2018-09-10 23:05:40

by Laura Abbott

[permalink] [raw]
Subject: [PATCH] misc: kgdbts: Fix restrict error

kgdbts current fails when compiled with restrict:

drivers/misc/kgdbts.c: In function ‘configure_kgdbts’:
drivers/misc/kgdbts.c:1070:2: error: ‘strcpy’ source argument is the same as destination [-Werror=restrict]
strcpy(config, opt);
^~~~~~~~~~~~~~~~~~~

As the error says, config is being used in both the source and destination.
Refactor the code to only do the copy when needed.

Signed-off-by: Laura Abbott <[email protected]>
---
drivers/misc/kgdbts.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index 6193270e7b3d..4447ad68ea39 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -1061,20 +1061,23 @@ static void kgdbts_run_tests(void)
configured = 0;
}

-static int kgdbts_option_setup(char *opt)
+static void kgdbts_set_verbose(void)
{
- if (strlen(opt) >= MAX_CONFIG_LEN) {
- printk(KERN_ERR "kgdbts: config string too long\n");
- return -ENOSPC;
- }
- strcpy(config, opt);
-
verbose = 0;
if (strstr(config, "V1"))
verbose = 1;
if (strstr(config, "V2"))
verbose = 2;
+}

+static int kgdbts_option_setup(char *opt)
+{
+ if (strlen(opt) >= MAX_CONFIG_LEN) {
+ printk(KERN_ERR "kgdbts: config string too long\n");
+ return -ENOSPC;
+ }
+ strcpy(config, opt);
+ kgdbts_set_verbose();
return 0;
}

@@ -1086,9 +1089,7 @@ static int configure_kgdbts(void)

if (!strlen(config) || isspace(config[0]))
goto noconfig;
- err = kgdbts_option_setup(config);
- if (err)
- goto noconfig;
+ kgdbts_set_verbose();

final_ack = 0;
run_plant_and_detach_test(1);
--
2.17.1



2018-09-11 09:21:54

by Daniel Thompson

[permalink] [raw]
Subject: Re: [PATCH] misc: kgdbts: Fix restrict error

On Mon, Sep 10, 2018 at 04:04:56PM -0700, Laura Abbott wrote:
> kgdbts current fails when compiled with restrict:
>
> drivers/misc/kgdbts.c: In function ‘configure_kgdbts’:
> drivers/misc/kgdbts.c:1070:2: error: ‘strcpy’ source argument is the same as destination [-Werror=restrict]
> strcpy(config, opt);
> ^~~~~~~~~~~~~~~~~~~
>
> As the error says, config is being used in both the source and destination.
> Refactor the code to only do the copy when needed.
>
> Signed-off-by: Laura Abbott <[email protected]>
> ---
> drivers/misc/kgdbts.c | 21 +++++++++++----------
> 1 file changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
> index 6193270e7b3d..4447ad68ea39 100644
> --- a/drivers/misc/kgdbts.c
> +++ b/drivers/misc/kgdbts.c
> @@ -1061,20 +1061,23 @@ static void kgdbts_run_tests(void)
> configured = 0;
> }
>
> -static int kgdbts_option_setup(char *opt)
> +static void kgdbts_set_verbose(void)
> {
> - if (strlen(opt) >= MAX_CONFIG_LEN) {
> - printk(KERN_ERR "kgdbts: config string too long\n");
> - return -ENOSPC;
> - }
> - strcpy(config, opt);
> -
> verbose = 0;
> if (strstr(config, "V1"))
> verbose = 1;
> if (strstr(config, "V2"))
> verbose = 2;
> +}
>
> +static int kgdbts_option_setup(char *opt)
> +{
> + if (strlen(opt) >= MAX_CONFIG_LEN) {
> + printk(KERN_ERR "kgdbts: config string too long\n");
> + return -ENOSPC;
> + }
> + strcpy(config, opt);
> + kgdbts_set_verbose();

I know this is honouring the existing code paths but I think
kgdbts_set_verbose() is redundant here. Directly setting up verbose from
kgdbts_run_tests() where the rest of the config string is parsed should
be sufficient.

