diff options
author | Richard Weinberger <richard@nod.at> | 2015-03-18 21:31:27 +0100 |
---|---|---|
committer | Richard Weinberger <richard@nod.at> | 2015-04-13 21:00:53 +0200 |
commit | d0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0 (patch) | |
tree | 7b833b85c0e2eabf6b38d8b94875b430554afae7 /arch/um/kernel | |
parent | aaeac66b1a02d399ec8ee63e8d617c1d601ea353 (diff) | |
download | op-kernel-dev-d0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0.zip op-kernel-dev-d0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0.tar.gz |
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default since 2005, SKAS3/4 is obsolete and can be removed.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.c | 32 | ||||
-rw-r--r-- | arch/um/kernel/reboot.c | 35 | ||||
-rw-r--r-- | arch/um/kernel/skas/mmu.c | 68 | ||||
-rw-r--r-- | arch/um/kernel/skas/process.c | 27 | ||||
-rw-r--r-- | arch/um/kernel/trap.c | 2 | ||||
-rw-r--r-- | arch/um/kernel/um_arch.c | 10 |
6 files changed, 38 insertions, 136 deletions
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 62435ef..174ee50 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 ced8903..9bdf67a 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 007d550..94abdcc 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 = ¤t->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 4da11b3..082955d6 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 2096173..8e4daf4 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 9274eae..dbd5bda 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); /* |