X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fentry.S;h=094b47426d0ce8d20800bc594d48ea6eae03587d;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=a14218c9ec6cf208d78fb9e1f15c877c5a84d8df;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index a14218c9e..094b47426 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -30,43 +30,43 @@
  *	18(%esp) - %eax
  *	1C(%esp) - %ds
  *	20(%esp) - %es
- *	24(%esp) - orig_eax
- *	28(%esp) - %eip
- *	2C(%esp) - %cs
- *	30(%esp) - %eflags
- *	34(%esp) - %oldesp
- *	38(%esp) - %oldss
+ *	24(%esp) - %gs
+ *	28(%esp) - orig_eax
+ *	2C(%esp) - %eip
+ *	30(%esp) - %cs
+ *	34(%esp) - %eflags
+ *	38(%esp) - %oldesp
+ *	3C(%esp) - %oldss
  *
  * "current" is in register %ebx during any slow entries.
  */
 
-#include <linux/config.h>
 #include <linux/linkage.h>
 #include <asm/thread_info.h>
+#include <asm/irqflags.h>
 #include <asm/errno.h>
 #include <asm/segment.h>
 #include <asm/smp.h>
 #include <asm/page.h>
 #include <asm/desc.h>
+#include <asm/percpu.h>
+#include <asm/dwarf2.h>
 #include "irq_vectors.h"
 
-#define nr_syscalls ((syscall_table_size)/4)
+/*
+ * We use macros for low-level operations which need to be overridden
+ * for paravirtualization.  The following will never clobber any registers:
+ *   INTERRUPT_RETURN (aka. "iret")
+ *   GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
+ *   ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
+ *
+ * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
+ * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
+ * Allowing a register to be clobbered can shrink the paravirt replacement
+ * enough to patch inline, increasing performance.
+ */
 
-EBX		= 0x00
-ECX		= 0x04
-EDX		= 0x08
-ESI		= 0x0C
-EDI		= 0x10
-EBP		= 0x14
-EAX		= 0x18
-DS		= 0x1C
-ES		= 0x20
-ORIG_EAX	= 0x24
-EIP		= 0x28
-CS		= 0x2C
-EFLAGS		= 0x30
-OLDESP		= 0x34
-OLDSS		= 0x38
+#define nr_syscalls ((syscall_table_size)/4)
 
 CF_MASK		= 0x00000001
 TF_MASK		= 0x00000100
@@ -76,61 +76,157 @@ NT_MASK		= 0x00004000
 VM_MASK		= 0x00020000
 
 #ifdef CONFIG_PREEMPT
-#define preempt_stop		cli
+#define preempt_stop(clobbers)	DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
 #else
-#define preempt_stop
+#define preempt_stop(clobbers)
 #define resume_kernel		restore_nocheck
 #endif
 
+.macro TRACE_IRQS_IRET
+#ifdef CONFIG_TRACE_IRQFLAGS
+	testl $IF_MASK,PT_EFLAGS(%esp)     # interrupts off?
+	jz 1f
+	TRACE_IRQS_ON
+1:
+#endif
+.endm
+
+#ifdef CONFIG_VM86
+#define resume_userspace_sig	check_userspace
+#else
+#define resume_userspace_sig	resume_userspace
+#endif
+
 #define SAVE_ALL \
 	cld; \
+	pushl %gs; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	/*CFI_REL_OFFSET gs, 0;*/\
 	pushl %es; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	/*CFI_REL_OFFSET es, 0;*/\
 	pushl %ds; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	/*CFI_REL_OFFSET ds, 0;*/\
 	pushl %eax; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET eax, 0;\
 	pushl %ebp; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET ebp, 0;\
 	pushl %edi; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET edi, 0;\
 	pushl %esi; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET esi, 0;\
 	pushl %edx; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET edx, 0;\
 	pushl %ecx; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET ecx, 0;\
 	pushl %ebx; \
+	CFI_ADJUST_CFA_OFFSET 4;\
+	CFI_REL_OFFSET ebx, 0;\
 	movl $(__USER_DS), %edx; \
 	movl %edx, %ds; \
-	movl %edx, %es;
+	movl %edx, %es; \
+	movl $(__KERNEL_PDA), %edx; \
+	movl %edx, %gs
 
