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Date:   Thu, 5 Apr 2018 22:48:33 +0200
From:   Rabin Vincent <rabin@rab.in>
To:     David Rivshin <drivshin@awxrd.com>
Cc:     linux-arm-kernel@lists.infradead.org,
        kgdb-bugreport@lists.sourceforge.net,
        Jason Wessel <jason.wessel@windriver.com>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] arm: kgdb: fix NUMREGBYTES so that gdb_regs[] is the
 correct size
Message-ID: <20180405204833.hn56zpd474jywrm3@lnxartpec.se.axis.com>
References: <20180405200916.27964-1-drivshin@awxrd.com>
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On Thu, Apr 05, 2018 at 04:09:16PM -0400, David Rivshin wrote:
> From: David Rivshin <DRivshin@allworx.com>
> 
> NUMREGBYTES (which is used as the size for gdb_regs[]) is incorrectly based
> on DBG_MAX_REG_NUM instead of GDB_MAX_REGS. DBG_MAX_REG_NUM is the number
> of total registers, while GDB_MAX_REGS is the number of 'unsigned longs'
> it takes to serialize those registers. Since FP registers require 3
> 'unsigned longs' each, DBG_MAX_REG_NUM is smaller than GDB_MAX_REGS.
> 
> This causes GDB 8.0 give the following error on connect:
> "Truncated register 19 in remote 'g' packet"
> 
> This also causes the register serialization/deserialization logic to
> overflow gdb_regs[], overwriting whatever follows.
> 
> Fixes: 834b2964b7ab ("kgdb,arm: fix register dump")
> Cc: <stable@vger.kernel.org> # 2.6.37+
> Signed-off-by: David Rivshin <drivshin@allworx.com>

Acked-by: Rabin Vincent <rabin@rab.in>