From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 In-Reply-To: <37158D29.132CCFC1@wanadoo.fr> Date: Thu, 15 Apr 1999 12:56:32 +0100 (BST) From: Gary Thomas To: Martin Costabel Subject: Re: [Patch] linuxppc gnuplot segfaults in save Cc: bug-gnuplot@dartmouth.edu, linuxppc-dev@lists.linuxppc.org, Tom Rini Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On 15-Apr-99 Martin Costabel wrote: > > Tom Rini wrote: > >> Hmm. I don't use gnuplot (and thus didn't see the bug and don't have the >> source handy), so if any x86/Linux users with glibc 2.1.x installed could >> see if they run into the bug.. > > When gnuplot-3.7 came out, this problem was mentioned to one of the > gnuplot discussion groups (which I don't normally read, I use gnuplot > only occasionally, with octave, for example). It didn't get much > attention, because it seems to affect only linuxppc (and who's using > that, anyway?) > >> > Or could someone find out what's wrong with the fprintf function in >> > LinuPPC? Note that this is not specific for one version of glibc. I >> > tried it on several from glibc-961212 to glibc-2.1.1-3a. Same result. >> >> It failed under the old libs? > > Yes, I compiled gnuplot-3.7 under glibc-961212 (rev 1o, IIRC), and the > result was the same. I managed to track the problem down to the fprintf > call, but I don't know enough C and glibc to go any further. > I'm not familiar with the specifics of the problem being discussed here but it seems to be a "varargs" problem. One of the key differences between Linux/PPC (and indeed PowerPC in general) and virtually every other system is how "varargs" works. For most architectures a simple pointer to a list of items [typically on the stack] is used. On the PowerPC, however, there is an invisible structure which is used to manage the parameters. Where just copying a pointer works fine on other architectures, these sort of operations fail on the PowerPC. This is where I'd look to start with. (Note: I'm not volunteering :-) ------------------------------------------------------------------------ Gary Thomas | email: gdt@linuxppc.org | "Fine wine is a necessity of ... opinions expressed here are mine | life for me" and no one else would claim them! | | Thomas Jefferson ------------------------------------------------------------------------ [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]