obj-$(CONFIG_ACPI_SRAT) += srat_32.o
obj-$(CONFIG_EFI) += efi.o efi_stub.o
obj-$(CONFIG_DOUBLEFAULT) += doublefault.o
-obj-$(CONFIG_VM86) += vm86.o
+obj-$(CONFIG_VM86) += vm86_32.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_HPET_TIMER) += hpet.o
obj-$(CONFIG_K8_NB) += k8.o
+++ /dev/null
-/*
- * linux/kernel/vm86.c
- *
- * Copyright (C) 1994 Linus Torvalds
- *
- * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86
- * stack - Manfred Spraul <manfred@colorfullife.com>
- *
- * 22 mar 2002 - Manfred detected the stackfaults, but didn't handle
- * them correctly. Now the emulation will be in a
- * consistent state after stackfaults - Kasper Dupont
- * <kasperd@daimi.au.dk>
- *
- * 22 mar 2002 - Added missing clear_IF in set_vflags_* Kasper Dupont
- * <kasperd@daimi.au.dk>
- *
- * ?? ??? 2002 - Fixed premature returns from handle_vm86_fault
- * caused by Kasper Dupont's changes - Stas Sergeev
- *
- * 4 apr 2002 - Fixed CHECK_IF_IN_TRAP broken by Stas' changes.
- * Kasper Dupont <kasperd@daimi.au.dk>
- *
- * 9 apr 2002 - Changed syntax of macros in handle_vm86_fault.
- * Kasper Dupont <kasperd@daimi.au.dk>
- *
- * 9 apr 2002 - Changed stack access macros to jump to a label
- * instead of returning to userspace. This simplifies
- * do_int, and is needed by handle_vm6_fault. Kasper
- * Dupont <kasperd@daimi.au.dk>
- *
- */
-
-#include <linux/capability.h>
-#include <linux/errno.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/signal.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/highmem.h>
-#include <linux/ptrace.h>
-#include <linux/audit.h>
-#include <linux/stddef.h>
-
-#include <asm/uaccess.h>
-#include <asm/io.h>
-#include <asm/tlbflush.h>
-#include <asm/irq.h>
-
-/*
- * Known problems:
- *
- * Interrupt handling is not guaranteed:
- * - a real x86 will disable all interrupts for one instruction
- * after a "mov ss,xx" to make stack handling atomic even without
- * the 'lss' instruction. We can't guarantee this in v86 mode,
- * as the next instruction might result in a page fault or similar.
- * - a real x86 will have interrupts disabled for one instruction
- * past the 'sti' that enables them. We don't bother with all the
- * details yet.
- *
- * Let's hope these problems do not actually matter for anything.
- */
-
-
-#define KVM86 ((struct kernel_vm86_struct *)regs)
-#define VMPI KVM86->vm86plus
-
-
-/*
- * 8- and 16-bit register defines..
- */
-#define AL(regs) (((unsigned char *)&((regs)->pt.eax))[0])
-#define AH(regs) (((unsigned char *)&((regs)->pt.eax))[1])
-#define IP(regs) (*(unsigned short *)&((regs)->pt.eip))
-#define SP(regs) (*(unsigned short *)&((regs)->pt.esp))
-
-/*
- * virtual flags (16 and 32-bit versions)
- */
-#define VFLAGS (*(unsigned short *)&(current->thread.v86flags))
-#define VEFLAGS (current->thread.v86flags)
-
-#define set_flags(X,new,mask) \
-((X) = ((X) & ~(mask)) | ((new) & (mask)))
-
-#define SAFE_MASK (0xDD5)
-#define RETURN_MASK (0xDFF)
-
-/* convert kernel_vm86_regs to vm86_regs */
-static int copy_vm86_regs_to_user(struct vm86_regs __user *user,
- const struct kernel_vm86_regs *regs)
-{
- int ret = 0;
-
- /* kernel_vm86_regs is missing xgs, so copy everything up to
- (but not including) orig_eax, and then rest including orig_eax. */
- ret += copy_to_user(user, regs, offsetof(struct kernel_vm86_regs, pt.orig_eax));
- ret += copy_to_user(&user->orig_eax, ®s->pt.orig_eax,
- sizeof(struct kernel_vm86_regs) -
- offsetof(struct kernel_vm86_regs, pt.orig_eax));
-
- return ret;
-}
-
-/* convert vm86_regs to kernel_vm86_regs */
-static int copy_vm86_regs_from_user(struct kernel_vm86_regs *regs,
- const struct vm86_regs __user *user,
- unsigned extra)
-{
- int ret = 0;
-
- /* copy eax-xfs inclusive */
- ret += copy_from_user(regs, user, offsetof(struct kernel_vm86_regs, pt.orig_eax));
- /* copy orig_eax-__gsh+extra */
- ret += copy_from_user(®s->pt.orig_eax, &user->orig_eax,
- sizeof(struct kernel_vm86_regs) -
- offsetof(struct kernel_vm86_regs, pt.orig_eax) +
- extra);
- return ret;
-}
-
-struct pt_regs * FASTCALL(save_v86_state(struct kernel_vm86_regs * regs));
-struct pt_regs * fastcall save_v86_state(struct kernel_vm86_regs * regs)
-{
- struct tss_struct *tss;
- struct pt_regs *ret;
- unsigned long tmp;
-
- /*
- * This gets called from entry.S with interrupts disabled, but
- * from process context. Enable interrupts here, before trying
- * to access user space.
- */
- local_irq_enable();
-
- if (!current->thread.vm86_info) {
- printk("no vm86_info: BAD\n");
- do_exit(SIGSEGV);
- }
- set_flags(regs->pt.eflags, VEFLAGS, VIF_MASK | current->thread.v86mask);
- tmp = copy_vm86_regs_to_user(¤t->thread.vm86_info->regs,regs);
- tmp += put_user(current->thread.screen_bitmap,¤t->thread.vm86_info->screen_bitmap);
- if (tmp) {
- printk("vm86: could not access userspace vm86_info\n");
- do_exit(SIGSEGV);
- }
-
- tss = &per_cpu(init_tss, get_cpu());
- current->thread.esp0 = current->thread.saved_esp0;
- current->thread.sysenter_cs = __KERNEL_CS;
- load_esp0(tss, ¤t->thread);
- current->thread.saved_esp0 = 0;
- put_cpu();
-
- ret = KVM86->regs32;
-
- ret->xfs = current->thread.saved_fs;
- loadsegment(gs, current->thread.saved_gs);
-
- return ret;
-}
-
-static void mark_screen_rdonly(struct mm_struct *mm)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- spinlock_t *ptl;
- int i;
-
- pgd = pgd_offset(mm, 0xA0000);
- if (pgd_none_or_clear_bad(pgd))
- goto out;
- pud = pud_offset(pgd, 0xA0000);
- if (pud_none_or_clear_bad(pud))
- goto out;
- pmd = pmd_offset(pud, 0xA0000);
- if (pmd_none_or_clear_bad(pmd))
- goto out;
- pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
- for (i = 0; i < 32; i++) {
- if (pte_present(*pte))
- set_pte(pte, pte_wrprotect(*pte));
- pte++;
- }
- pte_unmap_unlock(pte, ptl);
-out:
- flush_tlb();
-}
-
-
-
-static int do_vm86_irq_handling(int subfunction, int irqnumber);
-static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk);
-
-asmlinkage int sys_vm86old(struct pt_regs regs)
-{
- struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs.ebx;
- struct kernel_vm86_struct info; /* declare this _on top_,
- * this avoids wasting of stack space.
