Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1994 Linus Torvalds |
3 | * | |
4 | * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86 | |
624dffcb | 5 | * stack - Manfred Spraul <manfred@colorfullife.com> |
1da177e4 LT |
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 | ||
c767a54b JP |
31 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
32 | ||
a9415644 | 33 | #include <linux/capability.h> |
1da177e4 LT |
34 | #include <linux/errno.h> |
35 | #include <linux/interrupt.h> | |
5522ddb3 | 36 | #include <linux/syscalls.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
43 | #include <linux/highmem.h> |
44 | #include <linux/ptrace.h> | |
7e7f8a03 | 45 | #include <linux/audit.h> |
49d26b6e | 46 | #include <linux/stddef.h> |
9fda6a06 | 47 | #include <linux/slab.h> |
1da177e4 LT |
48 | |
49 | #include <asm/uaccess.h> | |
50 | #include <asm/io.h> | |
51 | #include <asm/tlbflush.h> | |
52 | #include <asm/irq.h> | |
5ed92a8a | 53 | #include <asm/traps.h> |
1da177e4 LT |
54 | |
55 | /* | |
56 | * Known problems: | |
57 | * | |
58 | * Interrupt handling is not guaranteed: | |
59 | * - a real x86 will disable all interrupts for one instruction | |
60 | * after a "mov ss,xx" to make stack handling atomic even without | |
61 | * the 'lss' instruction. We can't guarantee this in v86 mode, | |
62 | * as the next instruction might result in a page fault or similar. | |
63 | * - a real x86 will have interrupts disabled for one instruction | |
64 | * past the 'sti' that enables them. We don't bother with all the | |
65 | * details yet. | |
66 | * | |
67 | * Let's hope these problems do not actually matter for anything. | |
68 | */ | |
69 | ||
70 | ||
1da177e4 LT |
71 | /* |
72 | * 8- and 16-bit register defines.. | |
73 | */ | |
65ea5b03 PA |
74 | #define AL(regs) (((unsigned char *)&((regs)->pt.ax))[0]) |
75 | #define AH(regs) (((unsigned char *)&((regs)->pt.ax))[1]) | |
76 | #define IP(regs) (*(unsigned short *)&((regs)->pt.ip)) | |
77 | #define SP(regs) (*(unsigned short *)&((regs)->pt.sp)) | |
1da177e4 LT |
78 | |
79 | /* | |
80 | * virtual flags (16 and 32-bit versions) | |
81 | */ | |
9fda6a06 BG |
82 | #define VFLAGS (*(unsigned short *)&(current->thread.vm86->v86flags)) |
83 | #define VEFLAGS (current->thread.vm86->v86flags) | |
1da177e4 | 84 | |
83e714e8 | 85 | #define set_flags(X, new, mask) \ |
1da177e4 LT |
86 | ((X) = ((X) & ~(mask)) | ((new) & (mask))) |
87 | ||
88 | #define SAFE_MASK (0xDD5) | |
89 | #define RETURN_MASK (0xDFF) | |
90 | ||
5ed92a8a | 91 | void save_v86_state(struct kernel_vm86_regs *regs, int retval) |
1da177e4 LT |
92 | { |
93 | struct tss_struct *tss; | |
ed0b2edb BG |
94 | struct task_struct *tsk = current; |
95 | struct vm86plus_struct __user *user; | |
9fda6a06 | 96 | struct vm86 *vm86 = current->thread.vm86; |
ed0b2edb | 97 | long err = 0; |
1da177e4 LT |
98 | |
99 | /* | |
100 | * This gets called from entry.S with interrupts disabled, but | |
101 | * from process context. Enable interrupts here, before trying | |
102 | * to access user space. | |
103 | */ | |
104 | local_irq_enable(); | |
105 | ||
9fda6a06 | 106 | if (!vm86 || !vm86->vm86_info) { |
c767a54b | 107 | pr_alert("no vm86_info: BAD\n"); |
1da177e4 LT |
108 | do_exit(SIGSEGV); |
109 | } | |
9fda6a06 BG |
110 | set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->v86mask); |
111 | user = vm86->vm86_info; | |
ed0b2edb | 112 | |
d4ce0f26 | 113 | if (!access_ok(VERIFY_WRITE, user, vm86->vm86plus.is_vm86pus ? |
ed0b2edb BG |
114 | sizeof(struct vm86plus_struct) : |
115 | sizeof(struct vm86_struct))) { | |
116 | pr_alert("could not access userspace vm86_info\n"); | |
117 | do_exit(SIGSEGV); | |
118 | } | |
119 | ||
120 | put_user_try { | |
121 | put_user_ex(regs->pt.bx, &user->regs.ebx); | |
