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-rw-r--r--arch/x86/entry/entry_32.S24
-rw-r--r--arch/x86/include/asm/thread_info.h11
-rw-r--r--arch/x86/include/asm/vm86.h6
-rw-r--r--arch/x86/kernel/signal.c3
-rw-r--r--arch/x86/kernel/vm86_32.c110
5 files changed, 60 insertions, 94 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 21dc60a60b5f..f940e24acaf0 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -525,34 +525,12 @@ work_resched:
work_notifysig: # deal with pending signals and
# notify-resume requests
-#ifdef CONFIG_VM86
- testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
- movl %esp, %eax
- jnz work_notifysig_v86 # returning to kernel-space or
- # vm86-space
-1:
-#else
- movl %esp, %eax
-#endif
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
- movb PT_CS(%esp), %bl
- andb $SEGMENT_RPL_MASK, %bl
- cmpb $USER_RPL, %bl
- jb resume_kernel
+ movl %esp, %eax
xorl %edx, %edx
call do_notify_resume
jmp resume_userspace
-
-#ifdef CONFIG_VM86
- ALIGN
-work_notifysig_v86:
- pushl %ecx # save ti_flags for do_notify_resume
- call save_v86_state # %eax contains pt_regs pointer
- popl %ecx
- movl %eax, %esp
- jmp 1b
-#endif
END(work_pending)
# perform syscall exit tracing
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 225ee545e1a0..fdad5c244350 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -27,14 +27,17 @@
* Without this offset, that can result in a page fault. (We are
* careful that, in this case, the value we read doesn't matter.)
*
- * In vm86 mode, the hardware frame is much longer still, but we neither
- * access the extra members from NMI context, nor do we write such a
- * frame at sp0 at all.
+ * In vm86 mode, the hardware frame is much longer still, so add 16
+ * bytes to make room for the real-mode segments.
*
* x86_64 has a fixed-length stack frame.
*/
#ifdef CONFIG_X86_32
-# define TOP_OF_KERNEL_STACK_PADDING 8
+# ifdef CONFIG_VM86
+# define TOP_OF_KERNEL_STACK_PADDING 16
+# else
+# define TOP_OF_KERNEL_STACK_PADDING 8
+# endif
#else
# define TOP_OF_KERNEL_STACK_PADDING 0
#endif
diff --git a/arch/x86/include/asm/vm86.h b/arch/x86/include/asm/vm86.h
index 226d6c157ebc..e45386eee17a 100644
--- a/arch/x86/include/asm/vm86.h
+++ b/arch/x86/include/asm/vm86.h
@@ -29,7 +29,7 @@ struct kernel_vm86_regs {
struct vm86 {
struct vm86plus_struct __user *vm86_info;
- struct pt_regs *regs32;
+ struct pt_regs regs32;
unsigned long v86flags;
unsigned long v86mask;
unsigned long saved_sp0;
@@ -46,7 +46,7 @@ struct vm86 {
void handle_vm86_fault(struct kernel_vm86_regs *, long);
int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
-struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
+void save_v86_state(struct kernel_vm86_regs *, int);
struct task_struct;
void release_vm86_irqs(struct task_struct *);
@@ -69,6 +69,8 @@ static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
return 0;
}
+static inline void save_v86_state(struct kernel_vm86_regs *a, int b) { }
+
#define free_vm86(t) do { } while(0)
#endif /* CONFIG_VM86 */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 7e88cc782712..bfd736e80c89 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -635,6 +635,9 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
bool stepping, failed;
struct fpu *fpu = &current->thread.fpu;
+ if (v8086_mode(regs))
+ save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
+
/* Are we from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
/* If so, check system call restarting.. */
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 696ef767f2be..ffe98eceda77 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -50,6 +50,7 @@
#include <asm/io.h>
#include <asm/tlbflush.h>
#include <asm/irq.h>
+#include <asm/traps.h>
/*
* Known problems:
@@ -87,10 +88,9 @@
#define SAFE_MASK (0xDD5)
#define RETURN_MASK (0xDFF)
-struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
+void save_v86_state(struct kernel_vm86_regs *regs, int retval)
{
struct tss_struct *tss;
- struct pt_regs *ret;
struct task_struct *tsk = current;
struct vm86plus_struct __user *user;
struct vm86 *vm86 = current->thread.vm86;
@@ -149,11 +149,11 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
vm86->saved_sp0 = 0;
put_cpu();
- ret = vm86->regs32;
+ memcpy(&regs->pt, &vm86->regs32, sizeof(struct pt_regs));
- lazy_load_gs(ret->gs);
+ lazy_load_gs(vm86->regs32.gs);
- return ret;
+ regs->pt.ax = retval;
}
static void mark_screen_rdonly(struct mm_struct *mm)
@@ -228,7 +228,7 @@ static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus)
struct task_struct *tsk = current;
struct vm86 *vm86 = tsk->thread.vm86;
struct kernel_vm86_regs vm86regs;
- struct pt_regs *regs32 = current_pt_regs();
+ struct pt_regs *regs = current_pt_regs();
unsigned long err = 0;
if (!vm86) {
@@ -287,7 +287,8 @@ static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus)
} else
memset(&vm86->vm86plus, 0,
sizeof(struct vm86plus_info_struct));
- vm86->regs32 = regs32;
+
