[patch] drm/amd: cleanup get_mfd_cell_dev()
On Sat, Feb 27, 2016 at 10:50:40AM +0100, walter harms wrote:
>
>
> Am 25.02.2016 08:47, schrieb Dan Carpenter:
> > It's simpler to just use snprintf() to print this to one buffer instead
> > of using strcpy() and strcat(). Also using snprintf() is slightly safer
> > than using sprintf().
> >
> > Signed-off-by: Dan Carpenter
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> > index 9f8cfaa..d6b0bff 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> > @@ -240,12 +240,10 @@ static int acp_poweron(struct generic_pm_domain
> > *genpd)
> > static struct device *get_mfd_cell_dev(const char *device_name, int r)
> > {
> > char auto_dev_name[25];
> > - char buf[8];
> > struct device *dev;
> >
> > - sprintf(buf, ".%d.auto", r);
> > - strcpy(auto_dev_name, device_name);
> > - strcat(auto_dev_name, buf);
> > + snprintf(auto_dev_name, sizeof(auto_dev_name),
> > +"%s.%d.auto", device_name, r);
> > dev = bus_find_device_by_name(_bus_type, NULL, auto_dev_name);
> > dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
> >
>
> hi,
> i tried to understand what is the base for char auto_dev_name[25]. It is not
> clear
> from these snipped if that is large or small.
>
> (To be aware i assume that
> get_mfd_cell_dev("terrible_long_and_Stupid_name",1234567899346712) will never
> happen
> but i could find no reason)
>
> A small comment that explains the magic 25 would be nice.
I have no idea, either of course. For example,
mc13xxx_add_subdevice_pdata() assumes device_name by itself can be 30
characters. Hence the change to snprintf.
regards,
dan carpenter
[patch] drm/amd: cleanup get_mfd_cell_dev()
Am 27.02.2016 11:40, schrieb Dan Carpenter:
> On Sat, Feb 27, 2016 at 10:50:40AM +0100, walter harms wrote:
>>
>>
>> Am 25.02.2016 08:47, schrieb Dan Carpenter:
>>> It's simpler to just use snprintf() to print this to one buffer instead
>>> of using strcpy() and strcat(). Also using snprintf() is slightly safer
>>> than using sprintf().
>>>
>>> Signed-off-by: Dan Carpenter
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
>>> index 9f8cfaa..d6b0bff 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
>>> @@ -240,12 +240,10 @@ static int acp_poweron(struct generic_pm_domain
>>> *genpd)
>>> static struct device *get_mfd_cell_dev(const char *device_name, int r)
>>> {
>>> char auto_dev_name[25];
>>> - char buf[8];
>>> struct device *dev;
>>>
>>> - sprintf(buf, ".%d.auto", r);
>>> - strcpy(auto_dev_name, device_name);
>>> - strcat(auto_dev_name, buf);
>>> + snprintf(auto_dev_name, sizeof(auto_dev_name),
>>> +"%s.%d.auto", device_name, r);
>>> dev = bus_find_device_by_name(_bus_type, NULL, auto_dev_name);
>>> dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
>>>
>>
>> hi,
>> i tried to understand what is the base for char auto_dev_name[25]. It is not
>> clear
>> from these snipped if that is large or small.
>>
>> (To be aware i assume that
>> get_mfd_cell_dev("terrible_long_and_Stupid_name",1234567899346712) will
>> never happen
>> but i could find no reason)
>>
>> A small comment that explains the magic 25 would be nice.
>
> I have no idea, either of course. For example,
> mc13xxx_add_subdevice_pdata() assumes device_name by itself can be 30
> characters. Hence the change to snprintf.
>
Hi Dan,
i also think that this limit is artificial, one of those "it works" things.
The problem is that i have seen changes in the naming als ready done, like the
shift from /dev/sda to things like
/dev/disk/by-id/scsi-SATA_WDC_WD5000AAKS-_WD-WCASY5869245-part1
and you are out of the game here. snprintf will cut the tail and the %d.auto
stuff is dead in the water.
To make it clear, I do not thing that is security related issue but it could
result in annoying
failures. (the solution is obviously to use asprintf() and free the mem later
:) ).
re,
wh
[patch] drm/amd: cleanup get_mfd_cell_dev()
Am 25.02.2016 08:47, schrieb Dan Carpenter:
> It's simpler to just use snprintf() to print this to one buffer instead
> of using strcpy() and strcat(). Also using snprintf() is slightly safer
> than using sprintf().
>
> Signed-off-by: Dan Carpenter
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> index 9f8cfaa..d6b0bff 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> @@ -240,12 +240,10 @@ static int acp_poweron(struct generic_pm_domain *genpd)
> static struct device *get_mfd_cell_dev(const char *device_name, int r)
> {
> char auto_dev_name[25];
> - char buf[8];
> struct device *dev;
>
> - sprintf(buf, ".%d.auto", r);
> - strcpy(auto_dev_name, device_name);
> - strcat(auto_dev_name, buf);
> + snprintf(auto_dev_name, sizeof(auto_dev_name),
> + "%s.%d.auto", device_name, r);
> dev = bus_find_device_by_name(_bus_type, NULL, auto_dev_name);
> dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
>
hi,
i tried to understand what is the base for char auto_dev_name[25]. It is not
clear
from these snipped if that is large or small.
(To be aware i assume that
get_mfd_cell_dev("terrible_long_and_Stupid_name",1234567899346712) will never
happen
but i could find no reason)
A small comment that explains the magic 25 would be nice.
re,
wh
[patch] drm/amd: cleanup get_mfd_cell_dev()
On Thu, Feb 25, 2016 at 2:47 AM, Dan Carpenter
wrote:
> It's simpler to just use snprintf() to print this to one buffer instead
> of using strcpy() and strcat(). Also using snprintf() is slightly safer
> than using sprintf().
>
> Signed-off-by: Dan Carpenter
Applied. Thanks!
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> index 9f8cfaa..d6b0bff 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
> @@ -240,12 +240,10 @@ static int acp_poweron(struct generic_pm_domain *genpd)
> static struct device *get_mfd_cell_dev(const char *device_name, int r)
> {
> char auto_dev_name[25];
> - char buf[8];
> struct device *dev;
>
> - sprintf(buf, ".%d.auto", r);
> - strcpy(auto_dev_name, device_name);
> - strcat(auto_dev_name, buf);
> + snprintf(auto_dev_name, sizeof(auto_dev_name),
> +"%s.%d.auto", device_name, r);
> dev = bus_find_device_by_name(_bus_type, NULL,
> auto_dev_name);
> dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
>
> ___
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
[patch] drm/amd: cleanup get_mfd_cell_dev()
It's simpler to just use snprintf() to print this to one buffer instead
of using strcpy() and strcat(). Also using snprintf() is slightly safer
than using sprintf().
Signed-off-by: Dan Carpenter
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
index 9f8cfaa..d6b0bff 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
@@ -240,12 +240,10 @@ static int acp_poweron(struct generic_pm_domain *genpd)
static struct device *get_mfd_cell_dev(const char *device_name, int r)
{
char auto_dev_name[25];
- char buf[8];
struct device *dev;
- sprintf(buf, ".%d.auto", r);
- strcpy(auto_dev_name, device_name);
- strcat(auto_dev_name, buf);
+ snprintf(auto_dev_name, sizeof(auto_dev_name),
+"%s.%d.auto", device_name, r);
dev = bus_find_device_by_name(_bus_type, NULL, auto_dev_name);
dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
