Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * Copyright (C) 1994 Linus Torvalds |
| 4 | * |
| 5 | * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86 |
Christian Kujau | 624dffc | 2006-01-15 02:43:54 +0100 | [diff] [blame] | 6 | * stack - Manfred Spraul <manfred@colorfullife.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
| 8 | * 22 mar 2002 - Manfred detected the stackfaults, but didn't handle |
| 9 | * them correctly. Now the emulation will be in a |
| 10 | * consistent state after stackfaults - Kasper Dupont |
| 11 | * <kasperd@daimi.au.dk> |
| 12 | * |
| 13 | * 22 mar 2002 - Added missing clear_IF in set_vflags_* Kasper Dupont |
| 14 | * <kasperd@daimi.au.dk> |
| 15 | * |
| 16 | * ?? ??? 2002 - Fixed premature returns from handle_vm86_fault |
| 17 | * caused by Kasper Dupont's changes - Stas Sergeev |
| 18 | * |
| 19 | * 4 apr 2002 - Fixed CHECK_IF_IN_TRAP broken by Stas' changes. |
| 20 | * Kasper Dupont <kasperd@daimi.au.dk> |
| 21 | * |
| 22 | * 9 apr 2002 - Changed syntax of macros in handle_vm86_fault. |
| 23 | * Kasper Dupont <kasperd@daimi.au.dk> |
| 24 | * |
| 25 | * 9 apr 2002 - Changed stack access macros to jump to a label |
| 26 | * instead of returning to userspace. This simplifies |
| 27 | * do_int, and is needed by handle_vm6_fault. Kasper |
| 28 | * Dupont <kasperd@daimi.au.dk> |
| 29 | * |
| 30 | */ |
| 31 | |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 32 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 33 | |
Randy Dunlap | a941564 | 2006-01-11 12:17:48 -0800 | [diff] [blame] | 34 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <linux/errno.h> |
| 36 | #include <linux/interrupt.h> |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 37 | #include <linux/syscalls.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include <linux/sched.h> |
Ingo Molnar | 68db0cf | 2017-02-08 18:51:37 +0100 | [diff] [blame] | 39 | #include <linux/sched/task_stack.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | #include <linux/kernel.h> |
| 41 | #include <linux/signal.h> |
| 42 | #include <linux/string.h> |
| 43 | #include <linux/mm.h> |
| 44 | #include <linux/smp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <linux/highmem.h> |
| 46 | #include <linux/ptrace.h> |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 47 | #include <linux/audit.h> |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 48 | #include <linux/stddef.h> |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 49 | #include <linux/slab.h> |
Andy Lutomirski | 76fc5e7 | 2015-09-04 17:00:43 -0700 | [diff] [blame] | 50 | #include <linux/security.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 52 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <asm/io.h> |
| 54 | #include <asm/tlbflush.h> |
| 55 | #include <asm/irq.h> |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 56 | #include <asm/traps.h> |
Brian Gerst | ba3e127 | 2015-07-29 01:41:21 -0400 | [diff] [blame] | 57 | #include <asm/vm86.h> |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 58 | #include <asm/switch_to.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
| 60 | /* |
| 61 | * Known problems: |
| 62 | * |
| 63 | * Interrupt handling is not guaranteed: |
| 64 | * - a real x86 will disable all interrupts for one instruction |
| 65 | * after a "mov ss,xx" to make stack handling atomic even without |
| 66 | * the 'lss' instruction. We can't guarantee this in v86 mode, |
| 67 | * as the next instruction might result in a page fault or similar. |
| 68 | * - a real x86 will have interrupts disabled for one instruction |
| 69 | * past the 'sti' that enables them. We don't bother with all the |
| 70 | * details yet. |
| 71 | * |
| 72 | * Let's hope these problems do not actually matter for anything. |
| 73 | */ |
| 74 | |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | /* |
| 77 | * 8- and 16-bit register defines.. |
| 78 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 79 | #define AL(regs) (((unsigned char *)&((regs)->pt.ax))[0]) |
| 80 | #define AH(regs) (((unsigned char *)&((regs)->pt.ax))[1]) |
| 81 | #define IP(regs) (*(unsigned short *)&((regs)->pt.ip)) |
| 82 | #define SP(regs) (*(unsigned short *)&((regs)->pt.sp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
| 84 | /* |
| 85 | * virtual flags (16 and 32-bit versions) |
| 86 | */ |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 87 | #define VFLAGS (*(unsigned short *)&(current->thread.vm86->veflags)) |
| 88 | #define VEFLAGS (current->thread.vm86->veflags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 90 | #define set_flags(X, new, mask) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | ((X) = ((X) & ~(mask)) | ((new) & (mask))) |
| 92 | |
| 93 | #define SAFE_MASK (0xDD5) |
| 94 | #define RETURN_MASK (0xDFF) |
| 95 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 96 | void save_v86_state(struct kernel_vm86_regs *regs, int retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | { |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 98 | struct task_struct *tsk = current; |
