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	Thu, 18 Dec 2025 23:55:39 +0000
Date: Thu, 18 Dec 2025 23:55:39 +0000
From: Matthew Wilcox <willy@infradead.org>
To: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Shaurya Rane <ssrane_b23@ee.vjti.ac.in>,
	"Darrick J . Wong" <djwong@kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Meta kernel team <kernel-team@meta.com>, bpf@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	syzbot+09b7d050e4806540153d@syzkaller.appspotmail.com,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH bpf v2] lib/buildid: use __kernel_read() for sleepable
 context
Message-ID: <aUSUe9jHnYJ577Gh@casper.infradead.org>
References: <20251218205505.2415840-1-shakeel.butt@linux.dev>
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In-Reply-To: <20251218205505.2415840-1-shakeel.butt@linux.dev>

On Thu, Dec 18, 2025 at 12:55:05PM -0800, Shakeel Butt wrote:
> +	do {
> +		ret = __kernel_read(r->file, buf, sz, &pos);
> +		if (ret <= 0) {
> +			r->err = ret ?: -EIO;
> +			return NULL;
> +		}
> +		buf += ret;
> +		sz -= ret;
> +	} while (sz > 0);

Why are you doing a loop around __kernel_read()?  eg kernel_read() does
not do a read around __kernel_read().  The callers of kernel_read()
don't do a loop either.  So what makes you think it needs to have a loop
around it?