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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | #include <asm/uaccess.h> |
| 49 | #include <asm/io.h> |
| 50 | #include <asm/tlbflush.h> |
| 51 | #include <asm/irq.h> |
| 52 | |
| 53 | /* |
| 54 | * Known problems: |
| 55 | * |
| 56 | * Interrupt handling is not guaranteed: |
| 57 | * - a real x86 will disable all interrupts for one instruction |
| 58 | * after a "mov ss,xx" to make stack handling atomic even without |
| 59 | * the 'lss' instruction. We can't guarantee this in v86 mode, |
| 60 | * as the next instruction might result in a page fault or similar. |
| 61 | * - a real x86 will have interrupts disabled for one instruction |
| 62 | * past the 'sti' that enables them. We don't bother with all the |
| 63 | * details yet. |
| 64 | * |
| 65 | * Let's hope these problems do not actually matter for anything. |
| 66 | */ |
| 67 | |
| 68 | |
| 69 | #define KVM86 ((struct kernel_vm86_struct *)regs) |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 70 | #define VMPI KVM86->vm86plus |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
| 72 | |
| 73 | /* |
| 74 | * 8- and 16-bit register defines.. |
| 75 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 76 | #define AL(regs) (((unsigned char *)&((regs)->pt.ax))[0]) |
| 77 | #define AH(regs) (((unsigned char *)&((regs)->pt.ax))[1]) |
| 78 | #define IP(regs) (*(unsigned short *)&((regs)->pt.ip)) |
| 79 | #define SP(regs) (*(unsigned short *)&((regs)->pt.sp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
| 81 | /* |
| 82 | * virtual flags (16 and 32-bit versions) |
| 83 | */ |
| 84 | #define VFLAGS (*(unsigned short *)&(current->thread.v86flags)) |
| 85 | #define VEFLAGS (current->thread.v86flags) |
| 86 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 87 | #define set_flags(X, new, mask) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | ((X) = ((X) & ~(mask)) | ((new) & (mask))) |
| 89 | |
| 90 | #define SAFE_MASK (0xDD5) |
| 91 | #define RETURN_MASK (0xDFF) |
| 92 | |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 93 | /* convert kernel_vm86_regs to vm86_regs */ |
| 94 | static int copy_vm86_regs_to_user(struct vm86_regs __user *user, |
| 95 | const struct kernel_vm86_regs *regs) |
| 96 | { |
| 97 | int ret = 0; |
| 98 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 99 | /* |
| 100 | * kernel_vm86_regs is missing gs, so copy everything up to |
| 101 | * (but not including) orig_eax, and then rest including orig_eax. |
| 102 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 103 | ret += copy_to_user(user, regs, offsetof(struct kernel_vm86_regs, pt.orig_ax)); |
| 104 | ret += copy_to_user(&user->orig_eax, ®s->pt.orig_ax, |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 105 | sizeof(struct kernel_vm86_regs) - |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 106 | offsetof(struct kernel_vm86_regs, pt.orig_ax)); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 107 | |
| 108 | return ret; |
| 109 | } |
| 110 | |
| 111 | /* convert vm86_regs to kernel_vm86_regs */ |
| 112 | static int copy_vm86_regs_from_user(struct kernel_vm86_regs *regs, |
| 113 | const struct vm86_regs __user *user, |
| 114 | unsigned extra) |
| 115 | { |
| 116 | int ret = 0; |
| 117 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 118 | /* copy ax-fs inclusive */ |
| 119 | ret += copy_from_user(regs, user, offsetof(struct kernel_vm86_regs, pt.orig_ax)); |
| 120 | /* copy orig_ax-__gsh+extra */ |
| 121 | ret += copy_from_user(®s->pt.orig_ax, &user->orig_eax, |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 122 | sizeof(struct kernel_vm86_regs) - |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 123 | offsetof(struct kernel_vm86_regs, pt.orig_ax) + |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 124 | extra); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 125 | return ret; |
| 126 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 128 | struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | { |
| 130 | struct tss_struct *tss; |
| 131 | struct pt_regs *ret; |
| 132 | unsigned long tmp; |
| 133 | |
| 134 | /* |
| 135 | * This gets called from entry.S with interrupts disabled, but |
| 136 | * from process context. Enable interrupts here, before trying |
| 137 | * to access user space. |
| 138 | */ |
| 139 | local_irq_enable(); |
| 140 | |
| 141 | if (!current->thread.vm86_info) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 142 | pr_alert("no vm86_info: BAD\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | do_exit(SIGSEGV); |