| 99 | struct vm86plus_struct __user *user; |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 100 | struct vm86 *vm86 = current->thread.vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | |
| 102 | /* |
| 103 | * This gets called from entry.S with interrupts disabled, but |
| 104 | * from process context. Enable interrupts here, before trying |
| 105 | * to access user space. |
| 106 | */ |
| 107 | local_irq_enable(); |
| 108 | |
Eric W. Biederman | c7a9b64 | 2021-11-12 15:12:38 -0600 | [diff] [blame] | 109 | BUG_ON(!vm86); |
Eric W. Biederman | 1a4d21a | 2021-10-20 12:43:55 -0500 | [diff] [blame] | 110 | |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 111 | set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->veflags_mask); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 112 | user = vm86->user_vm86; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 113 | |
Al Viro | a37d01e | 2020-02-15 13:38:18 -0500 | [diff] [blame] | 114 | if (!user_access_begin(user, vm86->vm86plus.is_vm86pus ? |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 115 | sizeof(struct vm86plus_struct) : |
Al Viro | a37d01e | 2020-02-15 13:38:18 -0500 | [diff] [blame] | 116 | sizeof(struct vm86_struct))) |
| 117 | goto Efault; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 118 | |
Al Viro | a37d01e | 2020-02-15 13:38:18 -0500 | [diff] [blame] | 119 | unsafe_put_user(regs->pt.bx, &user->regs.ebx, Efault_end); |
| 120 | unsafe_put_user(regs->pt.cx, &user->regs.ecx, Efault_end); |
| 121 | unsafe_put_user(regs->pt.dx, &user->regs.edx, Efault_end); |
| 122 | unsafe_put_user(regs->pt.si, &user->regs.esi, Efault_end); |
| 123 | unsafe_put_user(regs->pt.di, &user->regs.edi, Efault_end); |
| 124 | unsafe_put_user(regs->pt.bp, &user->regs.ebp, Efault_end); |
| 125 | unsafe_put_user(regs->pt.ax, &user->regs.eax, Efault_end); |
| 126 | unsafe_put_user(regs->pt.ip, &user->regs.eip, Efault_end); |
| 127 | unsafe_put_user(regs->pt.cs, &user->regs.cs, Efault_end); |
| 128 | unsafe_put_user(regs->pt.flags, &user->regs.eflags, Efault_end); |
| 129 | unsafe_put_user(regs->pt.sp, &user->regs.esp, Efault_end); |
| 130 | unsafe_put_user(regs->pt.ss, &user->regs.ss, Efault_end); |
| 131 | unsafe_put_user(regs->es, &user->regs.es, Efault_end); |
| 132 | unsafe_put_user(regs->ds, &user->regs.ds, Efault_end); |
| 133 | unsafe_put_user(regs->fs, &user->regs.fs, Efault_end); |
| 134 | unsafe_put_user(regs->gs, &user->regs.gs, Efault_end); |
Andy Lutomirski | 8ece53e | 2021-01-19 09:40:55 -0800 | [diff] [blame] | 135 | |
| 136 | /* |
| 137 | * Don't write screen_bitmap in case some user had a value there |
| 138 | * and expected it to remain unchanged. |
| 139 | */ |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 140 | |
Al Viro | a37d01e | 2020-02-15 13:38:18 -0500 | [diff] [blame] | 141 | user_access_end(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
Eric W. Biederman | 1fbd60d | 2021-10-20 12:43:56 -0500 | [diff] [blame] | 143 | exit_vm86: |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 144 | preempt_disable(); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 145 | tsk->thread.sp0 = vm86->saved_sp0; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 146 | tsk->thread.sysenter_cs = __KERNEL_CS; |
Joerg Roedel | 252e1a0 | 2018-07-18 11:40:51 +0200 | [diff] [blame] | 147 | update_task_stack(tsk); |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 148 | refresh_sysenter_cs(&tsk->thread); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 149 | vm86->saved_sp0 = 0; |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 150 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 152 | memcpy(®s->pt, &vm86->regs32, sizeof(struct pt_regs)); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 153 | |
Brian Gerst | 3a24a60 | 2022-03-25 11:39:52 -0400 | [diff] [blame] | 154 | loadsegment(gs, vm86->regs32.gs); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 155 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 156 | regs->pt.ax = retval; |
Al Viro | a37d01e | 2020-02-15 13:38:18 -0500 | [diff] [blame] | 157 | return; |
| 158 | |
| 159 | Efault_end: |
| 160 | user_access_end(); |
| 161 | Efault: |
| 162 | pr_alert("could not access userspace vm86 info\n"); |
Eric W. Biederman | fcb116b | 2021-11-18 14:23:21 -0600 | [diff] [blame] | 163 | force_exit_sig(SIGSEGV); |
Eric W. Biederman | 1fbd60d | 2021-10-20 12:43:56 -0500 | [diff] [blame] | 164 | goto exit_vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | } |
| 166 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | static int do_vm86_irq_handling(int subfunction, int irqnumber); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 168 | static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 170 | SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, user_vm86) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 172 | return do_sys_vm86((struct vm86plus_struct __user *) user_vm86, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 176 | SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | { |
Brian Gerst | f1382f1 | 2009-12-09 19:01:55 -0500 | [diff] [blame] | 178 | switch (cmd) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 179 | case VM86_REQUEST_IRQ: |
| 180 | case VM86_FREE_IRQ: |
| 181 | case VM86_GET_IRQ_BITS: |
| 182 | case VM86_GET_AND_RESET_IRQ: |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 183 | return do_vm86_irq_handling(cmd, (int)arg); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 184 | case VM86_PLUS_INSTALL_CHECK: |
| 185 | /* |
| 186 | * NOTE: on old vm86 stuff this will return the error |
| 187 | * from access_ok(), because the subfunction is |
| 188 | * interpreted as (invalid) address to vm86_struct. |
| 189 | * So the installation check works. |
| 190 | */ |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 191 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | } |
| 193 | |
| 194 | /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 195 | return do_sys_vm86((struct vm86plus_struct __user *) arg, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | } |
| 197 | |
| 198 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 199 | static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | { |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 201 | struct task_struct *tsk = current; |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 202 | struct vm86 *vm86 = tsk->thread.vm86; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 203 | struct kernel_vm86_regs vm86regs; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 204 | struct pt_regs *regs = current_pt_regs(); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 205 | unsigned long err = 0; |
Al Viro | c63aad6 | 2020-02-15 12:09:14 -0500 | [diff] [blame] | 206 | struct vm86_struct v; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 207 | |
Andy Lutomirski | 76fc5e7 | 2015-09-04 17:00:43 -0700 | [diff] [blame] | 208 | err = security_mmap_addr(0); |
| 209 | if (err) { |
| 210 | /* |
| 211 | * vm86 cannot virtualize the address space, so vm86 users |
| 212 | * need to manage the low 1MB themselves using mmap. Given |
| 213 | * that BIOS places important data in the first page, vm86 |
| 214 | * is essentially useless if mmap_min_addr != 0. DOSEMU, |
| 215 | * for example, won't even bother trying to use vm86 if it |
| 216 | * can't map a page at virtual address 0. |
| 217 | * |
| 218 | * To reduce the available kernel attack surface, simply |
| 219 | * disallow vm86(old) for users who cannot mmap at va 0. |
| 220 | * |
| 221 | * The implementation of security_mmap_addr will allow |
| 222 | * suitably privileged users to map va 0 even if |
| 223 | * vm.mmap_min_addr is set above 0, and we want this |
| 224 | * behavior for vm86 as well, as it ensures that legacy |
| 225 | * tools like vbetool will not fail just because of |
| 226 | * vm.mmap_min_addr. |
| 227 | */ |
| 228 | pr_info_once("Denied a call to vm86(old) from %s[%d] (uid: %d). Set the vm.mmap_min_addr sysctl to 0 and/or adjust LSM mmap_min_addr policy to enable vm86 if you are using a vm86-based DOS emulator.\n", |
| 229 | current->comm, task_pid_nr(current), |
| 230 | from_kuid_munged(&init_user_ns, current_uid())); |
| 231 | return -EPERM; |
| 232 | } |
| 233 | |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 234 | if (!vm86) { |
| 235 | if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL))) |
| 236 | return -ENOMEM; |
| 237 | tsk->thread.vm86 = vm86; |
| 238 | } |
| 239 | if (vm86->saved_sp0) |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 240 | return -EPERM; |
| 241 | |
Al Viro | c63aad6 | 2020-02-15 12:09:14 -0500 | [diff] [blame] | 242 | if (copy_from_user(&v, user_vm86, |
| 243 | offsetof(struct vm86_struct, int_revectored))) |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 244 | return -EFAULT; |
| 245 | |
Andy Lutomirski | 8ece53e | 2021-01-19 09:40:55 -0800 | [diff] [blame] | 246 | |
| 247 | /* VM86_SCREEN_BITMAP had numerous bugs and appears to have no users. */ |
| 248 | if (v.flags & VM86_SCREEN_BITMAP) { |
| 249 | char comm[TASK_COMM_LEN]; |
| 250 | |
| 251 | pr_info_once("vm86: '%s' uses VM86_SCREEN_BITMAP, which is no longer supported\n", get_task_comm(comm, current)); |
| 252 | return -EINVAL; |
| 253 | } |
| 254 | |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 255 | memset(&vm86regs, 0, sizeof(vm86regs)); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 256 | |
Al Viro | c63aad6 | 2020-02-15 12:09:14 -0500 | [diff] [blame] | 257 | vm86regs.pt.bx = v.regs.ebx; |
| 258 | vm86regs.pt.cx = v.regs.ecx; |
| 259 | vm86regs.pt.dx = v.regs.edx; |
| 260 | vm86regs.pt.si = v.regs.esi; |
| 261 | vm86regs.pt.di = v.regs.edi; |
| 262 | vm86regs.pt.bp = v.regs.ebp; |
| 263 | vm86regs.pt.ax = v.regs.eax; |
| 264 | vm86regs.pt.ip = v.regs.eip; |
| 265 | vm86regs.pt.cs = v.regs.cs; |
| 266 | vm86regs.pt.flags = v.regs.eflags; |
| 267 | vm86regs.pt.sp = v.regs.esp; |
| 268 | vm86regs.pt.ss = v.regs.ss; |
| 269 | vm86regs.es = v.regs.es; |
| 270 | vm86regs.ds = v.regs.ds; |
| 271 | vm86regs.fs = v.regs.fs; |
| 272 | vm86regs.gs = v.regs.gs; |
| 273 | |
