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; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 101 | long err = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
| 103 | /* |
| 104 | * This gets called from entry.S with interrupts disabled, but |
| 105 | * from process context. Enable interrupts here, before trying |
| 106 | * to access user space. |
| 107 | */ |
| 108 | local_irq_enable(); |
| 109 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 110 | if (!vm86 || !vm86->user_vm86) { |
| 111 | pr_alert("no user_vm86: BAD\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | do_exit(SIGSEGV); |
| 113 | } |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 114 | set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->veflags_mask); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 115 | user = vm86->user_vm86; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 116 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 117 | if (!access_ok(VERIFY_WRITE, user, vm86->vm86plus.is_vm86pus ? |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 118 | sizeof(struct vm86plus_struct) : |
| 119 | sizeof(struct vm86_struct))) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 120 | pr_alert("could not access userspace vm86 info\n"); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 121 | do_exit(SIGSEGV); |
| 122 | } |
| 123 | |
| 124 | put_user_try { |
| 125 | put_user_ex(regs->pt.bx, &user->regs.ebx); |
| 126 | put_user_ex(regs->pt.cx, &user->regs.ecx); |
| 127 | put_user_ex(regs->pt.dx, &user->regs.edx); |
| 128 | put_user_ex(regs->pt.si, &user->regs.esi); |
| 129 | put_user_ex(regs->pt.di, &user->regs.edi); |
| 130 | put_user_ex(regs->pt.bp, &user->regs.ebp); |
| 131 | put_user_ex(regs->pt.ax, &user->regs.eax); |
| 132 | put_user_ex(regs->pt.ip, &user->regs.eip); |
| 133 | put_user_ex(regs->pt.cs, &user->regs.cs); |
| 134 | put_user_ex(regs->pt.flags, &user->regs.eflags); |
| 135 | put_user_ex(regs->pt.sp, &user->regs.esp); |
| 136 | put_user_ex(regs->pt.ss, &user->regs.ss); |
| 137 | put_user_ex(regs->es, &user->regs.es); |
| 138 | put_user_ex(regs->ds, &user->regs.ds); |
| 139 | put_user_ex(regs->fs, &user->regs.fs); |
| 140 | put_user_ex(regs->gs, &user->regs.gs); |
| 141 | |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 142 | put_user_ex(vm86->screen_bitmap, &user->screen_bitmap); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 143 | } put_user_catch(err); |
| 144 | if (err) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 145 | pr_alert("could not access userspace vm86 info\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | do_exit(SIGSEGV); |
| 147 | } |
| 148 | |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 149 | preempt_disable(); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 150 | tsk->thread.sp0 = vm86->saved_sp0; |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 151 | tsk->thread.sysenter_cs = __KERNEL_CS; |
Andy Lutomirski | 46f5a10 | 2017-11-02 00:59:14 -0700 | [diff] [blame] | 152 | update_sp0(tsk); |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 153 | refresh_sysenter_cs(&tsk->thread); |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 154 | vm86->saved_sp0 = 0; |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 155 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 157 | memcpy(®s->pt, &vm86->regs32, sizeof(struct pt_regs)); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 158 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 159 | lazy_load_gs(vm86->regs32.gs); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 160 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 161 | regs->pt.ax = retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | } |
| 163 | |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 164 | static void mark_screen_rdonly(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | { |
Kirill A. Shutemov | 3ba5b5e | 2017-02-13 15:52:28 +0300 | [diff] [blame] | 166 | struct vm_area_struct *vma; |
| 167 | spinlock_t *ptl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | pgd_t *pgd; |
Kirill A. Shutemov | e0c4f67 | 2017-03-13 17:33:05 +0300 | [diff] [blame] | 169 | p4d_t *p4d; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | pud_t *pud; |
| 171 | pmd_t *pmd; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 172 | pte_t *pte; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | int i; |
| 174 | |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 175 | down_write(&mm->mmap_sem); |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 176 | pgd = pgd_offset(mm, 0xA0000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | if (pgd_none_or_clear_bad(pgd)) |
| 178 | goto out; |
