~hc/RK356X_SDK_RELEASE.git

..	..	@@ -40,42 +40,16 @@
40	40	#include <asm/processor-flags.h>
41	41	#include <asm/irq_vectors.h>
42	42	#include <asm/cpufeatures.h>
43		-#include <asm/alternative-asm.h>
	43	+#include <asm/alternative.h>
44	44	#include <asm/asm.h>
45	45	#include <asm/smap.h>
46	46	#include <asm/frame.h>
	47	+#include <asm/trapnr.h>
47	48	#include <asm/nospec-branch.h>
48	49
	50	+#include "calling.h"
	51	+
49	52	.section .entry.text, "ax"
50		-
51		-/*
52		- * We use macros for low-level operations which need to be overridden
53		- * for paravirtualization. The following will never clobber any registers:
54		- * INTERRUPT_RETURN (aka. "iret")
55		- * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
56		- * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
57		- *
58		- * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
59		- * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
60		- * Allowing a register to be clobbered can shrink the paravirt replacement
61		- * enough to patch inline, increasing performance.
62		- */
63		-
64		-#ifdef CONFIG_PREEMPT
65		-# define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
66		-#else
67		-# define preempt_stop(clobbers)
68		-# define resume_kernel restore_all_kernel
69		-#endif
70		-
71		-.macro TRACE_IRQS_IRET
72		-#ifdef CONFIG_TRACE_IRQFLAGS
73		- testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off?
74		- jz 1f
75		- TRACE_IRQS_ON
76		-1:
77		-#endif
78		-.endm
79	53
80	54	#define PTI_SWITCH_MASK (1 << PAGE_SHIFT)
81	55
..	..	@@ -171,7 +145,7 @@
171	145	ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI
172	146	.if \no_user_check == 0
173	147	/* coming from usermode? */
174		- testl $SEGMENT_RPL_MASK, PT_CS(%esp)
	148	+ testl $USER_SEGMENT_RPL_MASK, PT_CS(%esp)
175	149	jz .Lend_\@
176	150	.endif
177	151	/* On user-cr3? */
..	..	@@ -201,10 +175,126 @@
201	175	.Lend_\@:
202	176	.endm
203	177
204		-.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0
	178	+#define CS_FROM_ENTRY_STACK (1 << 31)
	179	+#define CS_FROM_USER_CR3 (1 << 30)
	180	+#define CS_FROM_KERNEL (1 << 29)
	181	+#define CS_FROM_ESPFIX (1 << 28)
	182	+
	183	+.macro FIXUP_FRAME
	184	+ /*
	185	+ * The high bits of the CS dword (__csh) are used for CS_FROM_*.
	186	+ * Clear them in case hardware didn't do this for us.
	187	+ */
	188	+ andl $0x0000ffff, 4*4(%esp)
	189	+
	190	+#ifdef CONFIG_VM86
	191	+ testl $X86_EFLAGS_VM, 5*4(%esp)
	192	+ jnz .Lfrom_usermode_no_fixup_\@
	193	+#endif
	194	+ testl $USER_SEGMENT_RPL_MASK, 4*4(%esp)
	195	+ jnz .Lfrom_usermode_no_fixup_\@
	196	+
	197	+ orl $CS_FROM_KERNEL, 4*4(%esp)
	198	+
	199	+ /*
	200	+ * When we're here from kernel mode; the (exception) stack looks like:
	201	+ *
	202	+ * 6*4(%esp) - <previous context>
	203	+ * 5*4(%esp) - flags
	204	+ * 4*4(%esp) - cs
	205	+ * 3*4(%esp) - ip
	206	+ * 2*4(%esp) - orig_eax
	207	+ * 1*4(%esp) - gs / function
	208	+ * 0*4(%esp) - fs
	209	+ *
	210	+ * Lets build a 5 entry IRET frame after that, such that struct pt_regs
	211	+ * is complete and in particular regs->sp is correct. This gives us
	212	+ * the original 6 enties as gap:
	213	+ *
	214	+ * 14*4(%esp) - <previous context>
	215	+ * 13*4(%esp) - gap / flags
	216	+ * 12*4(%esp) - gap / cs
	217	+ * 11*4(%esp) - gap / ip
	218	+ * 10*4(%esp) - gap / orig_eax
	219	+ * 9*4(%esp) - gap / gs / function
	220	+ * 8*4(%esp) - gap / fs
	221	+ * 7*4(%esp) - ss
	222	+ * 6*4(%esp) - sp
	223	+ * 5*4(%esp) - flags
	224	+ * 4*4(%esp) - cs
	225	+ * 3*4(%esp) - ip
	226	+ * 2*4(%esp) - orig_eax
	227	+ * 1*4(%esp) - gs / function
	228	+ * 0*4(%esp) - fs
	229	+ */
	230	+
	231	+ pushl %ss # ss
	232	+ pushl %esp # sp (points at ss)
	233	+ addl $7*4, (%esp) # point sp back at the previous context
	234	+ pushl 7*4(%esp) # flags
	235	+ pushl 7*4(%esp) # cs
	236	+ pushl 7*4(%esp) # ip
	237	+ pushl 7*4(%esp) # orig_eax
	238	+ pushl 7*4(%esp) # gs / function
	239	+ pushl 7*4(%esp) # fs
	240	+.Lfrom_usermode_no_fixup_\@:
	241	+.endm
	242	+
	243	+.macro IRET_FRAME
	244	+ /*
	245	+ * We're called with %ds, %es, %fs, and %gs from the interrupted
	246	+ * frame, so we shouldn't use them. Also, we may be in ESPFIX
	247	+ * mode and therefore have a nonzero SS base and an offset ESP,
	248	+ * so any attempt to access the stack needs to use SS. (except for
	249	+ * accesses through %esp, which automatically use SS.)
