#include <linux/ptrace.h>
#include <linux/audit.h>
#include <linux/stddef.h>
+#include <linux/slab.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#define KVM86 ((struct kernel_vm86_struct *)regs)
-#define VMPI KVM86->vm86plus
/*
/*
* virtual flags (16 and 32-bit versions)
*/
-#define VFLAGS (*(unsigned short *)&(current->thread.v86flags))
-#define VEFLAGS (current->thread.v86flags)
+#define VFLAGS (*(unsigned short *)&(current->thread.vm86->v86flags))
+#define VEFLAGS (current->thread.vm86->v86flags)
#define set_flags(X, new, mask) \
((X) = ((X) & ~(mask)) | ((new) & (mask)))
#define SAFE_MASK (0xDD5)
#define RETURN_MASK (0xDFF)
-/* convert kernel_vm86_regs to vm86_regs */
-static int copy_vm86_regs_to_user(struct vm86_regs __user *user,
- const struct kernel_vm86_regs *regs)
-{
- int ret = 0;
-
- /*
- * kernel_vm86_regs is missing gs, so copy everything up to
- * (but not including) orig_eax, and then rest including orig_eax.
- */
- ret += copy_to_user(user, regs, offsetof(struct kernel_vm86_regs, pt.orig_ax));
- ret += copy_to_user(&user->orig_eax, ®s->pt.orig_ax,
- sizeof(struct kernel_vm86_regs) -
- offsetof(struct kernel_vm86_regs, pt.orig_ax));
-
- return ret;
-}
-
-/* convert vm86_regs to kernel_vm86_regs */
-static int copy_vm86_regs_from_user(struct kernel_vm86_regs *regs,
- const struct vm86_regs __user *user,
- unsigned extra)
-{
- int ret = 0;
-
- /* copy ax-fs inclusive */
- ret += copy_from_user(regs, user, offsetof(struct kernel_vm86_regs, pt.orig_ax));
- /* copy orig_ax-__gsh+extra */
- ret += copy_from_user(®s->pt.orig_ax, &user->orig_eax,
- sizeof(struct kernel_vm86_regs) -
- offsetof(struct kernel_vm86_regs, pt.orig_ax) +
- extra);
- return ret;
-}
-
struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
{
struct tss_struct *tss;
struct pt_regs *ret;
- unsigned long tmp;
+ struct task_struct *tsk = current;
+ struct vm86plus_struct __user *user;
+ struct vm86 *vm86 = current->thread.vm86;
+ long err = 0;
/*
* This gets called from entry.S with interrupts disabled, but
*/
local_irq_enable();
- if (!current->thread.vm86_info) {
+ if (!vm86 || !vm86->vm86_info) {
pr_alert("no vm86_info: BAD\n");
do_exit(SIGSEGV);
}
- set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | current->thread.v86mask);
- tmp = copy_vm86_regs_to_user(¤t->thread.vm86_info->regs, regs);
- tmp += put_user(current->thread.screen_bitmap, ¤t->thread.vm86_info->screen_bitmap);
- if (tmp) {
+ set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->v86mask);
+ user = vm86->vm86_info;
+
+ if (!access_ok(VERIFY_WRITE, user, vm86->vm86plus.is_vm86pus ?