Kirill A. Shutemov | e0c4f67 | 2017-03-13 17:33:05 +0300 | [diff] [blame] | 179 | p4d = p4d_offset(pgd, 0xA0000); |
| 180 | if (p4d_none_or_clear_bad(p4d)) |
| 181 | goto out; |
| 182 | pud = pud_offset(p4d, 0xA0000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | if (pud_none_or_clear_bad(pud)) |
| 184 | goto out; |
| 185 | pmd = pmd_offset(pud, 0xA0000); |
Kirill A. Shutemov | 78ddc53 | 2016-01-15 16:52:42 -0800 | [diff] [blame] | 186 | |
| 187 | if (pmd_trans_huge(*pmd)) { |
Kirill A. Shutemov | 3ba5b5e | 2017-02-13 15:52:28 +0300 | [diff] [blame] | 188 | vma = find_vma(mm, 0xA0000); |
Kirill A. Shutemov | 78ddc53 | 2016-01-15 16:52:42 -0800 | [diff] [blame] | 189 | split_huge_pmd(vma, pmd, 0xA0000); |
| 190 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | if (pmd_none_or_clear_bad(pmd)) |
| 192 | goto out; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 193 | pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | for (i = 0; i < 32; i++) { |
| 195 | if (pte_present(*pte)) |
| 196 | set_pte(pte, pte_wrprotect(*pte)); |
| 197 | pte++; |
| 198 | } |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 199 | pte_unmap_unlock(pte, ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | out: |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 201 | up_write(&mm->mmap_sem); |
Andy Lutomirski | 9ccee23 | 2017-04-22 00:01:19 -0700 | [diff] [blame] | 202 | flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, 0UL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | } |
| 204 | |
| 205 | |
| 206 | |
| 207 | static int do_vm86_irq_handling(int subfunction, int irqnumber); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 208 | 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] | 209 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 210 | SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, user_vm86) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 212 | return do_sys_vm86((struct vm86plus_struct __user *) user_vm86, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | } |
| 214 | |
| 215 | |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 216 | SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | { |
Brian Gerst | f1382f1 | 2009-12-09 19:01:55 -0500 | [diff] [blame] | 218 | switch (cmd) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 219 | case VM86_REQUEST_IRQ: |
| 220 | case VM86_FREE_IRQ: |
| 221 | case VM86_GET_IRQ_BITS: |
| 222 | case VM86_GET_AND_RESET_IRQ: |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 223 | return do_vm86_irq_handling(cmd, (int)arg); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 224 | case VM86_PLUS_INSTALL_CHECK: |
| 225 | /* |
| 226 | * NOTE: on old vm86 stuff this will return the error |
| 227 | * from access_ok(), because the subfunction is |
| 228 | * interpreted as (invalid) address to vm86_struct. |
| 229 | * So the installation check works. |
| 230 | */ |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 231 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | } |
| 233 | |
| 234 | /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 235 | return do_sys_vm86((struct vm86plus_struct __user *) arg, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | } |
| 237 | |
| 238 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 239 | 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] | 240 | { |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 241 | struct task_struct *tsk = current; |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 242 | struct vm86 *vm86 = tsk->thread.vm86; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 243 | struct kernel_vm86_regs vm86regs; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 244 | struct pt_regs *regs = current_pt_regs(); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 245 | unsigned long err = 0; |
| 246 | |
Andy Lutomirski | 76fc5e7 | 2015-09-04 17:00:43 -0700 | [diff] [blame] | 247 | err = security_mmap_addr(0); |
| 248 | if (err) { |
| 249 | /* |
| 250 | * vm86 cannot virtualize the address space, so vm86 users |
| 251 | * need to manage the low 1MB themselves using mmap. Given |
| 252 | * that BIOS places important data in the first page, vm86 |
| 253 | * is essentially useless if mmap_min_addr != 0. DOSEMU, |
| 254 | * for example, won't even bother trying to use vm86 if it |
| 255 | * can't map a page at virtual address 0. |
| 256 | * |
| 257 | * To reduce the available kernel attack surface, simply |
| 258 | * disallow vm86(old) for users who cannot mmap at va 0. |
| 259 | * |
| 260 | * The implementation of security_mmap_addr will allow |
| 261 | * suitably privileged users to map va 0 even if |
| 262 | * vm.mmap_min_addr is set above 0, and we want this |