 #define RESTORE_INT_REGS \
 	popl %ebx;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE ebx;\
 	popl %ecx;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE ecx;\
 	popl %edx;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE edx;\
 	popl %esi;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE esi;\
 	popl %edi;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE edi;\
 	popl %ebp;	\
-	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE ebp;\
+	popl %eax;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	CFI_RESTORE eax
 
 #define RESTORE_REGS	\
 	RESTORE_INT_REGS; \
 1:	popl %ds;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	/*CFI_RESTORE ds;*/\
 2:	popl %es;	\
-.section .fixup,"ax";	\
-3:	movl $0,(%esp);	\
-	jmp 1b;		\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	/*CFI_RESTORE es;*/\
+3:	popl %gs;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	/*CFI_RESTORE gs;*/\
+.pushsection .fixup,"ax";	\
 4:	movl $0,(%esp);	\
+	jmp 1b;		\
+5:	movl $0,(%esp);	\
 	jmp 2b;		\
-.previous;		\
+6:	movl $0,(%esp);	\
+	jmp 3b;		\
 .section __ex_table,"a";\
 	.align 4;	\
-	.long 1b,3b;	\
-	.long 2b,4b;	\
-.previous
-
+	.long 1b,4b;	\
+	.long 2b,5b;	\
+	.long 3b,6b;	\
+.popsection
+
+#define RING0_INT_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_SIGNAL_FRAME;\
+	CFI_DEF_CFA esp, 3*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_EC_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_SIGNAL_FRAME;\
+	CFI_DEF_CFA esp, 4*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_PTREGS_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_SIGNAL_FRAME;\
+	CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\
+	/*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\
+	CFI_OFFSET eip, PT_EIP-PT_OLDESP;\
+	/*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\
+	/*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\
+	CFI_OFFSET eax, PT_EAX-PT_OLDESP;\
+	CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\
+	CFI_OFFSET edi, PT_EDI-PT_OLDESP;\
+	CFI_OFFSET esi, PT_ESI-PT_OLDESP;\
+	CFI_OFFSET edx, PT_EDX-PT_OLDESP;\
+	CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\
+	CFI_OFFSET ebx, PT_EBX-PT_OLDESP
 
 ENTRY(ret_from_fork)
+	CFI_STARTPROC
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	call schedule_tail
 	GET_THREAD_INFO(%ebp)
 	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4
 	pushl $0x0202			# Reset kernel eflags
+	CFI_ADJUST_CFA_OFFSET 4
 	popfl
+	CFI_ADJUST_CFA_OFFSET -4
 	jmp syscall_exit
+	CFI_ENDPROC
 
 /*
  * Return to user mode is not as complex as all this looks,
@@ -141,16 +237,20 @@ ENTRY(ret_from_fork)
 
 	# userspace resumption stub bypassing syscall exit tracing
 	ALIGN
+	RING0_PTREGS_FRAME
 ret_from_exception:
-	preempt_stop
+	preempt_stop(CLBR_ANY)
 ret_from_intr:
 	GET_THREAD_INFO(%ebp)
-	movl EFLAGS(%esp), %eax		# mix EFLAGS and CS
-	movb CS(%esp), %al
-	testl $(VM_MASK | 3), %eax
-	jz resume_kernel
+check_userspace:
+	movl PT_EFLAGS(%esp), %eax	# mix EFLAGS and CS
+	movb PT_CS(%esp), %al
+	andl $(VM_MASK | SEGMENT_RPL_MASK), %eax
+	cmpl $USER_RPL, %eax
+	jb resume_kernel		# not returning to v8086 or userspace
+
 ENTRY(resume_userspace)
- 	cli				# make sure we don't miss an interrupt
+ 	DISABLE_INTERRUPTS(CLBR_ANY)	# make sure we don't miss an interrupt
 					# setting need_resched or sigpending
 					# between sampling and the iret
 	movl TI_flags(%ebp), %ecx
@@ -161,32 +261,59 @@ ENTRY(resume_userspace)
 
