Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 1994 Linus Torvalds |
| 3 | * |
| 4 | * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86 |
Christian Kujau | 624dffc | 2006-01-15 02:43:54 +0100 | [diff] [blame] | 5 | * stack - Manfred Spraul <manfred@colorfullife.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * 22 mar 2002 - Manfred detected the stackfaults, but didn't handle |
| 8 | * them correctly. Now the emulation will be in a |
| 9 | * consistent state after stackfaults - Kasper Dupont |
| 10 | * <kasperd@daimi.au.dk> |
| 11 | * |
| 12 | * 22 mar 2002 - Added missing clear_IF in set_vflags_* Kasper Dupont |
| 13 | * <kasperd@daimi.au.dk> |
| 14 | * |
| 15 | * ?? ??? 2002 - Fixed premature returns from handle_vm86_fault |
| 16 | * caused by Kasper Dupont's changes - Stas Sergeev |
| 17 | * |
| 18 | * 4 apr 2002 - Fixed CHECK_IF_IN_TRAP broken by Stas' changes. |
| 19 | * Kasper Dupont <kasperd@daimi.au.dk> |
| 20 | * |
| 21 | * 9 apr 2002 - Changed syntax of macros in handle_vm86_fault. |
| 22 | * Kasper Dupont <kasperd@daimi.au.dk> |
| 23 | * |
| 24 | * 9 apr 2002 - Changed stack access macros to jump to a label |
| 25 | * instead of returning to userspace. This simplifies |
| 26 | * do_int, and is needed by handle_vm6_fault. Kasper |
| 27 | * Dupont <kasperd@daimi.au.dk> |
| 28 | * |
| 29 | */ |
| 30 | |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 31 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 32 | |
Randy Dunlap | a941564 | 2006-01-11 12:17:48 -0800 | [diff] [blame] | 33 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/errno.h> |
| 35 | #include <linux/interrupt.h> |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 36 | #include <linux/syscalls.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <linux/sched.h> |
| 38 | #include <linux/kernel.h> |
| 39 | #include <linux/signal.h> |
| 40 | #include <linux/string.h> |
| 41 | #include <linux/mm.h> |
| 42 | #include <linux/smp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/highmem.h> |
| 44 | #include <linux/ptrace.h> |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 45 | #include <linux/audit.h> |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 46 | #include <linux/stddef.h> |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 47 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | #include <asm/uaccess.h> |
| 50 | #include <asm/io.h> |
| 51 | #include <asm/tlbflush.h> |
| 52 | #include <asm/irq.h> |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 53 | #include <asm/traps.h> |
Brian Gerst | ba3e127 | 2015-07-29 01:41:21 -0400 | [diff] [blame] | 54 | #include <asm/vm86.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
| 56 | /* |
| 57 | * Known problems: |
| 58 | * |
| 59 | * Interrupt handling is not guaranteed: |
| 60 | * - a real x86 will disable all interrupts for one instruction |
| 61 | * after a "mov ss,xx" to make stack handling atomic even without |
| 62 | * the 'lss' instruction. We can't guarantee this in v86 mode, |
| 63 | * as the next instruction might result in a page fault or similar. |
| 64 | * - a real x86 will have interrupts disabled for one instruction |
| 65 | * past the 'sti' that enables them. We don't bother with all the |
| 66 | * details yet. |
| 67 | * |
| 68 | * Let's hope these problems do not actually matter for anything. |
| 69 | */ |
| 70 | |
| 71 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | /* |
| 73 | * 8- and 16-bit register defines.. |
| 74 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 75 | #define AL(regs) (((unsigned char *)&((regs)->pt.ax))[0]) |
| 76 | #define AH(regs) (((unsigned char *)&((regs)->pt.ax))[1]) |
| 77 | #define IP(regs) (*(unsigned short *)&((regs)->pt.ip)) |
| 78 | #define SP(regs) (*(unsigned short *)&((regs)->pt.sp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | /* |
| 81 | * virtual flags (16 and 32-bit versions) |
| 82 | */ |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 83 | #define VFLAGS (*(unsigned short *)&(current->thread.vm86->veflags)) |
| 84 | #define VEFLAGS (current->thread.vm86->veflags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 86 | #define set_flags(X, new, mask) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | ((X) = ((X) & ~(mask)) | ((new) & (mask))) |
| 88 | |
| 89 | #define SAFE_MASK (0xDD5) |
| 90 | #define RETURN_MASK (0xDFF) |
| 91 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 92 | void save_v86_state(struct kernel_vm86_regs *regs, int retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | { |
| 94 | struct tss_struct *tss; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 95 | struct task_struct *tsk = current; |