| 263 | * behavior for vm86 as well, as it ensures that legacy |
| 264 | * tools like vbetool will not fail just because of |
| 265 | * vm.mmap_min_addr. |
| 266 | */ |
| 267 | 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", |
| 268 | current->comm, task_pid_nr(current), |
| 269 | from_kuid_munged(&init_user_ns, current_uid())); |
| 270 | return -EPERM; |
| 271 | } |
| 272 | |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 273 | if (!vm86) { |
| 274 | if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL))) |
| 275 | return -ENOMEM; |
| 276 | tsk->thread.vm86 = vm86; |
| 277 | } |
| 278 | if (vm86->saved_sp0) |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 279 | return -EPERM; |
| 280 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 281 | if (!access_ok(VERIFY_READ, user_vm86, plus ? |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 282 | sizeof(struct vm86_struct) : |
| 283 | sizeof(struct vm86plus_struct))) |
| 284 | return -EFAULT; |
| 285 | |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 286 | memset(&vm86regs, 0, sizeof(vm86regs)); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 287 | get_user_try { |
| 288 | unsigned short seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 289 | get_user_ex(vm86regs.pt.bx, &user_vm86->regs.ebx); |
| 290 | get_user_ex(vm86regs.pt.cx, &user_vm86->regs.ecx); |
| 291 | get_user_ex(vm86regs.pt.dx, &user_vm86->regs.edx); |
| 292 | get_user_ex(vm86regs.pt.si, &user_vm86->regs.esi); |
| 293 | get_user_ex(vm86regs.pt.di, &user_vm86->regs.edi); |
| 294 | get_user_ex(vm86regs.pt.bp, &user_vm86->regs.ebp); |
| 295 | get_user_ex(vm86regs.pt.ax, &user_vm86->regs.eax); |
| 296 | get_user_ex(vm86regs.pt.ip, &user_vm86->regs.eip); |
| 297 | get_user_ex(seg, &user_vm86->regs.cs); |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 298 | vm86regs.pt.cs = seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 299 | get_user_ex(vm86regs.pt.flags, &user_vm86->regs.eflags); |
| 300 | get_user_ex(vm86regs.pt.sp, &user_vm86->regs.esp); |
| 301 | get_user_ex(seg, &user_vm86->regs.ss); |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 302 | vm86regs.pt.ss = seg; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 303 | get_user_ex(vm86regs.es, &user_vm86->regs.es); |
| 304 | get_user_ex(vm86regs.ds, &user_vm86->regs.ds); |
| 305 | get_user_ex(vm86regs.fs, &user_vm86->regs.fs); |
| 306 | get_user_ex(vm86regs.gs, &user_vm86->regs.gs); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 307 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 308 | get_user_ex(vm86->flags, &user_vm86->flags); |
| 309 | get_user_ex(vm86->screen_bitmap, &user_vm86->screen_bitmap); |
| 310 | get_user_ex(vm86->cpu_type, &user_vm86->cpu_type); |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 311 | } get_user_catch(err); |
| 312 | if (err) |
| 313 | return err; |
| 314 | |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 315 | if (copy_from_user(&vm86->int_revectored, |
| 316 | &user_vm86->int_revectored, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 317 | sizeof(struct revectored_struct))) |
| 318 | return -EFAULT; |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 319 | if (copy_from_user(&vm86->int21_revectored, |
| 320 | &user_vm86->int21_revectored, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 321 | sizeof(struct revectored_struct))) |
| 322 | return -EFAULT; |
| 323 | if (plus) { |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 324 | if (copy_from_user(&vm86->vm86plus, &user_vm86->vm86plus, |
Brian Gerst | ed0b2ed | 2015-07-19 21:09:06 -0400 | [diff] [blame] | 325 | sizeof(struct vm86plus_info_struct))) |
| 326 | return -EFAULT; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 327 | vm86->vm86plus.is_vm86pus = 1; |
| 328 | } else |
| 329 | memset(&vm86->vm86plus, 0, |
| 330 | sizeof(struct vm86plus_info_struct)); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 331 | |
| 332 | memcpy(&vm86->regs32, regs, sizeof(struct pt_regs)); |
Brian Gerst | 1342635 | 2015-07-29 01:41:22 -0400 | [diff] [blame] | 333 | vm86->user_vm86 = user_vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | |
| 335 | /* |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 336 | * The flags register is also special: we cannot trust that the user |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | * has set it up safely, so this makes sure interrupt etc flags are |
| 338 | * inherited from protected mode. |
| 339 | */ |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 340 | VEFLAGS = vm86regs.pt.flags; |
