaddr,
   994                                                   GFP_KERNEL);
   995                  if (!dmah->vaddr) {
   996                          kfree(dmah);
   997  
   998                          /* Set count correctly so we free the proper amount. */
   999                          entry->buf_count = count;
  1000                          entry->seg_count = count;
  1001                          drm_cleanup_buf_error(dev, entry);
  1002                          kfree(temp_pagelist);
  1003                          mutex_unlock(&dev->struct_mutex);
  1004                          atomic_dec(&dev->buf_alloc);
  1005                          return -ENOMEM;
  1006                  }
  1007                  entry->seglist[entry->seg_count++] = dmah;
  1008                  for (i = 0; i < (1 << page_order); i++) {
  1009                          DRM_DEBUG("page %d @ 0x%08lx\n",

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [bug report] drm: remove usage of drm_pci_alloc/free
  2021-05-14 13:54 [bug report] drm: remove usage of drm_pci_alloc/free Dan Carpenter
@ 2021-05-14 15:13 ` Joseph Kogut
  2021-05-14 16:34   ` Joseph Kogut
  2021-05-14 20:48 ` [PATCH 1/1] drm: drm_legacy_addbufs_pci(): fix return without cleanup Joseph Kogut
  1 sibling, 1 reply; 5+ messages in thread
From: Joseph Kogut @ 2021-05-14 15:13 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: dri-devel

Hi Dan,

On Fri, May 14, 2021 at 6:54 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> Hello Joseph Kogut,
>
> The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free"
> from Apr 22, 2021, leads to the following static checker warning:
>
>     drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
>     warn: inconsistent returns '&dev->struct_mutex'.
>       Locked on  : 988
>       Unlocked on: 938,944,951,959,973,1005,1042,1060,1090
>
> drivers/gpu/drm/drm_bufs.c
>    965          temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
>    966                                        sizeof(*dma->pagelist),
>    967                                        GFP_KERNEL);
>    968          if (!temp_pagelist) {
>    969                  kfree(entry->buflist);
>    970                  kfree(entry->seglist);
>    971                  mutex_unlock(&dev->struct_mutex);
>    972                  atomic_dec(&dev->buf_alloc);
>    973                  return -ENOMEM;
>
> There is a bunch of clean up happenning on the existing returns.
>
>    974          }
>    975          memcpy(temp_pagelist,
>    976                 dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
>    977          DRM_DEBUG("pagelist: %d entries\n",
>    978                    dma->page_count + (count << page_order));
>    979
>    980          entry->buf_size = size;
>    981          entry->page_order = page_order;
>    982          byte_count = 0;
>    983          page_count = 0;
>    984
>    985          while (entry->buf_count < count) {
>    986                  dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
>    987                  if (!dmah)
>    988                          return -ENOMEM;
>
> This new return has no clean up.  We a mutex_unlock(&dev->struct_mutex).
>
>    989
>    990                  dmah->size = total;
>    991                  dmah->vaddr = dma_alloc_coherent(dev->dev,
>    992                                                   dmah->size,
>    993                                                   &dmah->busaddr,
>    994                                                   GFP_KERNEL);
>    995                  if (!dmah->vaddr) {
>    996                          kfree(dmah);
>    997
>    998                          /* Set count correctly so we free the proper amount. */
>    999                          entry->buf_count = count;
>   1000                          entry->seg_count = count;
>   1001                          drm_cleanup_buf_error(dev, entry);
>   1002                          kfree(temp_pagelist);
>   1003                          mutex_unlock(&dev->struct_mutex);
>   1004                          atomic_dec(&dev->buf_alloc);
>   1005                          return -ENOMEM;
>   1006                  }
>   1007                  entry->seglist[entry->seg_count++] = dmah;
>   1008                  for (i = 0; i < (1 << page_order); i++) {
>   1009                          DRM_DEBUG("page %d @ 0x%08lx\n",
>
> regards,
> dan carpenter

Thanks for the report, I'll follow up with a patch to fix this.

