Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML updates from Richard Weinberger:

 - Support for preemption

 - i386 Rust support

 - Huge cleanup by Benjamin Berg

 - UBSAN support

 - Removal of dead code

* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
  um: vector: always reset vp->opened
  um: vector: remove vp->lock
  um: register power-off handler
  um: line: always fill *error_out in setup_one_line()
  um: remove pcap driver from documentation
  um: Enable preemption in UML
  um: refactor TLB update handling
  um: simplify and consolidate TLB updates
  um: remove force_flush_all from fork_handler
  um: Do not flush MM in flush_thread
  um: Delay flushing syscalls until the thread is restarted
  um: remove copy_context_skas0
  um: remove LDT support
  um: compress memory related stub syscalls while adding them
  um: Rework syscall handling
  um: Add generic stub_syscall6 function
  um: Create signal stack memory assignment in stub_data
  um: Remove stub-data.h include from common-offsets.h
  um: time-travel: fix signal blocking race/hang
  um: time-travel: remove time_exit()
  ...

9 files changed, 42 insertions, 608 deletions

diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
index 8bc72a51b257..36e67fc97c22 100644
--- a/arch/x86/um/Makefile
+++ b/arch/x86/um/Makefile
@@ -9,9 +9,9 @@ else
 	BITS := 64
 endif
 
-obj-y = bugs_$(BITS).o delay.o fault.o ldt.o \
+obj-y = bugs_$(BITS).o delay.o fault.o \
 	ptrace_$(BITS).o ptrace_user.o setjmp_$(BITS).o signal.o \
-	stub_$(BITS).o stub_segv.o \
+	stub_segv.o \
 	sys_call_table_$(BITS).o sysrq_$(BITS).o tls_$(BITS).o \
 	mem_$(BITS).o subarch.o os-Linux/
 
@@ -31,7 +31,6 @@ obj-y += syscalls_64.o vdso/
 
 subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o \
 	../lib/memmove_64.o ../lib/memset_64.o
-subarch-$(CONFIG_PREEMPTION) += ../entry/thunk_64.o
 
