^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 1994 Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * 29 dec 2001 - Fixed oopses caused by unchecked access to the vm86
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * stack - Manfred Spraul <manfred@colorfullife.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * 22 mar 2002 - Manfred detected the stackfaults, but didn't handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * them correctly. Now the emulation will be in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * consistent state after stackfaults - Kasper Dupont
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * <kasperd@daimi.au.dk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * 22 mar 2002 - Added missing clear_IF in set_vflags_* Kasper Dupont
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * <kasperd@daimi.au.dk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * ?? ??? 2002 - Fixed premature returns from handle_vm86_fault
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * caused by Kasper Dupont's changes - Stas Sergeev
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * 4 apr 2002 - Fixed CHECK_IF_IN_TRAP broken by Stas' changes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Kasper Dupont <kasperd@daimi.au.dk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * 9 apr 2002 - Changed syntax of macros in handle_vm86_fault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * Kasper Dupont <kasperd@daimi.au.dk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * 9 apr 2002 - Changed stack access macros to jump to a label
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * instead of returning to userspace. This simplifies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * do_int, and is needed by handle_vm6_fault. Kasper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * Dupont <kasperd@daimi.au.dk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/capability.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <linux/smp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <linux/highmem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <linux/audit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/stddef.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/security.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #include <asm/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #include <asm/tlbflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) #include <asm/irq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #include <asm/traps.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #include <asm/vm86.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #include <asm/switch_to.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * Known problems:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * Interrupt handling is not guaranteed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * - a real x86 will disable all interrupts for one instruction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * after a "mov ss,xx" to make stack handling atomic even without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * the 'lss' instruction. We can't guarantee this in v86 mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * as the next instruction might result in a page fault or similar.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * - a real x86 will have interrupts disabled for one instruction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * past the 'sti' that enables them. We don't bother with all the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * details yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * Let's hope these problems do not actually matter for anything.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * 8- and 16-bit register defines..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) #define AL(regs) (((unsigned char *)&((regs)->pt.ax))[0])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) #define AH(regs) (((unsigned char *)&((regs)->pt.ax))[1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) #define IP(regs) (*(unsigned short *)&((regs)->pt.ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) #define SP(regs) (*(unsigned short *)&((regs)->pt.sp))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * virtual flags (16 and 32-bit versions)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) #define VFLAGS (*(unsigned short *)&(current->thread.vm86->veflags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) #define VEFLAGS (current->thread.vm86->veflags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) #define set_flags(X, new, mask) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) ((X) = ((X) & ~(mask)) | ((new) & (mask)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) #define SAFE_MASK (0xDD5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) #define RETURN_MASK (0xDFF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) void save_v86_state(struct kernel_vm86_regs *regs, int retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) struct task_struct *tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) struct vm86plus_struct __user *user;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct vm86 *vm86 = current->thread.vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * This gets called from entry.S with interrupts disabled, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * from process context. Enable interrupts here, before trying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * to access user space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if (!vm86 || !vm86->user_vm86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) pr_alert("no user_vm86: BAD\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) do_exit(SIGSEGV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->veflags_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) user = vm86->user_vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (!user_access_begin(user, vm86->vm86plus.is_vm86pus ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) sizeof(struct vm86plus_struct) :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) sizeof(struct vm86_struct)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) goto Efault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) unsafe_put_user(regs->pt.bx, &user->regs.ebx, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) unsafe_put_user(regs->pt.cx, &user->regs.ecx, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) unsafe_put_user(regs->pt.dx, &user->regs.edx, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) unsafe_put_user(regs->pt.si, &user->regs.esi, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) unsafe_put_user(regs->pt.di, &user->regs.edi, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) unsafe_put_user(regs->pt.bp, &user->regs.ebp, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) unsafe_put_user(regs->pt.ax, &user->regs.eax, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) unsafe_put_user(regs->pt.ip, &user->regs.eip, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unsafe_put_user(regs->pt.cs, &user->regs.cs, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) unsafe_put_user(regs->pt.flags, &user->regs.eflags, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) unsafe_put_user(regs->pt.sp, &user->regs.esp, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) unsafe_put_user(regs->pt.ss, &user->regs.ss, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) unsafe_put_user(regs->es, &user->regs.es, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) unsafe_put_user(regs->ds, &user->regs.ds, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) unsafe_put_user(regs->fs, &user->regs.fs, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) unsafe_put_user(regs->gs, &user->regs.gs, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) unsafe_put_user(vm86->screen_bitmap, &user->screen_bitmap, Efault_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) user_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) tsk->thread.sp0 = vm86->saved_sp0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) tsk->thread.sysenter_cs = __KERNEL_CS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) update_task_stack(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) refresh_sysenter_cs(&tsk->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) vm86->saved_sp0 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) memcpy(®s->pt, &vm86->regs32, sizeof(struct pt_regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) lazy_load_gs(vm86->regs32.gs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) regs->pt.ax = retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) Efault_end:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) user_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) Efault:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) pr_alert("could not access userspace vm86 info\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) do_exit(SIGSEGV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) static void mark_screen_rdonly(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) struct vm_area_struct *vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) spinlock_t *ptl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) pgd_t *pgd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) p4d_t *p4d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) pud_t *pud;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) pmd_t *pmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) mmap_write_lock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) pgd = pgd_offset(mm, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (pgd_none_or_clear_bad(pgd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) p4d = p4d_offset(pgd, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (p4d_none_or_clear_bad(p4d))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) pud = pud_offset(p4d, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (pud_none_or_clear_bad(pud))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) pmd = pmd_offset(pud, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (pmd_trans_huge(*pmd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) vma = find_vma(mm, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) split_huge_pmd(vma, pmd, 0xA0000);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (pmd_none_or_clear_bad(pmd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) for (i = 0; i < 32; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) if (pte_present(*pte))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) set_pte(pte, pte_wrprotect(*pte));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) pte++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) pte_unmap_unlock(pte, ptl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) mmap_write_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, PAGE_SHIFT, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) static int do_vm86_irq_handling(int subfunction, int irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, user_vm86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return do_sys_vm86((struct vm86plus_struct __user *) user_vm86, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) case VM86_REQUEST_IRQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) case VM86_FREE_IRQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) case VM86_GET_IRQ_BITS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) case VM86_GET_AND_RESET_IRQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return do_vm86_irq_handling(cmd, (int)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) case VM86_PLUS_INSTALL_CHECK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) * NOTE: on old vm86 stuff this will return the error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * from access_ok(), because the subfunction is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * interpreted as (invalid) address to vm86_struct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * So the installation check works.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) return do_sys_vm86((struct vm86plus_struct __user *) arg, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) struct task_struct *tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) struct vm86 *vm86 = tsk->thread.vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) struct kernel_vm86_regs vm86regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) struct pt_regs *regs = current_pt_regs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) unsigned long err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) struct vm86_struct v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) err = security_mmap_addr(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) * vm86 cannot virtualize the address space, so vm86 users
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) * need to manage the low 1MB themselves using mmap. Given
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * that BIOS places important data in the first page, vm86
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * is essentially useless if mmap_min_addr != 0. DOSEMU,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * for example, won't even bother trying to use vm86 if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * can't map a page at virtual address 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * To reduce the available kernel attack surface, simply
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) * disallow vm86(old) for users who cannot mmap at va 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) * The implementation of security_mmap_addr will allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) * suitably privileged users to map va 0 even if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) * vm.mmap_min_addr is set above 0, and we want this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * behavior for vm86 as well, as it ensures that legacy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) * tools like vbetool will not fail just because of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * vm.mmap_min_addr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) pr_info_once("Denied a call to vm86(old) from %s[%d] (uid: %d). Set the vm.mmap_min_addr sysctl to 0 and/or adjust LSM mmap_min_addr policy to enable vm86 if you are using a vm86-based DOS emulator.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) current->comm, task_pid_nr(current),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) from_kuid_munged(&init_user_ns, current_uid()));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) if (!vm86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) tsk->thread.vm86 = vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) if (vm86->saved_sp0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) if (copy_from_user(&v, user_vm86,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) offsetof(struct vm86_struct, int_revectored)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) memset(&vm86regs, 0, sizeof(vm86regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) vm86regs.pt.bx = v.regs.ebx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) vm86regs.pt.cx = v.regs.ecx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) vm86regs.pt.dx = v.regs.edx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) vm86regs.pt.si = v.regs.esi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) vm86regs.pt.di = v.regs.edi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) vm86regs.pt.bp = v.regs.ebp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) vm86regs.pt.ax = v.regs.eax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) vm86regs.pt.ip = v.regs.eip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) vm86regs.pt.cs = v.regs.cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) vm86regs.pt.flags = v.regs.eflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) vm86regs.pt.sp = v.regs.esp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) vm86regs.pt.ss = v.regs.ss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) vm86regs.es = v.regs.es;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) vm86regs.ds = v.regs.ds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) vm86regs.fs = v.regs.fs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) vm86regs.gs = v.regs.gs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) vm86->flags = v.flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) vm86->screen_bitmap = v.screen_bitmap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) vm86->cpu_type = v.cpu_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) if (copy_from_user(&vm86->int_revectored,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) &user_vm86->int_revectored,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) sizeof(struct revectored_struct)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) if (copy_from_user(&vm86->int21_revectored,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) &user_vm86->int21_revectored,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) sizeof(struct revectored_struct)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) if (plus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) if (copy_from_user(&vm86->vm86plus, &user_vm86->vm86plus,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) sizeof(struct