| 96 | struct vm86plus_struct __user *user; |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 97 | struct vm86 *vm86 = current->thread.vm86; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 98 | long err = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
| 100 | /* |
| 101 | * This gets called from entry.S with interrupts disabled, but |
| 102 | * from process context. Enable interrupts here, before trying |
| 103 | * to access user space. |
| 104 | */ |
| 105 | local_irq_enable(); |
| 106 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 107 | if (!vm86 || !vm86->user_vm86) { |
| 108 | pr_alert("no user_vm86: BAD\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | do_exit(SIGSEGV); |
| 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 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 114 | if (!access_ok(VERIFY_WRITE, user, vm86->vm86plus.is_vm86pus ? |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 115 | sizeof(struct vm86plus_struct) : |
| 116 | sizeof(struct vm86_struct))) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 117 | pr_alert("could not access userspace vm86 info\n"); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 118 | do_exit(SIGSEGV); |
| 119 | } |
| 120 | |
| 121 | put_user_try { |
| 122 | put_user_ex(regs->pt.bx, &user->regs.ebx); |
| 123 | put_user_ex(regs->pt.cx, &user->regs.ecx); |
| 124 | put_user_ex(regs->pt.dx, &user->regs.edx); |
| 125 | put_user_ex(regs->pt.si, &user->regs.esi); |
| 126 | put_user_ex(regs->pt.di, &user->regs.edi); |
| 127 | put_user_ex(regs->pt.bp, &user->regs.ebp); |
| 128 | put_user_ex(regs->pt.ax, &user->regs.eax); |
| 129 | put_user_ex(regs->pt.ip, &user->regs.eip); |
| 130 | put_user_ex(regs->pt.cs, &user->regs.cs); |
| 131 | put_user_ex(regs->pt.flags, &user->regs.eflags); |
| 132 | put_user_ex(regs->pt.sp, &user->regs.esp); |
| 133 | put_user_ex(regs->pt.ss, &user->regs.ss); |
| 134 | put_user_ex(regs->es, &user->regs.es); |
| 135 | put_user_ex(regs->ds, &user->regs.ds); |
| 136 | put_user_ex(regs->fs, &user->regs.fs); |
| 137 | put_user_ex(regs->gs, &user->regs.gs); |
| 138 | |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 139 | put_user_ex(vm86->screen_bitmap, &user->screen_bitmap); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 140 | } put_user_catch(err); |
| 141 | if (err) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 142 | pr_alert("could not access userspace vm86 info\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | do_exit(SIGSEGV); |
| 144 | } |
| 145 | |
Andy Lutomirski | 24933b8 | 2015-03-05 19:19:05 -0800 | [diff] [blame] | 146 | tss = &per_cpu(cpu_tss, get_cpu()); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 147 | tsk->thread.sp0 = vm86->saved_sp0; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 148 | tsk->thread.sysenter_cs = __KERNEL_CS; |
| 149 | load_sp0(tss, &tsk->thread); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 150 | vm86->saved_sp0 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | put_cpu(); |
| 152 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 153 | memcpy(®s->pt, &vm86->regs32, sizeof(struct pt_regs)); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 154 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 155 | lazy_load_gs(vm86->regs32.gs); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 156 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 157 | regs->pt.ax = retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | } |
| 159 | |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 160 | static void mark_screen_rdonly(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | { |
| 162 | pgd_t *pgd; |
| 163 | pud_t *pud; |
| 164 | pmd_t *pmd; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 165 | pte_t *pte; |
| 166 | spinlock_t *ptl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | int i; |
| 168 | |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 169 | down_write(&mm->mmap_sem); |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 170 | pgd = pgd_offset(mm, 0xA0000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | if (pgd_none_or_clear_bad(pgd)) |
| 172 | goto out; |
| 173 | pud = pud_offset(pgd, 0xA0000); |
| 174 | if (pud_none_or_clear_bad(pud)) |
| 175 | goto out; |
| 176 | pmd = pmd_offset(pud, 0xA0000); |
Kirill A. Shutemov | e180377 | 2012-12-12 13:50:59 -0800 | [diff] [blame] | 177 | split_huge_page_pmd_mm(mm, 0xA0000, pmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | if (pmd_none_or_clear_bad(pmd)) |
| 179 | goto out; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 180 | pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | for (i = 0; i < 32; i++) { |
| 182 | if (pte_present(*pte)) |
| 183 | set_pte(pte, pte_wrprotect(*pte)); |
