The patch replaces the macro with a function (dgnc_get_board) and
substitutes the macro statement with a call to that function and a
comparison on the returned value.
This removes a checkpatch warning.
Signed-off-by: Fernando Apesteguia <[email protected]>
---
drivers/staging/dgnc/dgnc_sysfs.c | 74 +++++++++++++++++++++++++++------------
1 file changed, 51 insertions(+), 23 deletions(-)
diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
index 290bf6e..3ea23a9 100644
--- a/drivers/staging/dgnc/dgnc_sysfs.c
+++ b/drivers/staging/dgnc/dgnc_sysfs.c
@@ -90,17 +90,21 @@ void dgnc_remove_driver_sysfiles(struct pci_driver *dgnc_driver)
driver_remove_file(driverfs, &driver_attr_pollrate);
}
-#define DGNC_VERIFY_BOARD(p, bd) \
- do { \
- if (!p) \
- return 0; \
- \
- bd = dev_get_drvdata(p); \
- if (!bd || bd->magic != DGNC_BOARD_MAGIC) \
- return 0; \
- if (bd->state != BOARD_READY) \
- return 0; \
- } while (0)
+static struct dgnc_board *dgnc_get_board(struct device *p)
+{
+ struct dgnc_board *bd;
+
+ if (!p)
+ return NULL;
+
+ bd = dev_get_drvdata(p);
+ if (!bd || bd->magic != DGNC_BOARD_MAGIC)
+ return NULL;
+ if (bd->state != BOARD_READY)
+ return NULL;
+
+ return bd;
+}
static ssize_t vpd_show(struct device *p, struct device_attribute *attr,
char *buf)
@@ -109,7 +113,9 @@ static ssize_t vpd_show(struct device *p, struct device_attribute *attr,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
count += sprintf(buf + count,
"\n 0 1 2 3 4 5 6 7 8 9 A B C D E F");
@@ -130,7 +136,9 @@ static ssize_t serial_number_show(struct device *p,
struct dgnc_board *bd;
int count = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
if (bd->serial_num[0] == '\0')
count += sprintf(buf + count, "<UNKNOWN>\n");
@@ -148,7 +156,9 @@ static ssize_t ports_state_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count,
@@ -166,7 +176,9 @@ static ssize_t ports_baud_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count,
@@ -184,7 +196,9 @@ static ssize_t ports_msignals_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
struct channel_t *ch = bd->channels[i];
@@ -215,7 +229,9 @@ static ssize_t ports_iflag_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %x\n",
@@ -233,7 +249,9 @@ static ssize_t ports_cflag_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %x\n",
@@ -251,7 +269,9 @@ static ssize_t ports_oflag_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %x\n",
@@ -269,7 +289,9 @@ static ssize_t ports_lflag_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %x\n",
@@ -287,7 +309,9 @@ static ssize_t ports_digi_flag_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %x\n",
@@ -305,7 +329,9 @@ static ssize_t ports_rxcount_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %ld\n",
@@ -323,7 +349,9 @@ static ssize_t ports_txcount_show(struct device *p,
int count = 0;
int i = 0;
- DGNC_VERIFY_BOARD(p, bd);
+ bd = dgnc_get_board(p);
+ if (!bd)
+ return 0;
for (i = 0; i < bd->nasync; i++) {
count += snprintf(buf + count, PAGE_SIZE - count, "%d %ld\n",
--
2.7.4
On Fri, Oct 14, 2016 at 07:22:57PM +0200, Fernando Apesteguia wrote:
> The patch replaces the macro with a function (dgnc_get_board) and
> substitutes the macro statement with a call to that function and a
> comparison on the returned value.
>
> This removes a checkpatch warning.
>
> Signed-off-by: Fernando Apesteguia <[email protected]>
> ---
> drivers/staging/dgnc/dgnc_sysfs.c | 74 +++++++++++++++++++++++++++------------
> 1 file changed, 51 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
> index 290bf6e..3ea23a9 100644
> --- a/drivers/staging/dgnc/dgnc_sysfs.c
> +++ b/drivers/staging/dgnc/dgnc_sysfs.c
> @@ -90,17 +90,21 @@ void dgnc_remove_driver_sysfiles(struct pci_driver *dgnc_driver)
> driver_remove_file(driverfs, &driver_attr_pollrate);
> }
>
> -#define DGNC_VERIFY_BOARD(p, bd) \
> - do { \
> - if (!p) \
> - return 0; \
> - \
> - bd = dev_get_drvdata(p); \
> - if (!bd || bd->magic != DGNC_BOARD_MAGIC) \
> - return 0; \
> - if (bd->state != BOARD_READY) \
> - return 0; \
> - } while (0)
> +static struct dgnc_board *dgnc_get_board(struct device *p)
> +{
> + struct dgnc_board *bd;
> +
> + if (!p)
> + return NULL;
> +
> + bd = dev_get_drvdata(p);
> + if (!bd || bd->magic != DGNC_BOARD_MAGIC)
> + return NULL;
> + if (bd->state != BOARD_READY)
> + return NULL;
> +
> + return bd;
> +}
No, this macro should be removed entirely as what it does is pointless
in some parts, wrong in others, and not needed at all in the rest :(
I've asked others to fix this up properly in the past, but it doesn't
seem like anyone wants to do the work...