| 274 | vm86->flags = v.flags; |
Al Viro | c63aad6 | 2020-02-15 12:09:14 -0500 | [diff] [blame] | 275 | vm86->cpu_type = v.cpu_type; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 276 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 277 | if (copy_from_user(&vm86->int_revectored, |
| 278 | &user_vm86->int_revectored, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 279 | sizeof(struct revectored_struct))) |
| 280 | return -EFAULT; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 281 | if (copy_from_user(&vm86->int21_revectored, |
| 282 | &user_vm86->int21_revectored, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 283 | sizeof(struct revectored_struct))) |
| 284 | return -EFAULT; |
| 285 | if (plus) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 286 | if (copy_from_user(&vm86->vm86plus, &user_vm86->vm86plus, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 287 | sizeof(struct vm86plus_info_struct))) |
| 288 | return -EFAULT; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 289 | vm86->vm86plus.is_vm86pus = 1; |
| 290 | } else |
| 291 | memset(&vm86->vm86plus, 0, |
| 292 | sizeof(struct vm86plus_info_struct)); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 293 | |
| 294 | memcpy(&vm86->regs32, regs, sizeof(struct pt_regs)); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 295 | vm86->user_vm86 = user_vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | |
| 297 | /* |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 298 | * The flags register is also special: we cannot trust that the user |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | * has set it up safely, so this makes sure interrupt etc flags are |
| 300 | * inherited from protected mode. |
| 301 | */ |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 302 | VEFLAGS = vm86regs.pt.flags; |
| 303 | vm86regs.pt.flags &= SAFE_MASK; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 304 | vm86regs.pt.flags |= regs->flags & ~SAFE_MASK; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 305 | vm86regs.pt.flags |= X86_VM_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 307 | vm86regs.pt.orig_ax = regs->orig_ax; |
Brian Gerst | df1ae9a | 2015-07-19 21:09:05 -0400 | [diff] [blame] | 308 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 309 | switch (vm86->cpu_type) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 310 | case CPU_286: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 311 | vm86->veflags_mask = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 312 | break; |
| 313 | case CPU_386: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 314 | vm86->veflags_mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 315 | break; |
| 316 | case CPU_486: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 317 | vm86->veflags_mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 318 | break; |
| 319 | default: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 320 | vm86->veflags_mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 321 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | /* |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 325 | * Save old state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | */ |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 327 | vm86->saved_sp0 = tsk->thread.sp0; |
Brian Gerst | 3a24a60 | 2022-03-25 11:39:52 -0400 | [diff] [blame] | 328 | savesegment(gs, vm86->regs32.gs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 330 | /* make room for real-mode segments */ |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 331 | preempt_disable(); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 332 | tsk->thread.sp0 += 16; |
Borislav Petkov | 362f924 | 2015-12-07 10:39:41 +0100 | [diff] [blame] | 333 | |
Borislav Petkov | 67e87d4 | 2019-03-29 19:52:59 +0100 | [diff] [blame] | 334 | if (boot_cpu_has(X86_FEATURE_SEP)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | tsk->thread.sysenter_cs = 0; |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 336 | refresh_sysenter_cs(&tsk->thread); |
| 337 | } |
Borislav Petkov | 362f924 | 2015-12-07 10:39:41 +0100 | [diff] [blame] | 338 | |
Joerg Roedel | 252e1a0 | 2018-07-18 11:40:51 +0200 | [diff] [blame] | 339 | update_task_stack(tsk); |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 340 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 342 | memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs)); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 343 | return regs->ax; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | } |
| 345 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 346 | static inline void set_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 348 | VEFLAGS |= X86_EFLAGS_VIF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | } |
| 350 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 351 | static inline void clear_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 353 | VEFLAGS &= ~X86_EFLAGS_VIF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | } |
| 355 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 356 | static inline void clear_TF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 358 | regs->pt.flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | } |
| 360 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 361 | static inline void clear_AC(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 363 | regs->pt.flags &= ~X86_EFLAGS_AC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | } |
| 365 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 366 | /* |
| 367 | * It is correct to call set_IF(regs) from the set_vflags_* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | * functions. However someone forgot to call clear_IF(regs) |
| 369 | * in the opposite case. |
| 370 | * After the command sequence CLI PUSHF STI POPF you should |
Joe Perches | ab4a574 | 2008-01-30 13:31:42 +0100 | [diff] [blame] | 371 | * end up with interrupts disabled, but you ended up with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | * interrupts enabled. |
| 373 | * ( I was testing my own changes, but the only bug I |
| 374 | * could find was in a function I had not changed. ) |
| 375 | * [KD] |
| 376 | */ |
| 377 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 378 | static inline void set_vflags_long(unsigned long flags, struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | { |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 380 | set_flags(VEFLAGS, flags, current->thread.vm86->veflags_mask); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 381 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 382 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | set_IF(regs); |
| 384 | else |
| 385 | clear_IF(regs); |
| 386 | } |
| 387 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 388 | static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | { |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 390 | set_flags(VFLAGS, flags, current->thread.vm86->veflags_mask); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 391 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 392 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | set_IF(regs); |
| 394 | else |
| 395 | clear_IF(regs); |
| 396 | } |
| 397 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 398 | static inline unsigned long get_vflags(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | { |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 400 | unsigned long flags = regs->pt.flags & RETURN_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 402 | if (VEFLAGS & X86_EFLAGS_VIF) |
| 403 | flags |= X86_EFLAGS_IF; |
| 404 | flags |= X86_EFLAGS_IOPL; |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 405 | return flags | (VEFLAGS & current->thread.vm86->veflags_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | } |
| 407 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 408 | static inline int is_revectored(int nr, struct revectored_struct *bitmap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | { |
H. Peter Anvin | 2823d4d | 2016-06-08 12:38:37 -0700 | [diff] [blame] | 410 | return test_bit(nr, bitmap->__map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | } |
| 412 | |
| 413 | #define val_byte(val, n) (((__u8 *)&val)[n]) |
| 414 | |
| 415 | #define pushb(base, ptr, val, err_label) \ |
| 416 | do { \ |
| 417 | __u8 __val = val; \ |
| 418 | ptr--; \ |
| 419 | if (put_user(__val, base + ptr) < 0) \ |
| 420 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 421 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | |
| 423 | #define pushw(base, ptr, val, err_label) \ |
| 424 | do { \ |
| 425 | __u16 __val = val; \ |
| 426 | ptr--; \ |
| 427 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 428 | goto err_label; \ |
| 429 | ptr--; \ |
| 430 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 431 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 432 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | |
| 434 | #define pushl(base, ptr, val, err_label) \ |
| 435 | do { \ |
| 436 | __u32 __val = val; \ |
| 437 | ptr--; \ |
| 438 | if (put_user(val_byte(__val, 3), base + ptr) < 0) \ |
| 439 | goto err_label; \ |
| 440 | ptr--; \ |
| 441 | if (put_user(val_byte(__val, 2), base + ptr) < 0) \ |
| 442 | goto err_label; \ |
| 443 | ptr--; \ |
| 444 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 445 | goto err_label; \ |
| 446 | ptr--; \ |
| 447 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 448 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 449 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
| 451 | #define popb(base, ptr, err_label) \ |
| 452 | ({ \ |
| 453 | __u8 __res; \ |
| 454 | if (get_user(__res, base + ptr) < 0) \ |
| 455 | goto err_label; \ |
| 456 | ptr++; \ |
| 457 | __res; \ |
| 458 | }) |
| 459 | |
| 460 | #define popw(base, ptr, err_label) \ |
| 461 | ({ \ |
| 462 | __u16 __res; \ |
| 463 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 464 | goto err_label; \ |
| 465 | ptr++; \ |
| 466 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 467 | goto err_label; \ |
| 468 | ptr++; \ |