122 | put_user_ex(regs->pt.cx, &user->regs.ecx); | |
123 | put_user_ex(regs->pt.dx, &user->regs.edx); | |
124 | put_user_ex(regs->pt.si, &user->regs.esi); | |
125 | put_user_ex(regs->pt.di, &user->regs.edi); | |
126 | put_user_ex(regs->pt.bp, &user->regs.ebp); | |
127 | put_user_ex(regs->pt.ax, &user->regs.eax); | |
128 | put_user_ex(regs->pt.ip, &user->regs.eip); | |
129 | put_user_ex(regs->pt.cs, &user->regs.cs); | |
130 | put_user_ex(regs->pt.flags, &user->regs.eflags); | |
131 | put_user_ex(regs->pt.sp, &user->regs.esp); | |
132 | put_user_ex(regs->pt.ss, &user->regs.ss); | |
133 | put_user_ex(regs->es, &user->regs.es); | |
134 | put_user_ex(regs->ds, &user->regs.ds); | |
135 | put_user_ex(regs->fs, &user->regs.fs); | |
136 | put_user_ex(regs->gs, &user->regs.gs); | |
137 | ||
9fda6a06 | 138 | put_user_ex(vm86->screen_bitmap, &user->screen_bitmap); |
ed0b2edb BG |
139 | } put_user_catch(err); |
140 | if (err) { | |
c767a54b | 141 | pr_alert("could not access userspace vm86_info\n"); |
1da177e4 LT |
142 | do_exit(SIGSEGV); |
143 | } | |
144 | ||
24933b82 | 145 | tss = &per_cpu(cpu_tss, get_cpu()); |
9fda6a06 | 146 | tsk->thread.sp0 = vm86->saved_sp0; |
ed0b2edb BG |
147 | tsk->thread.sysenter_cs = __KERNEL_CS; |
148 | load_sp0(tss, &tsk->thread); | |
9fda6a06 | 149 | vm86->saved_sp0 = 0; |
1da177e4 LT |
150 | put_cpu(); |
151 | ||
5ed92a8a | 152 | memcpy(®s->pt, &vm86->regs32, sizeof(struct pt_regs)); |
49d26b6e | 153 | |
5ed92a8a | 154 | lazy_load_gs(vm86->regs32.gs); |
49d26b6e | 155 | |
5ed92a8a | 156 | regs->pt.ax = retval; |
1da177e4 LT |
157 | } |
158 | ||
60ec5585 | 159 | static void mark_screen_rdonly(struct mm_struct *mm) |
1da177e4 LT |
160 | { |
161 | pgd_t *pgd; | |
162 | pud_t *pud; | |
163 | pmd_t *pmd; | |
60ec5585 HD |
164 | pte_t *pte; |
165 | spinlock_t *ptl; | |
1da177e4 LT |
166 | int i; |
167 | ||
1a5a9906 | 168 | down_write(&mm->mmap_sem); |
60ec5585 | 169 | pgd = pgd_offset(mm, 0xA0000); |
1da177e4 LT |
170 | if (pgd_none_or_clear_bad(pgd)) |
171 | goto out; | |
172 | pud = pud_offset(pgd, 0xA0000); | |
173 | if (pud_none_or_clear_bad(pud)) | |
174 | goto out; | |
175 | pmd = pmd_offset(pud, 0xA0000); | |
e180377f | 176 | split_huge_page_pmd_mm(mm, 0xA0000, pmd); |
1da177e4 LT |
177 | if (pmd_none_or_clear_bad(pmd)) |
178 | goto out; | |
60ec5585 | 179 | pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl); |
1da177e4 LT |
180 | for (i = 0; i < 32; i++) { |
181 | if (pte_present(*pte)) | |
182 | set_pte(pte, pte_wrprotect(*pte)); | |
183 | pte++; | |
184 | } | |
60ec5585 | 185 | pte_unmap_unlock(pte, ptl); |
1da177e4 | 186 | out: |
1a5a9906 | 187 | up_write(&mm->mmap_sem); |
1da177e4 LT |
188 | flush_tlb(); |
189 | } | |
190 | ||
191 | ||
192 | ||
193 | static int do_vm86_irq_handling(int subfunction, int irqnumber); | |
90c6085a | 194 | static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus); |
1da177e4 | 195 | |
5522ddb3 | 196 | SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86) |
1da177e4 | 197 | { |
90c6085a | 198 | return do_sys_vm86((struct vm86plus_struct __user *) v86, false); |
1da177e4 LT |
199 | } |
200 | ||
201 | ||
5522ddb3 | 202 | SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) |
1da177e4 | 203 | { |
f1382f15 | 204 | switch (cmd) { |
83e714e8 PC |
205 | case VM86_REQUEST_IRQ: |
206 | case VM86_FREE_IRQ: | |
207 | case VM86_GET_IRQ_BITS: | |
208 | case VM86_GET_AND_RESET_IRQ: | |
5522ddb3 | 209 | return do_vm86_irq_handling(cmd, (int)arg); |
83e714e8 PC |
210 | case VM86_PLUS_INSTALL_CHECK: |
211 | /* | |
212 | * NOTE: on old vm86 stuff this will return the error | |
213 | * from access_ok(), because the subfunction is | |
214 | * interpreted as (invalid) address to vm86_struct. | |
215 | * So the installation check works. | |
216 | */ | |
5522ddb3 | 217 | return 0; |