vm86plus_info_struct)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) vm86->vm86plus.is_vm86pus = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) memset(&vm86->vm86plus, 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) sizeof(struct vm86plus_info_struct));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) memcpy(&vm86->regs32, regs, sizeof(struct pt_regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) vm86->user_vm86 = user_vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * The flags register is also special: we cannot trust that the user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) * has set it up safely, so this makes sure interrupt etc flags are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) * inherited from protected mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) VEFLAGS = vm86regs.pt.flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) vm86regs.pt.flags &= SAFE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) vm86regs.pt.flags |= regs->flags & ~SAFE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) vm86regs.pt.flags |= X86_VM_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) vm86regs.pt.orig_ax = regs->orig_ax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) switch (vm86->cpu_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) case CPU_286:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) vm86->veflags_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) case CPU_386:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) vm86->veflags_mask = X86_EFLAGS_NT | X86_EFLAGS_IOPL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) case CPU_486:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) vm86->veflags_mask = X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) vm86->veflags_mask = X86_EFLAGS_ID | X86_EFLAGS_AC | X86_EFLAGS_NT | X86_EFLAGS_IOPL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * Save old state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) vm86->saved_sp0 = tsk->thread.sp0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) lazy_save_gs(vm86->regs32.gs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) /* make room for real-mode segments */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) tsk->thread.sp0 += 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) if (boot_cpu_has(X86_FEATURE_SEP)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) tsk->thread.sysenter_cs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) refresh_sysenter_cs(&tsk->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) update_task_stack(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) if (vm86->flags & VM86_SCREEN_BITMAP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) mark_screen_rdonly(tsk->mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return regs->ax;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) static inline void set_IF(struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) VEFLAGS |= X86_EFLAGS_VIF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) static inline void clear_IF(struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) VEFLAGS &= ~X86_EFLAGS_VIF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) static inline void clear_TF(struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) regs->pt.flags &= ~X86_EFLAGS_TF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) static inline void clear_AC(struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) regs->pt.flags &= ~X86_EFLAGS_AC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * It is correct to call set_IF(regs) from the set_vflags_*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * functions. However someone forgot to call clear_IF(regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) * in the opposite case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * After the command sequence CLI PUSHF STI POPF you should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * end up with interrupts disabled, but you ended up with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * interrupts enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * ( I was testing my own changes, but the only bug I
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * could find was in a function I had not changed. )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * [KD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) static inline void set_vflags_long(unsigned long flags, struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) set_flags(VEFLAGS, flags, current->thread.vm86->veflags_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) set_flags(regs->pt.flags, flags, SAFE_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) if (flags & X86_EFLAGS_IF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) set_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) clear_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) set_flags(VFLAGS, flags, current->thread.vm86->veflags_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) set_flags(regs->pt.flags, flags, SAFE_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) if (flags & X86_EFLAGS_IF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) set_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) clear_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) static inline unsigned long get_vflags(struct kernel_vm86_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) unsigned long flags = regs->pt.flags & RETURN_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (VEFLAGS & X86_EFLAGS_VIF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) flags |= X86_EFLAGS_IF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) flags |= X86_EFLAGS_IOPL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) return flags | (VEFLAGS & current->thread.vm86->veflags_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) static inline int is_revectored(int nr, struct revectored_struct *bitmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return test_bit(nr, bitmap->__map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) #define val_byte(val, n) (((__u8 *)&val)[n])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) #define pushb(base, ptr, val, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) __u8 __val = val; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) if (put_user(__val, base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) #define pushw(base, ptr, val, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) __u16 __val = val; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) if (put_user(val_byte(__val, 1), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (put_user(val_byte(__val, 0), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) #define pushl(base, ptr, val, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) __u32 __val = val; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) if (put_user(val_byte(__val, 3), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) if (put_user(val_byte(__val, 2), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) if (put_user(val_byte(__val, 1), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) ptr--; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) if (put_user(val_byte(__val, 0), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) #define popb(base, ptr, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) __u8 __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) if (get_user(__res, base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) #define popw(base, ptr, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) __u16 __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) if (get_user(val_byte(__res, 0), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) if (get_user(val_byte(__res, 1), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) #define popl(base, ptr, err_label) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) __u32 __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) if (get_user(val_byte(__res, 0), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) if (get_user(val_byte(__res, 1), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if (get_user(val_byte(__res, 2), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (get_user(val_byte(__res, 3), base + ptr) < 0) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) goto err_label; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) ptr++; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) __res; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) /* There are so many possible reasons for this function to return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) * VM86_INTx, so adding another doesn't bother me. We can expect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) * userspace programs to be