+ memcpy(&vm86->regs32, regs, sizeof(struct pt_regs));
vm86->vm86_info = v86;
/*
@@ -297,10 +298,10 @@ static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus)
*/
VEFLAGS = vm86regs.pt.flags;
vm86regs.pt.flags &= SAFE_MASK;
- vm86regs.pt.flags |= regs32->flags & ~SAFE_MASK;
+ vm86regs.pt.flags |= regs->flags & ~SAFE_MASK;
vm86regs.pt.flags |= X86_VM_MASK;
- vm86regs.pt.orig_ax = regs32->orig_ax;
+ vm86regs.pt.orig_ax = regs->orig_ax;
switch (vm86->cpu_type) {
case CPU_286:
@@ -318,15 +319,14 @@ static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus)
}
/*
- * Save old state, set default return value (%ax) to 0 (VM86_SIGNAL)
+ * Save old state
*/
- regs32->ax = VM86_SIGNAL;
vm86->saved_sp0 = tsk->thread.sp0;
- lazy_save_gs(regs32->gs);
+ lazy_save_gs(vm86->regs32.gs);
tss = &per_cpu(cpu_tss, get_cpu());
- /* Set new sp0 right below 32-bit regs */
- tsk->thread.sp0 = (unsigned long) regs32;
+ /* make room for real-mode segments */
+ tsk->thread.sp0 += 16;
if (cpu_has_sep)
tsk->thread.sysenter_cs = 0;
load_sp0(tss, &tsk->thread);
@@ -335,41 +335,14 @@ static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus)
if (vm86->flags & VM86_SCREEN_BITMAP)
mark_screen_rdonly(tsk->mm);
- /*call __audit_syscall_exit since we do not exit via the normal paths */
-#ifdef CONFIG_AUDITSYSCALL
- if (unlikely(current->audit_context))
- __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" (&vm86regs), "r" (task_thread_info(tsk)), "r" (0));
- unreachable(); /* 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->ax = retval;
- __asm__ __volatile__("movl %0,%%esp\n\t"
- "movl %1,%%ebp\n\t"
- "jmp resume_userspace"
- : : "r" (regs32), "r" (current_thread_info()));
+ memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs));
+ force_iret();
+ return regs->ax;
}
static inline void set_IF(struct kernel_vm86_regs *regs)
{
VEFLAGS |= X86_EFLAGS_VIF;
- if (VEFLAGS & X86_EFLAGS_VIP)
- return_to_32bit(regs, VM86_STI);
}
static inline void clear_IF(struct kernel_vm86_regs *regs)
@@ -549,7 +522,7 @@ static void do_int(struct kernel_vm86_regs *regs, int i,
return;
cannot_handle:
- return_to_32bit(regs, VM86_INTx + (i << 8));
+ save_v86_state(regs, VM86_INTx + (i << 8));
}
int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno)
@@ -558,11 +531,7 @@ int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno)
if (vm86->vm86plus.is_vm86pus) {
if ((trapno == 3) || (trapno == 1)) {
- vm86->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 regs32 */
- set_thread_flag(TIF_NOTIFY_RESUME);
+ save_v86_state(regs, VM86_TRAP + (trapno << 8));
return 0;
}
do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));
@@ -588,12 +557,6 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
#define CHECK_IF_IN_TRAP \
if (vmpi->vm86dbg_active && vmpi->vm86dbg_TFpendig) \
newflags |= X86_EFLAGS_TF
-#define VM86_FAULT_RETURN do { \
- if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) \
- return_to_32bit(regs, VM86_PICRETURN); \
- if (orig_flags & X86_EFLAGS_TF) \
- handle_vm86_trap(regs, 0, 1); \
- return; } while (0)
orig_flags = *(unsigned short *)&regs->pt.flags;
@@ -632,7 +595,7 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
SP(regs) -= 2;
}
IP(regs) = ip;
- VM86_FAULT_RETURN;
+ goto vm86_fault_return;
/* popf */
case 0x9d:
@@ -652,7 +615,7 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
else
set_vflags_short(newflags, regs);
- VM86_FAULT_RETURN;
+ goto check_vip;
}
/* int xx */
@@ -660,8 +623,10 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
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));
+ if ((1 << (intno & 7)) & vmpi->vm86dbg_intxxtab[intno >> 3]) {
+ save_v86_state(regs, VM86_INTx + (intno << 8));
+ return;
+ }
}
do_int(regs, intno, ssp, sp);
return;
@@ -692,14 +657,14 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
} else {
set_vflags_short(newflags, regs);
}
- VM86_FAULT_RETURN;
+ goto check_vip;
}
/* cli */
case 0xfa:
IP(regs) = ip;
clear_IF(regs);
- VM86_FAULT_RETURN;
+ goto vm86_fault_return;
/* sti */
/*
@@ -711,12 +676,27 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
case 0xfb:
IP(regs) = ip;
set_IF(regs);
- VM86_FAULT_RETURN;
+ goto check_vip;
default:
- return_to_32bit(regs, VM86_UNKNOWN);
+ save_v86_state(regs, VM86_UNKNOWN);
+ }
+
+ return;
+
+check_vip:
+ if (VEFLAGS & X86_EFLAGS_VIP) {
+ save_v86_state(regs, VM86_STI);
+ return;
}
+vm86_fault_return:
+ if (vmpi->force_return_for_pic && (VEFLAGS & (X86_EFLAGS_IF | X86_EFLAGS_VIF))) {
+ save_v86_state(regs, VM86_PICRETURN);
+ return;
+ }
+ if (orig_flags & X86_EFLAGS_TF)
+ handle_vm86_trap(regs, 0, X86_TRAP_DB);
return;
simulate_sigsegv:
@@ -730,7 +710,7 @@ simulate_sigsegv:
* should be a mixture of the two, but how do we
* get the information? [KD]
*/
- return_to_32bit(regs, VM86_UNKNOWN);
+ save_v86_state(regs, VM86_UNKNOWN);
}
/* ---------------- vm86 special IRQ passing stuff ----------------- */
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-11 19:00:13 +0000