 #ifdef CONFIG_PREEMPT
 ENTRY(resume_kernel)
-	cli
+	DISABLE_INTERRUPTS(CLBR_ANY)
 	cmpl $0,TI_preempt_count(%ebp)	# non-zero preempt_count ?
 	jnz restore_nocheck
 need_resched:
 	movl TI_flags(%ebp), %ecx	# need_resched set ?
 	testb $_TIF_NEED_RESCHED, %cl
 	jz restore_all
-	testl $IF_MASK,EFLAGS(%esp)     # interrupts off (exception path) ?
+	testl $IF_MASK,PT_EFLAGS(%esp)	# interrupts off (exception path) ?
 	jz restore_all
 	call preempt_schedule_irq
 	jmp need_resched
 #endif
+	CFI_ENDPROC
 
 /* SYSENTER_RETURN points to after the "sysenter" instruction in
    the vsyscall page.  See vsyscall-sysentry.S, which defines the symbol.  */
 
 	# sysenter call handler stub
 ENTRY(sysenter_entry)
-	movl TSS_sysenter_esp0(%esp),%esp
+	CFI_STARTPROC simple
+	CFI_SIGNAL_FRAME
+	CFI_DEF_CFA esp, 0
+	CFI_REGISTER esp, ebp
+	movl SYSENTER_stack_esp0(%esp),%esp
 sysenter_past_esp:
-	sti
+	/*
+	 * No need to follow this irqs on/off section: the syscall
+	 * disabled irqs and here we enable it straight after entry:
+	 */
+	ENABLE_INTERRUPTS(CLBR_NONE)
 	pushl $(__USER_DS)
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET ss, 0*/
 	pushl %ebp
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET esp, 0
 	pushfl
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $(__USER_CS)
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET cs, 0*/
+#ifndef CONFIG_COMPAT_VDSO
+	/*
+	 * Push current_thread_info()->sysenter_return to the stack.
+	 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
+	 * pushed above; +8 corresponds to copy_thread's esp0 setting.
+	 */
+	pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
+#else
 	pushl $SYSENTER_RETURN
+#endif
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eip, 0
 
 /*
  * Load the potential sixth argument from user stack.
@@ -201,67 +328,89 @@ sysenter_past_esp:
 .previous
 
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
 
 	/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
-	testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
+	testw $(_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
 	jnz syscall_trace_entry
 	cmpl $(nr_syscalls), %eax
 	jae syscall_badsys
 	call *sys_call_table(,%eax,4)
-	movl %eax,EAX(%esp)
-	cli
+	movl %eax,PT_EAX(%esp)
+	DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
+	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testw $_TIF_ALLWORK_MASK, %cx
 	jne syscall_exit_work
 /* if something modifies registers it must also disable sysexit */
-	movl EIP(%esp), %edx
-	movl OLDESP(%esp), %ecx
+	movl PT_EIP(%esp), %edx
+	movl PT_OLDESP(%esp), %ecx
 	xorl %ebp,%ebp
-	sti
-	sysexit
-
+	TRACE_IRQS_ON
+1:	mov  PT_GS(%esp), %gs
+	ENABLE_INTERRUPTS_SYSEXIT
+	CFI_ENDPROC
+.pushsection .fixup,"ax"
+2:	movl $0,PT_GS(%esp)
+	jmp 1b
+.section __ex_table,"a"
+	.align 4
+	.long 1b,2b
+.popsection
 
 	# system call handler stub
 ENTRY(system_call)
+	RING0_INT_FRAME			# can't unwind into user space anyway
 	pushl %eax			# save orig_eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
+	testl $TF_MASK,PT_EFLAGS(%esp)
+	jz no_singlestep
+	orl $_TIF_SINGLESTEP,TI_flags(%ebp)
+no_singlestep:
 					# system call tracing in operation / emulation
 	/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
-	testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
+	testw $(_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
 	jnz syscall_trace_entry
 	cmpl $(nr_syscalls), %eax
 	jae syscall_badsys
 syscall_call:
 	call *sys_call_table(,%eax,4)
-	movl %eax,EAX(%esp)		# store the return value
+	movl %eax,PT_EAX(%esp)		# store the return value
 syscall_exit:
-	cli				# make sure we don't miss an interrupt
+	DISABLE_INTERRUPTS(CLBR_ANY)	# make sure we don't miss an interrupt
 					# setting need_resched or sigpending
 					# between sampling and the iret
+	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testw $_TIF_ALLWORK_MASK, %cx	# current->work
 	jne syscall_exit_work
 