	250	+ */
	251	+ testl $CS_FROM_KERNEL, 1*4(%esp)
	252	+ jz .Lfinished_frame_\@
	253	+
	254	+ /*
	255	+ * Reconstruct the 3 entry IRET frame right after the (modified)
	256	+ * regs->sp without lowering %esp in between, such that an NMI in the
	257	+ * middle doesn't scribble our stack.
	258	+ */
	259	+ pushl %eax
	260	+ pushl %ecx
	261	+ movl 5*4(%esp), %eax # (modified) regs->sp
	262	+
	263	+ movl 4*4(%esp), %ecx # flags
	264	+ movl %ecx, %ss:-1*4(%eax)
	265	+
	266	+ movl 3*4(%esp), %ecx # cs
	267	+ andl $0x0000ffff, %ecx
	268	+ movl %ecx, %ss:-2*4(%eax)
	269	+
	270	+ movl 2*4(%esp), %ecx # ip
	271	+ movl %ecx, %ss:-3*4(%eax)
	272	+
	273	+ movl 1*4(%esp), %ecx # eax
	274	+ movl %ecx, %ss:-4*4(%eax)
	275	+
	276	+ popl %ecx
	277	+ lea -4*4(%eax), %esp
	278	+ popl %eax
	279	+.Lfinished_frame_\@:
	280	+.endm
	281	+
	282	+.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 unwind_espfix=0
205	283	cld
	284	+.if \skip_gs == 0
206	285	PUSH_GS
	286	+.endif
207	287	pushl %fs
	288	+
	289	+ pushl %eax
	290	+ movl $(__KERNEL_PERCPU), %eax
	291	+ movl %eax, %fs
	292	+.if \unwind_espfix > 0
	293	+ UNWIND_ESPFIX_STACK
	294	+.endif
	295	+ popl %eax
	296	+
	297	+ FIXUP_FRAME
208	298	pushl %es
209	299	pushl %ds
210	300	pushl \pt_regs_ax
..	..	@@ -217,19 +307,17 @@
217	307	movl $(__USER_DS), %edx
218	308	movl %edx, %ds
219	309	movl %edx, %es
220		- movl $(__KERNEL_PERCPU), %edx
221		- movl %edx, %fs
	310	+.if \skip_gs == 0
222	311	SET_KERNEL_GS %edx
223		-
	312	+.endif
224	313	/* Switch to kernel stack if necessary */
225	314	.if \switch_stacks > 0
226	315	SWITCH_TO_KERNEL_STACK
227	316	.endif
228		-
229	317	.endm
230	318
231		-.macro SAVE_ALL_NMI cr3_reg:req
232		- SAVE_ALL
	319	+.macro SAVE_ALL_NMI cr3_reg:req unwind_espfix=0
	320	+ SAVE_ALL unwind_espfix=\unwind_espfix
233	321
234	322	BUG_IF_WRONG_CR3
235	323
..	..	@@ -261,6 +349,7 @@
261	349	2: popl %es
262	350	3: popl %fs
263	351	POP_GS \pop
	352	+ IRET_FRAME
264	353	.pushsection .fixup, "ax"
265	354	4: movl $0, (%esp)
266	355	jmp 1b
..	..	@@ -299,7 +388,8 @@
299	388
300	389	.macro CHECK_AND_APPLY_ESPFIX
301	390	#ifdef CONFIG_X86_ESPFIX32
302		-#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
	391	+#define GDT_ESPFIX_OFFSET (GDT_ENTRY_ESPFIX_SS * 8)
	392	+#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + GDT_ESPFIX_OFFSET
303	393
304	394	ALTERNATIVE "jmp .Lend_\@", "", X86_BUG_ESPFIX
305	395
..	..	@@ -357,12 +447,7 @@
357	447	* switch to it before we do any copying.