- * This remains on the stack until we
- * return to 32 bit user space.
- */
- struct task_struct *tsk;
- int tmp, ret = -EPERM;
-
- tsk = current;
- if (tsk->thread.saved_esp0)
- goto out;
- tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
- offsetof(struct kernel_vm86_struct, vm86plus) -
- sizeof(info.regs));
- ret = -EFAULT;
- if (tmp)
- goto out;
- memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus);
- info.regs32 = ®s;
- tsk->thread.vm86_info = v86;
- do_sys_vm86(&info, tsk);
- ret = 0; /* we never return here */
-out:
- return ret;
-}
-
-
-asmlinkage int sys_vm86(struct pt_regs regs)
-{
- struct kernel_vm86_struct info; /* declare this _on top_,
- * this avoids wasting of stack space.
- * This remains on the stack until we
- * return to 32 bit user space.
- */
- struct task_struct *tsk;
- int tmp, ret;
- struct vm86plus_struct __user *v86;
-
- tsk = current;
- switch (regs.ebx) {
- case VM86_REQUEST_IRQ:
- case VM86_FREE_IRQ:
- case VM86_GET_IRQ_BITS:
- case VM86_GET_AND_RESET_IRQ:
- ret = do_vm86_irq_handling(regs.ebx, (int)regs.ecx);
- goto out;
- case VM86_PLUS_INSTALL_CHECK:
- /* NOTE: on old vm86 stuff this will return the error
- from access_ok(), because the subfunction is
- interpreted as (invalid) address to vm86_struct.
- So the installation check works.
- */
- ret = 0;
- goto out;
- }
-
- /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
- ret = -EPERM;
- if (tsk->thread.saved_esp0)
- goto out;
- v86 = (struct vm86plus_struct __user *)regs.ecx;
- tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
- offsetof(struct kernel_vm86_struct, regs32) -
- sizeof(info.regs));
- ret = -EFAULT;
- if (tmp)
- goto out;
- info.regs32 = ®s;
- info.vm86plus.is_vm86pus = 1;
- tsk->thread.vm86_info = (struct vm86_struct __user *)v86;
- do_sys_vm86(&info, tsk);
- ret = 0; /* we never return here */
-out:
- return ret;
-}
-
-
-static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk)
-{
- struct tss_struct *tss;
-/*
- * make sure the vm86() system call doesn't try to do anything silly
- */
- info->regs.pt.xds = 0;
- info->regs.pt.xes = 0;
- info->regs.pt.xfs = 0;
-
-/* we are clearing gs later just before "jmp resume_userspace",
- * because it is not saved/restored.
- */
-
-/*
- * The eflags register is also special: we cannot trust that the user
- * has set it up safely, so this makes sure interrupt etc flags are
- * inherited from protected mode.
- */
- VEFLAGS = info->regs.pt.eflags;
- info->regs.pt.eflags &= SAFE_MASK;
- info->regs.pt.eflags |= info->regs32->eflags & ~SAFE_MASK;
- info->regs.pt.eflags |= VM_MASK;
-
- switch (info->cpu_type) {
- case CPU_286:
- tsk->thread.v86mask = 0;
- break;
- case CPU_386:
- tsk->thread.v86mask = NT_MASK | IOPL_MASK;
- break;
- case CPU_486:
- tsk->thread.v86mask = AC_MASK | NT_MASK | IOPL_MASK;
- break;
- default:
- tsk->thread.v86mask = ID_MASK | AC_MASK | NT_MASK | IOPL_MASK;
- break;
- }
-
-/*
- * Save old state, set default return value (%eax) to 0
- */
- info->regs32->eax = 0;
- tsk->thread.saved_esp0 = tsk->thread.esp0;
- tsk->thread.saved_fs = info->regs32->xfs;
- savesegment(gs, tsk->thread.saved_gs);
-
- tss = &per_cpu(init_tss, get_cpu());
- tsk->thread.esp0 = (unsigned long) &info->VM86_TSS_ESP0;
- if (cpu_has_sep)
- tsk->thread.sysenter_cs = 0;
- load_esp0(tss, &tsk->thread);
- put_cpu();
-
- tsk->thread.screen_bitmap = info->screen_bitmap;
- if (info->flags & VM86_SCREEN_BITMAP)
- mark_screen_rdonly(tsk->mm);
-
- /*call audit_syscall_exit since we do not exit via the normal paths */
- if (unlikely(current->audit_context))
- audit_syscall_exit(AUDITSC_RESULT(0), 0);
-
- __asm__ __volatile__(
- "movl %0,%%esp\n\t"
- "movl %1,%%ebp\n\t"
- "mov %2, %%gs\n\t"
- "jmp resume_userspace"
- : /* no outputs */
- :"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0));
- /* we never return here */
-}
-
-static inline void return_to_32bit(struct kernel_vm86_regs * regs16, int retval)
-{
- struct pt_regs * regs32;
-
- regs32 = save_v86_state(regs16);
- regs32->eax = retval;
- __asm__ __volatile__("movl %0,%%esp\n\t"
- "movl %1,%%ebp\n\t"
- "jmp resume_userspace"
- : : "r" (regs32), "r" (current_thread_info()));
-}
-
-static inline void set_IF(struct kernel_vm86_regs * regs)
-{
- VEFLAGS |= VIF_MASK;
- if (VEFLAGS & VIP_MASK)
- return_to_32bit(regs, VM86_STI);
-}
-
-static inline void clear_IF(struct kernel_vm86_regs * regs)
-{
- VEFLAGS &= ~VIF_MASK;
-}
-
-static inline void clear_TF(struct kernel_vm86_regs * regs)
-{
- regs->pt.eflags &= ~TF_MASK;
-}
-
-static inline void clear_AC(struct kernel_vm86_regs * regs)
-{
- regs->pt.eflags &= ~AC_MASK;
-}
-
-/* It is correct to call set_IF(regs) from the set_vflags_*
- * functions. However someone forgot to call clear_IF(regs)
- * in the opposite case.
- * After the command sequence CLI PUSHF STI POPF you should
- * end up with interrups disabled, but you ended up with
- * interrupts enabled.