1da177e4 LT |
218 | } |
219 | ||
220 | /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ | |
90c6085a | 221 | return do_sys_vm86((struct vm86plus_struct __user *) arg, true); |
1da177e4 LT |
222 | } |
223 | ||
224 | ||
90c6085a | 225 | static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus) |
1da177e4 LT |
226 | { |
227 | struct tss_struct *tss; | |
ed0b2edb | 228 | struct task_struct *tsk = current; |
9fda6a06 | 229 | struct vm86 *vm86 = tsk->thread.vm86; |
90c6085a | 230 | struct kernel_vm86_regs vm86regs; |
5ed92a8a | 231 | struct pt_regs *regs = current_pt_regs(); |
ed0b2edb BG |
232 | unsigned long err = 0; |
233 | ||
9fda6a06 BG |
234 | if (!vm86) { |
235 | if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL))) | |
236 | return -ENOMEM; | |
237 | tsk->thread.vm86 = vm86; | |
238 | } | |
239 | if (vm86->saved_sp0) | |
ed0b2edb BG |
240 | return -EPERM; |
241 | ||
242 | if (!access_ok(VERIFY_READ, v86, plus ? | |
243 | sizeof(struct vm86_struct) : | |
244 | sizeof(struct vm86plus_struct))) | |
245 | return -EFAULT; | |
246 | ||
90c6085a | 247 | memset(&vm86regs, 0, sizeof(vm86regs)); |
ed0b2edb BG |
248 | get_user_try { |
249 | unsigned short seg; | |
90c6085a BG |
250 | get_user_ex(vm86regs.pt.bx, &v86->regs.ebx); |
251 | get_user_ex(vm86regs.pt.cx, &v86->regs.ecx); | |
252 | get_user_ex(vm86regs.pt.dx, &v86->regs.edx); | |
253 | get_user_ex(vm86regs.pt.si, &v86->regs.esi); | |
254 | get_user_ex(vm86regs.pt.di, &v86->regs.edi); | |
255 | get_user_ex(vm86regs.pt.bp, &v86->regs.ebp); | |
256 | get_user_ex(vm86regs.pt.ax, &v86->regs.eax); | |
257 | get_user_ex(vm86regs.pt.ip, &v86->regs.eip); | |
ed0b2edb | 258 | get_user_ex(seg, &v86->regs.cs); |
90c6085a BG |
259 | vm86regs.pt.cs = seg; |
260 | get_user_ex(vm86regs.pt.flags, &v86->regs.eflags); | |
261 | get_user_ex(vm86regs.pt.sp, &v86->regs.esp); | |
ed0b2edb | 262 | get_user_ex(seg, &v86->regs.ss); |
90c6085a BG |
263 | vm86regs.pt.ss = seg; |
264 | get_user_ex(vm86regs.es, &v86->regs.es); | |
265 | get_user_ex(vm86regs.ds, &v86->regs.ds); | |
266 | get_user_ex(vm86regs.fs, &v86->regs.fs); | |
267 | get_user_ex(vm86regs.gs, &v86->regs.gs); | |
ed0b2edb | 268 | |
d4ce0f26 BG |
269 | get_user_ex(vm86->flags, &v86->flags); |
270 | get_user_ex(vm86->screen_bitmap, &v86->screen_bitmap); | |
271 | get_user_ex(vm86->cpu_type, &v86->cpu_type); | |
ed0b2edb BG |
272 | } get_user_catch(err); |
273 | if (err) | |
274 | return err; | |
275 | ||
d4ce0f26 | 276 | if (copy_from_user(&vm86->int_revectored, &v86->int_revectored, |
ed0b2edb BG |
277 | sizeof(struct revectored_struct))) |
278 | return -EFAULT; | |
d4ce0f26 | 279 | if (copy_from_user(&vm86->int21_revectored, &v86->int21_revectored, |
ed0b2edb BG |
280 | sizeof(struct revectored_struct))) |
281 | return -EFAULT; | |
282 | if (plus) { | |
d4ce0f26 | 283 | if (copy_from_user(&vm86->vm86plus, &v86->vm86plus, |
ed0b2edb BG |
284 | sizeof(struct vm86plus_info_struct))) |
285 | return -EFAULT; | |
d4ce0f26 BG |
286 | vm86->vm86plus.is_vm86pus = 1; |
287 | } else | |
288 | memset(&vm86->vm86plus, 0, | |
289 | sizeof(struct vm86plus_info_struct)); | |
5ed92a8a BG |
290 | |
291 | memcpy(&vm86->regs32, regs, sizeof(struct pt_regs)); | |
9fda6a06 | 292 | vm86->vm86_info = v86; |
1da177e4 LT |
293 | |
294 | /* | |
65ea5b03 | 295 | * The flags register is also special: we cannot trust that the user |
1da177e4 LT |
296 | * has set it up safely, so this makes sure interrupt etc flags are |
297 | * inherited from protected mode. | |
298 | */ | |
90c6085a BG |
299 | VEFLAGS = vm86regs.pt.flags; |
300 | vm86regs.pt.flags &= SAFE_MASK; | |
5ed92a8a | 301 | vm86regs.pt.flags |= regs->flags & ~SAFE_MASK; |
90c6085a | 302 | vm86regs.pt.flags |= X86_VM_MASK; |
1da177e4 | 303 | |
5ed92a8a | 304 | vm86regs.pt.orig_ax = regs->orig_ax; |
