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From:   Song Liu <songliubraving@fb.com>
To:     Martin Lau <kafai@fb.com>
CC:     bpf <bpf@vger.kernel.org>, Networking <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "ast@kernel.org" <ast@kernel.org>,
        "daniel@iogearbox.net" <daniel@iogearbox.net>,
        Kernel Team <Kernel-team@fb.com>,
        "peterz@infradead.org" <peterz@infradead.org>,
        KP Singh <kpsingh@kernel.org>
Subject: Re: [PATCH v4 bpf-next 1/6] bpf: enable task local storage for
 tracing programs
Thread-Topic: [PATCH v4 bpf-next 1/6] bpf: enable task local storage for
 tracing programs
Thread-Index: AQHXCYIuKEHXcKCMU0m4MKXErpSFUqpmH7aAgAAYkoA=
Date:   Tue, 23 Feb 2021 20:51:26 +0000
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> On Feb 23, 2021, at 11:23 AM, Martin Lau <kafai@fb.com> wrote:
>=20
> On Mon, Feb 22, 2021 at 05:20:09PM -0800, Song Liu wrote:
> [ ... ]
>=20
>> diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage=
.c
>> index e0da0258b732d..2034019966d44 100644
>> --- a/kernel/bpf/bpf_task_storage.c
>> +++ b/kernel/bpf/bpf_task_storage.c
>> @@ -15,7 +15,6 @@
>> #include <linux/bpf_local_storage.h>
>> #include <linux/filter.h>
>> #include <uapi/linux/btf.h>
>> -#include <linux/bpf_lsm.h>
>> #include <linux/btf_ids.h>
>> #include <linux/fdtable.h>
>>=20
>> @@ -24,12 +23,8 @@ DEFINE_BPF_STORAGE_CACHE(task_cache);
>> static struct bpf_local_storage __rcu **task_storage_ptr(void *owner)
>> {
>> 	struct task_struct *task =3D owner;
>> -	struct bpf_storage_blob *bsb;
>>=20
>> -	bsb =3D bpf_task(task);
>> -	if (!bsb)
>> -		return NULL;
> task_storage_ptr() no longer returns NULL.  All "!task_storage_ptr(task)"
> checks should be removed also.  e.g. In bpf_task_storage_get
> and bpf_pid_task_storage_update_elem.

Good catch! Fixed it in v5.=20

Thanks,
Song

>=20
>> -	return &bsb->storage;
>> +	return &task->bpf_storage;
>> }
>>=20