[PATCH v2] lib/string_helpers: Use the given gfp flag when allocating memory

[PATCH v2] lib/string_helpers: Use the given gfp flag when allocating memory

[Christophe JAILLET]

kstrdup_quotable_cmdline() and kstrdup_quotable_file() are given a gfp flag
that is passed and used for memory allocation in kstrdup_quotable() just a
few lines below.

It looks reasonable to use this gfp value for the buffer allocated and
freed in these functions as well.

Fixes: 0ee931c4e31a ("mm: treewide: remove GFP_TEMPORARY allocation flag")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
According to what I've found in 5.16, all callers use GFP_KERNEL, so this
patch should be a no-op.
But who knows how it will be used in the future. Better safe than sorry.

v2: Add the change for kstrdup_quotable_file()
---
 lib/string_helpers.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 90f9f1b7afec..4433e486b725 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -624,7 +624,7 @@ char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
 	char *buffer, *quoted;
 	int i, res;
 
-	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	buffer = kmalloc(PAGE_SIZE, gfp);
 	if (!buffer)
 		return NULL;
 
@@ -660,7 +660,7 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
 		return kstrdup("<unknown>", gfp);
 
 	/* We add 11 spaces for ' (deleted)' to be appended */
-	temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
+	temp = kmalloc(PATH_MAX + 11, gfp);
 	if (!temp)
 		return kstrdup("<no_memory>", gfp);
 
-- 
2.32.0

Re: [PATCH v2] lib/string_helpers: Use the given gfp flag when allocating memory

[Andy Shevchenko]

On Sun, Jan 16, 2022 at 01:53:37PM +0100, Christophe JAILLET wrote:
> kstrdup_quotable_cmdline() and kstrdup_quotable_file() are given a gfp flag
> that is passed and used for memory allocation in kstrdup_quotable() just a
> few lines below.
> 
> It looks reasonable to use this gfp value for the buffer allocated and
> freed in these functions as well.

Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com>

> Fixes: 0ee931c4e31a ("mm: treewide: remove GFP_TEMPORARY allocation flag")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> According to what I've found in 5.16, all callers use GFP_KERNEL, so this
> patch should be a no-op.
> But who knows how it will be used in the future. Better safe than sorry.
> 
> v2: Add the change for kstrdup_quotable_file()
> ---
>  lib/string_helpers.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index 90f9f1b7afec..4433e486b725 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -624,7 +624,7 @@ char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
>  	char *buffer, *quoted;
>  	int i, res;
>  
> -	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
> +	buffer = kmalloc(PAGE_SIZE, gfp);
>  	if (!buffer)
>  		return NULL;
>  
> @@ -660,7 +660,7 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
>  		return kstrdup("<unknown>", gfp);
>  
>  	/* We add 11 spaces for ' (deleted)' to be appended */
> -	temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
> +	temp = kmalloc(PATH_MAX + 11, gfp);
>  	if (!temp)
>  		return kstrdup("<no_memory>", gfp);
>  
> -- 
> 2.32.0
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] lib/string_helpers: Use the given gfp flag when allocating memory

[Christophe JAILLET]

Le 24/01/2022 à 15:26, Andy Shevchenko a écrit :
> On Sun, Jan 16, 2022 at 01:53:37PM +0100, Christophe JAILLET wrote:
>> kstrdup_quotable_cmdline() and kstrdup_quotable_file() are given a gfp flag
>> that is passed and used for memory allocation in kstrdup_quotable() just a
>> few lines below.
>>
>> It looks reasonable to use this gfp value for the buffer allocated and
>> freed in these functions as well.
> 
> Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com>

Hi,
just in case, another patch has been proposed in the thread related to 
the v1 of this patch.
See [1].

I let you see which approach is the more relevant.

CJ

[1]: https://lore.kernel.org/linux-kernel/YeU8PhtvvXIWtTk%2F@dhcp22.suse.cz/

> 
>> Fixes: 0ee931c4e31a ("mm: treewide: remove GFP_TEMPORARY allocation flag")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>> According to what I've found in 5.16, all callers use GFP_KERNEL, so this
>> patch should be a no-op.
>> But who knows how it will be used in the future. Better safe than sorry.
>>
>> v2: Add the change for kstrdup_quotable_file()
>> ---
>>   lib/string_helpers.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
>> index 90f9f1b7afec..4433e486b725 100644
>> --- a/lib/string_helpers.c
>> +++ b/lib/string_helpers.c
>> @@ -624,7 +624,7 @@ char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
>>   	char *buffer, *quoted;
>>   	int i, res;
>>   
>> -	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
>> +	buffer = kmalloc(PAGE_SIZE, gfp);
>>   	if (!buffer)
>>   		return NULL;
>>   
>> @@ -660,7 +660,7 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
>>   		return kstrdup("<unknown>", gfp);
>>   
>>   	/* We add 11 spaces for ' (deleted)' to be appended */
>> -	temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
>> +	temp = kmalloc(PATH_MAX + 11, gfp);
>>   	if (!temp)
>>   		return kstrdup("<no_memory>", gfp);
>>   
>> -- 
>> 2.32.0
>>
>