able to handle it. (Getting a problem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) * in userspace is always better than an Oops anyway.) [KD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) static void do_int(struct kernel_vm86_regs *regs, int i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) unsigned char __user *ssp, unsigned short sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) unsigned long __user *intr_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) unsigned long segoffs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) struct vm86 *vm86 = current->thread.vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) if (regs->pt.cs == BIOSSEG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) goto cannot_handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) if (is_revectored(i, &vm86->int_revectored))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) goto cannot_handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) if (i == 0x21 && is_revectored(AH(regs), &vm86->int21_revectored))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) goto cannot_handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) intr_ptr = (unsigned long __user *) (i << 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) if (get_user(segoffs, intr_ptr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) goto cannot_handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) if ((segoffs >> 16) == BIOSSEG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) goto cannot_handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) pushw(ssp, sp, get_vflags(regs), cannot_handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) pushw(ssp, sp, regs->pt.cs, cannot_handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) pushw(ssp, sp, IP(regs), cannot_handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) regs->pt.cs = segoffs >> 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) SP(regs) -= 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) IP(regs) = segoffs & 0xffff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) clear_TF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) clear_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) clear_AC(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) cannot_handle:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) save_v86_state(regs, VM86_INTx + (i << 8));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) struct vm86 *vm86 = current->thread.vm86;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) if (vm86->vm86plus.is_vm86pus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) if ((trapno == 3) || (trapno == 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) save_v86_state(regs, VM86_TRAP + (trapno << 8));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if (trapno != 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) return 1; /* we let this handle by the calling routine */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) current->thread.trap_nr = trapno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) current->thread.error_code = error_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) force_sig(SIGTRAP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) unsigned char opcode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) unsigned char __user *csp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) unsigned char __user *ssp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) unsigned short ip, sp, orig_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) int data32, pref_done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) struct vm86plus_info_struct *vmpi = ¤t->thread.vm86->vm86plus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) #define CHECK_IF_IN_TRAP \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) newflags |= X86_EFLAGS_TF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) orig_flags = *(unsigned short *)®s->pt.flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) csp = (unsigned char __user *) (regs->pt.cs << 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) ssp = (unsigned char __user *) (regs->pt.ss << 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) sp = SP(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) ip = IP(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) data32 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) pref_done = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) switch (opcode = popb(csp, ip, simulate_sigsegv)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) case 0x66: /* 32-bit data */ data32 = 1; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) case 0x67: /* 32-bit address */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) case 0x2e: /* CS */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) case 0x3e: /* DS */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) case 0x26: /* ES */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) case 0x36: /* SS */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) case 0x65: /* GS */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) case 0x64: /* FS */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) case 0xf2: /* repnz */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) case 0xf3: /* rep */ break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) default: pref_done = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) } while (!pref_done);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) switch (opcode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) /* pushf */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) case 0x9c:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) if (data32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) pushl(ssp, sp, get_vflags(regs), simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) SP(regs) -= 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) pushw(ssp, sp, get_vflags(regs), simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) SP(regs) -= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) IP(regs) = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) goto vm86_fault_return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) /* popf */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) case 0x9d:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) unsigned long newflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) if (data32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) newflags = popl(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) SP(regs) += 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) newflags = popw(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) SP(regs) += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) IP(regs) = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) CHECK_IF_IN_TRAP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) if (data32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) set_vflags_long(newflags, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) set_vflags_short(newflags, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) goto check_vip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) /* int xx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) case 0xcd: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) int intno = popb(csp, ip, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) IP(regs) = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) if (vmpi->vm86dbg_active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) save_v86_state(regs, VM86_INTx + (intno << 8));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) do_int(regs, intno, ssp, sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) /* iret */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) case 0xcf:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) unsigned long newip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) unsigned long newcs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) unsigned long newflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) if (data32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) newip = popl(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) newcs = popl(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) newflags = popl(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) SP(regs) += 12;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) newip = popw(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) newcs = popw(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) newflags = popw(ssp, sp, simulate_sigsegv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) SP(regs) += 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) IP(regs) = newip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) regs->pt.cs = newcs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) CHECK_IF_IN_TRAP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) if (data32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) set_vflags_long(newflags, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) set_vflags_short(newflags, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) goto check_vip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) /* cli */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) case 0xfa:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) IP(regs) = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) clear_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) goto vm86_fault_return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) /* sti */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) * Damn. This is incorrect: the 'sti' instruction should actually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) * enable interrupts after the /next/ instruction. Not good.