358	448	*/
359	449
360		-#define CS_FROM_ENTRY_STACK (1 << 31)
361		-#define CS_FROM_USER_CR3 (1 << 30)
362		-
363	450	.macro SWITCH_TO_KERNEL_STACK
364		-
365		- ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV
366	451
367	452	BUG_IF_WRONG_CR3
368	453
..	..	@@ -372,13 +457,6 @@
372	457	* %eax now contains the entry cr3 and we carry it forward in
373	458	* that register for the time this macro runs
374	459	*/
375		-
376		- /*
377		- * The high bits of the CS dword (__csh) are used for
378		- * CS_FROM_ENTRY_STACK and CS_FROM_USER_CR3. Clear them in case
379		- * hardware didn't do this for us.
380		- */
381		- andl $(0x0000ffff), PT_CS(%esp)
382	460
383	461	/* Are we on the entry stack? Bail out if not! */
384	462	movl PER_CPU_VAR(cpu_entry_area), %ecx
..	..	@@ -519,8 +597,6 @@
519	597	*/
520	598	.macro SWITCH_TO_ENTRY_STACK
521	599
522		- ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV
523		-
524	600	/* Bytes to copy */
525	601	movl $PTREGS_SIZE, %ecx
526	602
..	..	@@ -619,11 +695,69 @@
619	695
620	696	.Lend_\@:
621	697	.endm
	698	+
	699	+/**
	700	+ * idtentry - Macro to generate entry stubs for simple IDT entries
	701	+ * @vector: Vector number
	702	+ * @asmsym: ASM symbol for the entry point
	703	+ * @cfunc: C function to be called
	704	+ * @has_error_code: Hardware pushed error code on stack
	705	+ */
	706	+.macro idtentry vector asmsym cfunc has_error_code:req
	707	+SYM_CODE_START(\asmsym)
	708	+ ASM_CLAC
	709	+ cld
	710	+
	711	+ .if \has_error_code == 0
	712	+ pushl $0 /* Clear the error code */
	713	+ .endif
	714	+
	715	+ /* Push the C-function address into the GS slot */
	716	+ pushl $\cfunc
	717	+ /* Invoke the common exception entry */
	718	+ jmp handle_exception
	719	+SYM_CODE_END(\asmsym)
	720	+.endm
	721	+
	722	+.macro idtentry_irq vector cfunc
	723	+ .p2align CONFIG_X86_L1_CACHE_SHIFT
	724	+SYM_CODE_START_LOCAL(asm_\cfunc)
	725	+ ASM_CLAC
	726	+ SAVE_ALL switch_stacks=1
	727	+ ENCODE_FRAME_POINTER
	728	+ movl %esp, %eax
	729	+ movl PT_ORIG_EAX(%esp), %edx /* get the vector from stack */
	730	+ movl $-1, PT_ORIG_EAX(%esp) /* no syscall to restart */
	731	+ call \cfunc
	732	+ jmp handle_exception_return
	733	+SYM_CODE_END(asm_\cfunc)
	734	+.endm
	735	+
	736	+.macro idtentry_sysvec vector cfunc
	737	+ idtentry \vector asm_\cfunc \cfunc has_error_code=0
	738	+.endm
	739	+
	740	+/*
	741	+ * Include the defines which emit the idt entries which are shared
	742	+ * shared between 32 and 64 bit and emit the __irqentry_text_* markers
	743	+ * so the stacktrace boundary checks work.
	744	+ */
	745	+ .align 16
	746	+ .globl __irqentry_text_start
	747	+__irqentry_text_start:
	748	+
	749	+#include <asm/idtentry.h>
	750	+
	751	+ .align 16
	752	+ .globl __irqentry_text_end
	753	+__irqentry_text_end:
	754	+
622	755	/*
623	756	* %eax: prev task
624	757	* %edx: next task
625	758	*/
626		-ENTRY(__switch_to_asm)
	759	+.pushsection .text, "ax"
	760	+SYM_CODE_START(__switch_to_asm)
627	761	/*
628	762	* Save callee-saved registers
629	763	* This must match the order in struct inactive_task_frame
..	..	@@ -632,6 +766,11 @@
632	766	pushl %ebx
633	767	pushl %edi
634	768	pushl %esi
	769	+ /*
	770	+ * Flags are saved to prevent AC leakage. This could go
	771	+ * away if objtool would have 32bit support to verify
	772	+ * the STAC/CLAC correctness.