df1ae9a5 | 305 | |
d4ce0f26 | 306 | switch (vm86->cpu_type) { |
83e714e8 | 307 | case CPU_286: |
9fda6a06 | 308 | vm86->v86mask = 0; |
83e714e8 PC |
309 | break; |
310 | case CPU_386: | |
9fda6a06 | 311 | vm86->v86mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
83e714e8 PC |
312 | break; |
313 | case CPU_486: | |
9fda6a06 | 314 | vm86->v86mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
83e714e8 PC |
315 | break; |
316 | default: | |
9fda6a06 | 317 | vm86->v86mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL; |
83e714e8 | 318 | break; |
1da177e4 LT |
319 | } |
320 | ||
321 | /* | |
5ed92a8a | 322 | * Save old state |
1da177e4 | 323 | */ |
9fda6a06 | 324 | vm86->saved_sp0 = tsk->thread.sp0; |
5ed92a8a | 325 | lazy_save_gs(vm86->regs32.gs); |
1da177e4 | 326 | |
24933b82 | 327 | tss = &per_cpu(cpu_tss, get_cpu()); |
5ed92a8a BG |
328 | /* make room for real-mode segments */ |
329 | tsk->thread.sp0 += 16; | |
1da177e4 LT |
330 | if (cpu_has_sep) |
331 | tsk->thread.sysenter_cs = 0; | |
faca6227 | 332 | load_sp0(tss, &tsk->thread); |
1da177e4 LT |
333 | put_cpu(); |
334 | ||
d4ce0f26 | 335 | if (vm86->flags & VM86_SCREEN_BITMAP) |
60ec5585 | 336 | mark_screen_rdonly(tsk->mm); |
7e7f8a03 | 337 | |
5ed92a8a BG |
338 | memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs)); |
339 | force_iret(); | |
340 | return regs->ax; | |
1da177e4 LT |
341 | } |
342 | ||
83e714e8 | 343 | static inline void set_IF(struct kernel_vm86_regs *regs) |
1da177e4 | 344 | { |
a5c15d41 | 345 | VEFLAGS |= X86_EFLAGS_VIF; |
1da177e4 LT |
346 | } |
347 | ||
83e714e8 | 348 | static inline void clear_IF(struct kernel_vm86_regs *regs) |
1da177e4 | 349 | { |
a5c15d41 | 350 | VEFLAGS &= ~X86_EFLAGS_VIF; |
1da177e4 LT |
351 | } |
352 | ||
83e714e8 | 353 | static inline void clear_TF(struct kernel_vm86_regs *regs) |
1da177e4 | 354 | { |
a5c15d41 | 355 | regs->pt.flags &= ~X86_EFLAGS_TF; |
1da177e4 LT |
356 | } |
357 | ||
83e714e8 | 358 | static inline void clear_AC(struct kernel_vm86_regs *regs) |
1da177e4 | 359 | { |
a5c15d41 | 360 | regs->pt.flags &= ~X86_EFLAGS_AC; |
1da177e4 LT |
361 | } |
362 | ||
83e714e8 PC |
363 | /* |
364 | * It is correct to call set_IF(regs) from the set_vflags_* | |
1da177e4 LT |
365 | * functions. However someone forgot to call clear_IF(regs) |
366 | * in the opposite case. | |
367 | * After the command sequence CLI PUSHF STI POPF you should | |
ab4a574e | 368 | * end up with interrupts disabled, but you ended up with |
1da177e4 LT |
369 | * interrupts enabled. |
370 | * ( I was testing my own changes, but the only bug I | |
371 | * could find was in a function I had not changed. ) | |
372 | * [KD] | |
373 | */ | |
374 | ||
83e714e8 | 375 | static inline void set_vflags_long(unsigned long flags, struct kernel_vm86_regs *regs) |
1da177e4 | 376 | { |
9fda6a06 | 377 | set_flags(VEFLAGS, flags, current->thread.vm86->v86mask); |
65ea5b03 | 378 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
a5c15d41 | 379 | if (flags & X86_EFLAGS_IF) |
1da177e4 LT |
380 | set_IF(regs); |
381 | else | |
382 | clear_IF(regs); | |
383 | } | |
384 | ||
83e714e8 | 385 | static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs *regs) |
1da177e4 | 386 | { |
9fda6a06 | 387 | set_flags(VFLAGS, flags, current->thread.vm86->v86mask); |
65ea5b03 | 388 | set_flags(regs->pt.flags, flags, SAFE_MASK); |
a5c15d41 | 389 | if (flags & X86_EFLAGS_IF) |
1da177e4 LT |
390 | set_IF(regs); |
391 | else | |
392 | clear_IF(regs); | |
393 | } | |
394 | ||
83e714e8 | 395 | static inline unsigned long get_vflags(struct kernel_vm86_regs *regs) |
1da177e4 | 396 | { |
65ea5b03 | 397 | unsigned long flags = regs->pt.flags & RETURN_MASK; |
1da177e4 | 398 | |
a5c15d41 | 399 | if (VEFLAGS & X86_EFLAGS_VIF) |