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) * Probably needs some horsing around with the TF flag. Aiee..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) case 0xfb:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) IP(regs) = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) set_IF(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) goto check_vip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) save_v86_state(regs, VM86_UNKNOWN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) check_vip:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) if ((VEFLAGS & (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) ==
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) save_v86_state(regs, VM86_STI);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) vm86_fault_return:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) save_v86_state(regs, VM86_PICRETURN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) if (orig_flags & X86_EFLAGS_TF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) handle_vm86_trap(regs, 0, X86_TRAP_DB);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) simulate_sigsegv:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) /* FIXME: After a long discussion with Stas we finally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) * agreed, that this is wrong. Here we should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) * really send a SIGSEGV to the user program.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) * But how do we create the correct context? We
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) * are inside a general protection fault handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) * and has just returned from a page fault handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) * The correct context for the signal handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) * should be a mixture of the two, but how do we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) * get the information? [KD]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) save_v86_state(regs, VM86_UNKNOWN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) /* ---------------- vm86 special IRQ passing stuff ----------------- */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) #define VM86_IRQNAME "vm86irq"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) static struct vm86_irqs {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) struct task_struct *tsk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) int sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) } vm86_irqs[16];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) static DEFINE_SPINLOCK(irqbits_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) static int irqbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) #define ALLOWED_SIGS (1 /* 0 = don't send a signal */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) | (1 << SIGUSR1) | (1 << SIGUSR2) | (1 << SIGIO) | (1 << SIGURG) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) | (1 << SIGUNUSED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) static irqreturn_t irq_handler(int intno, void *dev_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) int irq_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) spin_lock_irqsave(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) irq_bit = 1 << intno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) if ((irqbits & irq_bit) || !vm86_irqs[intno].tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) irqbits |= irq_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) if (vm86_irqs[intno].sig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) * IRQ will be re-enabled when user asks for the irq (whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) * polling or as a result of the signal)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) disable_irq_nosync(intno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) spin_unlock_irqrestore(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) return IRQ_HANDLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) spin_unlock_irqrestore(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) return IRQ_NONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) static inline void free_vm86_irq(int irqnumber)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) free_irq(irqnumber, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) vm86_irqs[irqnumber].tsk = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) spin_lock_irqsave(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) irqbits &= ~(1 << irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) spin_unlock_irqrestore(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) void release_vm86_irqs(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) for (i = FIRST_VM86_IRQ ; i <= LAST_VM86_IRQ; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) if (vm86_irqs[i].tsk == task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) free_vm86_irq(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) static inline int get_and_reset_irq(int irqnumber)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) int bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) if (invalid_vm86_irq(irqnumber)) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) if (vm86_irqs[irqnumber].tsk != current) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) spin_lock_irqsave(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) bit = irqbits & (1 << irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) irqbits &= ~bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) if (bit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) enable_irq(irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) spin_unlock_irqrestore(&irqbits_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) static int do_vm86_irq_handling(int subfunction, int irqnumber)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) switch (subfunction) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) case VM86_GET_AND_RESET_IRQ: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) return get_and_reset_irq(irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) case VM86_GET_IRQ_BITS: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) return irqbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) case VM86_REQUEST_IRQ: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) int sig = irqnumber >> 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) int irq = irqnumber & 255;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) if (!capable(CAP_SYS_ADMIN)) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) if (!((1 << sig) & ALLOWED_SIGS)) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) if (invalid_vm86_irq(irq)) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) if (vm86_irqs[irq].tsk) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) ret = request_irq(irq, &irq_handler, 0, VM86_IRQNAME, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) if (ret) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) vm86_irqs[irq].sig = sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) vm86_irqs[irq].tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) return irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) case VM86_FREE_IRQ: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) if (invalid_vm86_irq(irqnumber)) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) if (!vm86_irqs[irqnumber].tsk) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) if (vm86_irqs[irqnumber].tsk != current) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) free_vm86_irq(irqnumber);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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