- * ( I was testing my own changes, but the only bug I
- * could find was in a function I had not changed. )
- * [KD]
- */
-
-static inline void set_vflags_long(unsigned long eflags, struct kernel_vm86_regs * regs)
-{
- set_flags(VEFLAGS, eflags, current->thread.v86mask);
- set_flags(regs->pt.eflags, eflags, SAFE_MASK);
- if (eflags & IF_MASK)
- set_IF(regs);
- else
- clear_IF(regs);
-}
-
-static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs * regs)
-{
- set_flags(VFLAGS, flags, current->thread.v86mask);
- set_flags(regs->pt.eflags, flags, SAFE_MASK);
- if (flags & IF_MASK)
- set_IF(regs);
- else
- clear_IF(regs);
-}
-
-static inline unsigned long get_vflags(struct kernel_vm86_regs * regs)
-{
- unsigned long flags = regs->pt.eflags & RETURN_MASK;
-
- if (VEFLAGS & VIF_MASK)
- flags |= IF_MASK;
- flags |= IOPL_MASK;
- return flags | (VEFLAGS & current->thread.v86mask);
-}
-
-static inline int is_revectored(int nr, struct revectored_struct * bitmap)
-{
- __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0"
- :"=r" (nr)
- :"m" (*bitmap),"r" (nr));
- return nr;
-}
-
-#define val_byte(val, n) (((__u8 *)&val)[n])
-
-#define pushb(base, ptr, val, err_label) \
- do { \
- __u8 __val = val; \
- ptr--; \
- if (put_user(__val, base + ptr) < 0) \
- goto err_label; \
- } while(0)
-
-#define pushw(base, ptr, val, err_label) \
- do { \
- __u16 __val = val; \
- ptr--; \
- if (put_user(val_byte(__val, 1), base + ptr) < 0) \
- goto err_label; \
- ptr--; \
- if (put_user(val_byte(__val, 0), base + ptr) < 0) \
- goto err_label; \
- } while(0)
-
-#define pushl(base, ptr, val, err_label) \
- do { \
- __u32 __val = val; \
- ptr--; \
- if (put_user(val_byte(__val, 3), base + ptr) < 0) \
- goto err_label; \
- ptr--; \
- if (put_user(val_byte(__val, 2), base + ptr) < 0) \
- goto err_label; \
- ptr--; \
- if (put_user(val_byte(__val, 1), base + ptr) < 0) \
- goto err_label; \
- ptr--; \
- if (put_user(val_byte(__val, 0), base + ptr) < 0) \
- goto err_label; \
- } while(0)
-
-#define popb(base, ptr, err_label) \
- ({ \
- __u8 __res; \
- if (get_user(__res, base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- __res; \
- })
-
-#define popw(base, ptr, err_label) \
- ({ \
- __u16 __res; \
- if (get_user(val_byte(__res, 0), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- if (get_user(val_byte(__res, 1), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- __res; \
- })
-
-#define popl(base, ptr, err_label) \
- ({ \
- __u32 __res; \
- if (get_user(val_byte(__res, 0), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- if (get_user(val_byte(__res, 1), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- if (get_user(val_byte(__res, 2), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- if (get_user(val_byte(__res, 3), base + ptr) < 0) \
- goto err_label; \
- ptr++; \
- __res; \
- })
-
-/* There are so many possible reasons for this function to return
- * VM86_INTx, so adding another doesn't bother me. We can expect
- * userspace programs to be able to handle it. (Getting a problem
- * in userspace is always better than an Oops anyway.) [KD]
- */
-static void do_int(struct kernel_vm86_regs *regs, int i,
- unsigned char __user * ssp, unsigned short sp)
-{
- unsigned long __user *intr_ptr;
- unsigned long segoffs;
-
- if (regs->pt.xcs == BIOSSEG)
- goto cannot_handle;
- if (is_revectored(i, &KVM86->int_revectored))
- goto cannot_handle;
- if (i==0x21 && is_revectored(AH(regs),&KVM86->int21_revectored))
- goto cannot_handle;
- intr_ptr = (unsigned long __user *) (i << 2);
- if (get_user(segoffs, intr_ptr))
- goto cannot_handle;
- if ((segoffs >> 16) == BIOSSEG)
- goto cannot_handle;
- pushw(ssp, sp, get_vflags(regs), cannot_handle);
- pushw(ssp, sp, regs->pt.xcs, cannot_handle);
- pushw(ssp, sp, IP(regs), cannot_handle);
- regs->pt.xcs = segoffs >> 16;
- SP(regs) -= 6;
- IP(regs) = segoffs & 0xffff;
- clear_TF(regs);
- clear_IF(regs);
- clear_AC(regs);
- return;
-
-cannot_handle:
- return_to_32bit(regs, VM86_INTx + (i << 8));
-}
-
-int handle_vm86_trap(struct kernel_vm86_regs * regs, long error_code, int trapno)
-{
- if (VMPI.is_vm86pus) {
- if ( (trapno==3) || (trapno==1) )
- return_to_32bit(regs, VM86_TRAP + (trapno << 8));
- do_int(regs, trapno, (unsigned char __user *) (regs->pt.xss << 4), SP(regs));
- return 0;
- }
- if (trapno !=1)
- return 1; /* we let this handle by the calling routine */
- if (current->ptrace & PT_PTRACED) {
- unsigned long flags;
- spin_lock_irqsave(¤t->sighand->siglock, flags);
- sigdelset(¤t->blocked, SIGTRAP);
- recalc_sigpending();
- spin_unlock_irqrestore(¤t->sighand->siglock, flags);
- }
- send_sig(SIGTRAP, current, 1);
- current->thread.trap_no = trapno;
- current->thread.error_code = error_code;
- return 0;
-}
-
-void handle_vm86_fault(struct kernel_vm86_regs * regs, long error_code)
-{
- unsigned char opcode;
- unsigned char __user *csp;
- unsigned char __user *ssp;
- unsigned short ip, sp, orig_flags;
- int data32, pref_done;
-
-#define CHECK_IF_IN_TRAP \
- if (VMPI.vm86dbg_active && VMPI.vm86dbg_TFpendig) \
- newflags |= TF_MASK
-#define VM86_FAULT_RETURN do { \
- if (VMPI.force_return_for_pic && (VEFLAGS & (IF_MASK | VIF_MASK))) \
- return_to_32bit(regs, VM86_PICRETURN); \
- if (orig_flags & TF_MASK) \
- handle_vm86_trap(regs, 0, 1); \
- return; } while (0)
-
- orig_flags = *(unsigned short *)®s->pt.eflags;
-
- csp = (unsigned char __user *) (regs->pt.xcs << 4);
- ssp = (unsigned char __user *) (regs->pt.xss << 4);
- sp = SP(regs);
- ip = IP(regs);
-
- data32 = 0;
- pref_done = 0;
- do {
- switch (opcode = popb(csp, ip, simulate_sigsegv)) {
- case 0x66: /* 32-bit data */ data32=1; break;
- case 0x67: /* 32-bit address */ break;
- case 0x2e: /* CS */ break;
- case 0x3e: /* DS */ break;
- case 0x26: /* ES */ break;
- case 0x36: /* SS */ break;
- case 0x65: /* GS */ break;
- case 0x64: /* FS */ break;
- case 0xf2: /* repnz */ break;
- case 0xf3: /* rep */ break;
- default: pref_done = 1;
- }
- } while (!pref_done);
-
- switch (opcode) {
-
