From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1EL3zA-0007qj-4i for user-mode-linux-devel@lists.sourceforge.net; Thu, 29 Sep 2005 12:22:28 -0700 Received: from smtp007.mail.ukl.yahoo.com ([217.12.11.96]) by mail.sourceforge.net with smtp (Exim 4.44) id 1EL3z8-0000jf-9U for user-mode-linux-devel@lists.sourceforge.net; Thu, 29 Sep 2005 12:22:27 -0700 From: Blaisorblade Subject: Re: [uml-devel] Clearing kmalloc_ok during shutdown is broken - malloc will clear our data. References: <200509281346.23592.blaisorblade@yahoo.it> <20050928213125.GA16955@ccure.user-mode-linux.org> In-Reply-To: <20050928213125.GA16955@ccure.user-mode-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200509291614.03229.blaisorblade@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Thu, 29 Sep 2005 16:14:02 +0200 To: user-mode-linux-devel@lists.sourceforge.net, Allan Graves Cc: Jeff Dike On Wednesday 28 September 2005 23:31, Jeff Dike wrote: > On Wed, Sep 28, 2005 at 01:46:15PM +0200, Blaisorblade wrote: > > Also, there are some calls to kmalloc in the shutdown path - and they > > work. I know this because I saw a problem with one of them: it gave > > "might_sleep while atomic", and it was kmalloc in the shutdown, or > > rather, in panic() - for the broken sysrq t (where's the fix you > > promised?). > Attached. I now even found (by chance) the original mail from Allan Graves - and the changes in arch/um/include/sysdep-x86_64/ptrace.h weren't in his patch and are unrelated. Plus, I think they're also bogus (those registers exist), but I may be wrong, I'm not looking at these unrelated changes since they pertain to something else and I've no changelog. On the patch: it makes sense, and the "XXX" removed comment, which explained the bug, was added by myself. On the bogus value: I'm more accustomed to 0xdeadbeef, since 0xbadbabe could be valid while 0xdeadbeef not (it's in the last giga). The only problem I see is that we need to test it on a wide glibc range - you're using an internal header detail, so glibc will break it at will. Sadly, we haven't a better fix (except reimplementing setjmp(), which is even worse than the original problem - plus I don't like glibc sources enough to go picking the code). -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel