Arnd Bergmann wrote: > On Tuesday 14 July 2009, Michal Simek wrote: >> I found that I can setup text base in binutils/ld/emulparam/elf32mb_linux.sh >> >> The problem which I have is that if I run socketpair, getsockname, >> getpeername LTP >> tests with invalid salen pointer there are addresses close to 0x0. Microblaze >> has no text there and the sigsegv fault is generated. > > This sounds like a classic NULL pointer dereference that is handled correctly > by the kernel. The question is where the address came from.
It is not anly NULL pointer - is LTP tests are some fake addresses. From my tests I see that I am not able to access place till 1000 0000 in dec. Bad address come from tests to test it. Look at http://developer.petalogix.com/git/gitweb.cgi?p=ltp-microblaze.git;a=commitdiff;h=45f4cd783ce8b94f1267bb87c0c46e8536f62eca There are three affected tests and my quick fixes which I am trying to solve now. > >> This fault could be fixed by changed access_ok macro where I check bottom >> limit >> at 0x1000 0000 too. After this change the LTP program not failed but I am >> not sure >> if is the right solution because none arch do it. All archs just check upper >> limit >> not lower. >> >> What is the correct solution for it? Moving .text base to 0x0 or is there >> any other >> elegant solution? > > Moving .text is not the right solution, because it only papers over real bugs. I can confirm it - I moved it and rebuild toolchain. > access_ok() is also not the right place to check this, the only purpose it has > is to make sure that the argument is not a valid kernel address but either a > valid user address or possibly invalid address. Also, access_ok() is only used > together with the copy_from/to_user and get/put_user function families. These > need to catch invalid addresses with a fixup table entry in the kernel. ok - that mean that problem could be in bad fixup table? > > I briefly looked at your implementation but could not find any problems in > this area. Could you use gdb to find out whether the sigsegv happens in the > kernel at all, or in user space? We don't have gdb in place. The problem should come from get_user macro. net/socket.c:212 I was looking for it in the morning. I am checking it again. Thanks, Michal int move_addr_to_user(struct sockaddr *kaddr, int klen, void __user *uaddr, int __user *ulen) { int err; int len; err = get_user(len, ulen); if (err) return err; > > Arnd <>< -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ Ltp-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ltp-list