| 341 | vm86regs.pt.flags &= SAFE_MASK; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 342 | vm86regs.pt.flags |= regs->flags & ~SAFE_MASK; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 343 | vm86regs.pt.flags |= X86_VM_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 345 | vm86regs.pt.orig_ax = regs->orig_ax; |
Brian Gerst | df1ae9a | 2015-07-19 21:09:05 -0400 | [diff] [blame] | 346 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 347 | switch (vm86->cpu_type) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 348 | case CPU_286: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 349 | vm86->veflags_mask = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 350 | break; |
| 351 | case CPU_386: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 352 | vm86->veflags_mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 353 | break; |
| 354 | case CPU_486: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 355 | vm86->veflags_mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 356 | break; |
| 357 | default: |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 358 | 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] | 359 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | } |
| 361 | |
| 362 | /* |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 363 | * Save old state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | */ |
Brian Gerst | 9fda6a0 | 2015-07-29 01:41:16 -0400 | [diff] [blame] | 365 | vm86->saved_sp0 = tsk->thread.sp0; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 366 | lazy_save_gs(vm86->regs32.gs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 368 | /* make room for real-mode segments */ |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 369 | preempt_disable(); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 370 | tsk->thread.sp0 += 16; |
Borislav Petkov | 362f924 | 2015-12-07 10:39:41 +0100 | [diff] [blame] | 371 | |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 372 | if (static_cpu_has(X86_FEATURE_SEP)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | tsk->thread.sysenter_cs = 0; |
Andy Lutomirski | bd7dc5a | 2017-11-02 00:59:09 -0700 | [diff] [blame] | 374 | refresh_sysenter_cs(&tsk->thread); |
| 375 | } |
Borislav Petkov | 362f924 | 2015-12-07 10:39:41 +0100 | [diff] [blame] | 376 | |
Andy Lutomirski | 46f5a10 | 2017-11-02 00:59:14 -0700 | [diff] [blame] | 377 | update_sp0(tsk); |
Andy Lutomirski | da51da1 | 2017-11-02 00:59:10 -0700 | [diff] [blame] | 378 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 380 | if (vm86->flags & VM86_SCREEN_BITMAP) |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 381 | mark_screen_rdonly(tsk->mm); |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 382 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 383 | memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs)); |
| 384 | force_iret(); |
| 385 | return regs->ax; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | } |
| 387 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 388 | static inline void set_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 390 | VEFLAGS |= X86_EFLAGS_VIF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | } |
| 392 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 393 | static inline void clear_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 395 | VEFLAGS &= ~X86_EFLAGS_VIF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | } |
| 397 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 398 | static inline void clear_TF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 400 | regs->pt.flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
| 402 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 403 | static inline void clear_AC(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 405 | regs->pt.flags &= ~X86_EFLAGS_AC; |
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 | /* |
| 409 | * It is correct to call set_IF(regs) from the set_vflags_* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | * functions. However someone forgot to call clear_IF(regs) |
| 411 | * in the opposite case. |
| 412 | * After the command sequence CLI PUSHF STI POPF you should |
Joe Perches | ab4a574 | 2008-01-30 13:31:42 +0100 | [diff] [blame] | 413 | * end up with interrupts disabled, but you ended up with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | * interrupts enabled. |
| 415 | * ( I was testing my own changes, but the only bug I |
| 416 | * could find was in a function I had not changed. ) |
| 417 | * [KD] |
| 418 | */ |
| 419 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 420 | 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] | 421 | { |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 422 | set_flags(VEFLAGS, flags, current->thread.vm86->veflags_mask); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 423 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 424 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | set_IF(regs); |