| 469 | __res; \ |
| 470 | }) |
| 471 | |
| 472 | #define popl(base, ptr, err_label) \ |
| 473 | ({ \ |
| 474 | __u32 __res; \ |
| 475 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 476 | goto err_label; \ |
| 477 | ptr++; \ |
| 478 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 479 | goto err_label; \ |
| 480 | ptr++; \ |
| 481 | if (get_user(val_byte(__res, 2), base + ptr) < 0) \ |
| 482 | goto err_label; \ |
| 483 | ptr++; \ |
| 484 | if (get_user(val_byte(__res, 3), base + ptr) < 0) \ |
| 485 | goto err_label; \ |
| 486 | ptr++; \ |
| 487 | __res; \ |
| 488 | }) |
| 489 | |
| 490 | /* There are so many possible reasons for this function to return |
| 491 | * VM86_INTx, so adding another doesn't bother me. We can expect |
| 492 | * userspace programs to be able to handle it. (Getting a problem |
| 493 | * in userspace is always better than an Oops anyway.) [KD] |
| 494 | */ |
| 495 | static void do_int(struct kernel_vm86_regs *regs, int i, |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 496 | unsigned char __user *ssp, unsigned short sp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | { |
| 498 | unsigned long __user *intr_ptr; |
| 499 | unsigned long segoffs; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 500 | struct vm86 *vm86 = current->thread.vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 502 | if (regs->pt.cs == BIOSSEG) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 504 | if (is_revectored(i, &vm86->int_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 506 | if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | goto cannot_handle; |
| 508 | intr_ptr = (unsigned long __user *) (i << 2); |
| 509 | if (get_user(segoffs, intr_ptr)) |
| 510 | goto cannot_handle; |
| 511 | if ((segoffs >> 16) == BIOSSEG) |
| 512 | goto cannot_handle; |
| 513 | pushw(ssp, sp, get_vflags(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 514 | pushw(ssp, sp, regs->pt.cs, cannot_handle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | pushw(ssp, sp, IP(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 516 | regs->pt.cs = segoffs >> 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | SP(regs) -= 6; |
| 518 | IP(regs) = segoffs & 0xffff; |
| 519 | clear_TF(regs); |
| 520 | clear_IF(regs); |
| 521 | clear_AC(regs); |
| 522 | return; |
| 523 | |
| 524 | cannot_handle: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 525 | save_v86_state(regs, VM86_INTx + (i << 8)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | } |
| 527 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 528 | int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | { |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 530 | struct vm86 *vm86 = current->thread.vm86; |
| 531 | |
| 532 | if (vm86->vm86plus.is_vm86pus) { |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 533 | if ((trapno == 3) || (trapno == 1)) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 534 | save_v86_state(regs, VM86_TRAP + (trapno << 8)); |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 535 | return 0; |
| 536 | } |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 537 | do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | return 0; |
| 539 | } |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 540 | if (trapno != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | return 1; /* we let this handle by the calling routine */ |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 542 | current->thread.trap_nr = trapno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | current->thread.error_code = error_code; |
Eric W. Biederman | 3cf5d07 | 2019-05-23 10:17:27 -0500 | [diff] [blame] | 544 | force_sig(SIGTRAP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | return 0; |
| 546 | } |
| 547 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 548 | void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | { |
| 550 | unsigned char opcode; |
| 551 | unsigned char __user *csp; |
| 552 | unsigned char __user *ssp; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 553 | unsigned short ip, sp, orig_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | int data32, pref_done; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 555 | struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | |
| 557 | #define CHECK_IF_IN_TRAP \ |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 558 | if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 559 | newflags |= X86_EFLAGS_TF |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 561 | orig_flags = *(unsigned short *)®s->pt.flags; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 562 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 563 | csp = (unsigned char __user *) (regs->pt.cs << 4); |
| 564 | ssp = (unsigned char __user *) (regs->pt.ss << 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | sp = SP(regs); |
| 566 | ip = IP(regs); |
| 567 | |
| 568 | data32 = 0; |
| 569 | pref_done = 0; |
| 570 | do { |
| 571 | switch (opcode = popb(csp, ip, simulate_sigsegv)) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 572 | case 0x66: /* 32-bit data */ data32 = 1; break; |