400 | flags |= X86_EFLAGS_IF; | |
401 | flags |= X86_EFLAGS_IOPL; | |
9fda6a06 | 402 | return flags | (VEFLAGS & current->thread.vm86->v86mask); |
1da177e4 LT |
403 | } |
404 | ||
83e714e8 | 405 | static inline int is_revectored(int nr, struct revectored_struct *bitmap) |
1da177e4 LT |
406 | { |
407 | __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0" | |
408 | :"=r" (nr) | |
83e714e8 | 409 | :"m" (*bitmap), "r" (nr)); |
1da177e4 LT |
410 | return nr; |
411 | } | |
412 | ||
413 | #define val_byte(val, n) (((__u8 *)&val)[n]) | |
414 | ||
415 | #define pushb(base, ptr, val, err_label) \ | |
416 | do { \ | |
417 | __u8 __val = val; \ | |
418 | ptr--; \ | |
419 | if (put_user(__val, base + ptr) < 0) \ | |
420 | goto err_label; \ | |
83e714e8 | 421 | } while (0) |
1da177e4 LT |
422 | |
423 | #define pushw(base, ptr, val, err_label) \ | |
424 | do { \ | |
425 | __u16 __val = val; \ | |
426 | ptr--; \ | |
427 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ | |
428 | goto err_label; \ | |
429 | ptr--; \ | |
430 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ | |
431 | goto err_label; \ | |
83e714e8 | 432 | } while (0) |
1da177e4 LT |
433 | |
434 | #define pushl(base, ptr, val, err_label) \ | |
435 | do { \ | |
436 | __u32 __val = val; \ | |
437 | ptr--; \ | |
438 | if (put_user(val_byte(__val, 3), base + ptr) < 0) \ | |
439 | goto err_label; \ | |
440 | ptr--; \ | |
441 | if (put_user(val_byte(__val, 2), base + ptr) < 0) \ | |
442 | goto err_label; \ | |
443 | ptr--; \ | |
444 | if (put_user(val_byte(__val, 1), base + ptr) < 0) \ | |
445 | goto err_label; \ | |
446 | ptr--; \ | |
447 | if (put_user(val_byte(__val, 0), base + ptr) < 0) \ | |
448 | goto err_label; \ | |
83e714e8 | 449 | } while (0) |
1da177e4 LT |
450 | |
451 | #define popb(base, ptr, err_label) \ | |
452 | ({ \ | |
453 | __u8 __res; \ | |
454 | if (get_user(__res, base + ptr) < 0) \ | |
455 | goto err_label; \ | |
456 | ptr++; \ | |
457 | __res; \ | |
458 | }) | |
459 | ||
460 | #define popw(base, ptr, err_label) \ | |
461 | ({ \ | |
462 | __u16 __res; \ | |
463 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ | |
464 | goto err_label; \ | |
465 | ptr++; \ | |
466 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ | |
467 | goto err_label; \ | |
468 | ptr++; \ | |
469 | __res; \ | |
470 | }) | |
471 | ||
472 | #define popl(base, ptr, err_label) \ | |
473 | ({ \ | |
474 | __u32 __res; \ | |
475 | if (get_user(val_byte(__res, 0), base + ptr) < 0) \ | |
476 | goto err_label; \ | |
477 | ptr++; \ | |
478 | if (get_user(val_byte(__res, 1), base + ptr) < 0) \ | |
479 | goto err_label; \ | |
480 | ptr++; \ | |
481 | if (get_user(val_byte(__res, 2), base + ptr) < 0) \ | |
482 | goto err_label; \ | |
483 | ptr++; \ | |
484 | if (get_user(val_byte(__res, 3), base + ptr) < 0) \ | |
485 | goto err_label; \ | |
486 | ptr++; \ | |
487 | __res; \ | |
488 | }) | |
489 | ||
490 | /* There are so many possible reasons for this function to return | |
491 | * VM86_INTx, so adding another doesn't bother me. We can expect | |
492 | * userspace programs to be able to handle it. (Getting a problem | |
493 | * in userspace is always better than an Oops anyway.) [KD] | |
494 | */ | |
495 | static void do_int(struct kernel_vm86_regs *regs, int i, | |
83e714e8 | 496 | unsigned char __user *ssp, unsigned short sp) |
1da177e4 LT |
497 | { |
498 | unsigned long __user *intr_ptr; | |
499 | unsigned long segoffs; | |
90c6085a | 500 | struct vm86 *vm86 = current->thread.vm86; |
1da177e4 | 501 | |
65ea5b03 | 502 | if (regs->pt.cs == BIOSSEG) |
1da177e4 | 503 | goto cannot_handle; |
d4ce0f26 | 504 | if (is_revectored(i, &vm86->int_revectored)) |
1da177e4 | 505 | goto cannot_handle; |
d4ce0f26 | 506 | if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored)) |
1da177e4 LT |
