Re: [PATCH v2] drm/amdgpu: Fix realloc of ptr

[Alex Deucher]

Applied.  Thanks!

Alex

On Mon, Feb 28, 2022 at 5:55 AM Christian König
 wrote:
>
> Am 27.02.22 um 16:33 schrieb t...@redhat.com:
> > From: Tom Rix 
> >
> > Clang static analysis reports this error
> > amdgpu_debugfs.c:1690:9: warning: 1st function call
> >argument is an uninitialized value
> >tmp = krealloc_array(tmp, i + 1,
> >  ^~~
> >
> > realloc uses tmp, so tmp can not be garbage.
> > And the return needs to be checked.
> >
> > Fixes: 5ce5a584cb82 ("drm/amdgpu: add debugfs for reset registers list")
> > Signed-off-by: Tom Rix 
>
> Yeah, stuff I missed because of the long review. I was already wondering
> what semantics krealloc_array is following for freeing up the pointer on
> error.
>
> Reviewed-by: Christian König 
>
> Thanks,
> Christian.
>
> > ---
> > v2:
> >use 'new' to hold/check the ralloc return
> >fix commit log mistake on ralloc freeing to using input ptr
> >
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 9 +++--
> >   1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > index 9eb9b440bd438..2f4f8c5618d81 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > @@ -1676,7 +1676,7 @@ static ssize_t 
> > amdgpu_reset_dump_register_list_write(struct file *f,
> >   {
> >   struct amdgpu_device *adev = (struct amdgpu_device 
> > *)file_inode(f)->i_private;
> >   char reg_offset[11];
> > - uint32_t *tmp;
> > + uint32_t *new, *tmp = NULL;
> >   int ret, i = 0, len = 0;
> >
> >   do {
> > @@ -1687,7 +1687,12 @@ static ssize_t 
> > amdgpu_reset_dump_register_list_write(struct file *f,
> >   goto error_free;
> >   }
> >
> > - tmp = krealloc_array(tmp, i + 1, sizeof(uint32_t), 
> > GFP_KERNEL);
> > + new = krealloc_array(tmp, i + 1, sizeof(uint32_t), 
> > GFP_KERNEL);
> > + if (!new) {
> > + ret = -ENOMEM;
> > + goto error_free;
> > + }
> > + tmp = new;
> >   if (sscanf(reg_offset, "%X %n", [i], ) != 1) {
> >   ret = -EINVAL;
> >   goto error_free;
>

Re: [PATCH v2] drm/amdgpu: Fix realloc of ptr

[Christian König]

Am 27.02.22 um 16:33 schrieb t...@redhat.com:

From: Tom Rix 

Clang static analysis reports this error
amdgpu_debugfs.c:1690:9: warning: 1st function call
   argument is an uninitialized value
   tmp = krealloc_array(tmp, i + 1,
 ^~~

realloc uses tmp, so tmp can not be garbage.
And the return needs to be checked.

Fixes: 5ce5a584cb82 ("drm/amdgpu: add debugfs for reset registers list")
Signed-off-by: Tom Rix 


Yeah, stuff I missed because of the long review. I was already wondering 
what semantics krealloc_array is following for freeing up the pointer on 
error.


Reviewed-by: Christian König 

Thanks,
Christian.


---
v2:
   use 'new' to hold/check the ralloc return
   fix commit log mistake on ralloc freeing to using input ptr
   
  drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 9 +++--

  1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 9eb9b440bd438..2f4f8c5618d81 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1676,7 +1676,7 @@ static ssize_t 
amdgpu_reset_dump_register_list_write(struct file *f,
  {
struct amdgpu_device *adev = (struct amdgpu_device 
*)file_inode(f)->i_private;
char reg_offset[11];
-   uint32_t *tmp;
+   uint32_t *new, *tmp = NULL;
int ret, i = 0, len = 0;
  
  	do {

@@ -1687,7 +1687,12 @@ static ssize_t 
amdgpu_reset_dump_register_list_write(struct file *f,
goto error_free;
}
  
-		tmp = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);

+   new = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);
+   if (!new) {
+   ret = -ENOMEM;
+   goto error_free;
+   }
+   tmp = new;
if (sscanf(reg_offset, "%X %n", [i], ) != 1) {
ret = -EINVAL;
goto error_free;

[PATCH v2] drm/amdgpu: Fix realloc of ptr

[trix]

From: Tom Rix 

Clang static analysis reports this error
amdgpu_debugfs.c:1690:9: warning: 1st function call
  argument is an uninitialized value
  tmp = krealloc_array(tmp, i + 1,
^~~

realloc uses tmp, so tmp can not be garbage.
And the return needs to be checked.

Fixes: 5ce5a584cb82 ("drm/amdgpu: add debugfs for reset registers list")
Signed-off-by: Tom Rix 
---
v2:
  use 'new' to hold/check the ralloc return
  fix commit log mistake on ralloc freeing to using input ptr
  
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 9 +++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 9eb9b440bd438..2f4f8c5618d81 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1676,7 +1676,7 @@ static ssize_t 
amdgpu_reset_dump_register_list_write(struct file *f,
 {
struct amdgpu_device *adev = (struct amdgpu_device 
*)file_inode(f)->i_private;
char reg_offset[11];
-   uint32_t *tmp;
+   uint32_t *new, *tmp = NULL;
int ret, i = 0, len = 0;
 
do {
@@ -1687,7 +1687,12 @@ static ssize_t 
amdgpu_reset_dump_register_list_write(struct file *f,
goto error_free;
}
 
-   tmp = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);
+   new = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);
+   if (!new) {
+   ret = -ENOMEM;
+   goto error_free;
+   }
+   tmp = new;
if (sscanf(reg_offset, "%X %n", [i], ) != 1) {
ret = -EINVAL;
goto error_free;
-- 
2.26.3