I don't want to take this patch as it will hide the real issues here.
thanks,
greg k-h
On Mon, Oct 17, 2016 at 10:29 AM, Greg KH <[email protected]> wrote:
> On Fri, Oct 14, 2016 at 07:22:57PM +0200, Fernando Apesteguia wrote:
>> The patch replaces the macro with a function (dgnc_get_board) and
>> substitutes the macro statement with a call to that function and a
>> comparison on the returned value.
>>
>> This removes a checkpatch warning.
>>
>> Signed-off-by: Fernando Apesteguia <[email protected]>
>> ---
>> drivers/staging/dgnc/dgnc_sysfs.c | 74 +++++++++++++++++++++++++++------------
>> 1 file changed, 51 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
>> index 290bf6e..3ea23a9 100644
>> --- a/drivers/staging/dgnc/dgnc_sysfs.c
>> +++ b/drivers/staging/dgnc/dgnc_sysfs.c
>> @@ -90,17 +90,21 @@ void dgnc_remove_driver_sysfiles(struct pci_driver *dgnc_driver)
>> driver_remove_file(driverfs, &driver_attr_pollrate);
>> }
>>
>> -#define DGNC_VERIFY_BOARD(p, bd) \
>> - do { \
>> - if (!p) \
>> - return 0; \
>> - \
>> - bd = dev_get_drvdata(p); \
>> - if (!bd || bd->magic != DGNC_BOARD_MAGIC) \
>> - return 0; \
>> - if (bd->state != BOARD_READY) \
>> - return 0; \
>> - } while (0)
>> +static struct dgnc_board *dgnc_get_board(struct device *p)
>> +{
>> + struct dgnc_board *bd;
>> +
>> + if (!p)
>> + return NULL;
>> +
>> + bd = dev_get_drvdata(p);
>> + if (!bd || bd->magic != DGNC_BOARD_MAGIC)
>> + return NULL;
>> + if (bd->state != BOARD_READY)
>> + return NULL;
>> +
>> + return bd;
>> +}
>
> No, this macro should be removed entirely as what it does is pointless
> in some parts, wrong in others, and not needed at all in the rest :(
>
> I've asked others to fix this up properly in the past, but it doesn't
> seem like anyone wants to do the work...
>
I tried to find the discussion the relevant mails in lkml.org but
couldn't find them. Could you point me to them so I can have a look?
Thanks.
> I don't want to take this patch as it will hide the real issues here.
>
> thanks,
>
> greg k-h
On Mon, Oct 17, 2016 at 11:46:36PM +0200, Fernando Apestegu?a wrote:
> On Mon, Oct 17, 2016 at 10:29 AM, Greg KH <[email protected]> wrote:
> > On Fri, Oct 14, 2016 at 07:22:57PM +0200, Fernando Apesteguia wrote:
> >> The patch replaces the macro with a function (dgnc_get_board) and
> >> substitutes the macro statement with a call to that function and a
> >> comparison on the returned value.
> >>
> >> This removes a checkpatch warning.
> >>
> >> Signed-off-by: Fernando Apesteguia <[email protected]>
> >> ---
> >> drivers/staging/dgnc/dgnc_sysfs.c | 74 +++++++++++++++++++++++++++------------
> >> 1 file changed, 51 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
> >> index 290bf6e..3ea23a9 100644
> >> --- a/drivers/staging/dgnc/dgnc_sysfs.c
> >> +++ b/drivers/staging/dgnc/dgnc_sysfs.c
> >> @@ -90,17 +90,21 @@ void dgnc_remove_driver_sysfiles(struct pci_driver *dgnc_driver)
> >> driver_remove_file(driverfs, &driver_attr_pollrate);
> >> }
> >>
> >> -#define DGNC_VERIFY_BOARD(p, bd) \
> >> - do { \
> >> - if (!p) \
> >> - return 0; \
> >> - \
> >> - bd = dev_get_drvdata(p); \
> >> - if (!bd || bd->magic != DGNC_BOARD_MAGIC) \
> >> - return 0; \
> >> - if (bd->state != BOARD_READY) \
> >> - return 0; \
> >> - } while (0)
> >> +static struct dgnc_board *dgnc_get_board(struct device *p)
> >> +{
> >> + struct dgnc_board *bd;
> >> +
> >> + if (!p)
> >> + return NULL;
> >> +
> >> + bd = dev_get_drvdata(p);
> >> + if (!bd || bd->magic != DGNC_BOARD_MAGIC)
> >> + return NULL;
> >> + if (bd->state != BOARD_READY)
> >> + return NULL;
> >> +
> >> + return bd;
> >> +}
> >
> > No, this macro should be removed entirely as what it does is pointless
> > in some parts, wrong in others, and not needed at all in the rest :(
> >
> > I've asked others to fix this up properly in the past, but it doesn't
> > seem like anyone wants to do the work...
> >
>
> I tried to find the discussion the relevant mails in lkml.org but
> couldn't find them. Could you point me to them so I can have a look?
Last time I mentioned this, it was on the outreachy-kernel mailing list.
Just walk through the code for yourself and see which, if any, of these
things could ever actually cause the function to "fail". I think you
will find that none of them can ever happen...
The first test is a huge proof that the original author didn't
understand how sysfs or "container_of()" works, given that it is
impossible to ever have happen.
thanks,
greg k-h