| 144 | } |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 145 | set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | current->thread.v86mask); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 146 | tmp = copy_vm86_regs_to_user(¤t->thread.vm86_info->regs, regs); |
| 147 | tmp += put_user(current->thread.screen_bitmap, ¤t->thread.vm86_info->screen_bitmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | if (tmp) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 149 | pr_alert("could not access userspace vm86_info\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | do_exit(SIGSEGV); |
| 151 | } |
| 152 | |
| 153 | tss = &per_cpu(init_tss, get_cpu()); |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 154 | current->thread.sp0 = current->thread.saved_sp0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | current->thread.sysenter_cs = __KERNEL_CS; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 156 | load_sp0(tss, ¤t->thread); |
| 157 | current->thread.saved_sp0 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | put_cpu(); |
| 159 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | ret = KVM86->regs32; |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 161 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 162 | ret->fs = current->thread.saved_fs; |
Tejun Heo | d9a89a2 | 2009-02-09 22:17:40 +0900 | [diff] [blame] | 163 | set_user_gs(ret, current->thread.saved_gs); |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 164 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | return ret; |
| 166 | } |
| 167 | |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 168 | static void mark_screen_rdonly(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | { |
| 170 | pgd_t *pgd; |
| 171 | pud_t *pud; |
| 172 | pmd_t *pmd; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 173 | pte_t *pte; |
| 174 | spinlock_t *ptl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | int i; |
| 176 | |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 177 | down_write(&mm->mmap_sem); |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 178 | pgd = pgd_offset(mm, 0xA0000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | if (pgd_none_or_clear_bad(pgd)) |
| 180 | goto out; |
| 181 | pud = pud_offset(pgd, 0xA0000); |
| 182 | if (pud_none_or_clear_bad(pud)) |
| 183 | goto out; |
| 184 | pmd = pmd_offset(pud, 0xA0000); |
Kirill A. Shutemov | e180377 | 2012-12-12 13:50:59 -0800 | [diff] [blame] | 185 | split_huge_page_pmd_mm(mm, 0xA0000, pmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | if (pmd_none_or_clear_bad(pmd)) |
| 187 | goto out; |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 188 | pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | for (i = 0; i < 32; i++) { |
| 190 | if (pte_present(*pte)) |
| 191 | set_pte(pte, pte_wrprotect(*pte)); |
| 192 | pte++; |
| 193 | } |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 194 | pte_unmap_unlock(pte, ptl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | out: |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 196 | up_write(&mm->mmap_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | flush_tlb(); |
| 198 | } |
| 199 | |
| 200 | |
| 201 | |
| 202 | static int do_vm86_irq_handling(int subfunction, int irqnumber); |
| 203 | static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk); |
| 204 | |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 205 | SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | struct kernel_vm86_struct info; /* declare this _on top_, |
| 208 | * this avoids wasting of stack space. |
| 209 | * This remains on the stack until we |
| 210 | * return to 32 bit user space. |
| 211 | */ |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 212 | struct task_struct *tsk = current; |
| 213 | int tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 215 | if (tsk->thread.saved_sp0) |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 216 | return -EPERM; |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 217 | tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, |
| 218 | offsetof(struct kernel_vm86_struct, vm86plus) - |
| 219 | sizeof(info.regs)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | if (tmp) |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 221 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus); |
Al Viro | 49cb25e | 2012-11-12 14:38:28 -0500 | [diff] [blame] | 223 | info.regs32 = current_pt_regs(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | tsk->thread.vm86_info = v86; |
| 225 | do_sys_vm86(&info, tsk); |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 226 | return 0; /* we never return here */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | } |
| 228 | |
| 229 | |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 230 | SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | { |
| 232 | struct kernel_vm86_struct info; /* declare this _on top_, |
| 233 | * this avoids wasting of stack space. |
| 234 | * This remains on the stack until we |
| 235 | * return to 32 bit user space. |
| 236 | */ |
| 237 | struct task_struct *tsk; |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 238 | int tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | struct vm86plus_struct __user *v86; |
| 240 | |
| 241 | tsk = current; |
Brian Gerst | f1382f1 | 2009-12-09 19:01:55 -0500 | [diff] [blame] | 242 | switch (cmd) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 243 | case VM86_REQUEST_IRQ: |
| 244 | case VM86_FREE_IRQ: |
| 245 | case VM86_GET_IRQ_BITS: |
| 246 | case VM86_GET_AND_RESET_IRQ: |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 247 | return do_vm86_irq_handling(cmd, (int)arg); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 248 | case VM86_PLUS_INSTALL_CHECK: |
| 249 | /* |
| 250 | * NOTE: on old vm86 stuff this will return the error |
| 251 | * from access_ok(), because the subfunction is |
| 252 | * interpreted as (invalid) address to vm86_struct. |
| 253 | * So the installation check works. |
| 254 | */ |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 255 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
| 257 | |
| 258 | /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 259 | if (tsk->thread.saved_sp0) |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 260 | return -EPERM; |
Brian Gerst | f1382f1 | 2009-12-09 19:01:55 -0500 | [diff] [blame] | 261 | v86 = (struct vm86plus_struct __user *)arg; |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 262 | tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, |
| 263 | offsetof(struct kernel_vm86_struct, regs32) - |
| 264 | sizeof(info.regs)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | if (tmp) |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 266 | return -EFAULT; |
Al Viro | 49cb25e | 2012-11-12 14:38:28 -0500 | [diff] [blame] | 267 | info.regs32 = current_pt_regs(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | info.vm86plus.is_vm86pus = 1; |
| 269 | tsk->thread.vm86_info = (struct vm86_struct __user *)v86; |
| 270 | do_sys_vm86(&info, tsk); |
Alexander van Heukelum | 5522ddb | 2013-03-27 22:18:05 +0100 | [diff] [blame] | 271 | return 0; /* we never return here */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | } |
| 273 | |
| 274 | |
| 275 | static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk) |
| 276 | { |
| 277 | struct tss_struct *tss; |
| 278 | /* |
| 279 | * make sure the vm86() system call doesn't try to do anything silly |
| 280 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 281 | info->regs.pt.ds = 0; |
| 282 | info->regs.pt.es = 0; |
| 283 | info->regs.pt.fs = 0; |
Lubomir Rintel | 3aa6b18 | 2009-06-07 16:23:48 +0200 | [diff] [blame] | 284 | #ifndef CONFIG_X86_32_LAZY_GS |
| 285 | info->regs.pt.gs = 0; |
| 286 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
| 288 | /* |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 289 | * The flags register is also special: we cannot trust that the user |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | * has set it up safely, so this makes sure interrupt etc flags are |
| 291 | * inherited from protected mode. |
| 292 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 293 | VEFLAGS = info->regs.pt.flags; |
| 294 | info->regs.pt.flags &= SAFE_MASK; |
| 295 | info->regs.pt.flags |= info->regs32->flags & ~SAFE_MASK; |
gorcunov@gmail.com | 6b6891f | 2008-03-28 17:56:57 +0300 | [diff] [blame] | 296 | info->regs.pt.flags |= X86_VM_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | |
| 298 | switch (info->cpu_type) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 299 | case CPU_286: |
| 300 | tsk->thread.v86mask = 0; |
| 301 | break; |
| 302 | case CPU_386: |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 303 | tsk->thread.v86mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 304 | break; |
| 305 | case CPU_486: |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 306 | tsk->thread.v86mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 307 | break; |
| 308 | default: |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 309 | tsk->thread.v86mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 310 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | } |
| 312 | |
| 313 | /* |
Samuel Bronson | 975e5f4 | 2009-05-06 22:27:55 -0400 | [diff] [blame] | 314 | * Save old state, set default return value (%ax) to 0 (VM86_SIGNAL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | */ |
Samuel Bronson | 975e5f4 | 2009-05-06 22:27:55 -0400 | [diff] [blame] | 316 | info->regs32->ax = VM86_SIGNAL; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 317 | tsk->thread.saved_sp0 = tsk->thread.sp0; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 318 | tsk->thread.saved_fs = info->regs32->fs; |
Tejun Heo | d9a89a2 | 2009-02-09 22:17:40 +0900 | [diff] [blame] | 319 | tsk->thread.saved_gs = get_user_gs(info->regs32); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | |
| 321 | tss = &per_cpu(init_tss, get_cpu()); |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 322 | tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | if (cpu_has_sep) |
| 324 | tsk->thread.sysenter_cs = 0; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 325 | load_sp0(tss, &tsk->thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | put_cpu(); |
| 327 | |
| 328 | tsk->thread.screen_bitmap = info->screen_bitmap; |
| 329 | if (info->flags & VM86_SCREEN_BITMAP) |
Hugh Dickins | 60ec558 | 2005-10-29 18:16:34 -0700 | [diff] [blame] | 330 | mark_screen_rdonly(tsk->mm); |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 331 | |
Eric Paris | d7e7528 | 2012-01-03 14:23:06 -0500 | [diff] [blame] | 332 | /*call __audit_syscall_exit since we do not exit via the normal paths */ |
Al Viro | 6015ff1 | 2012-01-18 01:51:22 +0000 | [diff] [blame] | 333 | #ifdef CONFIG_AUDITSYSCALL |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 334 | if (unlikely(current->audit_context)) |
Eric Paris | d7e7528 | 2012-01-03 14:23:06 -0500 | [diff] [blame] | 335 | __audit_syscall_exit(1, 0); |
Al Viro | 6015ff1 | 2012-01-18 01:51:22 +0000 | [diff] [blame] | 336 | #endif |
Jason Baron | 7e7f8a0 | 2006-01-31 16:56:28 -0500 | [diff] [blame] | 337 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | __asm__ __volatile__( |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | "movl %0,%%esp\n\t" |
| 340 | "movl %1,%%ebp\n\t" |
Lubomir Rintel | 3aa6b18 | 2009-06-07 16:23:48 +0200 | [diff] [blame] | 341 | #ifdef CONFIG_X86_32_LAZY_GS |
Jeremy Fitzhardinge | 464d1a7 | 2007-02-13 13:26:20 +0100 | [diff] [blame] | 342 | "mov %2, %%gs\n\t" |
Lubomir Rintel | 3aa6b18 | 2009-06-07 16:23:48 +0200 | [diff] [blame] | 343 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | "jmp resume_userspace" |
| 345 | : /* no outputs */ |
Jeremy Fitzhardinge | 49d26b6 | 2006-12-07 02:14:03 +0100 | [diff] [blame] | 346 | :"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | /* we never return here */ |
| 348 | } |
| 349 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 350 | static inline void return_to_32bit(struct kernel_vm86_regs *regs16, int retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 352 | struct pt_regs *regs32; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | |
| 354 | regs32 = save_v86_state(regs16); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 355 | regs32->ax = retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | __asm__ __volatile__("movl %0,%%esp\n\t" |
| 357 | "movl %1,%%ebp\n\t" |
| 358 | "jmp resume_userspace" |
| 359 | : : "r" (regs32), "r" (current_thread_info())); |
| 360 | } |
| 361 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 362 | static inline void set_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 364 | VEFLAGS |= X86_EFLAGS_VIF; |
| 365 | if (VEFLAGS & X86_EFLAGS_VIP) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | return_to_32bit(regs, VM86_STI); |
| 367 | } |
| 368 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 369 | static inline void clear_IF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 371 | VEFLAGS &= ~X86_EFLAGS_VIF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
| 373 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 374 | static inline void clear_TF(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 376 | regs->pt.flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | } |
| 378 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 379 | static inline void clear_AC(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 381 | regs->pt.flags &= ~X86_EFLAGS_AC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | } |
| 383 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 384 | /* |
| 385 | * It is correct to call set_IF(regs) from the set_vflags_* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | * functions. However someone forgot to call clear_IF(regs) |
| 387 | * in the opposite case. |
| 388 | * After the command sequence CLI PUSHF STI POPF you should |
Joe Perches | ab4a574 | 2008-01-30 13:31:42 +0100 | [diff] [blame] | 389 | * end up with interrupts disabled, but you ended up with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | * interrupts enabled. |