| 573 | case 0x67: /* 32-bit address */ break; |
| 574 | case 0x2e: /* CS */ break; |
| 575 | case 0x3e: /* DS */ break; |
| 576 | case 0x26: /* ES */ break; |
| 577 | case 0x36: /* SS */ break; |
| 578 | case 0x65: /* GS */ break; |
| 579 | case 0x64: /* FS */ break; |
| 580 | case 0xf2: /* repnz */ break; |
| 581 | case 0xf3: /* rep */ break; |
| 582 | default: pref_done = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | } |
| 584 | } while (!pref_done); |
| 585 | |
| 586 | switch (opcode) { |
| 587 | |
| 588 | /* pushf */ |
| 589 | case 0x9c: |
| 590 | if (data32) { |
| 591 | pushl(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 592 | SP(regs) -= 4; |
| 593 | } else { |
| 594 | pushw(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 595 | SP(regs) -= 2; |
| 596 | } |
| 597 | IP(regs) = ip; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 598 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | |
| 600 | /* popf */ |
| 601 | case 0x9d: |
| 602 | { |
| 603 | unsigned long newflags; |
| 604 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 605 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | SP(regs) += 4; |
| 607 | } else { |
| 608 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 609 | SP(regs) += 2; |
| 610 | } |
| 611 | IP(regs) = ip; |
| 612 | CHECK_IF_IN_TRAP; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 613 | if (data32) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | set_vflags_long(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 615 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | set_vflags_short(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 617 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 618 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | } |
| 620 | |
| 621 | /* int xx */ |
| 622 | case 0xcd: { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 623 | int intno = popb(csp, ip, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | IP(regs) = ip; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 625 | if (vmpi->vm86dbg_active) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 626 | if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) { |
| 627 | save_v86_state(regs, VM86_INTx + (intno << 8)); |
| 628 | return; |
| 629 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | } |
| 631 | do_int(regs, intno, ssp, sp); |
| 632 | return; |
| 633 | } |
| 634 | |
| 635 | /* iret */ |
| 636 | case 0xcf: |
| 637 | { |
| 638 | unsigned long newip; |
| 639 | unsigned long newcs; |
| 640 | unsigned long newflags; |
| 641 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 642 | newip = popl(ssp, sp, simulate_sigsegv); |
| 643 | newcs = popl(ssp, sp, simulate_sigsegv); |
| 644 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | SP(regs) += 12; |
| 646 | } else { |
| 647 | newip = popw(ssp, sp, simulate_sigsegv); |
| 648 | newcs = popw(ssp, sp, simulate_sigsegv); |
| 649 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 650 | SP(regs) += 6; |
| 651 | } |
| 652 | IP(regs) = newip; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 653 | regs->pt.cs = newcs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | CHECK_IF_IN_TRAP; |
| 655 | if (data32) { |
| 656 | set_vflags_long(newflags, regs); |
| 657 | } else { |
| 658 | set_vflags_short(newflags, regs); |
| 659 | } |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 660 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | } |
| 662 | |
| 663 | /* cli */ |
| 664 | case 0xfa: |
| 665 | IP(regs) = ip; |
| 666 | clear_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 667 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | |
| 669 | /* sti */ |
| 670 | /* |
| 671 | * Damn. This is incorrect: the 'sti' instruction should actually |
| 672 | * enable interrupts after the /next/ instruction. Not good. |
| 673 | * |
| 674 | * Probably needs some horsing around with the TF flag. Aiee.. |
| 675 | */ |
| 676 | case 0xfb: |
| 677 | IP(regs) = ip; |
| 678 | set_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 679 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | |
| 681 | default: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 682 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | } |
| 684 | |
| 685 | return; |
| 686 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 687 | check_vip: |
Andy Lutomirski | b506978 | 2018-03-13 22:03:12 -0700 | [diff] [blame] | 688 | if ((VEFLAGS & (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) == |
| 689 | (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 690 | save_v86_state(regs, VM86_STI); |
| 691 | return; |
| 692 | } |
| 693 | |
| 694 | vm86_fault_return: |
| 695 | if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) { |
| 696 | save_v86_state(regs, VM86_PICRETURN); |
| 697 | return; |
| 698 | } |
| 699 | if (orig_flags & X86_EFLAGS_TF) |
| 700 | handle_vm86_trap(regs, 0, X86_TRAP_DB); |
| 701 | return; |
| 702 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | simulate_sigsegv: |
