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authorRichard Weinberger <richard@nod.at>2015-03-18 21:31:27 +0100
committerRichard Weinberger <richard@nod.at>2015-04-13 21:00:53 +0200
commitd0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0 (patch)
tree7b833b85c0e2eabf6b38d8b94875b430554afae7 /arch/um/kernel
parentaaeac66b1a02d399ec8ee63e8d617c1d601ea353 (diff)
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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 With SKAS0 mode (separated kernel address space using 0 host patches), default since 2005, SKAS3/4 is obsolete and can be removed.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>
Diffstat (limited to 'arch/um/kernel')
-rw-r--r--arch/um/kernel/ptrace.c32
-rw-r--r--arch/um/kernel/reboot.c35
-rw-r--r--arch/um/kernel/skas/mmu.c68
-rw-r--r--arch/um/kernel/skas/process.c27
-rw-r--r--arch/um/kernel/trap.c2
-rw-r--r--arch/um/kernel/um_arch.c10
6 files changed, 38 insertions, 136 deletions
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 62435ef003d9..174ee5017264 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -8,9 +8,6 @@
#include <linux/sched.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
-#include <skas_ptrace.h>
-
-
void user_enable_single_step(struct task_struct *child)
{
@@ -104,35 +101,6 @@ long arch_ptrace(struct task_struct *child, long request,
ret = ptrace_set_thread_area(child, addr, vp);
break;
- case PTRACE_FAULTINFO: {
- /*
- * Take the info from thread->arch->faultinfo,
- * but transfer max. sizeof(struct ptrace_faultinfo).
- * On i386, ptrace_faultinfo is smaller!
- */
- ret = copy_to_user(p, &child->thread.arch.faultinfo,
- sizeof(struct ptrace_faultinfo)) ?
- -EIO : 0;
- break;
- }
-
-#ifdef PTRACE_LDT
- case PTRACE_LDT: {
- struct ptrace_ldt ldt;
-
- if (copy_from_user(&ldt, p, sizeof(ldt))) {
- ret = -EIO;
- break;
- }
-
- /*
- * This one is confusing, so just punt and return -EIO for
- * now
- */
- ret = -EIO;
- break;
- }
-#endif
default:
ret = ptrace_request(child, request, addr, data);
if (ret == -EIO)
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index ced8903921ae..9bdf67a092a5 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -15,28 +15,21 @@ void (*pm_power_off)(void);
static void kill_off_processes(void)
{
- if (proc_mm)
- /*
- * FIXME: need to loop over userspace_pids
- */
- os_kill_ptraced_process(userspace_pid[0], 1);
- else {
- struct task_struct *p;
- int pid;
-
- read_lock(&tasklist_lock);
- for_each_process(p) {
- struct task_struct *t;
-
- t = find_lock_task_mm(p);
- if (!t)
- continue;
- pid = t->mm->context.id.u.pid;
- task_unlock(t);
- os_kill_ptraced_process(pid, 1);
- }
- read_unlock(&tasklist_lock);
+ struct task_struct *p;
+ int pid;
+
+ read_lock(&tasklist_lock);
+ for_each_process(p) {
+ struct task_struct *t;
+
+ t = find_lock_task_mm(p);
+ if (!t)
+ continue;
+ pid = t->mm->context.id.u.pid;
+ task_unlock(t);
+ os_kill_ptraced_process(pid, 1);
}
+ read_unlock(&tasklist_lock);
}
void uml_cleanup(void)
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 007d5503f49b..94abdcc1d6ad 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -54,35 +54,22 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
unsigned long stack = 0;
int ret = -ENOMEM;
- if (skas_needs_stub) {
- stack = get_zeroed_page(GFP_KERNEL);
- if (stack == 0)
- goto out;
- }
+ stack = get_zeroed_page(GFP_KERNEL);
+ if (stack == 0)
+ goto out;
to_mm->id.stack = stack;
if (current->mm != NULL && current->mm != &init_mm)
from_mm = &current->mm->context;
- if (proc_mm) {
- ret = new_mm(stack);
- if (ret < 0) {
- printk(KERN_ERR "init_new_context_skas - "
- "new_mm failed, errno = %d\n", ret);
- goto out_free;
- }
- to_mm->id.u.mm_fd = ret;
- }
- else {
- if (from_mm)
- to_mm->id.u.pid = copy_context_skas0(stack,
- from_mm->id.u.pid);
- else to_mm->id.u.pid = start_userspace(stack);
-
- if (to_mm->id.u.pid < 0) {
- ret = to_mm->id.u.pid;
- goto out_free;
- }
+ if (from_mm)
+ to_mm->id.u.pid = copy_context_skas0(stack,
+ from_mm->id.u.pid);
+ else to_mm->id.u.pid = start_userspace(stack);
+
+ if (to_mm->id.u.pid < 0) {
+ ret = to_mm->id.u.pid;
+ goto out_free;
}
ret = init_new_ldt(to_mm, from_mm);
@@ -105,9 +92,6 @@ void uml_setup_stubs(struct mm_struct *mm)
{
int err, ret;
- if (!skas_needs_stub)
- return;
-
ret = init_stub_pte(mm, STUB_CODE,
(unsigned long) &__syscall_stub_start);
if (ret)
@@ -154,25 +138,19 @@ void destroy_context(struct mm_struct *mm)
{
struct mm_context *mmu = &mm->context;
- if (proc_mm)
- os_close_file(mmu->id.u.mm_fd);
- else {
- /*
- * If init_new_context wasn't called, this will be
- * zero, resulting in a kill(0), which will result in the
- * whole UML suddenly dying. Also, cover negative and
- * 1 cases, since they shouldn't happen either.
- */
- if (mmu->id.u.pid < 2) {
- printk(KERN_ERR "corrupt mm_context - pid = %d\n",
- mmu->id.u.pid);
- return;
- }
- os_kill_ptraced_process(mmu->id.u.pid, 1);
+ /*
+ * If init_new_context wasn't called, this will be
+ * zero, resulting in a kill(0), which will result in the
+ * whole UML suddenly dying. Also, cover negative and
+ * 1 cases, since they shouldn't happen either.
+ */
+ if (mmu->id.u.pid < 2) {
+ printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+ mmu->id.u.pid);
+ return;
}
+ os_kill_ptraced_process(mmu->id.u.pid, 1);
- if (skas_needs_stub)
- free_page(mmu->id.stack);
-
+ free_page(mmu->id.stack);
free_ldt(mmu);
}
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();
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 209617302df8..8e4daf44e980 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -220,7 +220,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
panic("Segfault with no mm");
}
- if (SEGV_IS_FIXABLE(&fi) || SEGV_MAYBE_FIXABLE(&fi))
+ if (SEGV_IS_FIXABLE(&fi))
err = handle_page_fault(address, ip, is_write, is_user,
&si.si_code);
else {
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 9274eae6ae7b..dbd5bda1f184 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -268,7 +268,6 @@ int __init linux_main(int argc, char **argv)
unsigned long stack;
unsigned int i;
int add;
- char * mode;
for (i = 1; i < argc; i++) {
if ((i == 1) && (argv[i][0] == ' '))
@@ -291,15 +290,6 @@ int __init linux_main(int argc, char **argv)
/* OS sanity checks that need to happen before the kernel runs */
os_early_checks();
- can_do_skas();
-
- if (proc_mm && ptrace_faultinfo)
- mode = "SKAS3";
- else
- mode = "SKAS0";
-
- printf("UML running in %s mode\n", mode);
-
brk_start = (unsigned long) sbrk(0);
/*