- /* pushf */
- case 0x9c:
- if (data32) {
- pushl(ssp, sp, get_vflags(regs), simulate_sigsegv);
- SP(regs) -= 4;
- } else {
- pushw(ssp, sp, get_vflags(regs), simulate_sigsegv);
- SP(regs) -= 2;
- }
- IP(regs) = ip;
- VM86_FAULT_RETURN;
-
- /* popf */
- case 0x9d:
- {
- unsigned long newflags;
- if (data32) {
- newflags=popl(ssp, sp, simulate_sigsegv);
- SP(regs) += 4;
- } else {
- newflags = popw(ssp, sp, simulate_sigsegv);
- SP(regs) += 2;
- }
- IP(regs) = ip;
- CHECK_IF_IN_TRAP;
- if (data32) {
- set_vflags_long(newflags, regs);
- } else {
- set_vflags_short(newflags, regs);
- }
- VM86_FAULT_RETURN;
- }
-
- /* int xx */
- case 0xcd: {
- int intno=popb(csp, ip, simulate_sigsegv);
- IP(regs) = ip;
- if (VMPI.vm86dbg_active) {
- if ( (1 << (intno &7)) & VMPI.vm86dbg_intxxtab[intno >> 3] )
- return_to_32bit(regs, VM86_INTx + (intno << 8));
- }
- do_int(regs, intno, ssp, sp);
- return;
- }
-
- /* iret */
- case 0xcf:
- {
- unsigned long newip;
- unsigned long newcs;
- unsigned long newflags;
- if (data32) {
- newip=popl(ssp, sp, simulate_sigsegv);
- newcs=popl(ssp, sp, simulate_sigsegv);
- newflags=popl(ssp, sp, simulate_sigsegv);
- SP(regs) += 12;
- } else {
- newip = popw(ssp, sp, simulate_sigsegv);
- newcs = popw(ssp, sp, simulate_sigsegv);
- newflags = popw(ssp, sp, simulate_sigsegv);
- SP(regs) += 6;
- }
- IP(regs) = newip;
- regs->pt.xcs = newcs;
- CHECK_IF_IN_TRAP;
- if (data32) {
- set_vflags_long(newflags, regs);
- } else {
- set_vflags_short(newflags, regs);
- }
- VM86_FAULT_RETURN;
- }
-
- /* cli */
- case 0xfa:
- IP(regs) = ip;
- clear_IF(regs);
- VM86_FAULT_RETURN;
-
- /* sti */
- /*
- * Damn. This is incorrect: the 'sti' instruction should actually
- * enable interrupts after the /next/ instruction. Not good.
- *
- * Probably needs some horsing around with the TF flag. Aiee..
- */
- case 0xfb:
- IP(regs) = ip;
- set_IF(regs);
- VM86_FAULT_RETURN;
-
- default:
- return_to_32bit(regs, VM86_UNKNOWN);
- }
-
- return;
-
-simulate_sigsegv:
- /* FIXME: After a long discussion with Stas we finally
- * agreed, that this is wrong. Here we should
- * really send a SIGSEGV to the user program.
- * But how do we create the correct context? We
- * are inside a general protection fault handler
- * and has just returned from a page fault handler.
- * The correct context for the signal handler
- * should be a mixture of the two, but how do we
- * get the information? [KD]
- */
- return_to_32bit(regs, VM86_UNKNOWN);
-}
-
-/* ---------------- vm86 special IRQ passing stuff ----------------- */
-
-#define VM86_IRQNAME "vm86irq"
-
-static struct vm86_irqs {
- struct task_struct *tsk;
- int sig;
-} vm86_irqs[16];
-
-static DEFINE_SPINLOCK(irqbits_lock);
-static int irqbits;
-
-#define ALLOWED_SIGS ( 1 /* 0 = don't send a signal */ \
- | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \
- | (1 << SIGUNUSED) )
-
-static irqreturn_t irq_handler(int intno, void *dev_id)
-{
- int irq_bit;
- unsigned long flags;
-
- spin_lock_irqsave(&irqbits_lock, flags);
- irq_bit = 1 << intno;
- if ((irqbits & irq_bit) || ! vm86_irqs[intno].tsk)
- goto out;
- irqbits |= irq_bit;
- if (vm86_irqs[intno].sig)
- send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1);
- /*
- * IRQ will be re-enabled when user asks for the irq (whether
- * polling or as a result of the signal)
- */
- disable_irq_nosync(intno);
- spin_unlock_irqrestore(&irqbits_lock, flags);
- return IRQ_HANDLED;
-
-out:
- spin_unlock_irqrestore(&irqbits_lock, flags);
- return IRQ_NONE;
-}
-
-static inline void free_vm86_irq(int irqnumber)
-{
- unsigned long flags;
-
- free_irq(irqnumber, NULL);
- vm86_irqs[irqnumber].tsk = NULL;
-
- spin_lock_irqsave(&irqbits_lock, flags);
- irqbits &= ~(1 << irqnumber);
- spin_unlock_irqrestore(&irqbits_lock, flags);
-}
-
-void release_vm86_irqs(struct task_struct *task)
-{
- int i;
- for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++)
- if (vm86_irqs[i].tsk == task)
- free_vm86_irq(i);
-}
-
-static inline int get_and_reset_irq(int irqnumber)
-{
- int bit;
- unsigned long flags;
- int ret = 0;
-
- if (invalid_vm86_irq(irqnumber)) return 0;
- if (vm86_irqs[irqnumber].tsk != current) return 0;
- spin_lock_irqsave(&irqbits_lock, flags);
- bit = irqbits & (1 << irqnumber);
- irqbits &= ~bit;
- if (bit) {
- enable_irq(irqnumber);
- ret = 1;
- }
-
- spin_unlock_irqrestore(&irqbits_lock, flags);
- return ret;
-}
-
-
-static int do_vm86_irq_handling(int subfunction, int irqnumber)
-{
- int ret;
- switch (subfunction) {
- case VM86_GET_AND_RESET_IRQ: {
- return get_and_reset_irq(irqnumber);
- }
- case VM86_GET_IRQ_BITS: {
- return irqbits;
- }
- case VM86_REQUEST_IRQ: {
- int sig = irqnumber >> 8;
- int irq = irqnumber & 255;
- if (!capable(CAP_SYS_ADMIN)) return -EPERM;
- if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM;
- if (invalid_vm86_irq(irq)) return -EPERM;
- if (vm86_irqs[irq].tsk) return -EPERM;
- ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL);
- if (ret) return ret;
- vm86_irqs[irq].sig = sig;
- vm86_irqs[irq].tsk = current;
- return irq;
- }
- case VM86_FREE_IRQ: {
- if (invalid_vm86_irq(irqnumber)) return -EPERM;
- if (!vm86_irqs[irqnumber].tsk) return 0;
- if (vm86_irqs[irqnumber].tsk != current) return -EPERM;
- free_vm86_irq(irqnumber);
- return 0;
- }
- }
- return -EINVAL;
-}
-
--- /dev/null
+/*
+ * linux/kernel/vm86.c
+ *
+ * Copyright (C) 1994 Linus Torvalds
+ *
+ * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86
+ * stack - Manfred Spraul <manfred@colorfullife.com>
+ *
+ * 22 mar 2002 - Manfred detected the stackfaults, but didn't handle
+ * them correctly. Now the emulation will be in a
+ * consistent state after stackfaults - Kasper Dupont
+ * <kasperd@daimi.au.dk>
+ *
+ * 22 mar 2002 - Added missing clear_IF in set_vflags_* Kasper Dupont
+ * <kasperd@daimi.au.dk>
+ *
+ * ?? ??? 2002 - Fixed premature returns from handle_vm86_fault
+ * caused by Kasper Dupont's changes - Stas Sergeev
+ *
+ * 4 apr 2002 - Fixed CHECK_IF_IN_TRAP broken by Stas' changes.