	773	+ */
635	774	pushfl
636	775
637	776	/* switch stack */
..	..	@@ -643,7 +782,6 @@
643	782	movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset
644	783	#endif
645	784
646		-#ifdef CONFIG_RETPOLINE
647	785	/*
648	786	* When switching from a shallower to a deeper call stack
649	787	* the RSB may either underflow or use entries populated
..	..	@@ -652,17 +790,18 @@
652	790	* speculative execution to prevent attack.
653	791	*/
654	792	FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
655		-#endif
656	793
657		- /* restore callee-saved registers */
	794	+ /* Restore flags or the incoming task to restore AC state. */
658	795	popfl
	796	+ /* restore callee-saved registers */
659	797	popl %esi
660	798	popl %edi
661	799	popl %ebx
662	800	popl %ebp
663	801
664	802	jmp __switch_to
665		-END(__switch_to_asm)
	803	+SYM_CODE_END(__switch_to_asm)
	804	+.popsection
666	805
667	806	/*
668	807	* The unwinder expects the last frame on the stack to always be at the same
..	..	@@ -671,7 +810,8 @@
671	810	* asmlinkage function so its argument has to be pushed on the stack. This
672	811	* wrapper creates a proper "end of stack" frame header before the call.
673	812	*/
674		-ENTRY(schedule_tail_wrapper)
	813	+.pushsection .text, "ax"
	814	+SYM_FUNC_START(schedule_tail_wrapper)
675	815	FRAME_BEGIN
676	816
677	817	pushl %eax
..	..	@@ -679,8 +819,10 @@
679	819	popl %eax
680	820
681	821	FRAME_END
682		- ret
683		-ENDPROC(schedule_tail_wrapper)
	822	+ RET
	823	+SYM_FUNC_END(schedule_tail_wrapper)
	824	+.popsection
	825	+
684	826	/*
685	827	* A newly forked process directly context switches into this address.
686	828	*
..	..	@@ -688,7 +830,8 @@
688	830	* ebx: kernel thread func (NULL for user thread)
689	831	* edi: kernel thread arg
690	832	*/
691		-ENTRY(ret_from_fork)
	833	+.pushsection .text, "ax"
	834	+SYM_CODE_START(ret_from_fork)
692	835	call schedule_tail_wrapper
693	836
694	837	testl %ebx, %ebx
..	..	@@ -697,86 +840,23 @@
697	840	2:
698	841	/* When we fork, we trace the syscall return in the child, too. */
699	842	movl %esp, %eax
700		- call syscall_return_slowpath
701		- jmp restore_all
	843	+ call syscall_exit_to_user_mode
	844	+ jmp .Lsyscall_32_done
702	845
703	846	/* kernel thread */
704	847	1: movl %edi, %eax
705		- CALL_NOSPEC %ebx
	848	+ CALL_NOSPEC ebx
706	849	/*
707	850	* A kernel thread is allowed to return here after successfully
708		- * calling do_execve(). Exit to userspace to complete the execve()
	851	+ * calling kernel_execve(). Exit to userspace to complete the execve()
709	852	* syscall.
710	853	*/
711	854	movl $0, PT_EAX(%esp)
712	855	jmp 2b
713		-END(ret_from_fork)
	856	+SYM_CODE_END(ret_from_fork)
	857	+.popsection
714	858
715		-/*
716		- * Return to user mode is not as complex as all this looks,
717		- * but we want the default path for a system call return to
718		- * go as quickly as possible which is why some of this is
719		- * less clear than it otherwise should be.
720		- */
721		-
722		- # userspace resumption stub bypassing syscall exit tracing
723		- ALIGN
724		-ret_from_exception:
725		- preempt_stop(CLBR_ANY)
726		-ret_from_intr:
727		-#ifdef CONFIG_VM86
728		- movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
729		- movb PT_CS(%esp), %al
730		- andl $(X86_EFLAGS_VM \| SEGMENT_RPL_MASK), %eax
731		-#else
732		- /*
733		- * We can be coming here from child spawned by kernel_thread().
