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Date: Wed, 14 Sep 2016 11:59:26 +0200
From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Jens Axboe <axboe@fb.com>, Mike Christie <mchristi@redhat.com>,
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Subject: Re: [PATCH 3/3] block: Improve bio_set_op_attrs() robustness
Message-ID: <20160914095926.GC21938@lst.de>
References: <35e3cdd6-8983-6c84-cb4c-9a7be15aea55@sandisk.com> <2a6c6cbd-ccc6-ee89-99ca-c0267cf17ec0@sandisk.com>
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On Wed, Sep 14, 2016 at 10:46:22AM +0200, Bart Van Assche wrote:
> Since REQ_OP_BITS == 3 and __REQ_NR_BITS == 30 it is not that hard
> to pass an op_flags argument to bio_set_op_attrs() that is larger
> than the number of bits reserved for the op_flags argument. Complain
> if this happens. Additionally, ensure that negative arguments trigger
> a complaint (1 << ... is signed while 1U << ... is unsigned; adding
> 0U to an integer expression causes it to be promoted to an unsigned
> type).

And this does the proper check.

Reviewed-by: Christoph Hellwig <hch@lst.de>