diff mbox

efi_runtime: Use memdup_user helper

Message ID 1499068136-10597-1-git-send-email-ivan.hu@canonical.com
State Accepted
Headers show

Commit Message

Ivan Hu July 3, 2017, 7:48 a.m. UTC 
From: Geliang Tang <geliangtang@gmail.com>

Sync up with kernel driver efi_test:

efi/efi_test: Use memdup_user() helper

Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
---
 efi_runtime/efi_runtime.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

Comments

Colin Ian King July 3, 2017, 7:54 a.m. UTC | #1 
On 03/07/17 08:48, Ivan Hu wrote:
> From: Geliang Tang <geliangtang@gmail.com>
> 
> Sync up with kernel driver efi_test:
> 
> efi/efi_test: Use memdup_user() helper
> 
> Use memdup_user() helper instead of open-coding to simplify the code.
> 
> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
> Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
> ---
>  efi_runtime/efi_runtime.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
> index 19b624c..6570a54 100644
> --- a/efi_runtime/efi_runtime.c
> +++ b/efi_runtime/efi_runtime.c
> @@ -90,18 +90,13 @@ copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
>  	if (!access_ok(VERIFY_READ, src, 1))
>  		return -EFAULT;
>  
> -	buf = kmalloc(len, GFP_KERNEL);
> -	if (!buf) {
> +	buf = memdup_user(src, len);
> +	if (IS_ERR(buf)) {
>  		*dst = NULL;
> -		return -ENOMEM;
> +		return PTR_ERR(buf);
>  	}
>  	*dst = buf;
>  
> -	if (copy_from_user(*dst, src, len)) {
> -		kfree(buf);
> -		return -EFAULT;
> -	}
> -
>  	return 0;
>  }
>  
> 
Ivan, this is great for the latest kernel, what do we do for backwards
compatibility in the fwts DKMS driver?

Acked-by: Colin Ian King <colin.king@canonical.com>
Ivan Hu July 3, 2017, 8:14 a.m. UTC | #2 
On 07/03/2017 03:54 PM, Colin Ian King wrote:
> On 03/07/17 08:48, Ivan Hu wrote:
>> From: Geliang Tang <geliangtang@gmail.com>
>>
>> Sync up with kernel driver efi_test:
>>
>> efi/efi_test: Use memdup_user() helper
>>
>> Use memdup_user() helper instead of open-coding to simplify the code.
>>
>> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
>> Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
>> ---
>>   efi_runtime/efi_runtime.c | 11 +++--------
>>   1 file changed, 3 insertions(+), 8 deletions(-)
>>
>> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
>> index 19b624c..6570a54 100644
>> --- a/efi_runtime/efi_runtime.c
>> +++ b/efi_runtime/efi_runtime.c
>> @@ -90,18 +90,13 @@ copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
>>   	if (!access_ok(VERIFY_READ, src, 1))
>>   		return -EFAULT;
>>   
>> -	buf = kmalloc(len, GFP_KERNEL);
>> -	if (!buf) {
>> +	buf = memdup_user(src, len);
>> +	if (IS_ERR(buf)) {
>>   		*dst = NULL;
>> -		return -ENOMEM;
>> +		return PTR_ERR(buf);
>>   	}
>>   	*dst = buf;
>>   
>> -	if (copy_from_user(*dst, src, len)) {
>> -		kfree(buf);
>> -		return -EFAULT;
>> -	}
>> -
>>   	return 0;
>>   }
>>   
>>
> Ivan, this is great for the latest kernel, what do we do for backwards
> compatibility in the fwts DKMS driver?
> 

Colin, memdup_user has introduced for a very long time,since 2009. Looks 
like should not be a problem for the DKMS driver. What backward 
compatibility issue have you seen?