 restore_all:
-	movl EFLAGS(%esp), %eax		# mix EFLAGS, SS and CS
-	# Warning: OLDSS(%esp) contains the wrong/random values if we
+	movl PT_EFLAGS(%esp), %eax	# mix EFLAGS, SS and CS
+	# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
 	# are returning to the kernel.
 	# See comments in process.c:copy_thread() for details.
-	movb OLDSS(%esp), %ah
-	movb CS(%esp), %al
-	andl $(VM_MASK | (4 << 8) | 3), %eax
-	cmpl $((4 << 8) | 3), %eax
+	movb PT_OLDSS(%esp), %ah
+	movb PT_CS(%esp), %al
+	andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
+	cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
+	CFI_REMEMBER_STATE
 	je ldt_ss			# returning to user-space with LDT SS
 restore_nocheck:
+	TRACE_IRQS_IRET
+restore_nocheck_notrace:
 	RESTORE_REGS
-	addl $4, %esp
-1:	iret
+	addl $4, %esp			# skip orig_eax/error_code
+	CFI_ADJUST_CFA_OFFSET -4
+1:	INTERRUPT_RETURN
 .section .fixup,"ax"
 iret_exc:
-	sti
+	TRACE_IRQS_ON
+	ENABLE_INTERRUPTS(CLBR_NONE)
 	pushl $0			# no error code
 	pushl $do_iret_error
 	jmp error_code
@@ -271,41 +420,58 @@ iret_exc:
 	.long 1b,iret_exc
 .previous
 
+	CFI_RESTORE_STATE
 ldt_ss:
-	larl OLDSS(%esp), %eax
+	larl PT_OLDSS(%esp), %eax
 	jnz restore_nocheck
 	testl $0x00400000, %eax		# returning to 32bit stack?
 	jnz restore_nocheck		# allright, normal return
+
+#ifdef CONFIG_PARAVIRT
+	/*
+	 * The kernel can't run on a non-flat stack if paravirt mode
+	 * is active.  Rather than try to fixup the high bits of
+	 * ESP, bypass this code entirely.  This may break DOSemu
+	 * and/or Wine support in a paravirt VM, although the option
+	 * is still available to implement the setting of the high
+	 * 16-bits in the INTERRUPT_RETURN paravirt-op.
+	 */
+	cmpl $0, paravirt_ops+PARAVIRT_enabled
+	jne restore_nocheck
+#endif
+
 	/* If returning to userspace with 16bit stack,
 	 * try to fix the higher word of ESP, as the CPU
 	 * won't restore it.
 	 * This is an "official" bug of all the x86-compatible
 	 * CPUs, which we can try to work around to make
 	 * dosemu and wine happy. */
-	subl $8, %esp		# reserve space for switch16 pointer
-	cli
-	movl %esp, %eax
-	/* Set up the 16bit stack frame with switch32 pointer on top,
-	 * and a switch16 pointer on top of the current frame. */
-	call setup_x86_bogus_stack
-	RESTORE_REGS
-	lss 20+4(%esp), %esp	# switch to 16bit stack
-1:	iret
-.section __ex_table,"a"
-	.align 4
-	.long 1b,iret_exc
-.previous
+	movl PT_OLDESP(%esp), %eax
+	movl %esp, %edx
+	call patch_espfix_desc
+	pushl $__ESPFIX_SS
+	CFI_ADJUST_CFA_OFFSET 4
+	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	DISABLE_INTERRUPTS(CLBR_EAX)
+	TRACE_IRQS_OFF
+	lss (%esp), %esp
+	CFI_ADJUST_CFA_OFFSET -8
+	jmp restore_nocheck
+	CFI_ENDPROC
 
