From: <gr...@su...> - 2007-03-30 20:19:48
|
This is a note to let you know that we have just queued up the patch titled Subject: UML - host VDSO fix to the 2.6.20-stable tree. Its filename is uml-host-vdso-fix.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From sta...@li... Fri Mar 23 12:41:21 2007 From: Jeff Dike <jd...@ad...> Date: Fri, 23 Mar 2007 15:37:30 -0400 Subject: UML - host VDSO fix To: st...@ke... Cc: uml-devel <use...@li...> Message-ID: <200...@c2...> Content-Disposition: inline From: Jeff Dike <jd...@ad...> 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 <jd...@li...> Signed-off-by: Greg Kroah-Hartman <gr...@su...> --- 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; _______________________________________________ stable mailing list st...@li... http://linux.kernel.org/mailman/listinfo/stable Patches currently in stable-queue which might be from jd...@ad... are |