Having said that I don't want to bounce perfectly correct fixes just
because they could have done more. Do you want to send a v2 or prefer me
to put further clean up on my TODO list?


Daniel.

> return 0;
> }
>
> @@ -1086,9 +1089,7 @@ static int configure_kgdbts(void)
>
> if (!strlen(config) || isspace(config[0]))
> goto noconfig;
> - err = kgdbts_option_setup(config);
> - if (err)
> - goto noconfig;
> + kgdbts_set_verbose();
>
> final_ack = 0;
> run_plant_and_detach_test(1);
> --
> 2.17.1
>

2018-09-11 17:29:06

by Laura Abbott

[permalink] [raw]
Subject: Re: [PATCH] misc: kgdbts: Fix restrict error

On 09/11/2018 02:19 AM, Daniel Thompson wrote:
> On Mon, Sep 10, 2018 at 04:04:56PM -0700, Laura Abbott wrote:
>> kgdbts current fails when compiled with restrict:
>>
>> drivers/misc/kgdbts.c: In function ‘configure_kgdbts’:
>> drivers/misc/kgdbts.c:1070:2: error: ‘strcpy’ source argument is the same as destination [-Werror=restrict]
>> strcpy(config, opt);
>> ^~~~~~~~~~~~~~~~~~~
>>
>> As the error says, config is being used in both the source and destination.
>> Refactor the code to only do the copy when needed.
>>
>> Signed-off-by: Laura Abbott <[email protected]>
>> ---
>> drivers/misc/kgdbts.c | 21 +++++++++++----------
>> 1 file changed, 11 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
>> index 6193270e7b3d..4447ad68ea39 100644
>> --- a/drivers/misc/kgdbts.c
>> +++ b/drivers/misc/kgdbts.c
>> @@ -1061,20 +1061,23 @@ static void kgdbts_run_tests(void)
>> configured = 0;
>> }
>>
>> -static int kgdbts_option_setup(char *opt)
>> +static void kgdbts_set_verbose(void)
>> {
>> - if (strlen(opt) >= MAX_CONFIG_LEN) {
>> - printk(KERN_ERR "kgdbts: config string too long\n");
>> - return -ENOSPC;
>> - }
>> - strcpy(config, opt);
>> -
>> verbose = 0;
>> if (strstr(config, "V1"))
>> verbose = 1;
>> if (strstr(config, "V2"))
>> verbose = 2;
>> +}
>>
>> +static int kgdbts_option_setup(char *opt)
>> +{
>> + if (strlen(opt) >= MAX_CONFIG_LEN) {
>> + printk(KERN_ERR "kgdbts: config string too long\n");
>> + return -ENOSPC;
>> + }
>> + strcpy(config, opt);
>> + kgdbts_set_verbose();
>
> I know this is honouring the existing code paths but I think
> kgdbts_set_verbose() is redundant here. Directly setting up verbose from
> kgdbts_run_tests() where the rest of the config string is parsed should
> be sufficient.
>
> Having said that I don't want to bounce perfectly correct fixes just
> because they could have done more. Do you want to send a v2 or prefer me
> to put further clean up on my TODO list?
>
>

I'll go ahead and send a v2

> Daniel.
>
>> return 0;
>> }
>>
>> @@ -1086,9 +1089,7 @@ static int configure_kgdbts(void)
>>
>> if (!strlen(config) || isspace(config[0]))
>> goto noconfig;
>> - err = kgdbts_option_setup(config);
>> - if (err)
>> - goto noconfig;
>> + kgdbts_set_verbose();
>>
>> final_ack = 0;
>> run_plant_and_detach_test(1);
>> --
>> 2.17.1
>>