| 184 | pte++; |
| 185 | } |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 186 | pte_unmap_unlock(pte, ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | out: |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 188 | up_write(&mm->mmap_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | flush_tlb(); |
| 190 | } |
| 191 | |
| 192 | |
| 193 | |
| 194 | static int do_vm86_irq_handling(int subfunction, int irqnumber); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 195 | 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] | 196 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 197 | SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, user_vm86) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 199 | return do_sys_vm86((struct vm86plus_struct __user *) user_vm86, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | } |
| 201 | |
| 202 | |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 203 | SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | { |
Brian Gerst | f1382f1 | 2009-12-09 19:01:55 -0500 | [diff] [blame] | 205 | switch (cmd) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 206 | case VM86_REQUEST_IRQ: |
| 207 | case VM86_FREE_IRQ: |
| 208 | case VM86_GET_IRQ_BITS: |
| 209 | case VM86_GET_AND_RESET_IRQ: |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 210 | return do_vm86_irq_handling(cmd, (int)arg); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 211 | case VM86_PLUS_INSTALL_CHECK: |
| 212 | /* |
| 213 | * NOTE: on old vm86 stuff this will return the error |
| 214 | * from access_ok(), because the subfunction is |
| 215 | * interpreted as (invalid) address to vm86_struct. |
| 216 | * So the installation check works. |
| 217 | */ |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 218 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | } |
| 220 | |
| 221 | /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 222 | return do_sys_vm86((struct vm86plus_struct __user *) arg, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
| 224 | |
| 225 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 226 | 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] | 227 | { |
| 228 | struct tss_struct *tss; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 229 | struct task_struct *tsk = current; |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 230 | struct vm86 *vm86 = tsk->thread.vm86; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 231 | struct kernel_vm86_regs vm86regs; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 232 | struct pt_regs *regs = current_pt_regs(); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 233 | unsigned long err = 0; |
| 234 | |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 235 | if (!vm86) { |
| 236 | if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL))) |
| 237 | return -ENOMEM; |
| 238 | tsk->thread.vm86 = vm86; |
| 239 | } |
| 240 | if (vm86->saved_sp0) |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 241 | return -EPERM; |
| 242 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 243 | if (!access_ok(VERIFY_READ, user_vm86, plus ? |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 244 | sizeof(struct vm86_struct) : |
| 245 | sizeof(struct vm86plus_struct))) |
| 246 | return -EFAULT; |
| 247 | |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 248 | memset(&vm86regs, 0, sizeof(vm86regs)); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 249 | get_user_try { |
| 250 | unsigned short seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 251 | get_user_ex(vm86regs.pt.bx, &user_vm86->regs.ebx); |
| 252 | get_user_ex(vm86regs.pt.cx, &user_vm86->regs.ecx); |
| 253 | get_user_ex(vm86regs.pt.dx, &user_vm86->regs.edx); |
| 254 | get_user_ex(vm86regs.pt.si, &user_vm86->regs.esi); |
| 255 | get_user_ex(vm86regs.pt.di, &user_vm86->regs.edi); |
| 256 | get_user_ex(vm86regs.pt.bp, &user_vm86->regs.ebp); |
| 257 | get_user_ex(vm86regs.pt.ax, &user_vm86->regs.eax); |
| 258 | get_user_ex(vm86regs.pt.ip, &user_vm86->regs.eip); |
| 259 | get_user_ex(seg, &user_vm86->regs.cs); |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 260 | vm86regs.pt.cs = seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 261 | get_user_ex(vm86regs.pt.flags, &user_vm86->regs.eflags); |
| 262 | get_user_ex(vm86regs.pt.sp, &user_vm86->regs.esp); |
| 263 | get_user_ex(seg, &user_vm86->regs.ss); |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 264 | vm86regs.pt.ss = seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 265 | get_user_ex(vm86regs.es, &user_vm86->regs.es); |
| 266 | get_user_ex(vm86regs.ds, &user_vm86->regs.ds); |
| 267 | get_user_ex(vm86regs.fs, &user_vm86->regs.fs); |
