um: Remove SKAS3/4 support

Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.

With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.

Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 0 insertions, 27 deletions

diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index 4da11b3c8ddb..082955d694f3 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -10,25 +10,6 @@
 #include <os.h>
 #include <skas.h>
 
-int new_mm(unsigned long stack)
-{
-        int fd, err;
-
-        fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
-        if (fd < 0)
-                return fd;
-
-        if (skas_needs_stub) {
-                err = map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
-                if (err) {
-                        os_close_file(fd);
-                        return err;
-                }
-        }
-
-        return fd;
-}
-
 extern void start_kernel(void);
 
 static int __init start_kernel_proc(void *unused)
@@ -55,14 +36,6 @@ int __init start_uml(void)
 {
         stack_protections((unsigned long) &cpu0_irqstack);
         set_sigstack(cpu0_irqstack, THREAD_SIZE);
-        if (proc_mm) {
-                userspace_pid[0] = start_userspace(0);
-                if (userspace_pid[0] < 0) {
-                        printf("start_uml - start_userspace returned %d\n",
-                               userspace_pid[0]);
-                        exit(1);
-                }
-        }
 
         init_new_thread_signals();