2004-06-06 16:22:53

by Yury Umanets

Subject: [PATCH] 2.6.6 memory allocation checks in SliceBlock()

Adds memory allocation checks in SliceBlock()

./linux-2.6.6-modified/drivers/char/drm/sis_ds.c | 4 ++++
1 files changed, 4 insertions(+)

Signed-off-by: Yury Umanets <[email protected]>

diff -rupN ./linux-2.6.6/drivers/char/drm/sis_ds.c
./linux-2.6.6-modified/drivers/char/drm/sis_ds.c
--- ./linux-2.6.6/drivers/char/drm/sis_ds.c Mon May 10 05:33:19 2004
+++ ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c Wed Jun 2 14:19:22
2004
@@ -231,6 +231,8 @@ static TMemBlock* SliceBlock(TMemBlock *
if (startofs > p->ofs) {
newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
DRM_MEM_DRIVER);
+ if (!newblock)
+ return NULL;
newblock->ofs = startofs;
newblock->size = p->size - (startofs - p->ofs);
newblock->free = 1;
@@ -244,6 +246,8 @@ static TMemBlock* SliceBlock(TMemBlock *
if (size < p->size) {
newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
DRM_MEM_DRIVER);
+ if (!newblock)
+ return NULL;
newblock->ofs = startofs + size;
newblock->size = p->size - size;
newblock->free = 1;

--
umka

2004-06-06 18:08:01

by Randy.Dunlap

Subject: Re: [PATCH] 2.6.6 memory allocation checks in SliceBlock()

On Sun, 06 Jun 2004 19:23:12 +0300 Yury Umanets wrote:

| Adds memory allocation checks in SliceBlock()
|
| ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c | 4 ++++
| 1 files changed, 4 insertions(+)
|
| Signed-off-by: Yury Umanets <[email protected]>
|
| diff -rupN ./linux-2.6.6/drivers/char/drm/sis_ds.c
| ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c
| --- ./linux-2.6.6/drivers/char/drm/sis_ds.c Mon May 10 05:33:19 2004
| +++ ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c Wed Jun 2 14:19:22
| 2004
| @@ -231,6 +231,8 @@ static TMemBlock* SliceBlock(TMemBlock *
| if (startofs > p->ofs) {
| newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
| DRM_MEM_DRIVER);
| + if (!newblock)
| + return NULL;
| newblock->ofs = startofs;
| newblock->size = p->size - (startofs - p->ofs);
| newblock->free = 1;
| @@ -244,6 +246,8 @@ static TMemBlock* SliceBlock(TMemBlock *
| if (size < p->size) {
| newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
| DRM_MEM_DRIVER);
| + if (!newblock)
| + return NULL;
| newblock->ofs = startofs + size;
| newblock->size = p->size - size;
| newblock->free = 1;
|
| --

These look like the right thing to do, but one caller of
SliceBlock() has no error handling:

mmAllocMem():

p = SliceBlock(p,startofs,size,0,mask+1);
p->heap = heap;
return p;

However, callers of mmAllocMem() do have failure handling.

--
~Randy

2004-06-07 15:55:44

by Yury Umanets

Subject: Re: [PATCH] 2.6.6 memory allocation checks in SliceBlock()

On Sun, 2004-06-06 at 21:03, Randy.Dunlap wrote:
> On Sun, 06 Jun 2004 19:23:12 +0300 Yury Umanets wrote:
>
> | Adds memory allocation checks in SliceBlock()
> |
> | ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c | 4 ++++
> | 1 files changed, 4 insertions(+)
> |
> | Signed-off-by: Yury Umanets <[email protected]>
> |
> | diff -rupN ./linux-2.6.6/drivers/char/drm/sis_ds.c
> | ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c
> | --- ./linux-2.6.6/drivers/char/drm/sis_ds.c Mon May 10 05:33:19 2004
> | +++ ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c Wed Jun 2 14:19:22
> | 2004
> | @@ -231,6 +231,8 @@ static TMemBlock* SliceBlock(TMemBlock *
> | if (startofs > p->ofs) {
> | newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
> | DRM_MEM_DRIVER);
> | + if (!newblock)
> | + return NULL;
> | newblock->ofs = startofs;
> | newblock->size = p->size - (startofs - p->ofs);
> | newblock->free = 1;
> | @@ -244,6 +246,8 @@ static TMemBlock* SliceBlock(TMemBlock *
> | if (size < p->size) {
> | newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
> | DRM_MEM_DRIVER);
> | + if (!newblock)
> | + return NULL;
> | newblock->ofs = startofs + size;
> | newblock->size = p->size - size;
> | newblock->free = 1;
> |
> | --
>
> These look like the right thing to do, but one caller of
> SliceBlock() has no error handling:
>
> mmAllocMem():
>
> p = SliceBlock(p,startofs,size,0,mask+1);
> p->heap = heap;
> return p;
>
> However, callers of mmAllocMem() do have failure handling.
Hello Randy,

This is fixed version:

./linux-2.6.6-modified/drivers/char/drm/sis_ds.c | 6 ++++++
1 files changed, 6 insertions(+)

Signed-off-by: Yury Umanets <[email protected]>

diff -rupN ./linux-2.6.6/drivers/char/drm/sis_ds.c
./linux-2.6.6-modified/drivers/char/drm/sis_ds.c
--- ./linux-2.6.6/drivers/char/drm/sis_ds.c Mon May 10 05:33:19 2004
+++ ./linux-2.6.6-modified/drivers/char/drm/sis_ds.c Mon Jun 7 18:41:41
2004
@@ -231,6 +231,8 @@ static TMemBlock* SliceBlock(TMemBlock *
if (startofs > p->ofs) {
newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
DRM_MEM_DRIVER);
+ if (!newblock)
+ return NULL;
newblock->ofs = startofs;
newblock->size = p->size - (startofs - p->ofs);
newblock->free = 1;
@@ -244,6 +246,8 @@ static TMemBlock* SliceBlock(TMemBlock *
if (size < p->size) {
newblock = (TMemBlock*) DRM(calloc)(1, sizeof(TMemBlock),
DRM_MEM_DRIVER);
+ if (!newblock)
+ return NULL;
newblock->ofs = startofs + size;
newblock->size = p->size - size;
newblock->free = 1;
@@ -285,6 +289,8 @@ PMemBlock mmAllocMem( memHeap_t *heap, i
if (p == NULL)
return NULL;
p = SliceBlock(p,startofs,size,0,mask+1);
+ if (!p)
+ return NULL;
p->heap = heap;
return p;
}


--
umka