| 268 | get_user_ex(vm86regs.gs, &user_vm86->regs.gs); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 269 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 270 | get_user_ex(vm86->flags, &user_vm86->flags); |
| 271 | get_user_ex(vm86->screen_bitmap, &user_vm86->screen_bitmap); |
| 272 | get_user_ex(vm86->cpu_type, &user_vm86->cpu_type); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 273 | } get_user_catch(err); |
| 274 | if (err) |
| 275 | return err; |
| 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 | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 328 | lazy_save_gs(vm86->regs32.gs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
Andy Lutomirski | 24933b8 | 2015-03-05 19:19:05 -0800 | [diff] [blame] | 330 | tss = &per_cpu(cpu_tss, get_cpu()); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 331 | /* make room for real-mode segments */ |
| 332 | tsk->thread.sp0 += 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | if (cpu_has_sep) |
| 334 | tsk->thread.sysenter_cs = 0; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 335 | load_sp0(tss, &tsk->thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | put_cpu(); |
| 337 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 338 | if (vm86->flags & VM86_SCREEN_BITMAP) |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 339 | mark_screen_rdonly(tsk->mm); |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 340 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 341 | memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs)); |
| 342 | force_iret(); |
| 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 | { |
| 410 | __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0" |
| 411 | :"=r" (nr) |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 412 | :"m" (*bitmap), "r" (nr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | return nr; |
| 414 | } |
| 415 | |
| 416 | #define val_byte(val, n) (((__u8 *)&val)[n]) |
| 417 | |
| 418 | #define pushb(base, ptr, val, err_label) \ |
| 419 | do { \ |
| 420 | __u8 __val = val; \ |
| 421 | ptr--; \ |
| 422 | if (put_user(__val, base + ptr) < 0) \ |
| 423 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 424 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | |
| 426 | #define pushw(base, ptr, val, err_label) \ |
| 427 | do { \ |
| 428 | __u16 __val = val; \ |
| 429 | ptr--; \ |
| 430 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 431 | goto err_label; \ |
| 432 | ptr--; \ |
| 433 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 434 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 435 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | |
| 437 | #define pushl(base, ptr, val, err_label) \ |
| 438 | do { \ |
| 439 | __u32 __val = val; \ |
| 440 | ptr--; \ |
| 441 | if (put_user(val_byte(__val, 3), base + ptr) < 0) \ |
| 442 | goto err_label; \ |
| 443 | ptr--; \ |
| 444 | if (put_user(val_byte(__val, 2), base + ptr) < 0) \ |
| 445 | goto err_label; \ |
| 446 | ptr--; \ |
| 447 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 448 | goto err_label; \ |
| 449 | ptr--; \ |
| 450 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 451 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 452 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | |
| 454 | #define popb(base, ptr, err_label) \ |
| 455 | ({ \ |
| 456 | __u8 __res; \ |
| 457 | if (get_user(__res, base + ptr) < 0) \ |
| 458 | goto err_label; \ |
| 459 | ptr++; \ |
| 460 | __res; \ |
| 461 | }) |
| 462 | |
| 463 | #define popw(base, ptr, err_label) \ |
| 464 | ({ \ |
| 465 | __u16 __res; \ |
| 466 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 467 | goto err_label; \ |
| 468 | ptr++; \ |
| 469 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 470 | goto err_label; \ |
| 471 | ptr++; \ |
| 472 | __res; \ |
| 473 | }) |
| 474 | |
| 475 | #define popl(base, ptr, err_label) \ |
| 476 | ({ \ |
| 477 | __u32 __res; \ |
| 478 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 479 | goto err_label; \ |
| 480 | ptr++; \ |
| 481 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 482 | goto err_label; \ |
| 483 | ptr++; \ |
| 484 | if (get_user(val_byte(__res, 2), base + ptr) < 0) \ |
| 485 | goto err_label; \ |
| 486 | ptr++; \ |
| 487 | if (get_user(val_byte(__res, 3), base + ptr) < 0) \ |
| 488 | goto err_label; \ |
| 489 | ptr++; \ |
| 490 | __res; \ |
| 491 | }) |
| 492 | |
| 493 | /* There are so many possible reasons for this function to return |
| 494 | * VM86_INTx, so adding another doesn't bother me. We can expect |
| 495 | * userspace programs to be able to handle it. (Getting a problem |
| 496 | * in userspace is always better than an Oops anyway.) [KD] |
| 497 | */ |