| 391 | * ( I was testing my own changes, but the only bug I |
| 392 | * could find was in a function I had not changed. ) |
| 393 | * [KD] |
| 394 | */ |
| 395 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 396 | 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] | 397 | { |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 398 | set_flags(VEFLAGS, flags, current->thread.v86mask); |
| 399 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 400 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | set_IF(regs); |
| 402 | else |
| 403 | clear_IF(regs); |
| 404 | } |
| 405 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 406 | 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] | 407 | { |
| 408 | set_flags(VFLAGS, flags, current->thread.v86mask); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 409 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 410 | if (flags & X86_EFLAGS_IF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | set_IF(regs); |
| 412 | else |
| 413 | clear_IF(regs); |
| 414 | } |
| 415 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 416 | static inline unsigned long get_vflags(struct kernel_vm86_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | { |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 418 | unsigned long flags = regs->pt.flags & RETURN_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 420 | if (VEFLAGS & X86_EFLAGS_VIF) |
| 421 | flags |= X86_EFLAGS_IF; |
| 422 | flags |= X86_EFLAGS_IOPL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | return flags | (VEFLAGS & current->thread.v86mask); |
| 424 | } |
| 425 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 426 | static inline int is_revectored(int nr, struct revectored_struct *bitmap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
| 428 | __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0" |
| 429 | :"=r" (nr) |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 430 | :"m" (*bitmap), "r" (nr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | return nr; |
| 432 | } |
| 433 | |
| 434 | #define val_byte(val, n) (((__u8 *)&val)[n]) |
| 435 | |
| 436 | #define pushb(base, ptr, val, err_label) \ |
| 437 | do { \ |
| 438 | __u8 __val = val; \ |
| 439 | ptr--; \ |
| 440 | if (put_user(__val, base + ptr) < 0) \ |
| 441 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 442 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | |
| 444 | #define pushw(base, ptr, val, err_label) \ |
| 445 | do { \ |
| 446 | __u16 __val = val; \ |
| 447 | ptr--; \ |
| 448 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 449 | goto err_label; \ |
| 450 | ptr--; \ |
| 451 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 452 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 453 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
| 455 | #define pushl(base, ptr, val, err_label) \ |
| 456 | do { \ |
| 457 | __u32 __val = val; \ |
| 458 | ptr--; \ |
| 459 | if (put_user(val_byte(__val, 3), base + ptr) < 0) \ |
| 460 | goto err_label; \ |
| 461 | ptr--; \ |
| 462 | if (put_user(val_byte(__val, 2), base + ptr) < 0) \ |
| 463 | goto err_label; \ |
| 464 | ptr--; \ |
| 465 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ |
| 466 | goto err_label; \ |
| 467 | ptr--; \ |
| 468 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ |
| 469 | goto err_label; \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 470 | } while (0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | |
| 472 | #define popb(base, ptr, err_label) \ |
| 473 | ({ \ |
| 474 | __u8 __res; \ |
| 475 | if (get_user(__res, base + ptr) < 0) \ |
| 476 | goto err_label; \ |
| 477 | ptr++; \ |
| 478 | __res; \ |
| 479 | }) |
| 480 | |
| 481 | #define popw(base, ptr, err_label) \ |
| 482 | ({ \ |
| 483 | __u16 __res; \ |
| 484 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 485 | goto err_label; \ |
| 486 | ptr++; \ |
| 487 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 488 | goto err_label; \ |
| 489 | ptr++; \ |
| 490 | __res; \ |
| 491 | }) |
| 492 | |
| 493 | #define popl(base, ptr, err_label) \ |
| 494 | ({ \ |
| 495 | __u32 __res; \ |
| 496 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ |
| 497 | goto err_label; \ |
| 498 | ptr++; \ |
| 499 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ |
| 500 | goto err_label; \ |
| 501 | ptr++; \ |
| 502 | if (get_user(val_byte(__res, 2), base + ptr) < 0) \ |
| 503 | goto err_label; \ |
| 504 | ptr++; \ |
| 505 | if (get_user(val_byte(__res, 3), base + ptr) < 0) \ |
| 506 | goto err_label; \ |
| 507 | ptr++; \ |
| 508 | __res; \ |
| 509 | }) |
| 510 | |
| 511 | /* There are so many possible reasons for this function to return |
