From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Xi Wang <xi.wang@gmail.com>
Cc: Xiangliang Yu <yuxiangl@marvell.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] [SCSI] mvsas: fix shift in mvs_94xx_free_reg_set()
Date: Tue, 06 Nov 2012 13:06:58 +0100 [thread overview]
Message-ID: <1352203618.2529.22.camel@dabdike> (raw)
In-Reply-To: <1352145183-29355-3-git-send-email-xi.wang@gmail.com>
On Mon, 2012-11-05 at 14:53 -0500, Xi Wang wrote:
> Invoking bit(n) with n >= 64 is undefined behavior, since bit(n) does
> a 64-bit shift. This patch adds a check on the shifting amount.
Why is this necessary? As I read the reg set assignment code, it finds
a free bit in the 64 bit register and uses that ... which can never be
greater than 64 so there's no need for the check.
The other two look OK (probably redone as a single patch with a stable
tag), but I'd like the input of the mvs people since it seems with the
current code, we only use 32 bit regsets and probably hang if we go over
that. The bug fix is either to enable the full 64 if it works, or
possibly cap at 32 ... what works with all released devices?
James
next prev parent reply other threads:[~2012-11-06 12:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-05 19:53 [PATCH 0/3] [SCSI] mvsas: fix multiple shift issues Xi Wang
2012-11-05 19:53 ` [PATCH 1/3] [SCSI] mvsas: fix shift in mvs_94xx_assign_reg_set() Xi Wang
2012-11-05 19:53 ` [PATCH 2/3] [SCSI] mvsas: fix shift in mvs_94xx_free_reg_set() Xi Wang
2012-11-06 12:06 ` James Bottomley [this message]
2012-11-06 20:55 ` Xi Wang
2012-11-09 7:30 ` Xiangliang Yu
2012-11-09 13:44 ` Xi Wang
2012-11-16 7:39 ` Xiangliang Yu
2012-11-05 19:53 ` [PATCH 3/3] [SCSI] mvsas: fix shift in mv_ffc64() Xi Wang
2012-11-16 19:40 ` [PATCH v2] [SCSI] mvsas: fix undefined bit shift Xi Wang
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