 	# perform work that needs to be done immediately before resumption
 	ALIGN
+	RING0_PTREGS_FRAME		# can't unwind into user space anyway
 work_pending:
 	testb $_TIF_NEED_RESCHED, %cl
 	jz work_notifysig
 work_resched:
 	call schedule
-	cli				# make sure we don't miss an interrupt
+	DISABLE_INTERRUPTS(CLBR_ANY)	# make sure we don't miss an interrupt
 					# setting need_resched or sigpending
 					# between sampling and the iret
+	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	andl $_TIF_WORK_MASK, %ecx	# is there any work to be done other
 					# than syscall tracing?
@@ -315,37 +481,38 @@ work_resched:
 
 work_notifysig:				# deal with pending signals and
 					# notify-resume requests
-	testl $VM_MASK, EFLAGS(%esp)
+#ifdef CONFIG_VM86
+	testl $VM_MASK, PT_EFLAGS(%esp)
 	movl %esp, %eax
 	jne work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
 	xorl %edx, %edx
 	call do_notify_resume
-	jmp resume_userspace
+	jmp resume_userspace_sig
 
 	ALIGN
 work_notifysig_v86:
-#ifdef CONFIG_VM86
 	pushl %ecx			# save ti_flags for do_notify_resume
+	CFI_ADJUST_CFA_OFFSET 4
 	call save_v86_state		# %eax contains pt_regs pointer
 	popl %ecx
+	CFI_ADJUST_CFA_OFFSET -4
 	movl %eax, %esp
+#else
+	movl %esp, %eax
+#endif
 	xorl %edx, %edx
 	call do_notify_resume
-	jmp resume_userspace
-#endif
+	jmp resume_userspace_sig
 
 	# perform syscall exit tracing
 	ALIGN
 syscall_trace_entry:
-	movl $-ENOSYS,EAX(%esp)
+	movl $-ENOSYS,PT_EAX(%esp)
 	movl %esp, %eax
 	xorl %edx,%edx
 	call do_syscall_trace
-	cmpl $0, %eax
-	jne resume_userspace		# ret != 0 -> running under PTRACE_SYSEMU,
-					# so must skip actual syscall
-	movl ORIG_EAX(%esp), %eax
+	movl PT_ORIG_EAX(%esp), %eax
 	cmpl $(nr_syscalls), %eax
 	jnae syscall_call
 	jmp syscall_exit
@@ -355,46 +522,53 @@ syscall_trace_entry:
 syscall_exit_work:
 	testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
 	jz work_pending
-	sti				# could let do_syscall_trace() call
+	TRACE_IRQS_ON
+	ENABLE_INTERRUPTS(CLBR_ANY)	# could let do_syscall_trace() call
 					# schedule() instead
 	movl %esp, %eax
 	movl $1, %edx
 	call do_syscall_trace
 	jmp resume_userspace
+	CFI_ENDPROC
 
-	ALIGN
+	RING0_INT_FRAME			# can't unwind into user space anyway
 syscall_fault:
 	pushl %eax			# save orig_eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
-	movl $-EFAULT,EAX(%esp)
+	movl $-EFAULT,PT_EAX(%esp)
 	jmp resume_userspace
 
-	ALIGN
 syscall_badsys:
-	movl $-ENOSYS,EAX(%esp)
+	movl $-ENOSYS,PT_EAX(%esp)
 	jmp resume_userspace
+	CFI_ENDPROC
 
 #define FIXUP_ESPFIX_STACK \
-	movl %esp, %eax; \
-	/* switch to 32bit stack using the pointer on top of 16bit stack */ \
-	lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \
-	/* copy data from 16bit stack to 32bit stack */ \
-	call fixup_x86_bogus_stack; \
-	/* put ESP to the proper location */ \
-	movl %eax, %esp;
-#define UNWIND_ESPFIX_STACK \
+	/* since we are on a wrong stack, we cant make it a C code :( */ \
+	movl %gs:PDA_cpu, %ebx; \
+	PER_CPU(cpu_gdt_descr, %ebx); \
+	movl GDS_address(%ebx), %ebx; \
+	GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \
+	addl %esp, %eax; \
+	pushl $__KERNEL_DS; \
+	CFI_ADJUST_CFA_OFFSET 4; \
 	pushl %eax; \
+	CFI_ADJUST_CFA_OFFSET 4; \
+	lss (%esp), %esp; \
+	CFI_ADJUST_CFA_OFFSET -8;
+#define UNWIND_ESPFIX_STACK \
 	movl %ss, %eax; \
-	/* see if on 16bit stack */ \
+	/* see if on espfix stack */ \
 	cmpw $__ESPFIX_SS, %ax; \
-	jne 28f; \
-	movl $__KERNEL_DS, %edx; \
-	movl %edx, %ds; \
-	movl %edx, %es; \
-	/* switch to 32bit stack */ \
-	FIXUP_ESPFIX_STACK \
-28:	popl %eax;
+	jne 27f; \
+	movl $__KERNEL_DS, %eax; \
+	movl %eax, %ds; \
+	movl %eax, %es; \
+	/* switch to normal stack */ \
+	FIXUP_ESPFIX_STACK; \
+27:;
 