+ * Kasper Dupont <kasperd@daimi.au.dk>
+ *
+ * 9 apr 2002 - Changed syntax of macros in handle_vm86_fault.
+ * Kasper Dupont <kasperd@daimi.au.dk>
+ *
+ * 9 apr 2002 - Changed stack access macros to jump to a label
+ * instead of returning to userspace. This simplifies
+ * do_int, and is needed by handle_vm6_fault. Kasper
+ * Dupont <kasperd@daimi.au.dk>
+ *
+ */
+
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/audit.h>
+#include <linux/stddef.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/tlbflush.h>
+#include <asm/irq.h>
+
+/*
+ * Known problems:
+ *
+ * Interrupt handling is not guaranteed:
+ * - a real x86 will disable all interrupts for one instruction
+ * after a "mov ss,xx" to make stack handling atomic even without
+ * the 'lss' instruction. We can't guarantee this in v86 mode,
+ * as the next instruction might result in a page fault or similar.
+ * - a real x86 will have interrupts disabled for one instruction
+ * past the 'sti' that enables them. We don't bother with all the
+ * details yet.
+ *
+ * Let's hope these problems do not actually matter for anything.
+ */
+
+
+#define KVM86 ((struct kernel_vm86_struct *)regs)
+#define VMPI KVM86->vm86plus
+
+
+/*
+ * 8- and 16-bit register defines..
+ */
+#define AL(regs) (((unsigned char *)&((regs)->pt.eax))[0])
+#define AH(regs) (((unsigned char *)&((regs)->pt.eax))[1])
+#define IP(regs) (*(unsigned short *)&((regs)->pt.eip))
+#define SP(regs) (*(unsigned short *)&((regs)->pt.esp))
+
+/*
+ * virtual flags (16 and 32-bit versions)
+ */
+#define VFLAGS (*(unsigned short *)&(current->thread.v86flags))
+#define VEFLAGS (current->thread.v86flags)
+
+#define set_flags(X,new,mask) \
+((X) = ((X) & ~(mask)) | ((new) & (mask)))
+
+#define SAFE_MASK (0xDD5)
+#define RETURN_MASK (0xDFF)
+
+/* convert kernel_vm86_regs to vm86_regs */
+static int copy_vm86_regs_to_user(struct vm86_regs __user *user,
+ const struct kernel_vm86_regs *regs)
+{
+ int ret = 0;
+
+ /* kernel_vm86_regs is missing xgs, so copy everything up to
+ (but not including) orig_eax, and then rest including orig_eax. */
+ ret += copy_to_user(user, regs, offsetof(struct kernel_vm86_regs, pt.orig_eax));
+ ret += copy_to_user(&user->orig_eax, ®s->pt.orig_eax,
+ sizeof(struct kernel_vm86_regs) -
+ offsetof(struct kernel_vm86_regs, pt.orig_eax));
+
+ return ret;
+}
+
+/* convert vm86_regs to kernel_vm86_regs */
+static int copy_vm86_regs_from_user(struct kernel_vm86_regs *regs,
+ const struct vm86_regs __user *user,
+ unsigned extra)
+{
+ int ret = 0;
+
+ /* copy eax-xfs inclusive */
+ ret += copy_from_user(regs, user, offsetof(struct kernel_vm86_regs, pt.orig_eax));
+ /* copy orig_eax-__gsh+extra */
+ ret += copy_from_user(®s->pt.orig_eax, &user->orig_eax,
+ sizeof(struct kernel_vm86_regs) -
+ offsetof(struct kernel_vm86_regs, pt.orig_eax) +
+ extra);
+ return ret;
+}
+
+struct pt_regs * FASTCALL(save_v86_state(struct kernel_vm86_regs * regs));
+struct pt_regs * fastcall save_v86_state(struct kernel_vm86_regs * regs)
+{
+ struct tss_struct *tss;
+ struct pt_regs *ret;
+ unsigned long tmp;
+
+ /*
+ * This gets called from entry.S with interrupts disabled, but
+ * from process context. Enable interrupts here, before trying
+ * to access user space.
+ */
+ local_irq_enable();
+
+ if (!current->thread.vm86_info) {
+ printk("no vm86_info: BAD\n");
+ do_exit(SIGSEGV);
+ }
+ set_flags(regs->pt.eflags, VEFLAGS, VIF_MASK | current->thread.v86mask);
+ tmp = copy_vm86_regs_to_user(¤t->thread.vm86_info->regs,regs);
+ tmp += put_user(current->thread.screen_bitmap,¤t->thread.vm86_info->screen_bitmap);
+ if (tmp) {
+ printk("vm86: could not access userspace vm86_info\n");
+ do_exit(SIGSEGV);
+ }
+
+ tss = &per_cpu(init_tss, get_cpu());
+ current->thread.esp0 = current->thread.saved_esp0;
+ current->thread.sysenter_cs = __KERNEL_CS;
+ load_esp0(tss, ¤t->thread);
+ current->thread.saved_esp0 = 0;
+ put_cpu();
+
+ ret = KVM86->regs32;
+
+ ret->xfs = current->thread.saved_fs;
+ loadsegment(gs, current->thread.saved_gs);
+
+ return ret;
+}
+
+static void mark_screen_rdonly(struct mm_struct *mm)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ spinlock_t *ptl;
+ int i;
+
+ pgd = pgd_offset(mm, 0xA0000);
+ if (pgd_none_or_clear_bad(pgd))
+ goto out;
+ pud = pud_offset(pgd, 0xA0000);
+ if (pud_none_or_clear_bad(pud))
+ goto out;
+ pmd = pmd_offset(pud, 0xA0000);
+ if (pmd_none_or_clear_bad(pmd))
+ goto out;
+ pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
+ for (i = 0; i < 32; i++) {
+ if (pte_present(*pte))
+ set_pte(pte, pte_wrprotect(*pte));
+ pte++;
+ }
+ pte_unmap_unlock(pte, ptl);
+out:
+ flush_tlb();
+}
+
+
+
+static int do_vm86_irq_handling(int subfunction, int irqnumber);
+static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk);
+
+asmlinkage int sys_vm86old(struct pt_regs regs)
+{
+ struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs.ebx;
+ struct kernel_vm86_struct info; /* declare this _on top_,
+ * this avoids wasting of stack space.
+ * This remains on the stack until we
+ * return to 32 bit user space.