+ sizeof(struct vm86plus_struct) :
+ sizeof(struct vm86_struct))) {
+ pr_alert("could not access userspace vm86_info\n");
+ do_exit(SIGSEGV);
+ }
+
+ put_user_try {
+ put_user_ex(regs->pt.bx, &user->regs.ebx);
+ put_user_ex(regs->pt.cx, &user->regs.ecx);
+ put_user_ex(regs->pt.dx, &user->regs.edx);
+ put_user_ex(regs->pt.si, &user->regs.esi);
+ put_user_ex(regs->pt.di, &user->regs.edi);
+ put_user_ex(regs->pt.bp, &user->regs.ebp);
+ put_user_ex(regs->pt.ax, &user->regs.eax);
+ put_user_ex(regs->pt.ip, &user->regs.eip);
+ put_user_ex(regs->pt.cs, &user->regs.cs);
+ put_user_ex(regs->pt.flags, &user->regs.eflags);
+ put_user_ex(regs->pt.sp, &user->regs.esp);
+ put_user_ex(regs->pt.ss, &user->regs.ss);
+ put_user_ex(regs->es, &user->regs.es);
+ put_user_ex(regs->ds, &user->regs.ds);
+ put_user_ex(regs->fs, &user->regs.fs);
+ put_user_ex(regs->gs, &user->regs.gs);
+
+ put_user_ex(vm86->screen_bitmap, &user->screen_bitmap);
+ } put_user_catch(err);
+ if (err) {
pr_alert("could not access userspace vm86_info\n");
do_exit(SIGSEGV);
}
tss = &per_cpu(cpu_tss, get_cpu());
- current->thread.sp0 = current->thread.saved_sp0;
- current->thread.sysenter_cs = __KERNEL_CS;
- load_sp0(tss, ¤t->thread);
- current->thread.saved_sp0 = 0;
+ tsk->thread.sp0 = vm86->saved_sp0;
+ tsk->thread.sysenter_cs = __KERNEL_CS;
+ load_sp0(tss, &tsk->thread);
+ vm86->saved_sp0 = 0;
put_cpu();
ret = KVM86->regs32;
- ret->fs = current->thread.saved_fs;
- set_user_gs(ret, current->thread.saved_gs);
+ lazy_load_gs(ret->gs);
return ret;
}
static int do_vm86_irq_handling(int subfunction, int irqnumber);
-static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk);
+static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus,
+ struct kernel_vm86_struct *info);
SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86)
{
* This remains on the stack until we
* return to 32 bit user space.
*/
- struct task_struct *tsk = current;
- int tmp;
- if (tsk->thread.saved_sp0)
- return -EPERM;
- tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
- offsetof(struct kernel_vm86_struct, vm86plus) -
- sizeof(info.regs));
- if (tmp)
- return -EFAULT;
- memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus);
- info.regs32 = current_pt_regs();
- tsk->thread.vm86_info = v86;
- do_sys_vm86(&info, tsk);
- return 0; /* we never return here */
+ return do_sys_vm86((struct vm86plus_struct __user *) v86, false, &info);
}
* This remains on the stack until we
* return to 32 bit user space.
*/
- struct task_struct *tsk;
- int tmp;
- struct vm86plus_struct __user *v86;
- tsk = current;
switch (cmd) {
case VM86_REQUEST_IRQ:
case VM86_FREE_IRQ:
}
/* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
- if (tsk->thread.saved_sp0)
- return -EPERM;
- v86 = (struct vm86plus_struct __user *)arg;
- tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
- offsetof(struct kernel_vm86_struct, regs32) -
- sizeof(info.regs));
- if (tmp)
- return -EFAULT;
- info.regs32 = current_pt_regs();
- info.vm86plus.is_vm86pus = 1;
- tsk->thread.vm86_info = (struct vm86_struct __user *)v86;
- do_sys_vm86(&info, tsk);
- return 0; /* we never return here */
+ return do_sys_vm86((struct vm86plus_struct __user *) arg, true, &info);
}
-static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk)
+static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus,
+ struct kernel_vm86_struct *info)
{
struct tss_struct *tss;
-/*
- * make sure the vm86() system call doesn't try to do anything silly
- */
- info->regs.pt.ds = 0;
- info->regs.pt.es = 0;
- info->regs.pt.fs = 0;
-#ifndef CONFIG_X86_32_LAZY_GS
- info->regs.pt.gs = 0;
-#endif
+ struct task_struct *tsk = current;
+ struct vm86 *vm86 = tsk->thread.vm86;
+ unsigned long err = 0;
+
+ if (!vm86) {
+ if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL)))
+ return -ENOMEM;
+ tsk->thread.vm86 = vm86;
+ }
+ if (vm86->saved_sp0)
+ return -EPERM;
+
+ if (!access_ok(VERIFY_READ, v86, plus ?
