From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Date: Fri, 16 Jun 2006 15:11:10 +0000 Subject: Re: [RFC][PATCH]fix search_extable() to find correct entry Message-Id: <4492CA0E.7050308@sdl.hitachi.co.jp> List-Id: References: <44916017.5050006@sdl.hitachi.co.jp> In-Reply-To: <44916017.5050006@sdl.hitachi.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Hi, Chen, Kenneth W wrote: > Masami Hiramatsu wrote on Thursday, June 15, 2006 6:27 AM >> I found a suspicious buggy code in the linux kernel on IA64 arch. >> As far as I can see, search_extable() doesn't work correctly, because >> the lookup routine expects that the address format of the >> exception_table_entry is "IP + slot", but the compiler (gcc-3.4.5) >> generates it as "IP + (slot << 2)". Thus the lookup routine always >> fails to find the corresponding entry. >> You can check it by dumping __ex_table section of vmlinux. > > Chen, Kenneth W wrote on Thursday, June 15, 2006 2:22 PM >> But the tag address in the table is also bundle aligned, which I will >> look a bit more. > > I've double checked (triple checked with sample test code below). It's a > false alarm. Everyone should rest assure that exception table and compiler > do match and generates correct code. There is no bug AFAICT. Thank you for your comments. I had just checked the dump of __ex_table section of vmlinux. This time, I checked the __ex_table of running kernel. It is true that those format is "IP + slot". So you are right. I admit my mistake. Please dispose the previous patch. Thanks again. -- Masami HIRAMATSU 2nd Research Dept. Hitachi, Ltd., Systems Development Laboratory E-mail: hiramatu@sdl.hitachi.co.jp