| 426 | else |
| 427 | clear_IF(regs); |
| 428 | } |
| 429 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 430 | 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] | 431 | { |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 432 | set_flags(VFLAGS, flags, current->thread.vm86->veflags_mask); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 433 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 434 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | set_IF(regs); |
| 436 | else |
| 437 | clear_IF(regs); |
| 438 | } |
| 439 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 440 | static inline unsigned long get_vflags(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | { |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 442 | unsigned long flags = regs->pt.flags & RETURN_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 444 | if (VEFLAGS & X86_EFLAGS_VIF) |
| 445 | flags |= X86_EFLAGS_IF; |
| 446 | flags |= X86_EFLAGS_IOPL; |
Brian Gerst | decd275 | 2015-07-29 01:41:23 -0400 | [diff] [blame] | 447 | return flags | (VEFLAGS & current->thread.vm86->veflags_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | } |
| 449 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 450 | static inline int is_revectored(int nr, struct revectored_struct *bitmap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | { |
H. Peter Anvin | 2823d4d | 2016-06-08 12:38:37 -0700 | [diff] [blame] | 452 | return test_bit(nr, bitmap->__map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | } |
| 454 | |
| 455 | #define val_byte(val, n) (((__u8 *)&val)[n]) |
| 456 | |
| 457 | #define pushb(base, ptr, val, err_label) \ |
| 458 | do { \ |
| 459 | __u8 __val = val; \ |
| 460 | ptr--; \ |
| 461 | if (put_user(__val, base + ptr) < 0) \ |
| 462 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 463 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | |
| 465 | #define pushw(base, ptr, val, err_label) \ |
| 466 | do { \ |
| 467 | __u16 __val = val; \ |
| 468 | ptr--; \ |
| 469 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 470 | goto err_label; \ |
| 471 | ptr--; \ |
| 472 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 473 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 474 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | |
| 476 | #define pushl(base, ptr, val, err_label) \ |
| 477 | do { \ |
| 478 | __u32 __val = val; \ |
| 479 | ptr--; \ |
| 480 | if (put_user(val_byte(__val, 3), base + ptr) < 0) \ |
| 481 | goto err_label; \ |
| 482 | ptr--; \ |
| 483 | if (put_user(val_byte(__val, 2), base + ptr) < 0) \ |
| 484 | goto err_label; \ |
| 485 | ptr--; \ |
| 486 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 487 | goto err_label; \ |
| 488 | ptr--; \ |
| 489 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 490 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 491 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | |
| 493 | #define popb(base, ptr, err_label) \ |
| 494 | ({ \ |
| 495 | __u8 __res; \ |
| 496 | if (get_user(__res, base + ptr) < 0) \ |
| 497 | goto err_label; \ |
| 498 | ptr++; \ |
| 499 | __res; \ |
| 500 | }) |
| 501 | |
| 502 | #define popw(base, ptr, err_label) \ |
| 503 | ({ \ |
| 504 | __u16 __res; \ |
| 505 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 506 | goto err_label; \ |
| 507 | ptr++; \ |
| 508 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 509 | goto err_label; \ |
| 510 | ptr++; \ |
| 511 | __res; \ |
| 512 | }) |
| 513 | |
| 514 | #define popl(base, ptr, err_label) \ |
| 515 | ({ \ |
| 516 | __u32 __res; \ |
| 517 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 518 | goto err_label; \ |
| 519 | ptr++; \ |
| 520 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 521 | goto err_label; \ |
| 522 | ptr++; \ |
| 523 | if (get_user(val_byte(__res, 2), base + ptr) < 0) \ |
| 524 | goto err_label; \ |
| 525 | ptr++; \ |
| 526 | if (get_user(val_byte(__res, 3), base + ptr) < 0) \ |
| 527 | goto err_label; \ |
| 528 | ptr++; \ |
| 529 | __res; \ |
| 530 | }) |
| 531 | |
| 532 | /* There are so many possible reasons for this function to return |
| 533 | * VM86_INTx, so adding another doesn't bother me. We can expect |
| 534 | * userspace programs to be able to handle it. (Getting a problem |
| 535 | * in userspace is always better than an Oops anyway.) [KD] |
| 536 | */ |
| 537 | static void do_int(struct kernel_vm86_regs *regs, int i, |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 538 | unsigned char __user *ssp, unsigned short sp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | { |
| 540 | unsigned long __user *intr_ptr; |
| 541 | unsigned long segoffs; |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 542 | struct vm86 *vm86 = current->thread.vm86; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 544 | if (regs->pt.cs == BIOSSEG) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 546 | if (is_revectored(i, &vm86->int_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | goto cannot_handle; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 548 | if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | goto cannot_handle; |
| 550 | intr_ptr = (unsigned long __user *) (i << 2); |
| 551 | if (get_user(segoffs, intr_ptr)) |
| 552 | goto cannot_handle; |
| 553 | if ((segoffs >> 16) == BIOSSEG) |
| 554 | goto cannot_handle; |
| 555 | pushw(ssp, sp, get_vflags(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 556 | pushw(ssp, sp, regs->pt.cs, cannot_handle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | pushw(ssp, sp, IP(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 558 | regs->pt.cs = segoffs >> 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | SP(regs) -= 6; |
| 560 | IP(regs) = segoffs & 0xffff; |
| 561 | clear_TF(regs); |
| 562 | clear_IF(regs); |
| 563 | clear_AC(regs); |
| 564 | return; |
| 565 | |
| 566 | cannot_handle: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 567 | save_v86_state(regs, VM86_INTx + (i << 8)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | } |
| 569 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 570 | 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] | 571 | { |
Brian Gerst | 90c6085 | 2015-07-29 01:41:18 -0400 | [diff] [blame] | 572 | struct vm86 *vm86 = current->thread.vm86; |
| 573 | |
| 574 | if (vm86->vm86plus.is_vm86pus) { |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 575 | if ((trapno == 3) || (trapno == 1)) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 576 | save_v86_state(regs, VM86_TRAP + (trapno << 8)); |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 577 | return 0; |
| 578 | } |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 579 | 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] | 580 | return 0; |
| 581 | } |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 582 | if (trapno != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | return 1; /* we let this handle by the calling routine */ |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 584 | current->thread.trap_nr = trapno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | current->thread.error_code = error_code; |
Roland McGrath | 0f54091 | 2008-03-17 02:21:08 -0700 | [diff] [blame] | 586 | force_sig(SIGTRAP, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | return 0; |
| 588 | } |
| 589 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 590 | void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | { |
| 592 | unsigned char opcode; |
| 593 | unsigned char __user *csp; |
| 594 | unsigned char __user *ssp; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 595 | unsigned short ip, sp, orig_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | int data32, pref_done; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 597 | struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | |
| 599 | #define CHECK_IF_IN_TRAP \ |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 600 | if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 601 | newflags |= X86_EFLAGS_TF |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 603 | orig_flags = *(unsigned short *)®s->pt.flags; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 604 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 605 | csp = (unsigned char __user *) (regs->pt.cs << 4); |
| 606 | ssp = (unsigned char __user *) (regs->pt.ss << 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | sp = SP(regs); |
| 608 | ip = IP(regs); |
| 609 | |
| 610 | data32 = 0; |
| 611 | pref_done = 0; |
| 612 | do { |
| 613 | switch (opcode = popb(csp, ip, simulate_sigsegv)) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 614 | case 0x66: /* 32-bit data */ data32 = 1; break; |
| 615 | case 0x67: /* 32-bit address */ break; |
| 616 | case 0x2e: /* CS */ break; |
| 617 | case 0x3e: /* DS */ break; |
| 618 | case 0x26: /* ES */ break; |
| 619 | case 0x36: /* SS */ break; |
| 620 | case 0x65: /* GS */ break; |
| 621 | case 0x64: /* FS */ break; |
| 622 | case 0xf2: /* repnz */ break; |
| 623 | case 0xf3: /* rep */ break; |
| 624 | default: pref_done = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | } |
| 626 | } while (!pref_done); |
| 627 | |
| 628 | switch (opcode) { |
| 629 | |