734		- */
735		- movl PT_CS(%esp), %eax
736		- andl $SEGMENT_RPL_MASK, %eax
737		-#endif
738		- cmpl $USER_RPL, %eax
739		- jb resume_kernel # not returning to v8086 or userspace
740		-
741		-ENTRY(resume_userspace)
742		- DISABLE_INTERRUPTS(CLBR_ANY)
743		- TRACE_IRQS_OFF
744		- movl %esp, %eax
745		- call prepare_exit_to_usermode
746		- jmp restore_all
747		-END(ret_from_exception)
748		-
749		-#ifdef CONFIG_PREEMPT
750		-ENTRY(resume_kernel)
751		- DISABLE_INTERRUPTS(CLBR_ANY)
752		-.Lneed_resched:
753		- # preempt count == 0 + NEED_RS set?
754		- cmpl $0, PER_CPU_VAR(__preempt_count)
755		-#ifndef CONFIG_PREEMPT_LAZY
756		- jnz restore_all_kernel
757		-#else
758		- jz test_int_off
759		-
760		- # atleast preempt count == 0 ?
761		- cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
762		- jne restore_all_kernel
763		-
764		- movl PER_CPU_VAR(current_task), %ebp
765		- cmpl $0,TASK_TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ?
766		- jnz restore_all_kernel
767		-
768		- testl $_TIF_NEED_RESCHED_LAZY, TASK_TI_flags(%ebp)
769		- jz restore_all_kernel
770		-test_int_off:
771		-#endif
772		- testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
773		- jz restore_all_kernel
774		- call preempt_schedule_irq
775		- jmp .Lneed_resched
776		-END(resume_kernel)
777		-#endif
778		-
779		-GLOBAL(__begin_SYSENTER_singlestep_region)
	859	+SYM_ENTRY(__begin_SYSENTER_singlestep_region, SYM_L_GLOBAL, SYM_A_NONE)
780	860	/*
781	861	* All code from here through __end_SYSENTER_singlestep_region is subject
782	862	* to being single-stepped if a user program sets TF and executes SYSENTER.
..	..	@@ -785,16 +865,6 @@
785	865	* possible, we handle TF just like AC and NT, except that our #DB handler
786	866	* will ignore all of the single-step traps generated in this range.
787	867	*/
788		-
789		-#ifdef CONFIG_XEN
790		-/*
791		- * Xen doesn't set %esp to be precisely what the normal SYSENTER
792		- * entry point expects, so fix it up before using the normal path.
793		- */
794		-ENTRY(xen_sysenter_target)
795		- addl $54, %esp / remove xen-provided frame */
796		- jmp .Lsysenter_past_esp
797		-#endif
798	868
799	869	/*
800	870	* 32-bit SYSENTER entry.
..	..	@@ -828,7 +898,7 @@
828	898	* ebp user stack
829	899	* 0(%ebp) arg6
830	900	*/
831		-ENTRY(entry_SYSENTER_32)
	901	+SYM_FUNC_START(entry_SYSENTER_32)
832	902	/*
833	903	* On entry-stack with all userspace-regs live - save and
834	904	* restore eflags and %eax to use it as scratch-reg for the cr3
..	..	@@ -846,9 +916,8 @@
846	916
847	917	.Lsysenter_past_esp:
848	918	pushl $__USER_DS /* pt_regs->ss */
849		- pushl %ebp /* pt_regs->sp (stashed in bp) */
	919	+ pushl $0 /* pt_regs->sp (placeholder) */
850	920	pushfl /* pt_regs->flags (except IF = 0) */
851		- orl $X86_EFLAGS_IF, (%esp) /* Fix IF */
852	921	pushl $__USER_CS /* pt_regs->cs */
853	922	pushl $0 /* pt_regs->ip = 0 (placeholder) */
854	923	pushl %eax /* pt_regs->orig_ax */
..	..	@@ -877,20 +946,14 @@
877	946	jnz .Lsysenter_fix_flags
878	947	.Lsysenter_flags_fixed:
879	948
880		- /*
881		- * User mode is traced as though IRQs are on, and SYSENTER
882		- * turned them off.
