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References: <20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@kernel.org> <20240221-hid-bpf-sleepable-v3-2-1fb378ca6301@kernel.org>
In-Reply-To: <20240221-hid-bpf-sleepable-v3-2-1fb378ca6301@kernel.org>
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date: Thu, 22 Feb 2024 17:56:11 -0800
Message-ID: <CAADnVQKotZ0ki6p4DAydj=XE9hU6pPc+FdqU_WQ99NBK-qSe+A@mail.gmail.com>
Subject: Re: [PATCH RFC bpf-next v3 02/16] bpf/verifier: introduce
 in_sleepable() helper
To: Benjamin Tissoires <bentiss@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, 
	John Fastabend <john.fastabend@gmail.com>, Andrii Nakryiko <andrii@kernel.org>, 
	Martin KaFai Lau <martin.lau@linux.dev>, Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>, 
	Yonghong Song <yonghong.song@linux.dev>, KP Singh <kpsingh@kernel.org>, 
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>, 
	Jiri Kosina <jikos@kernel.org>, Benjamin Tissoires <benjamin.tissoires@redhat.com>, 
	Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>, bpf <bpf@vger.kernel.org>, 
	LKML <linux-kernel@vger.kernel.org>, 
	"open list:HID CORE LAYER" <linux-input@vger.kernel.org>, 
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>, 
	"open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org>
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On Wed, Feb 21, 2024 at 8:25=E2=80=AFAM Benjamin Tissoires <bentiss@kernel.=
org> wrote:
> @@ -18193,7 +18198,7 @@ static int resolve_pseudo_ldimm64(struct bpf_veri=
fier_env *env)
>                                 return -E2BIG;
>                         }
>
> -                       if (env->prog->aux->sleepable)
> +                       if (in_sleepable(env))
>                                 atomic64_inc(&map->sleepable_refcnt);

this one doesn't look correct.
The verifier didn't start its main loop when resolve_pseudo_ldimm64()
is called.
It also loses symmetry with other sleepable_refcnt operations
in syscall.c and core.c

I reverted this hunk and applied patches 1,2,3
with minor edits, like removing unnecessary parens in patch 3,
and patch subject rewords.