| 630 | /* pushf */ |
| 631 | case 0x9c: |
| 632 | if (data32) { |
| 633 | pushl(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 634 | SP(regs) -= 4; |
| 635 | } else { |
| 636 | pushw(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 637 | SP(regs) -= 2; |
| 638 | } |
| 639 | IP(regs) = ip; |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 640 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | |
| 642 | /* popf */ |
| 643 | case 0x9d: |
| 644 | { |
| 645 | unsigned long newflags; |
| 646 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 647 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | SP(regs) += 4; |
| 649 | } else { |
| 650 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 651 | SP(regs) += 2; |
| 652 | } |
| 653 | IP(regs) = ip; |
| 654 | CHECK_IF_IN_TRAP; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 655 | if (data32) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | set_vflags_long(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 657 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | set_vflags_short(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 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 | /* int xx */ |
| 664 | case 0xcd: { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 665 | int intno = popb(csp, ip, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | IP(regs) = ip; |
Brian Gerst | d4ce0f2 | 2015-07-29 01:41:17 -0400 | [diff] [blame] | 667 | if (vmpi->vm86dbg_active) { |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 668 | if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) { |
| 669 | save_v86_state(regs, VM86_INTx + (intno << 8)); |
| 670 | return; |
| 671 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | } |
| 673 | do_int(regs, intno, ssp, sp); |
| 674 | return; |
| 675 | } |
| 676 | |
| 677 | /* iret */ |
| 678 | case 0xcf: |
| 679 | { |
| 680 | unsigned long newip; |
| 681 | unsigned long newcs; |
| 682 | unsigned long newflags; |
| 683 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 684 | newip = popl(ssp, sp, simulate_sigsegv); |
| 685 | newcs = popl(ssp, sp, simulate_sigsegv); |
| 686 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | SP(regs) += 12; |
| 688 | } else { |
| 689 | newip = popw(ssp, sp, simulate_sigsegv); |
| 690 | newcs = popw(ssp, sp, simulate_sigsegv); |
| 691 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 692 | SP(regs) += 6; |
| 693 | } |
| 694 | IP(regs) = newip; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 695 | regs->pt.cs = newcs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | CHECK_IF_IN_TRAP; |
| 697 | if (data32) { |
| 698 | set_vflags_long(newflags, regs); |
| 699 | } else { |
| 700 | set_vflags_short(newflags, regs); |
| 701 | } |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 702 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | } |
| 704 | |
| 705 | /* cli */ |
| 706 | case 0xfa: |
| 707 | IP(regs) = ip; |
| 708 | clear_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 709 | goto vm86_fault_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | /* sti */ |
| 712 | /* |
| 713 | * Damn. This is incorrect: the 'sti' instruction should actually |
| 714 | * enable interrupts after the /next/ instruction. Not good. |
| 715 | * |
| 716 | * Probably needs some horsing around with the TF flag. Aiee.. |
| 717 | */ |
| 718 | case 0xfb: |
| 719 | IP(regs) = ip; |
| 720 | set_IF(regs); |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 721 | goto check_vip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | |
| 723 | default: |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 724 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | } |
| 726 | |
| 727 | return; |
| 728 | |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 729 | check_vip: |
| 730 | if (VEFLAGS & X86_EFLAGS_VIP) { |
| 731 | save_v86_state(regs, VM86_STI); |
| 732 | return; |
| 733 | } |
| 734 | |
| 735 | vm86_fault_return: |
| 736 | if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) { |
| 737 | save_v86_state(regs, VM86_PICRETURN); |
| 738 | return; |
| 739 | } |
| 740 | if (orig_flags & X86_EFLAGS_TF) |
| 741 | handle_vm86_trap(regs, 0, X86_TRAP_DB); |
| 742 | return; |
| 743 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | simulate_sigsegv: |
| 745 | /* FIXME: After a long discussion with Stas we finally |
| 746 | * agreed, that this is wrong. Here we should |
| 747 | * really send a SIGSEGV to the user program. |
| 748 | * But how do we create the correct context? We |
| 749 | * are inside a general protection fault handler |
| 750 | * and has just returned from a page fault handler. |
| 751 | * The correct context for the signal handler |