 /*
  * Build the entry stubs and pointer table with
@@ -406,9 +580,14 @@ ENTRY(interrupt)
 
 vector=0
 ENTRY(irq_entries_start)
+	RING0_INT_FRAME
 .rept NR_IRQS
 	ALIGN
-1:	pushl $vector-256
+ .if vector
+	CFI_ADJUST_CFA_OFFSET -4
+ .endif
+1:	pushl $~(vector)
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp common_interrupt
 .data
 	.long 1b
@@ -416,85 +595,136 @@ ENTRY(irq_entries_start)
 vector=vector+1
 .endr
 
+/*
+ * the CPU automatically disables interrupts when executing an IRQ vector,
+ * so IRQ-flags tracing has to follow that:
+ */
 	ALIGN
 common_interrupt:
 	SAVE_ALL
+	TRACE_IRQS_OFF
 	movl %esp,%eax
 	call do_IRQ
 	jmp ret_from_intr
+	CFI_ENDPROC
 
 #define BUILD_INTERRUPT(name, nr)	\
 ENTRY(name)				\
-	pushl $nr-256;			\
-	SAVE_ALL			\
+	RING0_INT_FRAME;		\
+	pushl $~(nr);			\
+	CFI_ADJUST_CFA_OFFSET 4;	\
+	SAVE_ALL;			\
+	TRACE_IRQS_OFF			\
 	movl %esp,%eax;			\
 	call smp_/**/name;		\
-	jmp ret_from_intr;
+	jmp ret_from_intr;		\
+	CFI_ENDPROC
 
 /* The include is where all of the SMP etc. interrupts come from */
 #include "entry_arch.h"
 
-ENTRY(divide_error)
-	pushl $0			# no error code
-	pushl $do_divide_error
+KPROBE_ENTRY(page_fault)
+	RING0_EC_FRAME
+	pushl $do_page_fault
+	CFI_ADJUST_CFA_OFFSET 4
 	ALIGN
 error_code:
+	/* the function address is in %gs's slot on the stack */
+	pushl %es
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET es, 0*/
 	pushl %ds
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET ds, 0*/
 	pushl %eax
-	xorl %eax, %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eax, 0
 	pushl %ebp
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET ebp, 0
 	pushl %edi
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET edi, 0
 	pushl %esi
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET esi, 0
 	pushl %edx
-	decl %eax			# eax = -1
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET edx, 0
 	pushl %ecx
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET ecx, 0
 	pushl %ebx
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET ebx, 0
 	cld
-	pushl %es
+	pushl %gs
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET gs, 0*/
+	movl $(__KERNEL_PDA), %ecx
+	movl %ecx, %gs
 	UNWIND_ESPFIX_STACK
 	popl %ecx
-	movl ES(%esp), %edi		# get the function address
-	movl ORIG_EAX(%esp), %edx	# get the error code
-	movl %eax, ORIG_EAX(%esp)
-	movl %ecx, ES(%esp)
+	CFI_ADJUST_CFA_OFFSET -4
+	/*CFI_REGISTER es, ecx*/
+	movl PT_GS(%esp), %edi		# get the function address
+	movl PT_ORIG_EAX(%esp), %edx	# get the error code
+	movl $-1, PT_ORIG_EAX(%esp)	# no syscall to restart
+	mov  %ecx, PT_GS(%esp)
+	/*CFI_REL_OFFSET gs, ES*/
 	movl $(__USER_DS), %ecx
 	movl %ecx, %ds
 	movl %ecx, %es
 	movl %esp,%eax			# pt_regs pointer
 	call *%edi
 	jmp ret_from_exception
+	CFI_ENDPROC
+KPROBE_END(page_fault)
 