 endif
 
diff --git a/arch/x86/um/asm/mm_context.h b/arch/x86/um/asm/mm_context.h
deleted file mode 100644
index dc32dc023c2f..000000000000
--- a/arch/x86/um/asm/mm_context.h
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
- * Licensed under the GPL
- *
- * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
- */
-
-#ifndef __ASM_LDT_H
-#define __ASM_LDT_H
-
-#include <linux/mutex.h>
-#include <asm/ldt.h>
-
-#define LDT_PAGES_MAX \
-	((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
-#define LDT_ENTRIES_PER_PAGE \
-	(PAGE_SIZE/LDT_ENTRY_SIZE)
-#define LDT_DIRECT_ENTRIES \
-	((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
-
-struct ldt_entry {
-	__u32 a;
-	__u32 b;
-};
-
-typedef struct uml_ldt {
-	int entry_count;
-	struct mutex lock;
-	union {
-		struct ldt_entry * pages[LDT_PAGES_MAX];
-		struct ldt_entry entries[LDT_DIRECT_ENTRIES];
-	} u;
-} uml_ldt_t;
-
-#define LDT_entry_a(info) \
-	((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
-
-#define LDT_entry_b(info) \
-	(((info)->base_addr & 0xff000000) | \
-	(((info)->base_addr & 0x00ff0000) >> 16) | \
-	((info)->limit & 0xf0000) | \
-	(((info)->read_exec_only ^ 1) << 9) | \
-	((info)->contents << 10) | \
-	(((info)->seg_not_present ^ 1) << 15) | \
-	((info)->seg_32bit << 22) | \
-	((info)->limit_in_pages << 23) | \
-	((info)->useable << 20) | \
-	0x7000)
-
-#define _LDT_empty(info) (\
-	(info)->base_addr	== 0	&& \
-	(info)->limit		== 0	&& \
-	(info)->contents	== 0	&& \
-	(info)->read_exec_only	== 1	&& \
-	(info)->seg_32bit	== 0	&& \
-	(info)->limit_in_pages	== 0	&& \
-	(info)->seg_not_present	== 1	&& \
-	(info)->useable		== 0	)
-
-#ifdef CONFIG_X86_64
-#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
-#else
-#define LDT_empty(info) (_LDT_empty(info))
-#endif
-
-struct uml_arch_mm_context {
-	uml_ldt_t ldt;
-};
-
-#endif
diff --git a/arch/x86/um/ldt.c b/arch/x86/um/ldt.c
deleted file mode 100644
index 255a44dd415a..000000000000
--- a/arch/x86/um/ldt.c
+++ /dev/null
@@ -1,380 +0,0 @@
-/*
- * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
- */
-
-#include <linux/mm.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/syscalls.h>
-#include <linux/uaccess.h>
-#include <asm/unistd.h>
-#include <os.h>
-#include <skas.h>
-#include <sysdep/tls.h>
-
-static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
-{
-	return syscall(__NR_modify_ldt, func, ptr, bytecount);
-}
-
-static long write_ldt_entry(struct mm_id *mm_idp, int func,
-		     struct user_desc *desc, void **addr, int done)
-{
-	long res;
-	void *stub_addr;
-
-	BUILD_BUG_ON(sizeof(*desc) % sizeof(long));
-
-	res = syscall_stub_data(mm_idp, (unsigned long *)desc,
-				sizeof(*desc) / sizeof(long),
-				addr, &stub_addr);
-	if (!res) {
-		unsigned long args[] = { func,
-					 (unsigned long)stub_addr,
-					 sizeof(*desc),
-					 0, 0, 0 };
-		res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
-				       0, addr, done);
-	}
-
-	return res;
-}
-
-/*
- * In skas mode, we hold our own ldt data in UML.
- * Thus, the code implementing sys_modify_ldt_skas
- * is very similar to (and mostly stolen from) sys_modify_ldt
- * for arch/i386/kernel/ldt.c
- * The routines copied and modified in part are:
- * - read_ldt
- * - read_default_ldt
- * - write_ldt
- * - sys_modify_ldt_skas
- */
-
-static int read_ldt(void __user * ptr, unsigned long bytecount)
-{
-	int i, err = 0;
-	unsigned long size;
-	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
-
-	if (!ldt->entry_count)
-		goto out;
-	if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
-		bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
-	err = bytecount;
-
-	mutex_lock(&ldt->lock);
-	if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
-		size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
-		if (size > bytecount)
-			size = bytecount;
-		if (copy_to_user(ptr, ldt->u.entries, size))
