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Diffstat (limited to 'arch/x86/kernel/vm86_32.c')
-rw-r--r--arch/x86/kernel/vm86_32.c90
1 files changed, 47 insertions, 43 deletions
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 38f566fa27d..e8edcf52e06 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -28,9 +28,12 @@
*
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
+#include <linux/syscalls.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
@@ -136,14 +139,14 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
local_irq_enable();
if (!current->thread.vm86_info) {
- printk("no vm86_info: BAD\n");
+ pr_alert("no vm86_info: BAD\n");
do_exit(SIGSEGV);
}
set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | current->thread.v86mask);
tmp = copy_vm86_regs_to_user(&current->thread.vm86_info->regs, regs);
tmp += put_user(current->thread.screen_bitmap, &current->thread.vm86_info->screen_bitmap);
if (tmp) {
- printk("vm86: could not access userspace vm86_info\n");
+ pr_alert("could not access userspace vm86_info\n");
do_exit(SIGSEGV);
}
@@ -157,7 +160,7 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
ret = KVM86->regs32;
ret->fs = current->thread.saved_fs;
- loadsegment(gs, current->thread.saved_gs);
+ set_user_gs(ret, current->thread.saved_gs);
return ret;
}
@@ -171,6 +174,7 @@ static void mark_screen_rdonly(struct mm_struct *mm)
spinlock_t *ptl;
int i;
+ down_write(&mm->mmap_sem);
pgd = pgd_offset(mm, 0xA0000);
if (pgd_none_or_clear_bad(pgd))
goto out;
@@ -178,6 +182,7 @@ static void mark_screen_rdonly(struct mm_struct *mm)
if (pud_none_or_clear_bad(pud))
goto out;
pmd = pmd_offset(pud, 0xA0000);
+ split_huge_page_pmd_mm(mm, 0xA0000, pmd);
if (pmd_none_or_clear_bad(pmd))
goto out;
pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
@@ -188,6 +193,7 @@ static void mark_screen_rdonly(struct mm_struct *mm)
}
pte_unmap_unlock(pte, ptl);
out:
+ up_write(&mm->mmap_sem);
flush_tlb();
}
@@ -196,37 +202,32 @@ out:
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)
+SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86)
{
- struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs.bx;
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;
+ struct task_struct *tsk = current;
+ int tmp;
- tsk = current;
if (tsk->thread.saved_sp0)
- goto out;
+ return -EPERM;
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;
+ return -EFAULT;
memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus);
- info.regs32 = &regs;
+ info.regs32 = current_pt_regs();
tsk->thread.vm86_info = v86;
do_sys_vm86(&info, tsk);
- ret = 0; /* we never return here */
-out:
- return ret;
+ return 0; /* we never return here */
}
-asmlinkage int sys_vm86(struct pt_regs regs)
+SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg)
{
struct kernel_vm86_struct info; /* declare this _on top_,
* this avoids wasting of stack space.
@@ -234,17 +235,16 @@ asmlinkage int sys_vm86(struct pt_regs regs)
* return to 32 bit user space.
*/
struct task_struct *tsk;
- int tmp, ret;
+ int tmp;
struct vm86plus_struct __user *v86;
tsk = current;
- switch (regs.bx) {
+ switch (cmd) {
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.bx, (int)regs.cx);
- goto out;
+ return do_vm86_irq_handling(cmd, (int)arg);
case VM86_PLUS_INSTALL_CHECK:
/*
* NOTE: on old vm86 stuff this will return the error
@@ -252,28 +252,23 @@ asmlinkage int sys_vm86(struct pt_regs regs)
* interpreted as (invalid) address to vm86_struct.
* So the installation check works.
*/
- ret = 0;
- goto out;
+ return 0;
}
/* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
- ret = -EPERM;
if (tsk->thread.saved_sp0)
- goto out;
- v86 = (struct vm86plus_struct __user *)regs.cx;
+ return -EPERM;
+ v86 = (struct vm86plus_struct __user *)arg;
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 = &regs;
+ return -EFAULT;
+ info.regs32 = current_pt_regs();
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;
+ return 0; /* we never return here */
}
@@ -286,10 +281,9 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
info->regs.pt.ds = 0;
info->regs.pt.es = 0;
info->regs.pt.fs = 0;
-
-/* we are clearing gs later just before "jmp resume_userspace",
- * because it is not saved/restored.
- */
+#ifndef CONFIG_X86_32_LAZY_GS
+ info->regs.pt.gs = 0;
+#endif
/*
* The flags register is also special: we cannot trust that the user
@@ -317,12 +311,12 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
}
/*
- * Save old state, set default return value (%ax) to 0
+ * Save old state, set default return value (%ax) to 0 (VM86_SIGNAL)
*/
- info->regs32->ax = 0;
+ info->regs32->ax = VM86_SIGNAL;
tsk->thread.saved_sp0 = tsk->thread.sp0;
tsk->thread.saved_fs = info->regs32->fs;
- savesegment(gs, tsk->thread.saved_gs);
+ tsk->thread.saved_gs = get_user_gs(info->regs32);
tss = &per_cpu(init_tss, get_cpu());
tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0;
@@ -335,14 +329,18 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
if (info->flags & VM86_SCREEN_BITMAP)
mark_screen_rdonly(tsk->mm);
- /*call audit_syscall_exit since we do not exit via the normal paths */
+ /*call __audit_syscall_exit since we do not exit via the normal paths */
+#ifdef CONFIG_AUDITSYSCALL
if (unlikely(current->audit_context))
- audit_syscall_exit(AUDITSC_RESULT(0), 0);
+ __audit_syscall_exit(1, 0);
+#endif
__asm__ __volatile__(
"movl %0,%%esp\n\t"
"movl %1,%%ebp\n\t"
+#ifdef CONFIG_X86_32_LAZY_GS
"mov %2, %%gs\n\t"
+#endif
"jmp resume_userspace"
: /* no outputs */
:"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0));
@@ -550,14 +548,20 @@ cannot_handle:
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));
+ if ((trapno == 3) || (trapno == 1)) {
+ KVM86->regs32->ax = VM86_TRAP + (trapno << 8);
+ /* setting this flag forces the code in entry_32.S to
+ the path where we call save_v86_state() and change
+ the stack pointer to KVM86->regs32 */
+ set_thread_flag(TIF_NOTIFY_RESUME);
+ return 0;
+ }
do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));
return 0;
}
if (trapno != 1)
return 1; /* we let this handle by the calling routine */
- current->thread.trap_no = trapno;
+ current->thread.trap_nr = trapno;
current->thread.error_code = error_code;
force_sig(SIGTRAP, current);
return 0;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-05 18:28:01 +0000