| 498 | static void do_int(struct kernel_vm86_regs *regs, int i, |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 499 | unsigned char __user *ssp, unsigned short sp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | { |
| 501 | unsigned long __user *intr_ptr; |
| 502 | unsigned long segoffs; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 503 | struct vm86 *vm86 = current->thread.vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 505 | if (regs->pt.cs == BIOSSEG) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 507 | if (is_revectored(i, &vm86->int_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 509 | if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | goto cannot_handle; |
| 511 | intr_ptr = (unsigned long __user *) (i << 2); |
| 512 | if (get_user(segoffs, intr_ptr)) |
| 513 | goto cannot_handle; |
| 514 | if ((segoffs >> 16) == BIOSSEG) |
| 515 | goto cannot_handle; |
| 516 | pushw(ssp, sp, get_vflags(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 517 | pushw(ssp, sp, regs->pt.cs, cannot_handle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | pushw(ssp, sp, IP(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 519 | regs->pt.cs = segoffs >> 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | SP(regs) -= 6; |
| 521 | IP(regs) = segoffs & 0xffff; |
| 522 | clear_TF(regs); |
| 523 | clear_IF(regs); |
| 524 | clear_AC(regs); |
| 525 | return; |
| 526 | |
| 527 | cannot_handle: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 528 | save_v86_state(regs, VM86_INTx + (i << 8)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | } |
| 530 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 531 | 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] | 532 | { |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 533 | struct vm86 *vm86 = current->thread.vm86; |
| 534 | |
| 535 | if (vm86->vm86plus.is_vm86pus) { |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 536 | if ((trapno == 3) || (trapno == 1)) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 537 | save_v86_state(regs, VM86_TRAP + (trapno << 8)); |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 538 | return 0; |
| 539 | } |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 540 | 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] | 541 | return 0; |
| 542 | } |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 543 | if (trapno != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | return 1; /* we let this handle by the calling routine */ |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 545 | current->thread.trap_nr = trapno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | current->thread.error_code = error_code; |
Roland McGrath | 0f54091 | 2008-03-17 02:21:08 -0700 | [diff] [blame] | 547 | force_sig(SIGTRAP, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | return 0; |
| 549 | } |
| 550 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 551 | void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | { |
| 553 | unsigned char opcode; |
| 554 | unsigned char __user *csp; |
| 555 | unsigned char __user *ssp; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 556 | unsigned short ip, sp, orig_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | int data32, pref_done; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 558 | struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | |
| 560 | #define CHECK_IF_IN_TRAP \ |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 561 | if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 562 | newflags |= X86_EFLAGS_TF |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 564 | orig_flags = *(unsigned short *)®s->pt.flags; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 565 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 566 | csp = (unsigned char __user *) (regs->pt.cs << 4); |
| 567 | ssp = (unsigned char __user *) (regs->pt.ss << 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | sp = SP(regs); |
| 569 | ip = IP(regs); |
| 570 | |
| 571 | data32 = 0; |
| 572 | pref_done = 0; |
| 573 | do { |
| 574 | switch (opcode = popb(csp, ip, simulate_sigsegv)) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 575 | case 0x66: /* 32-bit data */ data32 = 1; break; |
| 576 | case 0x67: /* 32-bit address */ break; |
| 577 | case 0x2e: /* CS */ break; |
| 578 | case 0x3e: /* DS */ break; |
| 579 | case 0x26: /* ES */ break; |
| 580 | case 0x36: /* SS */ break; |
| 581 | case 0x65: /* GS */ break; |
| 582 | case 0x64: /* FS */ break; |
| 583 | case 0xf2: /* repnz */ break; |
| 584 | case 0xf3: /* rep */ break; |
| 585 | default: pref_done = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | } |
| 587 | } while (!pref_done); |
| 588 | |