-			err = -EFAULT;
-		bytecount -= size;
-		ptr += size;
-	}
-	else {
-		for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
-		     i++) {
-			size = PAGE_SIZE;
-			if (size > bytecount)
-				size = bytecount;
-			if (copy_to_user(ptr, ldt->u.pages[i], size)) {
-				err = -EFAULT;
-				break;
-			}
-			bytecount -= size;
-			ptr += size;
-		}
-	}
-	mutex_unlock(&ldt->lock);
-
-	if (bytecount == 0 || err == -EFAULT)
-		goto out;
-
-	if (clear_user(ptr, bytecount))
-		err = -EFAULT;
-
-out:
-	return err;
-}
-
-static int read_default_ldt(void __user * ptr, unsigned long bytecount)
-{
-	int err;
-
-	if (bytecount > 5*LDT_ENTRY_SIZE)
-		bytecount = 5*LDT_ENTRY_SIZE;
-
-	err = bytecount;
-	/*
-	 * UML doesn't support lcall7 and lcall27.
-	 * So, we don't really have a default ldt, but emulate
-	 * an empty ldt of common host default ldt size.
-	 */
-	if (clear_user(ptr, bytecount))
-		err = -EFAULT;
-
-	return err;
-}
-
-static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
-{
-	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
-	struct mm_id * mm_idp = &current->mm->context.id;
-	int i, err;
-	struct user_desc ldt_info;
-	struct ldt_entry entry0, *ldt_p;
-	void *addr = NULL;
-
-	err = -EINVAL;
-	if (bytecount != sizeof(ldt_info))
-		goto out;
-	err = -EFAULT;
-	if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
-		goto out;
-
-	err = -EINVAL;
-	if (ldt_info.entry_number >= LDT_ENTRIES)
-		goto out;
-	if (ldt_info.contents == 3) {
-		if (func == 1)
-			goto out;
-		if (ldt_info.seg_not_present == 0)
-			goto out;
-	}
-
-	mutex_lock(&ldt->lock);
-
-	err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
-	if (err)
-		goto out_unlock;
-
-	if (ldt_info.entry_number >= ldt->entry_count &&
-	    ldt_info.entry_number >= LDT_DIRECT_ENTRIES) {
-		for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
-		     i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
-		     i++) {
-			if (i == 0)
-				memcpy(&entry0, ldt->u.entries,
-				       sizeof(entry0));
-			ldt->u.pages[i] = (struct ldt_entry *)
-				__get_free_page(GFP_KERNEL|__GFP_ZERO);
-			if (!ldt->u.pages[i]) {
-				err = -ENOMEM;
-				/* Undo the change in host */
-				memset(&ldt_info, 0, sizeof(ldt_info));
-				write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
-				goto out_unlock;
-			}
-			if (i == 0) {
-				memcpy(ldt->u.pages[0], &entry0,
-				       sizeof(entry0));
-				memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
-				       sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
-			}
-			ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
-		}
-	}
-	if (ldt->entry_count <= ldt_info.entry_number)
-		ldt->entry_count = ldt_info.entry_number + 1;
-
-	if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
-		ldt_p = ldt->u.entries + ldt_info.entry_number;
-	else
-		ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
-			ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
-
-	if (ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
-	   (func == 1 || LDT_empty(&ldt_info))) {
-		ldt_p->a = 0;
-		ldt_p->b = 0;
-	}
-	else{
-		if (func == 1)
-			ldt_info.useable = 0;
-		ldt_p->a = LDT_entry_a(&ldt_info);
-		ldt_p->b = LDT_entry_b(&ldt_info);
-	}
-	err = 0;
-
-out_unlock:
-	mutex_unlock(&ldt->lock);
-out:
-	return err;
-}
-
-static long do_modify_ldt_skas(int func, void __user *ptr,
-			       unsigned long bytecount)
-{
-	int ret = -ENOSYS;
-
-	switch (func) {
-		case 0:
-			ret = read_ldt(ptr, bytecount);
-			break;
-		case 1:
-		case 0x11:
-			ret = write_ldt(ptr, bytecount, func);
-			break;
-		case 2:
-			ret = read_default_ldt(ptr, bytecount);
-			break;
-	}
-	return ret;
-}
-
-static DEFINE_SPINLOCK(host_ldt_lock);
-static short dummy_list[9] = {0, -1};
-static short * host_ldt_entries = NULL;
-
-static void ldt_get_host_info(void)
-{
-	long ret;
-	struct ldt_entry * ldt;
-	short *tmp;