+ */
+ struct task_struct *tsk;
+ int tmp, ret = -EPERM;
+
+ tsk = current;
+ if (tsk->thread.saved_esp0)
+ goto out;
+ tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
+ offsetof(struct kernel_vm86_struct, vm86plus) -
+ sizeof(info.regs));
+ ret = -EFAULT;
+ if (tmp)
+ goto out;
+ memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus);
+ info.regs32 = ®s;
+ tsk->thread.vm86_info = v86;
+ do_sys_vm86(&info, tsk);
+ ret = 0; /* we never return here */
+out:
+ return ret;
+}
+
+
+asmlinkage int sys_vm86(struct pt_regs regs)
+{
+ struct kernel_vm86_struct info; /* declare this _on top_,
+ * this avoids wasting of stack space.
+ * This remains on the stack until we
+ * return to 32 bit user space.
+ */
+ struct task_struct *tsk;
+ int tmp, ret;
+ struct vm86plus_struct __user *v86;
+
+ tsk = current;
+ switch (regs.ebx) {
+ case VM86_REQUEST_IRQ:
+ case VM86_FREE_IRQ:
+ case VM86_GET_IRQ_BITS:
+ case VM86_GET_AND_RESET_IRQ:
+ ret = do_vm86_irq_handling(regs.ebx, (int)regs.ecx);
+ goto out;
+ case VM86_PLUS_INSTALL_CHECK:
+ /* NOTE: on old vm86 stuff this will return the error
+ from access_ok(), because the subfunction is
+ interpreted as (invalid) address to vm86_struct.
+ So the installation check works.
+ */
+ ret = 0;
+ goto out;
+ }
+
+ /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
+ ret = -EPERM;
+ if (tsk->thread.saved_esp0)
+ goto out;
+ v86 = (struct vm86plus_struct __user *)regs.ecx;
+ tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
+ offsetof(struct kernel_vm86_struct, regs32) -
+ sizeof(info.regs));
+ ret = -EFAULT;
+ if (tmp)
+ goto out;
+ info.regs32 = ®s;
+ info.vm86plus.is_vm86pus = 1;
+ tsk->thread.vm86_info = (struct vm86_struct __user *)v86;
+ do_sys_vm86(&info, tsk);
+ ret = 0; /* we never return here */
+out:
+ return ret;
+}
+
+
+static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk)
+{
+ struct tss_struct *tss;
+/*
+ * make sure the vm86() system call doesn't try to do anything silly
+ */
+ info->regs.pt.xds = 0;
+ info->regs.pt.xes = 0;
+ info->regs.pt.xfs = 0;
+
+/* we are clearing gs later just before "jmp resume_userspace",
+ * because it is not saved/restored.
+ */
+
+/*
+ * The eflags register is also special: we cannot trust that the user
+ * has set it up safely, so this makes sure interrupt etc flags are
+ * inherited from protected mode.
+ */
+ VEFLAGS = info->regs.pt.eflags;
+ info->regs.pt.eflags &= SAFE_MASK;
+ info->regs.pt.eflags |= info->regs32->eflags & ~SAFE_MASK;
+ info->regs.pt.eflags |= VM_MASK;
+
+ switch (info->cpu_type) {
+ case CPU_286:
+ tsk->thread.v86mask = 0;
+ break;
+ case CPU_386:
+ tsk->thread.v86mask = NT_MASK | IOPL_MASK;
+ break;
+ case CPU_486:
+ tsk->thread.v86mask = AC_MASK | NT_MASK | IOPL_MASK;
+ break;
+ default:
+ tsk->thread.v86mask = ID_MASK | AC_MASK | NT_MASK | IOPL_MASK;
+ break;
+ }
+
+/*
+ * Save old state, set default return value (%eax) to 0
+ */
+ info->regs32->eax = 0;
+ tsk->thread.saved_esp0 = tsk->thread.esp0;
+ tsk->thread.saved_fs = info->regs32->xfs;
+ savesegment(gs, tsk->thread.saved_gs);
+
+ tss = &per_cpu(init_tss, get_cpu());
+ tsk->thread.esp0 = (unsigned long) &info->VM86_TSS_ESP0;
+ if (cpu_has_sep)
+ tsk->thread.sysenter_cs = 0;
+ load_esp0(tss, &tsk->thread);
+ put_cpu();
+
+ tsk->thread.screen_bitmap = info->screen_bitmap;
+ if (info->flags & VM86_SCREEN_BITMAP)
+ mark_screen_rdonly(tsk->mm);
+
+ /*call audit_syscall_exit since we do not exit via the normal paths */
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(0), 0);
+
+ __asm__ __volatile__(
+ "movl %0,%%esp\n\t"
+ "movl %1,%%ebp\n\t"
+ "mov %2, %%gs\n\t"
+ "jmp resume_userspace"
+ : /* no outputs */
+ :"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0));
+ /* we never return here */
+}
+
+static inline void return_to_32bit(struct kernel_vm86_regs * regs16, int retval)
+{
+ struct pt_regs * regs32;
+
+ regs32 = save_v86_state(regs16);
+ regs32->eax = retval;
+ __asm__ __volatile__("movl %0,%%esp\n\t"
+ "movl %1,%%ebp\n\t"
+ "jmp resume_userspace"
+ : : "r" (regs32), "r" (current_thread_info()));
+}
+
+static inline void set_IF(struct kernel_vm86_regs * regs)
+{
+ VEFLAGS |= VIF_MASK;
+ if (VEFLAGS & VIP_MASK)
+ return_to_32bit(regs, VM86_STI);
+}
+
+static inline void clear_IF(struct kernel_vm86_regs * regs)
+{
+ VEFLAGS &= ~VIF_MASK;
+}
+
+static inline void clear_TF(struct kernel_vm86_regs * regs)
+{
+ regs->pt.eflags &= ~TF_MASK;
+}
+
+static inline void clear_AC(struct kernel_vm86_regs * regs)
+{
+ regs->pt.eflags &= ~AC_MASK;
+}
+
+/* It is correct to call set_IF(regs) from the set_vflags_*
+ * functions. However someone forgot to call clear_IF(regs)
+ * in the opposite case.
+ * After the command sequence CLI PUSHF STI POPF you should
+ * end up with interrups disabled, but you ended up with
+ * interrupts enabled.