| 589 | switch (opcode) { |
| 590 | |
| 591 | /* pushf */ |
| 592 | case 0x9c: |
| 593 | if (data32) { |
| 594 | pushl(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 595 | SP(regs) -= 4; |
| 596 | } else { |
| 597 | pushw(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 598 | SP(regs) -= 2; |
| 599 | } |
| 600 | IP(regs) = ip; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 601 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | |
| 603 | /* popf */ |
| 604 | case 0x9d: |
| 605 | { |
| 606 | unsigned long newflags; |
| 607 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 608 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | SP(regs) += 4; |
| 610 | } else { |
| 611 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 612 | SP(regs) += 2; |
| 613 | } |
| 614 | IP(regs) = ip; |
| 615 | CHECK_IF_IN_TRAP; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 616 | if (data32) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | set_vflags_long(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 618 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | set_vflags_short(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 620 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 621 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | } |
| 623 | |
| 624 | /* int xx */ |
| 625 | case 0xcd: { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 626 | int intno = popb(csp, ip, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | IP(regs) = ip; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 628 | if (vmpi->vm86dbg_active) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 629 | if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) { |
| 630 | save_v86_state(regs, VM86_INTx + (intno << 8)); |
| 631 | return; |
| 632 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | } |
| 634 | do_int(regs, intno, ssp, sp); |
| 635 | return; |
| 636 | } |
| 637 | |
| 638 | /* iret */ |
| 639 | case 0xcf: |
| 640 | { |
| 641 | unsigned long newip; |
| 642 | unsigned long newcs; |
| 643 | unsigned long newflags; |
| 644 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 645 | newip = popl(ssp, sp, simulate_sigsegv); |
| 646 | newcs = popl(ssp, sp, simulate_sigsegv); |
| 647 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | SP(regs) += 12; |
| 649 | } else { |
| 650 | newip = popw(ssp, sp, simulate_sigsegv); |
| 651 | newcs = popw(ssp, sp, simulate_sigsegv); |
| 652 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 653 | SP(regs) += 6; |
| 654 | } |
| 655 | IP(regs) = newip; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 656 | regs->pt.cs = newcs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | CHECK_IF_IN_TRAP; |
| 658 | if (data32) { |
| 659 | set_vflags_long(newflags, regs); |
| 660 | } else { |
| 661 | set_vflags_short(newflags, regs); |
| 662 | } |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 663 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | } |
| 665 | |
| 666 | /* cli */ |
| 667 | case 0xfa: |
| 668 | IP(regs) = ip; |
| 669 | clear_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 670 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
| 672 | /* sti */ |
| 673 | /* |
| 674 | * Damn. This is incorrect: the 'sti' instruction should actually |
| 675 | * enable interrupts after the /next/ instruction. Not good. |
| 676 | * |
| 677 | * Probably needs some horsing around with the TF flag. Aiee.. |
| 678 | */ |
| 679 | case 0xfb: |
| 680 | IP(regs) = ip; |
| 681 | set_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 682 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | |
| 684 | default: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 685 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | } |
| 687 | |
| 688 | return; |
| 689 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 690 | check_vip: |
| 691 | if (VEFLAGS & X86_EFLAGS_VIP) { |
| 692 | save_v86_state(regs, VM86_STI); |
| 693 | return; |
| 694 | } |
| 695 | |
| 696 | vm86_fault_return: |
| 697 | if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) { |
| 698 | save_v86_state(regs, VM86_PICRETURN); |
| 699 | return; |
| 700 | } |
| 701 | if (orig_flags & X86_EFLAGS_TF) |
| 702 | handle_vm86_trap(regs, 0, X86_TRAP_DB); |
| 703 | return; |
| 704 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | simulate_sigsegv: |
| 706 | /* FIXME: After a long discussion with Stas we finally |
| 707 | * agreed, that this is wrong. Here we should |
| 708 | * really send a SIGSEGV to the user program. |
| 709 | * But how do we create the correct context? We |
| 710 | * are inside a general protection fault handler |
| 711 | * and has just returned from a page fault handler. |
