aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJeff Dike <jdike@addtoit.com>2007-03-23 15:37:30 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-04-06 03:43:11 -0700
commit6f6017090339ddb751b3c71840c214282214f6bc (patch)
tree85292a6a7251d8689b8378ffeb134736243f51ef
parentedfcf73f3005c29f7f28f4fcd47cfbfc06af10bb (diff)
downloadlinux-linaro-stable-6f6017090339ddb751b3c71840c214282214f6bc.tar.gz
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 <jdike@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/um/os-Linux/elf_aux.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index 5a99dd3fbed0..13c6cb56e315 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -40,6 +40,9 @@ __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;