507 | goto cannot_handle; |
508 | intr_ptr = (unsigned long __user *) (i << 2); | |
509 | if (get_user(segoffs, intr_ptr)) | |
510 | goto cannot_handle; | |
511 | if ((segoffs >> 16) == BIOSSEG) | |
512 | goto cannot_handle; | |
513 | pushw(ssp, sp, get_vflags(regs), cannot_handle); | |
65ea5b03 | 514 | pushw(ssp, sp, regs->pt.cs, cannot_handle); |
1da177e4 | 515 | pushw(ssp, sp, IP(regs), cannot_handle); |
65ea5b03 | 516 | regs->pt.cs = segoffs >> 16; |
1da177e4 LT |
517 | SP(regs) -= 6; |
518 | IP(regs) = segoffs & 0xffff; | |
519 | clear_TF(regs); | |
520 | clear_IF(regs); | |
521 | clear_AC(regs); | |
522 | return; | |
523 | ||
524 | cannot_handle: | |
5ed92a8a | 525 | save_v86_state(regs, VM86_INTx + (i << 8)); |
1da177e4 LT |
526 | } |
527 | ||
83e714e8 | 528 | int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno) |
1da177e4 | 529 | { |
90c6085a BG |
530 | struct vm86 *vm86 = current->thread.vm86; |
531 | ||
532 | if (vm86->vm86plus.is_vm86pus) { | |
6554287b | 533 | if ((trapno == 3) || (trapno == 1)) { |
5ed92a8a | 534 | save_v86_state(regs, VM86_TRAP + (trapno << 8)); |
6554287b BO |
535 | return 0; |
536 | } | |
65ea5b03 | 537 | do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs)); |
1da177e4 LT |
538 | return 0; |
539 | } | |
83e714e8 | 540 | if (trapno != 1) |
1da177e4 | 541 | return 1; /* we let this handle by the calling routine */ |
51e7dc70 | 542 | current->thread.trap_nr = trapno; |
1da177e4 | 543 | current->thread.error_code = error_code; |
0f540910 | 544 | force_sig(SIGTRAP, current); |
1da177e4 LT |
545 | return 0; |
546 | } | |
547 | ||
83e714e8 | 548 | void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code) |
1da177e4 LT |
549 | { |
550 | unsigned char opcode; | |
551 | unsigned char __user *csp; | |
552 | unsigned char __user *ssp; | |
5fd75ebb | 553 | unsigned short ip, sp, orig_flags; |
1da177e4 | 554 | int data32, pref_done; |
d4ce0f26 | 555 | struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus; |
1da177e4 LT |
556 | |
557 | #define CHECK_IF_IN_TRAP \ | |
d4ce0f26 | 558 | if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \ |
a5c15d41 | 559 | newflags |= X86_EFLAGS_TF |
1da177e4 | 560 | |
65ea5b03 | 561 | orig_flags = *(unsigned short *)®s->pt.flags; |
5fd75ebb | 562 | |
65ea5b03 PA |
563 | csp = (unsigned char __user *) (regs->pt.cs << 4); |
564 | ssp = (unsigned char __user *) (regs->pt.ss << 4); | |
1da177e4 LT |
565 | sp = SP(regs); |
566 | ip = IP(regs); | |
567 | ||
568 | data32 = 0; | |
569 | pref_done = 0; | |
570 | do { | |
571 | switch (opcode = popb(csp, ip, simulate_sigsegv)) { | |
83e714e8 PC |
572 | case 0x66: /* 32-bit data */ data32 = 1; break; |
573 | case 0x67: /* 32-bit address */ break; | |
574 | case 0x2e: /* CS */ break; | |
575 | case 0x3e: /* DS */ break; | |
576 | case 0x26: /* ES */ break; | |
577 | case 0x36: /* SS */ break; | |
578 | case 0x65: /* GS */ break; | |
579 | case 0x64: /* FS */ break; | |
580 | case 0xf2: /* repnz */ break; | |
581 | case 0xf3: /* rep */ break; | |
582 | default: pref_done = 1; | |
1da177e4 LT |
583 | } |
584 | } while (!pref_done); | |
585 | ||
586 | switch (opcode) { | |
587 | ||
588 | /* pushf */ | |
589 | case 0x9c: | |
590 | if (data32) { | |
591 | pushl(ssp, sp, get_vflags(regs), simulate_sigsegv); | |
592 | SP(regs) -= 4; | |
593 | } else { | |
594 | pushw(ssp, sp, get_vflags(regs), simulate_sigsegv); | |
595 | SP(regs) -= 2; | |
596 | } | |
597 | IP(regs) = ip; | |
5ed92a8a | 598 | goto vm86_fault_return; |
1da177e4 LT |
599 | |
600 | /* popf */ | |
601 | case 0x9d: | |
602 | { | |
603 | unsigned long newflags; | |
604 | if (data32) { | |
83e714e8 | 605 | newflags = popl(ssp, sp, simulate_sigsegv); |
1da177e4 LT |
606 | SP(regs) += 4; |
607 | } else { | |
608 | newflags = popw(ssp, sp, simulate_sigsegv); | |
