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From: Atsuo Igarashi <atsuo_igarashi@tripeaks.co.jp>
To: jason.wessel@windriver.com
Cc: linux-kernel@vger.kernel.org,
	Atsuo Igarashi <atsuo_igarashi@tripeaks.co.jp>,
	Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Subject: [PATCH] kgdb: could not write to the last of valid memory with kgdb.
Date: Tue, 09 Sep 2008 09:04:48 +0900	[thread overview]
Message-ID: <48C5BDA0.90105@tripeaks.co.jp> (raw)

[-- Attachment #1: Type: text/plain, Size: 738 bytes --]

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@tripeaks.co.jp>

[-- Attachment #2: kgdb_write_mem_msg.diff --]
[-- Type: text/x-diff, Size: 415 bytes --]

 kernel/kgdb.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index eaa21fc..949806a 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -488,7 +488,7 @@ static int write_mem_msg(int binary)
 		if (err)
 			return err;
 		if (CACHE_FLUSH_IS_SAFE)
-			flush_icache_range(addr, addr + length + 1);
+			flush_icache_range(addr, addr + length);
 		return 0;
 	}
 

             reply	other threads:[~2008-09-09  0:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-09  0:04 Atsuo Igarashi [this message]
2008-09-09 13:14 ` [PATCH] kgdb: could not write to the last of valid memory with kgdb Jason Wessel

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