| 704 | /* FIXME: After a long discussion with Stas we finally |
| 705 | * agreed, that this is wrong. Here we should |
| 706 | * really send a SIGSEGV to the user program. |
| 707 | * But how do we create the correct context? We |
| 708 | * are inside a general protection fault handler |
| 709 | * and has just returned from a page fault handler. |
| 710 | * The correct context for the signal handler |
| 711 | * should be a mixture of the two, but how do we |
| 712 | * get the information? [KD] |
| 713 | */ |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 714 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | } |
| 716 | |
| 717 | /* ---------------- vm86 special IRQ passing stuff ----------------- */ |
| 718 | |
| 719 | #define VM86_IRQNAME "vm86irq" |
| 720 | |
| 721 | static struct vm86_irqs { |
| 722 | struct task_struct *tsk; |
| 723 | int sig; |
| 724 | } vm86_irqs[16]; |
| 725 | |
| 726 | static DEFINE_SPINLOCK(irqbits_lock); |
| 727 | static int irqbits; |
| 728 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 729 | #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 731 | | (1 << SIGUNUSED)) |
| 732 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 733 | static irqreturn_t irq_handler(int intno, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | { |
| 735 | int irq_bit; |
| 736 | unsigned long flags; |
| 737 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 738 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | irq_bit = 1 << intno; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 740 | if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | goto out; |
| 742 | irqbits |= irq_bit; |
| 743 | if (vm86_irqs[intno].sig) |
| 744 | send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | /* |
| 746 | * IRQ will be re-enabled when user asks for the irq (whether |
| 747 | * polling or as a result of the signal) |
| 748 | */ |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 749 | disable_irq_nosync(intno); |
| 750 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | return IRQ_HANDLED; |
| 752 | |
| 753 | out: |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 754 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | return IRQ_NONE; |
| 756 | } |
| 757 | |
| 758 | static inline void free_vm86_irq(int irqnumber) |
| 759 | { |
| 760 | unsigned long flags; |
| 761 | |
| 762 | free_irq(irqnumber, NULL); |
| 763 | vm86_irqs[irqnumber].tsk = NULL; |
| 764 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 765 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | irqbits &= ~(1 << irqnumber); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 767 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | } |
| 769 | |
| 770 | void release_vm86_irqs(struct task_struct *task) |
| 771 | { |
| 772 | int i; |
| 773 | for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++) |
| 774 | if (vm86_irqs[i].tsk == task) |
| 775 | free_vm86_irq(i); |
| 776 | } |
| 777 | |
| 778 | static inline int get_and_reset_irq(int irqnumber) |
| 779 | { |
| 780 | int bit; |
| 781 | unsigned long flags; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 782 | int ret = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 783 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | if (invalid_vm86_irq(irqnumber)) return 0; |
| 785 | if (vm86_irqs[irqnumber].tsk != current) return 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 786 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | bit = irqbits & (1 << irqnumber); |
| 788 | irqbits &= ~bit; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 789 | if (bit) { |
| 790 | enable_irq(irqnumber); |
| 791 | ret = 1; |
| 792 | } |
| 793 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 794 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 795 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | } |
| 797 | |
| 798 | |
| 799 | static int do_vm86_irq_handling(int subfunction, int irqnumber) |
| 800 | { |
| 801 | int ret; |
| 802 | switch (subfunction) { |
| 803 | case VM86_GET_AND_RESET_IRQ: { |
| 804 | return get_and_reset_irq(irqnumber); |
| 805 | } |
| 806 | case VM86_GET_IRQ_BITS: { |
| 807 | return irqbits; |
| 808 | } |
| 809 | case VM86_REQUEST_IRQ: { |
| 810 | int sig = irqnumber >> 8; |
| 811 | int irq = irqnumber & 255; |
| 812 | if (!capable(CAP_SYS_ADMIN)) return -EPERM; |
| 813 | if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM; |
| 814 | if (invalid_vm86_irq(irq)) return -EPERM; |
| 815 | if (vm86_irqs[irq].tsk) return -EPERM; |
| 816 | ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL); |
| 817 | if (ret) return ret; |
| 818 | vm86_irqs[irq].sig = sig; |
| 819 | vm86_irqs[irq].tsk = current; |
| 820 | return irq; |
| 821 | } |
| 822 | case VM86_FREE_IRQ: { |
| 823 | if (invalid_vm86_irq(irqnumber)) return -EPERM; |
| 824 | if (!vm86_irqs[irqnumber].tsk) return 0; |
| 825 | if (vm86_irqs[irqnumber].tsk != current) return -EPERM; |
| 826 | free_vm86_irq(irqnumber); |
| 827 | return 0; |
| 828 | } |
| 829 | } |
| 830 | return -EINVAL; |
| 831 | } |
| 832 | |