| 512 | * VM86_INTx, so adding another doesn't bother me. We can expect |
| 513 | * userspace programs to be able to handle it. (Getting a problem |
| 514 | * in userspace is always better than an Oops anyway.) [KD] |
| 515 | */ |
| 516 | static void do_int(struct kernel_vm86_regs *regs, int i, |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 517 | unsigned char __user *ssp, unsigned short sp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | { |
| 519 | unsigned long __user *intr_ptr; |
| 520 | unsigned long segoffs; |
| 521 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 522 | if (regs->pt.cs == BIOSSEG) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | goto cannot_handle; |
| 524 | if (is_revectored(i, &KVM86->int_revectored)) |
| 525 | goto cannot_handle; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 526 | if (i == 0x21 && is_revectored(AH(regs), &KVM86->int21_revectored)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | goto cannot_handle; |
| 528 | intr_ptr = (unsigned long __user *) (i << 2); |
| 529 | if (get_user(segoffs, intr_ptr)) |
| 530 | goto cannot_handle; |
| 531 | if ((segoffs >> 16) == BIOSSEG) |
| 532 | goto cannot_handle; |
| 533 | pushw(ssp, sp, get_vflags(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 534 | pushw(ssp, sp, regs->pt.cs, cannot_handle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | pushw(ssp, sp, IP(regs), cannot_handle); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 536 | regs->pt.cs = segoffs >> 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | SP(regs) -= 6; |
| 538 | IP(regs) = segoffs & 0xffff; |
| 539 | clear_TF(regs); |
| 540 | clear_IF(regs); |
| 541 | clear_AC(regs); |
| 542 | return; |
| 543 | |
| 544 | cannot_handle: |
| 545 | return_to_32bit(regs, VM86_INTx + (i << 8)); |
| 546 | } |
| 547 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 548 | 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] | 549 | { |
| 550 | if (VMPI.is_vm86pus) { |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 551 | if ((trapno == 3) || (trapno == 1)) { |
| 552 | KVM86->regs32->ax = VM86_TRAP + (trapno << 8); |
| 553 | /* setting this flag forces the code in entry_32.S to |
Al Viro | e76623d | 2012-08-02 22:12:06 +0400 | [diff] [blame] | 554 | the path where we call save_v86_state() and change |
| 555 | the stack pointer to KVM86->regs32 */ |
| 556 | set_thread_flag(TIF_NOTIFY_RESUME); |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 557 | return 0; |
| 558 | } |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 559 | 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] | 560 | return 0; |
| 561 | } |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 562 | if (trapno != 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | return 1; /* we let this handle by the calling routine */ |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 564 | current->thread.trap_nr = trapno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | current->thread.error_code = error_code; |
Roland McGrath | 0f54091 | 2008-03-17 02:21:08 -0700 | [diff] [blame] | 566 | force_sig(SIGTRAP, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | return 0; |
| 568 | } |
| 569 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 570 | void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | { |
| 572 | unsigned char opcode; |
| 573 | unsigned char __user *csp; |
| 574 | unsigned char __user *ssp; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 575 | unsigned short ip, sp, orig_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | int data32, pref_done; |
| 577 | |
| 578 | #define CHECK_IF_IN_TRAP \ |
| 579 | if (VMPI.vm86dbg_active && VMPI.vm86dbg_TFpendig) \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 580 | newflags |= X86_EFLAGS_TF |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | #define VM86_FAULT_RETURN do { \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 582 | if (VMPI.force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | return_to_32bit(regs, VM86_PICRETURN); \ |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 584 | if (orig_flags & X86_EFLAGS_TF) \ |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 585 | handle_vm86_trap(regs, 0, 1); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | return; } while (0) |
| 587 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 588 | orig_flags = *(unsigned short *)®s->pt.flags; |
Petr Tesarik | 5fd75eb | 2005-09-03 15:56:28 -0700 | [diff] [blame] | 589 | |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 590 | csp = (unsigned char __user *) (regs->pt.cs << 4); |
| 591 | ssp = (unsigned char __user *) (regs->pt.ss << 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | sp = SP(regs); |