| 752 | * should be a mixture of the two, but how do we |
| 753 | * get the information? [KD] |
| 754 | */ |
Brian Gerst | 5ed92a8 | 2015-07-29 01:41:19 -0400 | [diff] [blame] | 755 | save_v86_state(regs, VM86_UNKNOWN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | } |
| 757 | |
| 758 | /* ---------------- vm86 special IRQ passing stuff ----------------- */ |
| 759 | |
| 760 | #define VM86_IRQNAME "vm86irq" |
| 761 | |
| 762 | static struct vm86_irqs { |
| 763 | struct task_struct *tsk; |
| 764 | int sig; |
| 765 | } vm86_irqs[16]; |
| 766 | |
| 767 | static DEFINE_SPINLOCK(irqbits_lock); |
| 768 | static int irqbits; |
| 769 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 770 | #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 772 | | (1 << SIGUNUSED)) |
| 773 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 774 | static irqreturn_t irq_handler(int intno, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | { |
| 776 | int irq_bit; |
| 777 | unsigned long flags; |
| 778 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 779 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | irq_bit = 1 << intno; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 781 | if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | goto out; |
| 783 | irqbits |= irq_bit; |
| 784 | if (vm86_irqs[intno].sig) |
| 785 | send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | /* |
| 787 | * IRQ will be re-enabled when user asks for the irq (whether |
| 788 | * polling or as a result of the signal) |
| 789 | */ |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 790 | disable_irq_nosync(intno); |
| 791 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | return IRQ_HANDLED; |
| 793 | |
| 794 | out: |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 795 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | return IRQ_NONE; |
| 797 | } |
| 798 | |
| 799 | static inline void free_vm86_irq(int irqnumber) |
| 800 | { |
| 801 | unsigned long flags; |
| 802 | |
| 803 | free_irq(irqnumber, NULL); |
| 804 | vm86_irqs[irqnumber].tsk = NULL; |
| 805 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 806 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | irqbits &= ~(1 << irqnumber); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 808 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | } |
| 810 | |
| 811 | void release_vm86_irqs(struct task_struct *task) |
| 812 | { |
| 813 | int i; |
| 814 | for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++) |
| 815 | if (vm86_irqs[i].tsk == task) |
| 816 | free_vm86_irq(i); |
| 817 | } |
| 818 | |
| 819 | static inline int get_and_reset_irq(int irqnumber) |
| 820 | { |
| 821 | int bit; |
| 822 | unsigned long flags; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 823 | int ret = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 824 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | if (invalid_vm86_irq(irqnumber)) return 0; |
| 826 | if (vm86_irqs[irqnumber].tsk != current) return 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 827 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | bit = irqbits & (1 << irqnumber); |
| 829 | irqbits &= ~bit; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 830 | if (bit) { |
| 831 | enable_irq(irqnumber); |
| 832 | ret = 1; |
| 833 | } |
| 834 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 835 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 836 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | } |
| 838 | |
| 839 | |
| 840 | static int do_vm86_irq_handling(int subfunction, int irqnumber) |
| 841 | { |
| 842 | int ret; |
| 843 | switch (subfunction) { |
| 844 | case VM86_GET_AND_RESET_IRQ: { |
| 845 | return get_and_reset_irq(irqnumber); |
| 846 | } |
| 847 | case VM86_GET_IRQ_BITS: { |
| 848 | return irqbits; |
| 849 | } |
| 850 | case VM86_REQUEST_IRQ: { |
| 851 | int sig = irqnumber >> 8; |
| 852 | int irq = irqnumber & 255; |
| 853 | if (!capable(CAP_SYS_ADMIN)) return -EPERM; |
| 854 | if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM; |
| 855 | if (invalid_vm86_irq(irq)) return -EPERM; |
| 856 | if (vm86_irqs[irq].tsk) return -EPERM; |
| 857 | ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL); |
| 858 | if (ret) return ret; |
| 859 | vm86_irqs[irq].sig = sig; |
| 860 | vm86_irqs[irq].tsk = current; |
| 861 | return irq; |
| 862 | } |
| 863 | case VM86_FREE_IRQ: { |
| 864 | if (invalid_vm86_irq(irqnumber)) return -EPERM; |
| 865 | if (!vm86_irqs[irqnumber].tsk) return 0; |
| 866 | if (vm86_irqs[irqnumber].tsk != current) return -EPERM; |
| 867 | free_vm86_irq(irqnumber); |
| 868 | return 0; |
| 869 | } |
| 870 | } |
| 871 | return -EINVAL; |
| 872 | } |
| 873 | |