 ENTRY(coprocessor_error)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_coprocessor_error
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(simd_coprocessor_error)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_simd_coprocessor_error
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(device_not_available)
+	RING0_INT_FRAME
 	pushl $-1			# mark this as an int
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
-	movl %cr0, %eax
+	GET_CR0_INTO_EAX
 	testl $0x4, %eax		# EM (math emulation bit)
 	jne device_not_available_emulate
-	preempt_stop
+	preempt_stop(CLBR_ANY)
 	call math_state_restore
 	jmp ret_from_exception
 device_not_available_emulate:
 	pushl $0			# temporary storage for ORIG_EIP
+	CFI_ADJUST_CFA_OFFSET 4
 	call math_emulate
 	addl $4, %esp
+	CFI_ADJUST_CFA_OFFSET -4
 	jmp ret_from_exception
+	CFI_ENDPROC
 
 /*
  * Debug traps and NMI can happen at the one SYSENTER instruction
  * that sets up the real kernel stack. Check here, since we can't
  * allow the wrong stack to be used.
  *
- * "TSS_sysenter_esp0+12" is because the NMI/debug handler will have
+ * "SYSENTER_stack_esp0+12" is because the NMI/debug handler will have
  * already pushed 3 words if it hits on the sysenter instruction:
  * eflags, cs and eip.
  *
@@ -506,23 +736,33 @@ device_not_available_emulate:
 	cmpw $__KERNEL_CS,4(%esp);		\
 	jne ok;					\
 label:						\
-	movl TSS_sysenter_esp0+offset(%esp),%esp;	\
+	movl SYSENTER_stack_esp0+offset(%esp),%esp;	\
+	CFI_DEF_CFA esp, 0;			\
+	CFI_UNDEFINED eip;			\
 	pushfl;					\
+	CFI_ADJUST_CFA_OFFSET 4;		\
 	pushl $__KERNEL_CS;			\
-	pushl $sysenter_past_esp
+	CFI_ADJUST_CFA_OFFSET 4;		\
+	pushl $sysenter_past_esp;		\
+	CFI_ADJUST_CFA_OFFSET 4;		\
+	CFI_REL_OFFSET eip, 0
 
 KPROBE_ENTRY(debug)
+	RING0_INT_FRAME
 	cmpl $sysenter_entry,(%esp)
 	jne debug_stack_correct
 	FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
 debug_stack_correct:
 	pushl $-1			# mark this as an int
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	xorl %edx,%edx			# error code 0
 	movl %esp,%eax			# pt_regs pointer
 	call do_debug
 	jmp ret_from_exception
-	.previous .text
+	CFI_ENDPROC
+KPROBE_END(debug)
+
 /*
  * NMI is doubly nasty. It can happen _while_ we're handling
  * a debug fault, and the debug fault hasn't yet been able to
@@ -531,15 +771,19 @@ debug_stack_correct:
  * check whether we got an NMI on the debug path where the debug
  * fault happened on the sysenter path.
  */
-ENTRY(nmi)
+KPROBE_ENTRY(nmi)
+	RING0_INT_FRAME
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	movl %ss, %eax
 	cmpw $__ESPFIX_SS, %ax
 	popl %eax
-	je nmi_16bit_stack
+	CFI_ADJUST_CFA_OFFSET -4
+	je nmi_espfix_stack
 	cmpl $sysenter_entry,(%esp)
 	je nmi_stack_fixup
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	movl %esp,%eax
 	/* Do not access memory above the end of our stack page,
 	 * it might not exist.
@@ -547,21 +791,28 @@ ENTRY(nmi)
 	andl $(THREAD_SIZE-1),%eax
 	cmpl $(THREAD_SIZE-20),%eax
 	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4
 	jae nmi_stack_correct
 	cmpl $sysenter_entry,12(%esp)
 	je nmi_debug_stack_check
 nmi_stack_correct:
+	/* We have a RING0_INT_FRAME here */
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	xorl %edx,%edx		# zero error code
 	movl %esp,%eax		# pt_regs pointer
 	call do_nmi
-	jmp restore_all
+	jmp restore_nocheck_notrace
+	CFI_ENDPROC
 
 nmi_stack_fixup:
+	RING0_INT_FRAME
 	FIX_STACK(12,nmi_stack_correct, 1)
 	jmp nmi_stack_correct
+
 nmi_debug_stack_check:
+	/* We have a RING0_INT_FRAME here */
 	cmpw $__KERNEL_CS,16(%esp)
 	jne nmi_stack_correct
 	cmpl $debug,(%esp)
@@ -571,95 +822,176 @@ nmi_debug_stack_check:
 	FIX_STACK(24,nmi_stack_correct, 1)
 	jmp nmi_stack_correct
 