| 593 | ip = IP(regs); |
| 594 | |
| 595 | data32 = 0; |
| 596 | pref_done = 0; |
| 597 | do { |
| 598 | switch (opcode = popb(csp, ip, simulate_sigsegv)) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 599 | case 0x66: /* 32-bit data */ data32 = 1; break; |
| 600 | case 0x67: /* 32-bit address */ break; |
| 601 | case 0x2e: /* CS */ break; |
| 602 | case 0x3e: /* DS */ break; |
| 603 | case 0x26: /* ES */ break; |
| 604 | case 0x36: /* SS */ break; |
| 605 | case 0x65: /* GS */ break; |
| 606 | case 0x64: /* FS */ break; |
| 607 | case 0xf2: /* repnz */ break; |
| 608 | case 0xf3: /* rep */ break; |
| 609 | default: pref_done = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | } |
| 611 | } while (!pref_done); |
| 612 | |
| 613 | switch (opcode) { |
| 614 | |
| 615 | /* pushf */ |
| 616 | case 0x9c: |
| 617 | if (data32) { |
| 618 | pushl(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 619 | SP(regs) -= 4; |
| 620 | } else { |
| 621 | pushw(ssp, sp, get_vflags(regs), simulate_sigsegv); |
| 622 | SP(regs) -= 2; |
| 623 | } |
| 624 | IP(regs) = ip; |
| 625 | VM86_FAULT_RETURN; |
| 626 | |
| 627 | /* popf */ |
| 628 | case 0x9d: |
| 629 | { |
| 630 | unsigned long newflags; |
| 631 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 632 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | SP(regs) += 4; |
| 634 | } else { |
| 635 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 636 | SP(regs) += 2; |
| 637 | } |
| 638 | IP(regs) = ip; |
| 639 | CHECK_IF_IN_TRAP; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 640 | if (data32) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | set_vflags_long(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 642 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | set_vflags_short(newflags, regs); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 644 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | VM86_FAULT_RETURN; |
| 646 | } |
| 647 | |
| 648 | /* int xx */ |
| 649 | case 0xcd: { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 650 | int intno = popb(csp, ip, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | IP(regs) = ip; |
| 652 | if (VMPI.vm86dbg_active) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 653 | if ((1 << (intno & 7)) & VMPI.vm86dbg_intxxtab[intno >> 3]) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | return_to_32bit(regs, VM86_INTx + (intno << 8)); |
| 655 | } |
| 656 | do_int(regs, intno, ssp, sp); |
| 657 | return; |
| 658 | } |
| 659 | |
| 660 | /* iret */ |
| 661 | case 0xcf: |
| 662 | { |
| 663 | unsigned long newip; |
| 664 | unsigned long newcs; |
| 665 | unsigned long newflags; |
| 666 | if (data32) { |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 667 | newip = popl(ssp, sp, simulate_sigsegv); |
| 668 | newcs = popl(ssp, sp, simulate_sigsegv); |
| 669 | newflags = popl(ssp, sp, simulate_sigsegv); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | SP(regs) += 12; |
| 671 | } else { |
| 672 | newip = popw(ssp, sp, simulate_sigsegv); |
| 673 | newcs = popw(ssp, sp, simulate_sigsegv); |
| 674 | newflags = popw(ssp, sp, simulate_sigsegv); |
| 675 | SP(regs) += 6; |
| 676 | } |
| 677 | IP(regs) = newip; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 678 | regs->pt.cs = newcs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | CHECK_IF_IN_TRAP; |
| 680 | if (data32) { |
| 681 | set_vflags_long(newflags, regs); |
| 682 | } else { |
| 683 | set_vflags_short(newflags, regs); |
| 684 | } |
| 685 | VM86_FAULT_RETURN; |
| 686 | } |
| 687 | |
| 688 | /* cli */ |
| 689 | case 0xfa: |
| 690 | IP(regs) = ip; |
| 691 | clear_IF(regs); |
| 692 | VM86_FAULT_RETURN; |
| 693 | |
| 694 | /* sti */ |
| 695 | /* |
| 696 | * Damn. This is incorrect: the 'sti' instruction should actually |
| 697 | * enable interrupts after the /next/ instruction. Not good. |
| 698 | * |
| 699 | * Probably needs some horsing around with the TF flag. Aiee.. |
| 700 | */ |
| 701 | case 0xfb: |
| 702 | IP(regs) = ip; |
| 703 | set_IF(regs); |
| 704 | VM86_FAULT_RETURN; |
| 705 | |
| 706 | default: |
| 707 | return_to_32bit(regs, VM86_UNKNOWN); |
| 708 | } |
| 709 | |
| 710 | return; |
| 711 | |
| 712 | simulate_sigsegv: |
| 713 | /* FIXME: After a long discussion with Stas we finally |
| 714 | * agreed, that this is wrong. Here we should |
| 715 | * really send a SIGSEGV to the user program. |
| 716 | * But how do we create the correct context? We |
| 717 | * are inside a general protection fault handler |
| 718 | * and has just returned from a page fault handler. |
| 719 | * The correct context for the signal handler |
| 720 | * should be a mixture of the two, but how do we |
| 721 | * get the information? [KD] |
