nfc_llc_register() calls pass a string literal as the 'name' parameter.
So kstrdup_const() can be used instead of kfree() to avoid a memory
allocation in such cases.
Signed-off-by: Christophe JAILLET <[email protected]>
---
net/nfc/hci/llc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c
index 2140f6724644..8c7b5a817b25 100644
--- a/net/nfc/hci/llc.c
+++ b/net/nfc/hci/llc.c
@@ -49,7 +49,7 @@ int nfc_llc_register(const char *name, const struct nfc_llc_ops *ops)
if (llc_engine == NULL)
return -ENOMEM;
- llc_engine->name = kstrdup(name, GFP_KERNEL);
+ llc_engine->name = kstrdup_const(name, GFP_KERNEL);
if (llc_engine->name == NULL) {
kfree(llc_engine);
return -ENOMEM;
@@ -83,7 +83,7 @@ void nfc_llc_unregister(const char *name)
return;
list_del(&llc_engine->entry);
- kfree(llc_engine->name);
+ kfree_const(llc_engine->name);
kfree(llc_engine);
}
--
2.43.0
On Sat, Jan 20, 2024 at 10:56:06AM +0100, Christophe JAILLET wrote:
> nfc_llc_register() calls pass a string literal as the 'name' parameter.
>
> So kstrdup_const() can be used instead of kfree() to avoid a memory
> allocation in such cases.
>
> Signed-off-by: Christophe JAILLET <[email protected]>
## Form letter - net-next-closed
[adapted from text by Jakub]
The merge window for v6.8 has begun and therefore net-next is closed
for new drivers, features, code refactoring and optimizations.
We are currently accepting bug fixes only.
Please repost when net-next reopens on or after 22nd January.
RFC patches sent for review only are obviously welcome at any time.
See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
--
pw-bot: defer
On 20/01/2024 10:56, Christophe JAILLET wrote:
> nfc_llc_register() calls pass a string literal as the 'name' parameter.
>
> So kstrdup_const() can be used instead of kfree() to avoid a memory
> allocation in such cases.
>
> Signed-off-by: Christophe JAILLET <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
You probably need to resend it, because that time net-next was closed.
If resending, keep my tag.
Best regards,
Krzysztof
On Sat, 27 Jan 2024 10:58:29 +0100 Christophe JAILLET wrote:
> nfc_llc_register() calls pass a string literal as the 'name' parameter.
>
> So kstrdup_const() can be used instead of kfree() to avoid a memory
> allocation in such cases.
>
> Signed-off-by: Christophe JAILLET <[email protected]>
> Reviewed-by: Krzysztof Kozlowski <[email protected]>
There is a kfree() call in nfc_llc_exit() that looks suspiciously
like it may also free the name.
Le 01/02/2024 à 00:08, Jakub Kicinski a écrit :
> On Sat, 27 Jan 2024 10:58:29 +0100 Christophe JAILLET wrote:
>> nfc_llc_register() calls pass a string literal as the 'name' parameter.
>>
>> So kstrdup_const() can be used instead of kfree() to avoid a memory
>> allocation in such cases.
>>
>> Signed-off-by: Christophe JAILLET <[email protected]>
>> Reviewed-by: Krzysztof Kozlowski <[email protected]>
>
> There is a kfree() call in nfc_llc_exit() that looks suspiciously
> like it may also free the name.
>
>
Hi,
you are right.
Should we have something like:
void nfc_llc_exit(void)
{
struct nfc_llc_engine *llc_engine, *n;
list_for_each_entry_safe(llc_engine, n, &llc_engines, entry)
nfc_llc_unregister(&llc_engine->name);
}
It would be slower, but it would reduce code duplication as well.
This is just an _exit() function, so it shouldn't be called that often
anyway, if called at all.
Or, add another function with the list_del()+kfree_const()+kfree(), that
would be called from nfc_llc_exit() and nfc_llc_unregister(), to have
the best of the 2 worlds?
CJ
On Fri, 2 Feb 2024 20:11:56 +0100 Christophe JAILLET wrote:
> It would be slower, but it would reduce code duplication as well.
> This is just an _exit() function, so it shouldn't be called that often
> anyway, if called at all.
>
> Or, add another function with the list_del()+kfree_const()+kfree(), that
> would be called from nfc_llc_exit() and nfc_llc_unregister(), to have
> the best of the 2 worlds?
My vote is the latter - factor out the 3 calls into a new helper, call
it where appropriate.