609 | SP(regs) += 2; | |
610 | } | |
611 | IP(regs) = ip; | |
612 | CHECK_IF_IN_TRAP; | |
83e714e8 | 613 | if (data32) |
1da177e4 | 614 | set_vflags_long(newflags, regs); |
83e714e8 | 615 | else |
1da177e4 | 616 | set_vflags_short(newflags, regs); |
83e714e8 | 617 | |
5ed92a8a | 618 | goto check_vip; |
1da177e4 LT |
619 | } |
620 | ||
621 | /* int xx */ | |
622 | case 0xcd: { | |
83e714e8 | 623 | int intno = popb(csp, ip, simulate_sigsegv); |
1da177e4 | 624 | IP(regs) = ip; |
d4ce0f26 | 625 | if (vmpi->vm86dbg_active) { |
5ed92a8a BG |
626 | if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) { |
627 | save_v86_state(regs, VM86_INTx + (intno << 8)); | |
628 | return; | |
629 | } | |
1da177e4 LT |
630 | } |
631 | do_int(regs, intno, ssp, sp); | |
632 | return; | |
633 | } | |
634 | ||
635 | /* iret */ | |
636 | case 0xcf: | |
637 | { | |
638 | unsigned long newip; | |
639 | unsigned long newcs; | |
640 | unsigned long newflags; | |
641 | if (data32) { | |
83e714e8 PC |
642 | newip = popl(ssp, sp, simulate_sigsegv); |
643 | newcs = popl(ssp, sp, simulate_sigsegv); | |
644 | newflags = popl(ssp, sp, simulate_sigsegv); | |
1da177e4 LT |
645 | SP(regs) += 12; |
646 | } else { | |
647 | newip = popw(ssp, sp, simulate_sigsegv); | |
648 | newcs = popw(ssp, sp, simulate_sigsegv); | |
649 | newflags = popw(ssp, sp, simulate_sigsegv); | |
650 | SP(regs) += 6; | |
651 | } | |
652 | IP(regs) = newip; | |
65ea5b03 | 653 | regs->pt.cs = newcs; |
1da177e4 LT |
654 | CHECK_IF_IN_TRAP; |
655 | if (data32) { | |
656 | set_vflags_long(newflags, regs); | |
657 | } else { | |
658 | set_vflags_short(newflags, regs); | |
659 | } | |
5ed92a8a | 660 | goto check_vip; |
1da177e4 LT |
661 | } |
662 | ||
663 | /* cli */ | |
664 | case 0xfa: | |
665 | IP(regs) = ip; | |
666 | clear_IF(regs); | |
5ed92a8a | 667 | goto vm86_fault_return; |
1da177e4 LT |
668 | |
669 | /* sti */ | |
670 | /* | |
671 | * Damn. This is incorrect: the 'sti' instruction should actually | |
672 | * enable interrupts after the /next/ instruction. Not good. | |
673 | * | |
674 | * Probably needs some horsing around with the TF flag. Aiee.. | |
675 | */ | |
676 | case 0xfb: | |
677 | IP(regs) = ip; | |
678 | set_IF(regs); | |
5ed92a8a | 679 | goto check_vip; |
1da177e4 LT |
680 | |
681 | default: | |
5ed92a8a | 682 | save_v86_state(regs, VM86_UNKNOWN); |
1da177e4 LT |
683 | } |
684 | ||
685 | return; | |
686 | ||
5ed92a8a BG |
687 | check_vip: |
688 | if (VEFLAGS & X86_EFLAGS_VIP) { | |
689 | save_v86_state(regs, VM86_STI); | |
690 | return; | |
691 | } | |
692 | ||
693 | vm86_fault_return: | |
694 | if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) { | |
695 | save_v86_state(regs, VM86_PICRETURN); | |
696 | return; | |
697 | } | |
698 | if (orig_flags & X86_EFLAGS_TF) | |
699 | handle_vm86_trap(regs, 0, X86_TRAP_DB); | |
700 | return; | |
701 | ||
1da177e4 LT |
702 | simulate_sigsegv: |
703 | /* FIXME: After a long discussion with Stas we finally | |
704 | * agreed, that this is wrong. Here we should | |
705 | * really send a SIGSEGV to the user program. | |
706 | * But how do we create the correct context? We | |
707 | * are inside a general protection fault handler | |
708 | * and has just returned from a page fault handler. | |
709 | * The correct context for the signal handler | |
710 | * should be a mixture of the two, but how do we | |
711 | * get the information? [KD] | |
712 | */ | |
5ed92a8a | 713 | save_v86_state(regs, VM86_UNKNOWN); |
1da177e4 LT |
714 | } |
715 | ||
716 | /* ---------------- vm86 special IRQ passing stuff ----------------- */ | |
717 | ||
718 | #define VM86_IRQNAME "vm86irq" | |
719 | ||
720 | static struct vm86_irqs { | |
721 | struct task_struct *tsk; | |
722 | int sig; | |
723 | } vm86_irqs[16]; | |