-	int i, size, k, order;
-
-	spin_lock(&host_ldt_lock);
-
-	if (host_ldt_entries != NULL) {
-		spin_unlock(&host_ldt_lock);
-		return;
-	}
-	host_ldt_entries = dummy_list+1;
-
-	spin_unlock(&host_ldt_lock);
-
-	for (i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++)
-		;
-
-	ldt = (struct ldt_entry *)
-	      __get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
-	if (ldt == NULL) {
-		printk(KERN_ERR "ldt_get_host_info: couldn't allocate buffer "
-		       "for host ldt\n");
-		return;
-	}
-
-	ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
-	if (ret < 0) {
-		printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
-		goto out_free;
-	}
-	if (ret == 0) {
-		/* default_ldt is active, simply write an empty entry 0 */
-		host_ldt_entries = dummy_list;
-		goto out_free;
-	}
-
-	for (i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++) {
-		if (ldt[i].a != 0 || ldt[i].b != 0)
-			size++;
-	}
-
-	if (size < ARRAY_SIZE(dummy_list))
-		host_ldt_entries = dummy_list;
-	else {
-		size = (size + 1) * sizeof(dummy_list[0]);
-		tmp = kmalloc(size, GFP_KERNEL);
-		if (tmp == NULL) {
-			printk(KERN_ERR "ldt_get_host_info: couldn't allocate "
-			       "host ldt list\n");
-			goto out_free;
-		}
-		host_ldt_entries = tmp;
-	}
-
-	for (i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++) {
-		if (ldt[i].a != 0 || ldt[i].b != 0)
-			host_ldt_entries[k++] = i;
-	}
-	host_ldt_entries[k] = -1;
-
-out_free:
-	free_pages((unsigned long)ldt, order);
-}
-
-long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
-{
-	struct user_desc desc;
-	short * num_p;
-	int i;
-	long page, err=0;
-	void *addr = NULL;
-
-
-	mutex_init(&new_mm->arch.ldt.lock);
-
-	if (!from_mm) {
-		memset(&desc, 0, sizeof(desc));
-		/*
-		 * Now we try to retrieve info about the ldt, we
-		 * inherited from the host. All ldt-entries found
-		 * will be reset in the following loop
-		 */
-		ldt_get_host_info();
-		for (num_p=host_ldt_entries; *num_p != -1; num_p++) {
-			desc.entry_number = *num_p;
-			err = write_ldt_entry(&new_mm->id, 1, &desc,
-					      &addr, *(num_p + 1) == -1);
-			if (err)
-				break;
-		}
-		new_mm->arch.ldt.entry_count = 0;
-
-		goto out;
-	}
-
-	/*
-	 * Our local LDT is used to supply the data for
-	 * modify_ldt(READLDT), if PTRACE_LDT isn't available,
-	 * i.e., we have to use the stub for modify_ldt, which
-	 * can't handle the big read buffer of up to 64kB.
-	 */
-	mutex_lock(&from_mm->arch.ldt.lock);
-	if (from_mm->arch.ldt.entry_count <= LDT_DIRECT_ENTRIES)
-		memcpy(new_mm->arch.ldt.u.entries, from_mm->arch.ldt.u.entries,
-		       sizeof(new_mm->arch.ldt.u.entries));
-	else {
-		i = from_mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
-		while (i-->0) {
-			page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
-			if (!page) {
-				err = -ENOMEM;
-				break;
-			}
-			new_mm->arch.ldt.u.pages[i] =
-				(struct ldt_entry *) page;
-			memcpy(new_mm->arch.ldt.u.pages[i],
-			       from_mm->arch.ldt.u.pages[i], PAGE_SIZE);
-		}
-	}
-	new_mm->arch.ldt.entry_count = from_mm->arch.ldt.entry_count;
-	mutex_unlock(&from_mm->arch.ldt.lock);
-
-    out:
-	return err;
-}
-
-
-void free_ldt(struct mm_context *mm)
-{
-	int i;
-
-	if (mm->arch.ldt.entry_count > LDT_DIRECT_ENTRIES) {
-		i = mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
-		while (i-- > 0)
-			free_page((long) mm->arch.ldt.u.pages[i]);
-	}
-	mm->arch.ldt.entry_count = 0;
-}
-
-SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr ,
-		unsigned long , bytecount)
-{
-	/* See non-um modify_ldt() for why we do this cast */
-	return (unsigned int)do_modify_ldt_skas(func, ptr, bytecount);
-}
diff --git a/arch/x86/um/shared/sysdep/stub.h b/arch/x86/um/shared/sysdep/stub.h
index ce0ca46ad383..dc89f4423454 100644
--- a/arch/x86/um/shared/sysdep/stub.h
+++ b/arch/x86/um/shared/sysdep/stub.h
@@ -12,4 +12,4 @@
 #endif
 