883		- */
884		- TRACE_IRQS_OFF
885		-
886	949	movl %esp, %eax
887		- call do_fast_syscall_32
888		- /* XEN PV guests always use IRET path */
889		- ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \
890		- "jmp .Lsyscall_32_done", X86_FEATURE_XENPV
	950	+ call do_SYSENTER_32
	951	+ testl %eax, %eax
	952	+ jz .Lsyscall_32_done
891	953
892		-/* Opportunistic SYSEXIT */
893		- TRACE_IRQS_ON /* User mode traces as IRQs on. */
	954	+ STACKLEAK_ERASE
	955	+
	956	+ /* Opportunistic SYSEXIT */
894	957
895	958	/*
896	959	* Setup entry stack - we keep the pointer in %eax and do the
..	..	@@ -953,8 +1016,8 @@
953	1016	pushl $X86_EFLAGS_FIXED
954	1017	popfl
955	1018	jmp .Lsysenter_flags_fixed
956		-GLOBAL(__end_SYSENTER_singlestep_region)
957		-ENDPROC(entry_SYSENTER_32)
	1019	+SYM_ENTRY(__end_SYSENTER_singlestep_region, SYM_L_GLOBAL, SYM_A_NONE)
	1020	+SYM_FUNC_END(entry_SYSENTER_32)
958	1021
959	1022	/*
960	1023	* 32-bit legacy system call entry.
..	..	@@ -984,28 +1047,21 @@
984	1047	* edi arg5
985	1048	* ebp arg6
986	1049	*/
987		-ENTRY(entry_INT80_32)
	1050	+SYM_FUNC_START(entry_INT80_32)
988	1051	ASM_CLAC
989	1052	pushl %eax /* pt_regs->orig_ax */
990	1053
991	1054	SAVE_ALL pt_regs_ax=$-ENOSYS switch_stacks=1 /* save rest */
992	1055
993		- /*
994		- * User mode is traced as though IRQs are on, and the interrupt gate
995		- * turned them off.
996		- */
997		- TRACE_IRQS_OFF
998		-
999	1056	movl %esp, %eax
1000	1057	call do_int80_syscall_32
1001	1058	.Lsyscall_32_done:
	1059	+ STACKLEAK_ERASE
1002	1060
1003		-restore_all:
1004		- TRACE_IRQS_IRET
	1061	+restore_all_switch_stack:
1005	1062	SWITCH_TO_ENTRY_STACK
1006		-.Lrestore_all_notrace:
1007	1063	CHECK_AND_APPLY_ESPFIX
1008		-.Lrestore_nocheck:
	1064	+
1009	1065	/* Switch back to user CR3 */
1010	1066	SWITCH_TO_USER_CR3 scratch_reg=%eax
1011	1067
..	..	@@ -1021,17 +1077,10 @@
1021	1077	*/
1022	1078	INTERRUPT_RETURN
1023	1079
1024		-restore_all_kernel:
1025		- TRACE_IRQS_IRET
1026		- PARANOID_EXIT_TO_KERNEL_MODE
1027		- BUG_IF_WRONG_CR3
1028		- RESTORE_REGS 4
1029		- jmp .Lirq_return
1030		-
1031	1080	.section .fixup, "ax"
1032		-ENTRY(iret_exc )
	1081	+SYM_CODE_START(asm_iret_error)
1033	1082	pushl $0 # no error code
1034		- pushl $do_iret_error
	1083	+ pushl $iret_error
1035	1084
1036	1085	#ifdef CONFIG_DEBUG_ENTRY
1037	1086	/*
..	..	@@ -1045,10 +1094,11 @@
1045	1094	popl %eax
1046	1095	#endif
1047	1096
1048		- jmp common_exception
	1097	+ jmp handle_exception
	1098	+SYM_CODE_END(asm_iret_error)
1049	1099	.previous
1050		- _ASM_EXTABLE(.Lirq_return, iret_exc)
1051		-ENDPROC(entry_INT80_32)
	1100	+ _ASM_EXTABLE(.Lirq_return, asm_iret_error)
	1101	+SYM_FUNC_END(entry_INT80_32)
1052	1102
1053	1103	.macro FIXUP_ESPFIX_STACK
1054	1104	/*
..	..	@@ -1057,366 +1107,128 @@
1057	1107	* We can't call C functions using the ESPFIX stack. This code reads
1058	1108	* the high word of the segment base from the GDT and swiches to the
1059	1109	* normal stack and adjusts ESP with the matching offset.
	1110	+ *
	1111	+ * We might be on user CR3 here, so percpu data is not mapped and we can't
	1112	+ * access the GDT through the percpu segment. Instead, use SGDT to find
	1113	+ * the cpu_entry_area alias of the GDT.
1060	1114	*/
1061	1115	#ifdef CONFIG_X86_ESPFIX32
1062	1116	/* fixup the stack */
1063		- mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
1064		- mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
	1117	+ pushl %ecx
	1118	+ subl $2*4, %esp
	1119	+ sgdt (%esp)
	1120	+ movl 2(%esp), %ecx /* GDT address */
	1121	+ /*
	1122	+ * Careful: ECX is a linear pointer, so we need to force base
	1123	+ * zero. %cs is the only known-linear segment we have right now.
