[GIT pull] x86 vm86 for 2.6.37

[GIT pull] x86 vm86 for 2.6.37

[Thomas Gleixner]

Linus,

Please pull the latest x86-vm86-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-vm86-for-linus

Thanks,

	tglx

------------------>
Bart Oldeman (1):
      x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.


 arch/x86/kernel/traps.c   |    1 +
 arch/x86/kernel/vm86_32.c |   10 ++++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 60788de..9f4edeb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -575,6 +575,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 	if (regs->flags & X86_VM_MASK) {
 		handle_vm86_trap((struct kernel_vm86_regs *) regs,
 				error_code, 1);
+		preempt_conditional_cli(regs);
 		return;
 	}
 
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 5ffb562..61fb985 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -551,8 +551,14 @@ 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
+			   call save_v86_state() and change the stack pointer
+			   to KVM86->regs32 */
+			set_thread_flag(TIF_IRET);
+			return 0;
+		}
 		do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));
 		return 0;
 	}