um: merge arch/um/sys-{i386,x86_64}

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 0 insertions, 396 deletions

diff --git a/arch/um/sys-i386/tls.c b/arch/um/sys-i386/tls.c
deleted file mode 100644
index c6c7131e563..00000000000
--- a/arch/um/sys-i386/tls.c
+++ /dev/null
@@ -1,396 +0,0 @@
-/*
- * Copyright (C) 2005 Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
- * Licensed under the GPL
- */
-
-#include "linux/percpu.h"
-#include "linux/sched.h"
-#include "asm/uaccess.h"
-#include "os.h"
-#include "skas.h"
-#include "sysdep/tls.h"
-
-/*
- * If needed we can detect when it's uninitialized.
- *
- * These are initialized in an initcall and unchanged thereafter.
- */
-static int host_supports_tls = -1;
-int host_gdt_entry_tls_min;
-
-int do_set_thread_area(struct user_desc *info)
-{
-	int ret;
-	u32 cpu;
-
-	cpu = get_cpu();
-	ret = os_set_thread_area(info, userspace_pid[cpu]);
-	put_cpu();
-
-	if (ret)
-		printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
-		       "index = %d\n", ret, info->entry_number);
-
-	return ret;
-}
-
-int do_get_thread_area(struct user_desc *info)
-{
-	int ret;
-	u32 cpu;
-
-	cpu = get_cpu();
-	ret = os_get_thread_area(info, userspace_pid[cpu]);
-	put_cpu();
-
-	if (ret)
-		printk(KERN_ERR "PTRACE_GET_THREAD_AREA failed, err = %d, "
-		       "index = %d\n", ret, info->entry_number);
-
-	return ret;
-}
-
-/*
- * sys_get_thread_area: get a yet unused TLS descriptor index.
- * XXX: Consider leaving one free slot for glibc usage at first place. This must
- * be done here (and by changing GDT_ENTRY_TLS_* macros) and nowhere else.
- *
- * Also, this must be tested when compiling in SKAS mode with dynamic linking
- * and running against NPTL.
- */
-static int get_free_idx(struct task_struct* task)
-{
-	struct thread_struct *t = &task->thread;
-	int idx;
-
-	if (!t->arch.tls_array)
-		return GDT_ENTRY_TLS_MIN;
-
-	for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
-		if (!t->arch.tls_array[idx].present)
-			return idx + GDT_ENTRY_TLS_MIN;
-	return -ESRCH;
-}
-
-static inline void clear_user_desc(struct user_desc* info)
-{
-	/* Postcondition: LDT_empty(info) returns true. */
-	memset(info, 0, sizeof(*info));
-
-	/*
-	 * Check the LDT_empty or the i386 sys_get_thread_area code - we obtain
-	 * indeed an empty user_desc.
-	 */
-	info->read_exec_only = 1;
-	info->seg_not_present = 1;
-}
-
-#define O_FORCE 1
-
-static int load_TLS(int flags, struct task_struct *to)
-{
-	int ret = 0;
-	int idx;
-
-	for (idx = GDT_ENTRY_TLS_MIN; idx < GDT_ENTRY_TLS_MAX; idx++) {
-		struct uml_tls_struct* curr =
-			&to->thread.arch.tls_array[idx - GDT_ENTRY_TLS_MIN];
-
-		/*
-		 * Actually, now if it wasn't flushed it gets cleared and
-		 * flushed to the host, which will clear it.
-		 */
-		if (!curr->present) {
-			if (!curr->flushed) {
-				clear_user_desc(&curr->tls);
-				curr->tls.entry_number = idx;
-			} else {
-				WARN_ON(!LDT_empty(&curr->tls));
-				continue;
-			}
-		}
-
-		if (!(flags & O_FORCE) && curr->flushed)
-			continue;
-
-		ret = do_set_thread_area(&curr->tls);
-		if (ret)
-			goto out;
-
-		curr->flushed = 1;
-	}
-out:
-	return ret;
-}
-
-/*
- * Verify if we need to do a flush for the new process, i.e. if there are any
- * present desc's, only if they haven't been flushed.
- */
-static inline int needs_TLS_update(struct task_struct *task)
-{
-	int i;
-	int ret = 0;
-
-	for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
-		struct uml_tls_struct* curr =
-			&task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
-
-		/*
-		 * Can't test curr->present, we may need to clear a descriptor
-		 * which had a value.
-		 */
-		if (curr->flushed)
-			continue;
-		ret = 1;
-		break;
-	}
-	return ret;
-}
-
-/*
- * On a newly forked process, the TLS descriptors haven't yet been flushed. So
- * we mark them as such and the first switch_to will do the job.
- */
-void clear_flushed_tls(struct task_struct *task)
-{
-	int i;
-
-	for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
-		struct uml_tls_struct* curr =
-			&task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
-
-		/*
-		 * Still correct to do this, if it wasn't present on the host it
-		 * will remain as flushed as it was.
-		 */
-		if (!curr->present)
-			continue;
-
-		curr->flushed = 0;
-	}
-}
-
-/*
- * In SKAS0 mode, currently, multiple guest threads sharing the same ->mm have a
- * common host process. So this is needed in SKAS0 too.
- *
- * However, if each thread had a different host process (and this was discussed
- * for SMP support) this won't be needed.
- *
- * And this will not need be used when (and if) we'll add support to the host
- * SKAS patch.
- */
-
-int arch_switch_tls(struct task_struct *to)
-{
-	if (!host_supports_tls)
-		return 0;
-
-	/*
-	 * We have no need whatsoever to switch TLS for kernel threads; beyond
-	 * that, that would also result in us calling os_set_thread_area with
-	 * userspace_pid[cpu] == 0, which gives an error.