Ivan

> Acked-by: Colin Ian King <colin.king@canonical.com>
>
Colin Ian King July 3, 2017, 8:15 a.m. UTC | #3 
On 03/07/17 09:14, ivanhu wrote:
> 
> 
> On 07/03/2017 03:54 PM, Colin Ian King wrote:
>> On 03/07/17 08:48, Ivan Hu wrote:
>>> From: Geliang Tang <geliangtang@gmail.com>
>>>
>>> Sync up with kernel driver efi_test:
>>>
>>> efi/efi_test: Use memdup_user() helper
>>>
>>> Use memdup_user() helper instead of open-coding to simplify the code.
>>>
>>> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
>>> Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
>>> ---
>>>   efi_runtime/efi_runtime.c | 11 +++--------
>>>   1 file changed, 3 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
>>> index 19b624c..6570a54 100644
>>> --- a/efi_runtime/efi_runtime.c
>>> +++ b/efi_runtime/efi_runtime.c
>>> @@ -90,18 +90,13 @@ copy_ucs2_from_user_len(efi_char16_t **dst,
>>> efi_char16_t __user *src,
>>>       if (!access_ok(VERIFY_READ, src, 1))
>>>           return -EFAULT;
>>>   -    buf = kmalloc(len, GFP_KERNEL);
>>> -    if (!buf) {
>>> +    buf = memdup_user(src, len);
>>> +    if (IS_ERR(buf)) {
>>>           *dst = NULL;
>>> -        return -ENOMEM;
>>> +        return PTR_ERR(buf);
>>>       }
>>>       *dst = buf;
>>>   -    if (copy_from_user(*dst, src, len)) {
>>> -        kfree(buf);
>>> -        return -EFAULT;
>>> -    }
>>> -
>>>       return 0;
>>>   }
>>>  
>> Ivan, this is great for the latest kernel, what do we do for backwards
>> compatibility in the fwts DKMS driver?
>>
> 
> Colin, memdup_user has introduced for a very long time,since 2009. Looks
> like should not be a problem for the DKMS driver. What backward
> compatibility issue have you seen?

Ah, I hadn't realized that memdep_user was quite that old. No problem
then. Sorry for the noise.

Colin

> 
> Ivan
> 
>> Acked-by: Colin Ian King <colin.king@canonical.com>
>>
Alex Hung July 4, 2017, 8:11 a.m. UTC | #4 
On 2017-07-03 12:48 AM, Ivan Hu wrote:
> From: Geliang Tang <geliangtang@gmail.com>
> 
> Sync up with kernel driver efi_test:
> 
> efi/efi_test: Use memdup_user() helper
> 
> Use memdup_user() helper instead of open-coding to simplify the code.
> 
> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
> Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
> ---
>   efi_runtime/efi_runtime.c | 11 +++--------
>   1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
> index 19b624c..6570a54 100644
> --- a/efi_runtime/efi_runtime.c
> +++ b/efi_runtime/efi_runtime.c
> @@ -90,18 +90,13 @@ copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
>   	if (!access_ok(VERIFY_READ, src, 1))
>   		return -EFAULT;
>   
> -	buf = kmalloc(len, GFP_KERNEL);
> -	if (!buf) {
> +	buf = memdup_user(src, len);
> +	if (IS_ERR(buf)) {
>   		*dst = NULL;
> -		return -ENOMEM;
> +		return PTR_ERR(buf);
>   	}
>   	*dst = buf;
>   
> -	if (copy_from_user(*dst, src, len)) {
> -		kfree(buf);
> -		return -EFAULT;
> -	}
> -
>   	return 0;
>   }
>   
> 
Acked-by: Alex Hung <alex.hung@canonical.com>
diff mbox

Patch

diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
index 19b624c..6570a54 100644
--- a/efi_runtime/efi_runtime.c
+++ b/efi_runtime/efi_runtime.c
@@ -90,18 +90,13 @@  copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
 	if (!access_ok(VERIFY_READ, src, 1))
 		return -EFAULT;
 
-	buf = kmalloc(len, GFP_KERNEL);
-	if (!buf) {
+	buf = memdup_user(src, len);
+	if (IS_ERR(buf)) {
 		*dst = NULL;
-		return -ENOMEM;
+		return PTR_ERR(buf);
 	}
 	*dst = buf;
 
-	if (copy_from_user(*dst, src, len)) {
-		kfree(buf);
-		return -EFAULT;
-	}
-
 	return 0;
 }