+ * ( I was testing my own changes, but the only bug I
+ * could find was in a function I had not changed. )
+ * [KD]
+ */
+
+static inline void set_vflags_long(unsigned long eflags, struct kernel_vm86_regs * regs)
+{
+ set_flags(VEFLAGS, eflags, current->thread.v86mask);
+ set_flags(regs->pt.eflags, eflags, SAFE_MASK);
+ if (eflags & IF_MASK)
+ set_IF(regs);
+ else
+ clear_IF(regs);
+}
+
+static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs * regs)
+{
+ set_flags(VFLAGS, flags, current->thread.v86mask);
+ set_flags(regs->pt.eflags, flags, SAFE_MASK);
+ if (flags & IF_MASK)
+ set_IF(regs);
+ else
+ clear_IF(regs);
+}
+
+static inline unsigned long get_vflags(struct kernel_vm86_regs * regs)
+{
+ unsigned long flags = regs->pt.eflags & RETURN_MASK;
+
+ if (VEFLAGS & VIF_MASK)
+ flags |= IF_MASK;
+ flags |= IOPL_MASK;
+ return flags | (VEFLAGS & current->thread.v86mask);
+}
+
+static inline int is_revectored(int nr, struct revectored_struct * bitmap)
+{
+ __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0"
+ :"=r" (nr)
+ :"m" (*bitmap),"r" (nr));
+ return nr;
+}
+
+#define val_byte(val, n) (((__u8 *)&val)[n])
+
+#define pushb(base, ptr, val, err_label) \
+ do { \
+ __u8 __val = val; \
+ ptr--; \
+ if (put_user(__val, base + ptr) < 0) \
+ goto err_label; \
+ } while(0)
+
+#define pushw(base, ptr, val, err_label) \
+ do { \
+ __u16 __val = val; \
+ ptr--; \
+ if (put_user(val_byte(__val, 1), base + ptr) < 0) \
+ goto err_label; \
+ ptr--; \
+ if (put_user(val_byte(__val, 0), base + ptr) < 0) \
+ goto err_label; \
+ } while(0)
+
+#define pushl(base, ptr, val, err_label) \
+ do { \
+ __u32 __val = val; \
+ ptr--; \
+ if (put_user(val_byte(__val, 3), base + ptr) < 0) \
+ goto err_label; \
+ ptr--; \
+ if (put_user(val_byte(__val, 2), base + ptr) < 0) \
+ goto err_label; \
+ ptr--; \
+ if (put_user(val_byte(__val, 1), base + ptr) < 0) \
+ goto err_label; \
+ ptr--; \
+ if (put_user(val_byte(__val, 0), base + ptr) < 0) \
+ goto err_label; \
+ } while(0)
+
+#define popb(base, ptr, err_label) \
+ ({ \
+ __u8 __res; \
+ if (get_user(__res, base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ __res; \
+ })
+
+#define popw(base, ptr, err_label) \
+ ({ \
+ __u16 __res; \
+ if (get_user(val_byte(__res, 0), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ if (get_user(val_byte(__res, 1), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ __res; \
+ })
+
+#define popl(base, ptr, err_label) \
+ ({ \
+ __u32 __res; \
+ if (get_user(val_byte(__res, 0), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ if (get_user(val_byte(__res, 1), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ if (get_user(val_byte(__res, 2), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ if (get_user(val_byte(__res, 3), base + ptr) < 0) \
+ goto err_label; \
+ ptr++; \
+ __res; \
+ })
+
+/* There are so many possible reasons for this function to return
+ * VM86_INTx, so adding another doesn't bother me. We can expect
+ * userspace programs to be able to handle it. (Getting a problem
+ * in userspace is always better than an Oops anyway.) [KD]
+ */
+static void do_int(struct kernel_vm86_regs *regs, int i,
+ unsigned char __user * ssp, unsigned short sp)
+{
+ unsigned long __user *intr_ptr;
+ unsigned long segoffs;
+
+ if (regs->pt.xcs == BIOSSEG)
+ goto cannot_handle;
+ if (is_revectored(i, &KVM86->int_revectored))
+ goto cannot_handle;
+ if (i==0x21 && is_revectored(AH(regs),&KVM86->int21_revectored))
+ goto cannot_handle;
+ intr_ptr = (unsigned long __user *) (i << 2);
+ if (get_user(segoffs, intr_ptr))
+ goto cannot_handle;
+ if ((segoffs >> 16) == BIOSSEG)
+ goto cannot_handle;
+ pushw(ssp, sp, get_vflags(regs), cannot_handle);
+ pushw(ssp, sp, regs->pt.xcs, cannot_handle);
+ pushw(ssp, sp, IP(regs), cannot_handle);
+ regs->pt.xcs = segoffs >> 16;
+ SP(regs) -= 6;
+ IP(regs) = segoffs & 0xffff;
+ clear_TF(regs);
+ clear_IF(regs);
+ clear_AC(regs);
+ return;
+
+cannot_handle:
+ return_to_32bit(regs, VM86_INTx + (i << 8));
+}
+
+int handle_vm86_trap(struct kernel_vm86_regs * regs, long error_code, int trapno)
+{
+ if (VMPI.is_vm86pus) {
+ if ( (trapno==3) || (trapno==1) )
+ return_to_32bit(regs, VM86_TRAP + (trapno << 8));
+ do_int(regs, trapno, (unsigned char __user *) (regs->pt.xss << 4), SP(regs));
+ return 0;
+ }
+ if (trapno !=1)
+ return 1; /* we let this handle by the calling routine */
+ if (current->ptrace & PT_PTRACED) {
+ unsigned long flags;
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ sigdelset(¤t->blocked, SIGTRAP);
+ recalc_sigpending();
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
+ }
+ send_sig(SIGTRAP, current, 1);
+ current->thread.trap_no = trapno;
+ current->thread.error_code = error_code;
+ return 0;
+}
+
+void handle_vm86_fault(struct kernel_vm86_regs * regs, long error_code)
+{
+ unsigned char opcode;
+ unsigned char __user *csp;
+ unsigned char __user *ssp;
+ unsigned short ip, sp, orig_flags;
+ int data32, pref_done;
+
+#define CHECK_IF_IN_TRAP \
+ if (VMPI.vm86dbg_active && VMPI.vm86dbg_TFpendig) \
+ newflags |= TF_MASK
+#define VM86_FAULT_RETURN do { \
+ if (VMPI.force_return_for_pic && (VEFLAGS & (IF_MASK | VIF_MASK))) \
+ return_to_32bit(regs, VM86_PICRETURN); \
+ if (orig_flags & TF_MASK) \
+ handle_vm86_trap(regs, 0, 1); \
+ return; } while (0)
+
+ orig_flags = *(unsigned short *)®s->pt.eflags;
+
+ csp = (unsigned char __user *) (regs->pt.xcs << 4);
+ ssp = (unsigned char __user *) (regs->pt.xss << 4);
+ sp = SP(regs);
+ ip = IP(regs);
+
+ data32 = 0;
+ pref_done = 0;
+ do {
+ switch (opcode = popb(csp, ip, simulate_sigsegv)) {
+ case 0x66: /* 32-bit data */ data32=1; break;
+ case 0x67: /* 32-bit address */ break;