+ sizeof(struct vm86_struct) :
+ sizeof(struct vm86plus_struct)))
+ return -EFAULT;
+
+ memset(info, 0, sizeof(*info));
+ get_user_try {
+ unsigned short seg;
+ get_user_ex(info->regs.pt.bx, &v86->regs.ebx);
+ get_user_ex(info->regs.pt.cx, &v86->regs.ecx);
+ get_user_ex(info->regs.pt.dx, &v86->regs.edx);
+ get_user_ex(info->regs.pt.si, &v86->regs.esi);
+ get_user_ex(info->regs.pt.di, &v86->regs.edi);
+ get_user_ex(info->regs.pt.bp, &v86->regs.ebp);
+ get_user_ex(info->regs.pt.ax, &v86->regs.eax);
+ get_user_ex(info->regs.pt.ip, &v86->regs.eip);
+ get_user_ex(seg, &v86->regs.cs);
+ info->regs.pt.cs = seg;
+ get_user_ex(info->regs.pt.flags, &v86->regs.eflags);
+ get_user_ex(info->regs.pt.sp, &v86->regs.esp);
+ get_user_ex(seg, &v86->regs.ss);
+ info->regs.pt.ss = seg;
+ get_user_ex(info->regs.es, &v86->regs.es);
+ get_user_ex(info->regs.ds, &v86->regs.ds);
+ get_user_ex(info->regs.fs, &v86->regs.fs);
+ get_user_ex(info->regs.gs, &v86->regs.gs);
+
+ get_user_ex(vm86->flags, &v86->flags);
+ get_user_ex(vm86->screen_bitmap, &v86->screen_bitmap);
+ get_user_ex(vm86->cpu_type, &v86->cpu_type);
+ } get_user_catch(err);
+ if (err)
+ return err;
+
+ if (copy_from_user(&vm86->int_revectored, &v86->int_revectored,
+ sizeof(struct revectored_struct)))
+ return -EFAULT;
+ if (copy_from_user(&vm86->int21_revectored, &v86->int21_revectored,
+ sizeof(struct revectored_struct)))
+ return -EFAULT;
+ if (plus) {
+ if (copy_from_user(&vm86->vm86plus, &v86->vm86plus,
+ sizeof(struct vm86plus_info_struct)))
+ return -EFAULT;
+ vm86->vm86plus.is_vm86pus = 1;
+ } else
+ memset(&vm86->vm86plus, 0,
+ sizeof(struct vm86plus_info_struct));
+
+ info->regs32 = current_pt_regs();
+ vm86->vm86_info = v86;
/*
* The flags register is also special: we cannot trust that the user
info->regs.pt.flags |= info->regs32->flags & ~SAFE_MASK;
info->regs.pt.flags |= X86_VM_MASK;
- switch (info->cpu_type) {
+ info->regs.pt.orig_ax = info->regs32->orig_ax;
+
+ switch (vm86->cpu_type) {
case CPU_286:
- tsk->thread.v86mask = 0;
+ vm86->v86mask = 0;
break;
case CPU_386:
- tsk->thread.v86mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL;
+ vm86->v86mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL;
break;
case CPU_486:
- tsk->thread.v86mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
+ vm86->v86mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
break;
default:
- tsk->thread.v86mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
+ vm86->v86mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
break;
}
* Save old state, set default return value (%ax) to 0 (VM86_SIGNAL)
*/
info->regs32->ax = VM86_SIGNAL;
- tsk->thread.saved_sp0 = tsk->thread.sp0;
- tsk->thread.saved_fs = info->regs32->fs;
- tsk->thread.saved_gs = get_user_gs(info->regs32);
+ vm86->saved_sp0 = tsk->thread.sp0;
+ lazy_save_gs(info->regs32->gs);
tss = &per_cpu(cpu_tss, get_cpu());
tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0;
load_sp0(tss, &tsk->thread);
put_cpu();
- tsk->thread.screen_bitmap = info->screen_bitmap;
