Jeff, Is this going into stable or devel? If stable, what version? Also, do you know what version of the host kernels introduced this behavior?
Sorry for all the questions, but I believe this is the bug I've been waiting on for a while (affecting host kernels greater than 2.6.17, or something of that nature). Thanks! Tony > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > On Behalf Of Jeff Dike > Sent: Friday, March 23, 2007 12:38 PM > To: [EMAIL PROTECTED] > Cc: LKML; uml-devel > Subject: [uml-devel] [PATCH] UML - host VDSO fix > > This fixes a problem seen by a number of people running UML > on newer host > kernels. init would hang with an infinite segfault loop. > > It turns out that the host kernel was providing a AT_SYSINFO_EHDR of > 0xffffe000, which faked UML into believing that the host VDSO > page could be > reused. However, AT_SYSINFO pointed into the middle of the > address space, and > was unmapped as a result. Because UML was providing > AT_SYSINFO_EHDR and > AT_SYSINFO to its own processes, these would branch to > nowhere when trying to > use the VDSO. > > The fix is to also check the location of AT_SYSINFO when > deciding whether to > use the host's VDSO. > > Signed-off-by: Jeff Dike <[EMAIL PROTECTED]> > -- > arch/um/os-Linux/elf_aux.c | 3 +++ > 1 file changed, 3 insertions(+) > > Index: linux-2.6.17/arch/um/os-Linux/elf_aux.c > =================================================================== > --- linux-2.6.17.orig/arch/um/os-Linux/elf_aux.c > 2007-02-23 15:00:51.000000000 -0500 > +++ linux-2.6.17/arch/um/os-Linux/elf_aux.c 2007-02-23 > 15:09:58.000000000 -0500 > @@ -39,6 +39,9 @@ __init void scan_elf_aux( char **envp) > switch ( auxv->a_type ) { > case AT_SYSINFO: > __kernel_vsyscall = auxv->a_un.a_val; > + /* See if the page is under TASK_SIZE */ > + if (__kernel_vsyscall < > (unsigned long) envp) > + __kernel_vsyscall = 0; > break; > case AT_SYSINFO_EHDR: > vsyscall_ehdr = auxv->a_un.a_val; > > -------------------------------------------------------------- > ----------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the > chance to share your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge > &CID=DEVDEV > _______________________________________________ > User-mode-linux-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