-	 */
-	if (likely(to->mm))
-		return load_TLS(O_FORCE, to);
-
-	return 0;
-}
-
-static int set_tls_entry(struct task_struct* task, struct user_desc *info,
-			 int idx, int flushed)
-{
-	struct thread_struct *t = &task->thread;
-
-	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
-		return -EINVAL;
-
-	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].tls = *info;
-	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].present = 1;
-	t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed = flushed;
-
-	return 0;
-}
-
-int arch_copy_tls(struct task_struct *new)
-{
-	struct user_desc info;
-	int idx, ret = -EFAULT;
-
-	if (copy_from_user(&info,
-			   (void __user *) UPT_ESI(&new->thread.regs.regs),
-			   sizeof(info)))
-		goto out;
-
-	ret = -EINVAL;
-	if (LDT_empty(&info))
-		goto out;
-
-	idx = info.entry_number;
-
-	ret = set_tls_entry(new, &info, idx, 0);
-out:
-	return ret;
-}
-
-/* XXX: use do_get_thread_area to read the host value? I'm not at all sure! */
-static int get_tls_entry(struct task_struct *task, struct user_desc *info,
-			 int idx)
-{
-	struct thread_struct *t = &task->thread;
-
-	if (!t->arch.tls_array)
-		goto clear;
-
-	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
-		return -EINVAL;
-
-	if (!t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].present)
-		goto clear;
-
-	*info = t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].tls;
-
-out:
-	/*
-	 * Temporary debugging check, to make sure that things have been
-	 * flushed. This could be triggered if load_TLS() failed.
-	 */
-	if (unlikely(task == current &&
-		     !t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed)) {
-		printk(KERN_ERR "get_tls_entry: task with pid %d got here "
-				"without flushed TLS.", current->pid);
-	}
-
-	return 0;
-clear:
-	/*
-	 * When the TLS entry has not been set, the values read to user in the
-	 * tls_array are 0 (because it's cleared at boot, see
-	 * arch/i386/kernel/head.S:cpu_gdt_table). Emulate that.
-	 */
-	clear_user_desc(info);
-	info->entry_number = idx;
-	goto out;
-}
-
-int sys_set_thread_area(struct user_desc __user *user_desc)
-{
-	struct user_desc info;
-	int idx, ret;
-
-	if (!host_supports_tls)
-		return -ENOSYS;
-
-	if (copy_from_user(&info, user_desc, sizeof(info)))
-		return -EFAULT;
-
-	idx = info.entry_number;
-
-	if (idx == -1) {
-		idx = get_free_idx(current);
-		if (idx < 0)
-			return idx;
-		info.entry_number = idx;
-		/* Tell the user which slot we chose for him.*/
-		if (put_user(idx, &user_desc->entry_number))
-			return -EFAULT;
-	}
-
-	ret = do_set_thread_area(&info);
-	if (ret)
-		return ret;
-	return set_tls_entry(current, &info, idx, 1);
-}
-
-/*
- * Perform set_thread_area on behalf of the traced child.
- * Note: error handling is not done on the deferred load, and this differ from
- * i386. However the only possible error are caused by bugs.
- */
-int ptrace_set_thread_area(struct task_struct *child, int idx,
-			   struct user_desc __user *user_desc)
-{
-	struct user_desc info;
-
-	if (!host_supports_tls)
-		return -EIO;
-
-	if (copy_from_user(&info, user_desc, sizeof(info)))
-		return -EFAULT;
-
-	return set_tls_entry(child, &info, idx, 0);
-}
-
-int sys_get_thread_area(struct user_desc __user *user_desc)
-{
-	struct user_desc info;
-	int idx, ret;
-
-	if (!host_supports_tls)
-		return -ENOSYS;
-
-	if (get_user(idx, &user_desc->entry_number))
-		return -EFAULT;
-
-	ret = get_tls_entry(current, &info, idx);
-	if (ret < 0)
-		goto out;
-
-	if (copy_to_user(user_desc, &info, sizeof(info)))
-		ret = -EFAULT;
-
-out:
-	return ret;
-}
-
-/*
- * Perform get_thread_area on behalf of the traced child.
- */
-int ptrace_get_thread_area(struct task_struct *child, int idx,
-		struct user_desc __user *user_desc)
-{
-	struct user_desc info;
-	int ret;
-
-	if (!host_supports_tls)
-		return -EIO;
-
-	ret = get_tls_entry(child, &info, idx);
-	if (ret < 0)
-		goto out;
-
-	if (copy_to_user(user_desc, &info, sizeof(info)))
-		ret = -EFAULT;
-out:
-	return ret;
-}
-
-/*
- * This code is really i386-only, but it detects and logs x86_64 GDT indexes
- * if a 32-bit UML is running on a 64-bit host.
- */
-static int __init __setup_host_supports_tls(void)
-{
-	check_host_supports_tls(&host_supports_tls, &host_gdt_entry_tls_min);
-	if (host_supports_tls) {
-		printk(KERN_INFO "Host TLS support detected\n");
-		printk(KERN_INFO "Detected host type: ");
-		switch (host_gdt_entry_tls_min) {
-		case GDT_ENTRY_TLS_MIN_I386:
-			printk(KERN_CONT "i386");
-			break;
-		case GDT_ENTRY_TLS_MIN_X86_64:
-			printk(KERN_CONT "x86_64");
-			break;
-		}
-		printk(KERN_CONT " (GDT indexes %d to %d)\n",
-		       host_gdt_entry_tls_min,
-		       host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES);
-	} else
-		printk(KERN_ERR "  Host TLS support NOT detected! "
-				"TLS support inside UML will not work\n");
-	return 0;
-}
-
-__initcall(__setup_host_supports_tls);