 extern void stub_segv_handler(int, siginfo_t *, void *);
-extern void stub_clone_handler(void);
+extern void stub_syscall_handler(void);
diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h
index ea8b5a2d67af..0b44a86dd346 100644
--- a/arch/x86/um/shared/sysdep/stub_32.h
+++ b/arch/x86/um/shared/sysdep/stub_32.h
@@ -6,6 +6,7 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <stddef.h>
 #include <asm/ptrace.h>
 #include <generated/asm-offsets.h>
 
@@ -79,33 +80,31 @@ static __always_inline long stub_syscall5(long syscall, long arg1, long arg2,
 	return ret;
 }
 
-static __always_inline void trap_myself(void)
+static __always_inline long stub_syscall6(long syscall, long arg1, long arg2,
+					  long arg3, long arg4, long arg5,
+					  long arg6)
 {
-	__asm("int3");
+	struct syscall_args {
+		int ebx, ebp;
+	} args = { arg1, arg6 };
+	long ret;
+
+	__asm__ volatile ("pushl %%ebp;"
+			"movl 0x4(%%ebx),%%ebp;"
+			"movl (%%ebx),%%ebx;"
+			"int $0x80;"
+			"popl %%ebp"
+			: "=a" (ret)
+			: "0" (syscall), "b" (&args),
+			"c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5)
+			: "memory");
+
+	return ret;
 }
 
-static __always_inline void remap_stack_and_trap(void)
+static __always_inline void trap_myself(void)
 {
-	__asm__ volatile (
-		"movl %%esp,%%ebx ;"
-		"andl %0,%%ebx ;"
-		"movl %1,%%eax ;"
-		"movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;"
-		"movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;"
-		"int $0x80 ;"
-		"addl %4,%%ebx ; movl %%eax, (%%ebx) ;"
-		"int $3"
-		: :
-		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
-		"g" (STUB_MMAP_NR),
-		"g" (UML_STUB_FIELD_FD),
-		"g" (UML_STUB_FIELD_OFFSET),
-		"g" (UML_STUB_FIELD_CHILD_ERR),
-		"c" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
-		"d" (PROT_READ | PROT_WRITE),
-		"S" (MAP_FIXED | MAP_SHARED)
-		:
-		"memory");
+	__asm("int3");
 }
 
 static __always_inline void *get_stub_data(void)
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
index b24168ef0ac4..67f44284f1aa 100644
--- a/arch/x86/um/shared/sysdep/stub_64.h
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -6,6 +6,7 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <stddef.h>
 #include <sysdep/ptrace_user.h>
 #include <generated/asm-offsets.h>
 #include <linux/stddef.h>
@@ -79,35 +80,25 @@ static __always_inline long stub_syscall5(long syscall, long arg1, long arg2,
 	return ret;
 }
 
-static __always_inline void trap_myself(void)
+static __always_inline long stub_syscall6(long syscall, long arg1, long arg2,
+					  long arg3, long arg4, long arg5,
+					  long arg6)
 {
-	__asm("int3");
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; movq %7,%%r9 ; "
+		__syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4), "g" (arg5), "g" (arg6)
+		: __syscall_clobber, "r10", "r8", "r9");
+
+	return ret;
 }
 
-static __always_inline void remap_stack_and_trap(void)
+static __always_inline void trap_myself(void)
 {
-	__asm__ volatile (
-		"movq %0,%%rax ;"
-		"movq %%rsp,%%rdi ;"
-		"andq %1,%%rdi ;"
-		"movq %2,%%r10 ;"
-		"movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
-		"movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
-		__syscall ";"
-		"movq %%rsp,%%rdi ; andq %1,%%rdi ;"
-		"addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
-		"int3"
-		: :
-		"g" (STUB_MMAP_NR),
-		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
-		"g" (MAP_FIXED | MAP_SHARED),
-		"g" (UML_STUB_FIELD_FD),
-		"g" (UML_STUB_FIELD_OFFSET),
-		"g" (UML_STUB_FIELD_CHILD_ERR),
-		"S" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
-		"d" (PROT_READ | PROT_WRITE)
-		:
-		__syscall_clobber, "r10", "r8", "r9");
+	__asm("int3");
 }
 