724 | ||
725 | static DEFINE_SPINLOCK(irqbits_lock); | |
726 | static int irqbits; | |
727 | ||
83e714e8 | 728 | #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \ |
1da177e4 | 729 | | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \ |
83e714e8 PC |
730 | | (1 << SIGUNUSED)) |
731 | ||
7d12e780 | 732 | static irqreturn_t irq_handler(int intno, void *dev_id) |
1da177e4 LT |
733 | { |
734 | int irq_bit; | |
735 | unsigned long flags; | |
736 | ||
83e714e8 | 737 | spin_lock_irqsave(&irqbits_lock, flags); |
1da177e4 | 738 | irq_bit = 1 << intno; |
83e714e8 | 739 | if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk) |
1da177e4 LT |
740 | goto out; |
741 | irqbits |= irq_bit; | |
742 | if (vm86_irqs[intno].sig) | |
743 | send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1); | |
1da177e4 LT |
744 | /* |
745 | * IRQ will be re-enabled when user asks for the irq (whether | |
746 | * polling or as a result of the signal) | |
747 | */ | |
ad671423 PP |
748 | disable_irq_nosync(intno); |
749 | spin_unlock_irqrestore(&irqbits_lock, flags); | |
1da177e4 LT |
750 | return IRQ_HANDLED; |
751 | ||
752 | out: | |
83e714e8 | 753 | spin_unlock_irqrestore(&irqbits_lock, flags); |
1da177e4 LT |
754 | return IRQ_NONE; |
755 | } | |
756 | ||
757 | static inline void free_vm86_irq(int irqnumber) | |
758 | { | |
759 | unsigned long flags; | |
760 | ||
761 | free_irq(irqnumber, NULL); | |
762 | vm86_irqs[irqnumber].tsk = NULL; | |
763 | ||
83e714e8 | 764 | spin_lock_irqsave(&irqbits_lock, flags); |
1da177e4 | 765 | irqbits &= ~(1 << irqnumber); |
83e714e8 | 766 | spin_unlock_irqrestore(&irqbits_lock, flags); |
1da177e4 LT |
767 | } |
768 | ||
769 | void release_vm86_irqs(struct task_struct *task) | |
770 | { | |
771 | int i; | |
772 | for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++) | |
773 | if (vm86_irqs[i].tsk == task) | |
774 | free_vm86_irq(i); | |
775 | } | |
776 | ||
777 | static inline int get_and_reset_irq(int irqnumber) | |
778 | { | |
779 | int bit; | |
780 | unsigned long flags; | |
ad671423 | 781 | int ret = 0; |
83e714e8 | 782 | |
1da177e4 LT |
783 | if (invalid_vm86_irq(irqnumber)) return 0; |
784 | if (vm86_irqs[irqnumber].tsk != current) return 0; | |
83e714e8 | 785 | spin_lock_irqsave(&irqbits_lock, flags); |
1da177e4 LT |
786 | bit = irqbits & (1 << irqnumber); |
787 | irqbits &= ~bit; | |
ad671423 PP |
788 | if (bit) { |
789 | enable_irq(irqnumber); | |
790 | ret = 1; | |
791 | } | |
792 | ||
83e714e8 | 793 | spin_unlock_irqrestore(&irqbits_lock, flags); |
ad671423 | 794 | return ret; |
1da177e4 LT |
795 | } |
796 | ||
797 | ||
798 | static int do_vm86_irq_handling(int subfunction, int irqnumber) | |
799 | { | |
800 | int ret; | |
801 | switch (subfunction) { | |
802 | case VM86_GET_AND_RESET_IRQ: { | |
803 | return get_and_reset_irq(irqnumber); | |
804 | } | |
805 | case VM86_GET_IRQ_BITS: { | |
806 | return irqbits; | |
807 | } | |
808 | case VM86_REQUEST_IRQ: { | |
809 | int sig = irqnumber >> 8; | |
810 | int irq = irqnumber & 255; | |
811 | if (!capable(CAP_SYS_ADMIN)) return -EPERM; | |
812 | if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM; | |
813 | if (invalid_vm86_irq(irq)) return -EPERM; | |
814 | if (vm86_irqs[irq].tsk) return -EPERM; | |
815 | ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL); | |
816 | if (ret) return ret; | |
817 | vm86_irqs[irq].sig = sig; | |
818 | vm86_irqs[irq].tsk = current; | |
819 | return irq; | |
820 | } | |
821 | case VM86_FREE_IRQ: { | |
822 | if (invalid_vm86_irq(irqnumber)) return -EPERM; | |
823 | if (!vm86_irqs[irqnumber].tsk) return 0; | |
824 | if (vm86_irqs[irqnumber].tsk != current) return -EPERM; | |
825 | free_vm86_irq(irqnumber); | |
826 | return 0; | |
827 | } | |
828 | } | |
829 | return -EINVAL; | |
830 | } | |
831 |