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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
Date: Tue, 23 Feb 2021 20:51:26 +0000
Message-ID: <CB9251DE-7372-4AE1-B758-528DFA22D515@fb.com> (raw)
In-Reply-To: <20210223192329.lutwo4ols75ut5ai@kafai-mbp.dhcp.thefacebook.com>



> On Feb 23, 2021, at 11:23 AM, Martin Lau <kafai@fb.com> wrote:
> 
> On Mon, Feb 22, 2021 at 05:20:09PM -0800, Song Liu wrote:
> [ ... ]
> 
>> 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>
>> 
>> @@ -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 = owner;
>> -	struct bpf_storage_blob *bsb;
>> 
>> -	bsb = 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. 

Thanks,
Song

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


  reply index

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-23  1:20 [PATCH v4 bpf-next 0/6] " Song Liu
2021-02-23  1:20 ` [PATCH v4 bpf-next 1/6] " Song Liu
2021-02-23  3:08   ` kernel test robot
2021-02-23  4:04   ` kernel test robot
2021-02-23 19:23   ` Martin KaFai Lau
2021-02-23 20:51     ` Song Liu [this message]
2021-02-23  1:20 ` [PATCH v4 bpf-next 2/6] bpf: prevent deadlock from recursive bpf_task_storage_[get|delete] Song Liu
2021-02-23  6:21   ` Andrii Nakryiko
2021-02-23  7:16     ` Song Liu
2021-02-23  7:19       ` Andrii Nakryiko
2021-02-23 16:44         ` Alexei Starovoitov
2021-02-23 11:06   ` Peter Zijlstra
2021-02-23 20:49     ` Song Liu
2021-02-23  1:20 ` [PATCH v4 bpf-next 3/6] selftests/bpf: add non-BPF_LSM test for task local storage Song Liu
2021-02-23  1:20 ` [PATCH v4 bpf-next 4/6] selftests/bpf: test deadlock from recursive bpf_task_storage_[get|delete] Song Liu
2021-02-23  1:20 ` [PATCH v4 bpf-next 5/6] bpf: runqslower: prefer using local vmlimux to generate vmlinux.h Song Liu
2021-02-23  6:26   ` Andrii Nakryiko
2021-02-23 21:24   ` Martin KaFai Lau
2021-02-23  1:20 ` [PATCH v4 bpf-next 6/6] bpf: runqslower: use task local storage Song Liu
2021-02-23 21:33   ` Martin KaFai Lau

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