 static __always_inline void *get_stub_data(void)
diff --git a/arch/x86/um/stub_32.S b/arch/x86/um/stub_32.S
deleted file mode 100644
index 8291899e6aaf..000000000000
--- a/arch/x86/um/stub_32.S
+++ /dev/null
@@ -1,56 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <as-layout.h>
-
-.section .__syscall_stub, "ax"
-
-	.globl batch_syscall_stub
-batch_syscall_stub:
-	/* %esp comes in as "top of page" */
-	mov %esp, %ecx
-	/* %esp has pointer to first operation */
-	add $8, %esp
-again:
-	/* load length of additional data */
-	mov	0x0(%esp), %eax
-
-	/* if(length == 0) : end of list */
-	/* write possible 0 to header */
-	mov	%eax, 0x4(%ecx)
-	cmpl	$0, %eax
-	jz	done
-
-	/* save current pointer */
-	mov	%esp, 0x4(%ecx)
-
-	/* skip additional data */
-	add	%eax, %esp
-
-	/* load syscall-# */
-	pop	%eax
-
-	/* load syscall params */
-	pop	%ebx
-	pop	%ecx
-	pop	%edx
-	pop	%esi
- 	pop	%edi
-	pop	%ebp
-
-	/* execute syscall */
-	int	$0x80
-
-	/* restore top of page pointer in %ecx */
-	mov	%esp, %ecx
-	andl	$(~UM_KERN_PAGE_SIZE) + 1, %ecx
-
-	/* check return value */
-	pop	%ebx
-	cmp	%ebx, %eax
-	je	again
-
-done:
-	/* save return value */
-	mov	%eax, (%ecx)
-
-	/* stop */
-	int3
diff --git a/arch/x86/um/stub_64.S b/arch/x86/um/stub_64.S
deleted file mode 100644
index f3404640197a..000000000000
--- a/arch/x86/um/stub_64.S
+++ /dev/null
@@ -1,50 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <as-layout.h>
-
-.section .__syscall_stub, "ax"
-	.globl batch_syscall_stub
-batch_syscall_stub:
-	/* %rsp has the pointer to first operation */
-	mov	%rsp, %rbx
-	add	$0x10, %rsp
-again:
-	/* load length of additional data */
-	mov	0x0(%rsp), %rax
-
-	/* if(length == 0) : end of list */
-	/* write possible 0 to header */
-	mov	%rax, 8(%rbx)
-	cmp	$0, %rax
-	jz	done
-
-	/* save current pointer */
-	mov	%rsp, 8(%rbx)
-
-	/* skip additional data */
-	add	%rax, %rsp
-
-	/* load syscall-# */
-	pop	%rax
-
-	/* load syscall params */
-	pop	%rdi
-	pop	%rsi
-	pop	%rdx
-	pop	%r10
- 	pop	%r8
-	pop	%r9
-
-	/* execute syscall */
-	syscall
-
-	/* check return value */
-	pop	%rcx
-	cmp	%rcx, %rax
-	je	again
-
-done:
-	/* save return value */
-	mov	%rax, (%rbx)
-
-	/* stop */
-	int3
diff --git a/arch/x86/um/tls_32.c b/arch/x86/um/tls_32.c
index d301deee041f..fbb129023080 100644
--- a/arch/x86/um/tls_32.c
+++ b/arch/x86/um/tls_32.c
@@ -11,6 +11,7 @@
 #include <os.h>
 #include <skas.h>
 #include <sysdep/tls.h>
+#include <asm/desc.h>
 
 /*
  * If needed we can detect when it's uninitialized.