- if (info->flags & VM86_SCREEN_BITMAP)
+ if (vm86->flags & VM86_SCREEN_BITMAP)
mark_screen_rdonly(tsk->mm);
/*call __audit_syscall_exit since we do not exit via the normal paths */
"jmp resume_userspace"
: /* no outputs */
:"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0));
- /* we never return here */
+ unreachable(); /* we never return here */
}
static inline void return_to_32bit(struct kernel_vm86_regs *regs16, int retval)
static inline void set_vflags_long(unsigned long flags, struct kernel_vm86_regs *regs)
{
- set_flags(VEFLAGS, flags, current->thread.v86mask);
+ set_flags(VEFLAGS, flags, current->thread.vm86->v86mask);
set_flags(regs->pt.flags, flags, SAFE_MASK);
if (flags & X86_EFLAGS_IF)
set_IF(regs);
static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs *regs)
{
- set_flags(VFLAGS, flags, current->thread.v86mask);
+ set_flags(VFLAGS, flags, current->thread.vm86->v86mask);
set_flags(regs->pt.flags, flags, SAFE_MASK);
if (flags & X86_EFLAGS_IF)
set_IF(regs);
if (VEFLAGS & X86_EFLAGS_VIF)
flags |= X86_EFLAGS_IF;
flags |= X86_EFLAGS_IOPL;
- return flags | (VEFLAGS & current->thread.v86mask);
+ return flags | (VEFLAGS & current->thread.vm86->v86mask);
}
static inline int is_revectored(int nr, struct revectored_struct *bitmap)
{
unsigned long __user *intr_ptr;
unsigned long segoffs;
+ struct kernel_vm86_info *vm86 = current->thread.vm86;
if (regs->pt.cs == BIOSSEG)
goto cannot_handle;
- if (is_revectored(i, &KVM86->int_revectored))
+ if (is_revectored(i, &vm86->int_revectored))
goto cannot_handle;
- if (i == 0x21 && is_revectored(AH(regs), &KVM86->int21_revectored))
+ if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored))
goto cannot_handle;
intr_ptr = (unsigned long __user *) (i << 2);
if (get_user(segoffs, intr_ptr))
int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno)
{
- if (VMPI.is_vm86pus) {
+ if (current->thread.vm86->vm86plus.is_vm86pus) {
if ((trapno == 3) || (trapno == 1)) {
KVM86->regs32->ax = VM86_TRAP + (trapno << 8);
/* setting this flag forces the code in entry_32.S to
unsigned char __user *ssp;
unsigned short ip, sp, orig_flags;
int data32, pref_done;
+ struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus;
#define CHECK_IF_IN_TRAP \
- if (VMPI.vm86dbg_active && VMPI.vm86dbg_TFpendig) \
+ if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \
newflags |= X86_EFLAGS_TF
#define VM86_FAULT_RETURN do { \
- if (VMPI.force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) \
+ if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) \
return_to_32bit(regs, VM86_PICRETURN); \
if (orig_flags & X86_EFLAGS_TF) \
handle_vm86_trap(regs, 0, 1); \
case 0xcd: {
int intno = popb(csp, ip, simulate_sigsegv);
IP(regs) = ip;
- if (VMPI.vm86dbg_active) {
- if ((1 << (intno & 7)) & VMPI.vm86dbg_intxxtab[intno >> 3])
+ if (vmpi->vm86dbg_active) {
+ if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3])
return_to_32bit(regs, VM86_INTx + (intno << 8));
}
do_int(regs, intno, ssp, sp);
projects / mirror_ubuntu-bionic-kernel.git / blobdiff