Best,
Joseph

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [bug report] drm: remove usage of drm_pci_alloc/free
  2021-05-14 15:13 ` Joseph Kogut
@ 2021-05-14 16:34   ` Joseph Kogut
  2021-05-15  6:57     ` Dan Carpenter
  0 siblings, 1 reply; 5+ messages in thread
From: Joseph Kogut @ 2021-05-14 16:34 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: dri-devel

On Fri, May 14, 2021 at 8:13 AM Joseph Kogut <joseph.kogut@gmail.com> wrote:
>
> Hi Dan,
>
> On Fri, May 14, 2021 at 6:54 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > Hello Joseph Kogut,
> >
> > The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free"
> > from Apr 22, 2021, leads to the following static checker warning:
> >
> >     drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
> >     warn: inconsistent returns '&dev->struct_mutex'.
> >       Locked on  : 988
> >       Unlocked on: 938,944,951,959,973,1005,1042,1060,1090
> >

Do you mind if I copy this portion of the bug report in the commit message?

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH 1/1] drm: drm_legacy_addbufs_pci(): fix return without cleanup
  2021-05-14 13:54 [bug report] drm: remove usage of drm_pci_alloc/free Dan Carpenter
  2021-05-14 15:13 ` Joseph Kogut
@ 2021-05-14 20:48 ` Joseph Kogut
  1 sibling, 0 replies; 5+ messages in thread
From: Joseph Kogut @ 2021-05-14 20:48 UTC (permalink / raw)
  To: Daniel Vetter; +Cc: Joseph Kogut, dri-devel, Dan Carpenter

The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free" leads
to the following static checker warning:

    drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
    warn: inconsistent returns '&dev->struct_mutex'.
      Locked on  : 988
      Unlocked on: 938,944,951,959,973,1005,1042,1060,1090

Fix the return without cleanup by removing the early return and taking
the original return path on allocation failure, including the intended
unlocks.

Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com>
---
 drivers/gpu/drm/drm_bufs.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 94bc1f6049c9..ea3ca81be9dd 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -984,17 +984,18 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 
 	while (entry->buf_count < count) {
 		dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
-		if (!dmah)
-			return -ENOMEM;
-
-		dmah->size = total;
-		dmah->vaddr = dma_alloc_coherent(dev->dev,
-						 dmah->size,
-						 &dmah->busaddr,
-						 GFP_KERNEL);
-		if (!dmah->vaddr) {
-			kfree(dmah);
-
+		if (dmah) {
+			dmah->size = total;
+			dmah->vaddr = dma_alloc_coherent(dev->dev,
+							 dmah->size,
+							 &dmah->busaddr,
+							 GFP_KERNEL);
+			if (!dmah->vaddr) {
+				kfree(dmah);
+				dmah = NULL;
+			}
+		}
+		if (!dmah) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;
 			entry->seg_count = count;
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [bug report] drm: remove usage of drm_pci_alloc/free
  2021-05-14 16:34   ` Joseph Kogut
@ 2021-05-15  6:57     ` Dan Carpenter
  0 siblings, 0 replies; 5+ messages in thread
From: Dan Carpenter @ 2021-05-15  6:57 UTC (permalink / raw)
  To: Joseph Kogut; +Cc: dri-devel

On Fri, May 14, 2021 at 09:34:27AM -0700, Joseph Kogut wrote:
> On Fri, May 14, 2021 at 8:13 AM Joseph Kogut <joseph.kogut@gmail.com> wrote:
> >
> > Hi Dan,
> >
> > On Fri, May 14, 2021 at 6:54 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > >
> > > Hello Joseph Kogut,
> > >
> > > The patch 70556e24e18e: "drm: remove usage of drm_pci_alloc/free"
> > > from Apr 22, 2021, leads to the following static checker warning:
> > >
> > >     drivers/gpu/drm/drm_bufs.c:1090 drm_legacy_addbufs_pci()
> > >     warn: inconsistent returns '&dev->struct_mutex'.
> > >       Locked on  : 988
> > >       Unlocked on: 938,944,951,959,973,1005,1042,1060,1090
> > >
> 
> Do you mind if I copy this portion of the bug report in the commit message?

Yeah, that's normal.  No need to ask.

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-05-15  7:18 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-14 13:54 [bug report] drm: remove usage of drm_pci_alloc/free Dan Carpenter
2021-05-14 15:13 ` Joseph Kogut
2021-05-14 16:34   ` Joseph Kogut
2021-05-15  6:57     ` Dan Carpenter
2021-05-14 20:48 ` [PATCH 1/1] drm: drm_legacy_addbufs_pci(): fix return without cleanup Joseph Kogut

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