	1124	+ */
	1125	+ mov %cs:GDT_ESPFIX_OFFSET + 4(%ecx), %al /* bits 16..23 */
	1126	+ mov %cs:GDT_ESPFIX_OFFSET + 7(%ecx), %ah /* bits 24..31 */
1065	1127	shl $16, %eax
	1128	+ addl $2*4, %esp
	1129	+ popl %ecx
1066	1130	addl %esp, %eax /* the adjusted stack pointer */
1067	1131	pushl $__KERNEL_DS
1068	1132	pushl %eax
1069	1133	lss (%esp), %esp /* switch to the normal stack segment */
1070	1134	#endif
1071	1135	.endm
	1136	+
1072	1137	.macro UNWIND_ESPFIX_STACK
	1138	+ /* It's safe to clobber %eax, all other regs need to be preserved */
1073	1139	#ifdef CONFIG_X86_ESPFIX32
1074	1140	movl %ss, %eax
1075	1141	/* see if on espfix stack */
1076	1142	cmpw $__ESPFIX_SS, %ax
1077		- jne 27f
1078		- movl $__KERNEL_DS, %eax
1079		- movl %eax, %ds
1080		- movl %eax, %es
	1143	+ jne .Lno_fixup_\@
1081	1144	/* switch to normal stack */
1082	1145	FIXUP_ESPFIX_STACK
1083		-27:
	1146	+.Lno_fixup_\@:
1084	1147	#endif
1085	1148	.endm
1086	1149
1087		-/*
1088		- * Build the entry stubs with some assembler magic.
1089		- * We pack 1 stub into every 8-byte block.
1090		- */
1091		- .align 8
1092		-ENTRY(irq_entries_start)
1093		- vector=FIRST_EXTERNAL_VECTOR
1094		- .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
1095		- pushl $(~vector+0x80) /* Note: always in signed byte range */
1096		- vector=vector+1
1097		- jmp common_interrupt
1098		- .align 8
1099		- .endr
1100		-END(irq_entries_start)
1101		-
1102		-#ifdef CONFIG_X86_LOCAL_APIC
1103		- .align 8
1104		-ENTRY(spurious_entries_start)
1105		- vector=FIRST_SYSTEM_VECTOR
1106		- .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)
1107		- pushl $(~vector+0x80) /* Note: always in signed byte range */
1108		- vector=vector+1
1109		- jmp common_spurious
1110		- .align 8
1111		- .endr
1112		-END(spurious_entries_start)
1113		-
1114		-common_spurious:
1115		- ASM_CLAC
1116		- addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */
1117		- SAVE_ALL switch_stacks=1
1118		- ENCODE_FRAME_POINTER
1119		- TRACE_IRQS_OFF
1120		- movl %esp, %eax
1121		- call smp_spurious_interrupt
1122		- jmp ret_from_intr
1123		-ENDPROC(common_spurious)
1124		-#endif
1125		-
1126		-/*
1127		- * the CPU automatically disables interrupts when executing an IRQ vector,
1128		- * so IRQ-flags tracing has to follow that:
1129		- */
1130		- .p2align CONFIG_X86_L1_CACHE_SHIFT
1131		-common_interrupt:
1132		- ASM_CLAC
1133		- addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */
1134		-
1135		- SAVE_ALL switch_stacks=1
1136		- ENCODE_FRAME_POINTER
1137		- TRACE_IRQS_OFF
1138		- movl %esp, %eax
1139		- call do_IRQ
1140		- jmp ret_from_intr
1141		-ENDPROC(common_interrupt)
1142		-
1143		-#define BUILD_INTERRUPT3(name, nr, fn) \
1144		-ENTRY(name) \
1145		- ASM_CLAC; \
1146		- pushl $~(nr); \
1147		- SAVE_ALL switch_stacks=1; \
1148		- ENCODE_FRAME_POINTER; \
1149		- TRACE_IRQS_OFF \
1150		- movl %esp, %eax; \
1151		- call fn; \
1152		- jmp ret_from_intr; \
1153		-ENDPROC(name)
1154		-
1155		-#define BUILD_INTERRUPT(name, nr) \
1156		- BUILD_INTERRUPT3(name, nr, smp_##name); \
1157		-
1158		-/* The include is where all of the SMP etc. interrupts come from */
1159		-#include <asm/entry_arch.h>
1160		-
1161		-ENTRY(coprocessor_error)
1162		- ASM_CLAC
1163		- pushl $0
1164		- pushl $do_coprocessor_error
1165		- jmp common_exception