+ case 0x2e: /* CS */ break;
+ case 0x3e: /* DS */ break;
+ case 0x26: /* ES */ break;
+ case 0x36: /* SS */ break;
+ case 0x65: /* GS */ break;
+ case 0x64: /* FS */ break;
+ case 0xf2: /* repnz */ break;
+ case 0xf3: /* rep */ break;
+ default: pref_done = 1;
+ }
+ } while (!pref_done);
+
+ switch (opcode) {
+
+ /* pushf */
+ case 0x9c:
+ if (data32) {
+ pushl(ssp, sp, get_vflags(regs), simulate_sigsegv);
+ SP(regs) -= 4;
+ } else {
+ pushw(ssp, sp, get_vflags(regs), simulate_sigsegv);
+ SP(regs) -= 2;
+ }
+ IP(regs) = ip;
+ VM86_FAULT_RETURN;
+
+ /* popf */
+ case 0x9d:
+ {
+ unsigned long newflags;
+ if (data32) {
+ newflags=popl(ssp, sp, simulate_sigsegv);
+ SP(regs) += 4;
+ } else {
+ newflags = popw(ssp, sp, simulate_sigsegv);
+ SP(regs) += 2;
+ }
+ IP(regs) = ip;
+ CHECK_IF_IN_TRAP;
+ if (data32) {
+ set_vflags_long(newflags, regs);
+ } else {
+ set_vflags_short(newflags, regs);
+ }
+ VM86_FAULT_RETURN;
+ }
+
+ /* int xx */
+ case 0xcd: {
+ int intno=popb(csp, ip, simulate_sigsegv);
+ IP(regs) = ip;
+ if (VMPI.vm86dbg_active) {
+ if ( (1 << (intno &7)) & VMPI.vm86dbg_intxxtab[intno >> 3] )
+ return_to_32bit(regs, VM86_INTx + (intno << 8));
+ }
+ do_int(regs, intno, ssp, sp);
+ return;
+ }
+
+ /* iret */
+ case 0xcf:
+ {
+ unsigned long newip;
+ unsigned long newcs;
+ unsigned long newflags;
+ if (data32) {
+ newip=popl(ssp, sp, simulate_sigsegv);
+ newcs=popl(ssp, sp, simulate_sigsegv);
+ newflags=popl(ssp, sp, simulate_sigsegv);
+ SP(regs) += 12;
+ } else {
+ newip = popw(ssp, sp, simulate_sigsegv);
+ newcs = popw(ssp, sp, simulate_sigsegv);
+ newflags = popw(ssp, sp, simulate_sigsegv);
+ SP(regs) += 6;
+ }
+ IP(regs) = newip;
+ regs->pt.xcs = newcs;
+ CHECK_IF_IN_TRAP;
+ if (data32) {
+ set_vflags_long(newflags, regs);
+ } else {
+ set_vflags_short(newflags, regs);
+ }
+ VM86_FAULT_RETURN;
+ }
+
+ /* cli */
+ case 0xfa:
+ IP(regs) = ip;
+ clear_IF(regs);
+ VM86_FAULT_RETURN;
+
+ /* sti */
+ /*
+ * Damn. This is incorrect: the 'sti' instruction should actually
+ * enable interrupts after the /next/ instruction. Not good.
+ *
+ * Probably needs some horsing around with the TF flag. Aiee..
+ */
+ case 0xfb:
+ IP(regs) = ip;
+ set_IF(regs);
+ VM86_FAULT_RETURN;
+
+ default:
+ return_to_32bit(regs, VM86_UNKNOWN);
+ }
+
+ return;
+
+simulate_sigsegv:
+ /* FIXME: After a long discussion with Stas we finally
+ * agreed, that this is wrong. Here we should
+ * really send a SIGSEGV to the user program.
+ * But how do we create the correct context? We
+ * are inside a general protection fault handler
+ * and has just returned from a page fault handler.
+ * The correct context for the signal handler
+ * should be a mixture of the two, but how do we
+ * get the information? [KD]
+ */
+ return_to_32bit(regs, VM86_UNKNOWN);
+}
+
+/* ---------------- vm86 special IRQ passing stuff ----------------- */
+
+#define VM86_IRQNAME "vm86irq"
+
+static struct vm86_irqs {
+ struct task_struct *tsk;
+ int sig;
+} vm86_irqs[16];
+
+static DEFINE_SPINLOCK(irqbits_lock);
+static int irqbits;
+
+#define ALLOWED_SIGS ( 1 /* 0 = don't send a signal */ \
+ | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \
+ | (1 << SIGUNUSED) )
+
+static irqreturn_t irq_handler(int intno, void *dev_id)
+{
+ int irq_bit;
+ unsigned long flags;
+
+ spin_lock_irqsave(&irqbits_lock, flags);
+ irq_bit = 1 << intno;
+ if ((irqbits & irq_bit) || ! vm86_irqs[intno].tsk)
+ goto out;
+ irqbits |= irq_bit;
+ if (vm86_irqs[intno].sig)
+ send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1);
+ /*
+ * IRQ will be re-enabled when user asks for the irq (whether
+ * polling or as a result of the signal)
+ */
+ disable_irq_nosync(intno);
+ spin_unlock_irqrestore(&irqbits_lock, flags);
+ return IRQ_HANDLED;
+
+out:
+ spin_unlock_irqrestore(&irqbits_lock, flags);
+ return IRQ_NONE;
+}
+
+static inline void free_vm86_irq(int irqnumber)
+{
+ unsigned long flags;
+
+ free_irq(irqnumber, NULL);
+ vm86_irqs[irqnumber].tsk = NULL;
+
+ spin_lock_irqsave(&irqbits_lock, flags);
+ irqbits &= ~(1 << irqnumber);
+ spin_unlock_irqrestore(&irqbits_lock, flags);
+}
+
+void release_vm86_irqs(struct task_struct *task)
+{
+ int i;
+ for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++)
+ if (vm86_irqs[i].tsk == task)
+ free_vm86_irq(i);
+}
+
+static inline int get_and_reset_irq(int irqnumber)
+{
+ int bit;
+ unsigned long flags;
+ int ret = 0;
+
+ if (invalid_vm86_irq(irqnumber)) return 0;
+ if (vm86_irqs[irqnumber].tsk != current) return 0;
+ spin_lock_irqsave(&irqbits_lock, flags);
+ bit = irqbits & (1 << irqnumber);
+ irqbits &= ~bit;
+ if (bit) {
+ enable_irq(irqnumber);
+ ret = 1;
+ }
+
+ spin_unlock_irqrestore(&irqbits_lock, flags);
+ return ret;
+}
+
+
+static int do_vm86_irq_handling(int subfunction, int irqnumber)
+{
+ int ret;
+ switch (subfunction) {
+ case VM86_GET_AND_RESET_IRQ: {
+ return get_and_reset_irq(irqnumber);
+ }
+ case VM86_GET_IRQ_BITS: {
+ return irqbits;
+ }
+ case VM86_REQUEST_IRQ: {
+ int sig = irqnumber >> 8;
+ int irq = irqnumber & 255;
+ if (!capable(CAP_SYS_ADMIN)) return -EPERM;
+ if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM;
+ if (invalid_vm86_irq(irq)) return -EPERM;
+ if (vm86_irqs[irq].tsk) return -EPERM;
+ ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL);
+ if (ret) return ret;
+ vm86_irqs[irq].sig = sig;
+ vm86_irqs[irq].tsk = current;
+ return irq;
+ }
+ case VM86_FREE_IRQ: {
+ if (invalid_vm86_irq(irqnumber)) return -EPERM;
+ if (!vm86_irqs[irqnumber].tsk) return 0;
+ if (vm86_irqs[irqnumber].tsk != current) return -EPERM;
+ free_vm86_irq(irqnumber);
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
projects / firefly-linux-kernel-4.4.55.git / commitdiff