| 712 | * The correct context for the signal handler |
| 713 | * should be a mixture of the two, but how do we |
| 714 | * get the information? [KD] |
| 715 | */ |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 716 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | } |
| 718 | |
| 719 | /* ---------------- vm86 special IRQ passing stuff ----------------- */ |
| 720 | |
| 721 | #define VM86_IRQNAME "vm86irq" |
| 722 | |
| 723 | static struct vm86_irqs { |
| 724 | struct task_struct *tsk; |
| 725 | int sig; |
| 726 | } vm86_irqs[16]; |
| 727 | |
| 728 | static DEFINE_SPINLOCK(irqbits_lock); |
| 729 | static int irqbits; |
| 730 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 731 | #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 733 | | (1 << SIGUNUSED)) |
| 734 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 735 | static irqreturn_t irq_handler(int intno, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | { |
| 737 | int irq_bit; |
| 738 | unsigned long flags; |
| 739 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 740 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | irq_bit = 1 << intno; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 742 | if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | goto out; |
| 744 | irqbits |= irq_bit; |
| 745 | if (vm86_irqs[intno].sig) |
| 746 | send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | /* |
| 748 | * IRQ will be re-enabled when user asks for the irq (whether |
| 749 | * polling or as a result of the signal) |
| 750 | */ |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 751 | disable_irq_nosync(intno); |
| 752 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | return IRQ_HANDLED; |
| 754 | |
| 755 | out: |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 756 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | return IRQ_NONE; |
| 758 | } |
| 759 | |
| 760 | static inline void free_vm86_irq(int irqnumber) |
| 761 | { |
| 762 | unsigned long flags; |
| 763 | |
| 764 | free_irq(irqnumber, NULL); |
| 765 | vm86_irqs[irqnumber].tsk = NULL; |
| 766 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 767 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | irqbits &= ~(1 << irqnumber); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 769 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | } |
| 771 | |
| 772 | void release_vm86_irqs(struct task_struct *task) |
| 773 | { |
| 774 | int i; |
| 775 | for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++) |
| 776 | if (vm86_irqs[i].tsk == task) |
| 777 | free_vm86_irq(i); |
| 778 | } |
| 779 | |
| 780 | static inline int get_and_reset_irq(int irqnumber) |
| 781 | { |
| 782 | int bit; |
| 783 | unsigned long flags; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 784 | int ret = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 785 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | if (invalid_vm86_irq(irqnumber)) return 0; |
| 787 | if (vm86_irqs[irqnumber].tsk != current) return 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 788 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 789 | bit = irqbits & (1 << irqnumber); |
| 790 | irqbits &= ~bit; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 791 | if (bit) { |
| 792 | enable_irq(irqnumber); |
| 793 | ret = 1; |
| 794 | } |
| 795 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 796 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 797 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | } |
| 799 | |
| 800 | |
| 801 | static int do_vm86_irq_handling(int subfunction, int irqnumber) |
| 802 | { |
| 803 | int ret; |
| 804 | switch (subfunction) { |
| 805 | case VM86_GET_AND_RESET_IRQ: { |
| 806 | return get_and_reset_irq(irqnumber); |
| 807 | } |
| 808 | case VM86_GET_IRQ_BITS: { |
| 809 | return irqbits; |
| 810 | } |
| 811 | case VM86_REQUEST_IRQ: { |
| 812 | int sig = irqnumber >> 8; |
| 813 | int irq = irqnumber & 255; |
| 814 | if (!capable(CAP_SYS_ADMIN)) return -EPERM; |
| 815 | if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM; |
| 816 | if (invalid_vm86_irq(irq)) return -EPERM; |
| 817 | if (vm86_irqs[irq].tsk) return -EPERM; |
| 818 | ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL); |
| 819 | if (ret) return ret; |
| 820 | vm86_irqs[irq].sig = sig; |
| 821 | vm86_irqs[irq].tsk = current; |
| 822 | return irq; |
| 823 | } |
| 824 | case VM86_FREE_IRQ: { |
| 825 | if (invalid_vm86_irq(irqnumber)) return -EPERM; |
| 826 | if (!vm86_irqs[irqnumber].tsk) return 0; |
| 827 | if (vm86_irqs[irqnumber].tsk != current) return -EPERM; |
| 828 | free_vm86_irq(irqnumber); |
| 829 | return 0; |
| 830 | } |
| 831 | } |
| 832 | return -EINVAL; |
| 833 | } |
| 834 | |