| 722 | */ |
| 723 | return_to_32bit(regs, VM86_UNKNOWN); |
| 724 | } |
| 725 | |
| 726 | /* ---------------- vm86 special IRQ passing stuff ----------------- */ |
| 727 | |
| 728 | #define VM86_IRQNAME "vm86irq" |
| 729 | |
| 730 | static struct vm86_irqs { |
| 731 | struct task_struct *tsk; |
| 732 | int sig; |
| 733 | } vm86_irqs[16]; |
| 734 | |
| 735 | static DEFINE_SPINLOCK(irqbits_lock); |
| 736 | static int irqbits; |
| 737 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 738 | #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \ |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 740 | | (1 << SIGUNUSED)) |
| 741 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 742 | static irqreturn_t irq_handler(int intno, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
| 744 | int irq_bit; |
| 745 | unsigned long flags; |
| 746 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 747 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | irq_bit = 1 << intno; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 749 | if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | goto out; |
| 751 | irqbits |= irq_bit; |
| 752 | if (vm86_irqs[intno].sig) |
| 753 | send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 754 | /* |
| 755 | * IRQ will be re-enabled when user asks for the irq (whether |
| 756 | * polling or as a result of the signal) |
| 757 | */ |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 758 | disable_irq_nosync(intno); |
| 759 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | return IRQ_HANDLED; |
| 761 | |
| 762 | out: |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 763 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | return IRQ_NONE; |
| 765 | } |
| 766 | |
| 767 | static inline void free_vm86_irq(int irqnumber) |
| 768 | { |
| 769 | unsigned long flags; |
| 770 | |
| 771 | free_irq(irqnumber, NULL); |
| 772 | vm86_irqs[irqnumber].tsk = NULL; |
| 773 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 774 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | irqbits &= ~(1 << irqnumber); |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 776 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | } |
| 778 | |
| 779 | void release_vm86_irqs(struct task_struct *task) |
| 780 | { |
| 781 | int i; |
| 782 | for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++) |
| 783 | if (vm86_irqs[i].tsk == task) |
| 784 | free_vm86_irq(i); |
| 785 | } |
| 786 | |
| 787 | static inline int get_and_reset_irq(int irqnumber) |
| 788 | { |
| 789 | int bit; |
| 790 | unsigned long flags; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 791 | int ret = 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 792 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 793 | if (invalid_vm86_irq(irqnumber)) return 0; |
| 794 | if (vm86_irqs[irqnumber].tsk != current) return 0; |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 795 | spin_lock_irqsave(&irqbits_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | bit = irqbits & (1 << irqnumber); |
| 797 | irqbits &= ~bit; |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 798 | if (bit) { |
| 799 | enable_irq(irqnumber); |
| 800 | ret = 1; |
| 801 | } |
| 802 | |
Paolo Ciarrocchi | 83e714e | 2008-02-22 23:10:40 +0100 | [diff] [blame] | 803 | spin_unlock_irqrestore(&irqbits_lock, flags); |
Pavel Pisa | ad67142 | 2005-05-01 08:58:52 -0700 | [diff] [blame] | 804 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | } |
| 806 | |
| 807 | |
| 808 | static int do_vm86_irq_handling(int subfunction, int irqnumber) |
| 809 | { |
| 810 | int ret; |
| 811 | switch (subfunction) { |
| 812 | case VM86_GET_AND_RESET_IRQ: { |
| 813 | return get_and_reset_irq(irqnumber); |
| 814 | } |
| 815 | case VM86_GET_IRQ_BITS: { |
| 816 | return irqbits; |
| 817 | } |
| 818 | case VM86_REQUEST_IRQ: { |
| 819 | int sig = irqnumber >> 8; |
| 820 | int irq = irqnumber & 255; |
| 821 | if (!capable(CAP_SYS_ADMIN)) return -EPERM; |
| 822 | if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM; |
| 823 | if (invalid_vm86_irq(irq)) return -EPERM; |
| 824 | if (vm86_irqs[irq].tsk) return -EPERM; |
| 825 | ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL); |
| 826 | if (ret) return ret; |
| 827 | vm86_irqs[irq].sig = sig; |
| 828 | vm86_irqs[irq].tsk = current; |
| 829 | return irq; |
| 830 | } |
| 831 | case VM86_FREE_IRQ: { |
| 832 | if (invalid_vm86_irq(irqnumber)) return -EPERM; |
| 833 | if (!vm86_irqs[irqnumber].tsk) return 0; |
| 834 | if (vm86_irqs[irqnumber].tsk != current) return -EPERM; |
| 835 | free_vm86_irq(irqnumber); |
| 836 | return 0; |
| 837 | } |
| 838 | } |
| 839 | return -EINVAL; |
| 840 | } |
| 841 | |