linux-kernel - [PATCH] kgdb: could not write to the last of valid memory with kgdb.

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Date:	Tue, 09 Sep 2008 09:04:48 +0900
From:	Atsuo Igarashi <atsuo_igarashi@...peaks.co.jp>
To:	jason.wessel@...driver.com
CC:	linux-kernel@...r.kernel.org,
	Atsuo Igarashi <atsuo_igarashi@...peaks.co.jp>,
	Yoichi Yuasa <yoichi_yuasa@...peaks.co.jp>
Subject: [PATCH] kgdb: could not write to the last of valid memory with kgdb.

Hi,

I'm using i.MX31 ARM11 board which has 104Mbyte valid memory.
When I'd invoked a print command to write the last of valid memory from gdb,
there was no response from kgdb.

It seems that the following line causes this problem.

kernel/kgdb.c: write_mem_msg()
...
 491 			flush_icache_range(addr, addr + length + 1);

If the last byte of valid memory is specified, the last cache line and the next
cache line will be flushed by the ARM11 V6's function from flush_icache_range().
I'm not sure why the 2nd parameter has +1, I assume this +1 is unnecessary for
ARM11 V6's cache.
I send a patch to remove this +1, does anyone know necessity for other architectures?

Regards,

Signed-off-by Atsuo Igarashi <atsuo_igarashi@...peaks.co.jp>

View attachment "kgdb_write_mem_msg.diff" of type "text/x-diff" (416 bytes)