-nmi_16bit_stack:
-	/* create the pointer to lss back */
+nmi_espfix_stack:
+	/* We have a RING0_INT_FRAME here.
+	 *
+	 * create the pointer to lss back
+	 */
 	pushl %ss
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl %esp
-	movzwl %sp, %esp
+	CFI_ADJUST_CFA_OFFSET 4
 	addw $4, (%esp)
 	/* copy the iret frame of 12 bytes */
 	.rept 3
 	pushl 16(%esp)
+	CFI_ADJUST_CFA_OFFSET 4
 	.endr
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	FIXUP_ESPFIX_STACK		# %eax == %esp
 	xorl %edx,%edx			# zero error code
 	call do_nmi
 	RESTORE_REGS
-	lss 12+4(%esp), %esp		# back to 16bit stack
+	lss 12+4(%esp), %esp		# back to espfix stack
+	CFI_ADJUST_CFA_OFFSET -24
+1:	INTERRUPT_RETURN
+	CFI_ENDPROC
+.section __ex_table,"a"
+	.align 4
+	.long 1b,iret_exc
+.previous
+KPROBE_END(nmi)
+
+#ifdef CONFIG_PARAVIRT
+ENTRY(native_iret)
 1:	iret
 .section __ex_table,"a"
 	.align 4
 	.long 1b,iret_exc
 .previous
 
+ENTRY(native_irq_enable_sysexit)
+	sti
+	sysexit
+#endif
+
 KPROBE_ENTRY(int3)
+	RING0_INT_FRAME
 	pushl $-1			# mark this as an int
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	xorl %edx,%edx		# zero error code
 	movl %esp,%eax		# pt_regs pointer
 	call do_int3
 	jmp ret_from_exception
-	.previous .text
+	CFI_ENDPROC
+KPROBE_END(int3)
 
 ENTRY(overflow)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_overflow
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(bounds)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_bounds
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(invalid_op)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_invalid_op
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(coprocessor_segment_overrun)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_coprocessor_segment_overrun
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(invalid_TSS)
+	RING0_EC_FRAME
 	pushl $do_invalid_TSS
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(segment_not_present)
+	RING0_EC_FRAME
 	pushl $do_segment_not_present
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(stack_segment)
+	RING0_EC_FRAME
 	pushl $do_stack_segment
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 KPROBE_ENTRY(general_protection)
+	RING0_EC_FRAME
 	pushl $do_general_protection
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
-	.previous .text
+	CFI_ENDPROC
+KPROBE_END(general_protection)
 
 ENTRY(alignment_check)
+	RING0_EC_FRAME
 	pushl $do_alignment_check
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
-KPROBE_ENTRY(page_fault)
-	pushl $do_page_fault
+ENTRY(divide_error)
+	RING0_INT_FRAME
+	pushl $0			# no error code
+	CFI_ADJUST_CFA_OFFSET 4
+	pushl $do_divide_error
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
-	.previous .text
+	CFI_ENDPROC
 
 #ifdef CONFIG_X86_MCE
 ENTRY(machine_check)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl machine_check_vector
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 #endif
 
 ENTRY(spurious_interrupt_bug)
+	RING0_INT_FRAME
 	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_spurious_interrupt_bug
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
+
+ENTRY(kernel_thread_helper)
+	pushl $0		# fake return address for unwinder
+	CFI_STARTPROC
+	movl %edx,%eax
+	push %edx
+	CFI_ADJUST_CFA_OFFSET 4
+	call *%ebx
+	push %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	call do_exit
+	CFI_ENDPROC
+ENDPROC(kernel_thread_helper)
 
 .section .rodata,"a"
 #include "syscall_table.S"