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@xxxxxxxxx>

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@xxxxxxxxxxxxxx/

> > Fixes: 0ee931c4e31a ("mm: treewide: remove GFP_TEMPORARY allocation flag")
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > ---
> > 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