1166		-END(coprocessor_error)
1167		-
1168		-ENTRY(simd_coprocessor_error)
1169		- ASM_CLAC
1170		- pushl $0
1171		-#ifdef CONFIG_X86_INVD_BUG
1172		- /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
1173		- ALTERNATIVE "pushl $do_general_protection", \
1174		- "pushl $do_simd_coprocessor_error", \
1175		- X86_FEATURE_XMM
1176		-#else
1177		- pushl $do_simd_coprocessor_error
1178		-#endif
1179		- jmp common_exception
1180		-END(simd_coprocessor_error)
1181		-
1182		-ENTRY(device_not_available)
1183		- ASM_CLAC
1184		- pushl $-1 # mark this as an int
1185		- pushl $do_device_not_available
1186		- jmp common_exception
1187		-END(device_not_available)
1188		-
1189		-#ifdef CONFIG_PARAVIRT
1190		-ENTRY(native_iret)
1191		- iret
1192		- _ASM_EXTABLE(native_iret, iret_exc)
1193		-END(native_iret)
1194		-#endif
1195		-
1196		-ENTRY(overflow)
1197		- ASM_CLAC
1198		- pushl $0
1199		- pushl $do_overflow
1200		- jmp common_exception
1201		-END(overflow)
1202		-
1203		-ENTRY(bounds)
1204		- ASM_CLAC
1205		- pushl $0
1206		- pushl $do_bounds
1207		- jmp common_exception
1208		-END(bounds)
1209		-
1210		-ENTRY(invalid_op)
1211		- ASM_CLAC
1212		- pushl $0
1213		- pushl $do_invalid_op
1214		- jmp common_exception
1215		-END(invalid_op)
1216		-
1217		-ENTRY(coprocessor_segment_overrun)
1218		- ASM_CLAC
1219		- pushl $0
1220		- pushl $do_coprocessor_segment_overrun
1221		- jmp common_exception
1222		-END(coprocessor_segment_overrun)
1223		-
1224		-ENTRY(invalid_TSS)
1225		- ASM_CLAC
1226		- pushl $do_invalid_TSS
1227		- jmp common_exception
1228		-END(invalid_TSS)
1229		-
1230		-ENTRY(segment_not_present)
1231		- ASM_CLAC
1232		- pushl $do_segment_not_present
1233		- jmp common_exception
1234		-END(segment_not_present)
1235		-
1236		-ENTRY(stack_segment)
1237		- ASM_CLAC
1238		- pushl $do_stack_segment
1239		- jmp common_exception
1240		-END(stack_segment)
1241		-
1242		-ENTRY(alignment_check)
1243		- ASM_CLAC
1244		- pushl $do_alignment_check
1245		- jmp common_exception
1246		-END(alignment_check)
1247		-
1248		-ENTRY(divide_error)
1249		- ASM_CLAC
1250		- pushl $0 # no error code
1251		- pushl $do_divide_error
1252		- jmp common_exception
1253		-END(divide_error)
1254		-
1255		-#ifdef CONFIG_X86_MCE
1256		-ENTRY(machine_check)
1257		- ASM_CLAC
1258		- pushl $0
1259		- pushl machine_check_vector
1260		- jmp common_exception
1261		-END(machine_check)
1262		-#endif
1263		-
1264		-ENTRY(spurious_interrupt_bug)
1265		- ASM_CLAC
1266		- pushl $0
1267		- pushl $do_spurious_interrupt_bug
1268		- jmp common_exception
1269		-END(spurious_interrupt_bug)
1270		-
1271		-#ifdef CONFIG_XEN
1272		-ENTRY(xen_hypervisor_callback)
1273		- pushl $-1 /* orig_ax = -1 => not a system call */
1274		- SAVE_ALL
1275		- ENCODE_FRAME_POINTER
1276		- TRACE_IRQS_OFF
1277		-
1278		- /*
1279		- * Check to see if we got the event in the critical
1280		- * region in xen_iret_direct, after we've reenabled
1281		- * events and checked for pending events. This simulates
1282		- * iret instruction's behaviour where it delivers a
1283		- * pending interrupt when enabling interrupts:
1284		- */
1285		- movl PT_EIP(%esp), %eax
1286		- cmpl $xen_iret_start_crit, %eax
1287		- jb 1f
1288		- cmpl $xen_iret_end_crit, %eax
1289		- jae 1f
1290		-
1291		- jmp xen_iret_crit_fixup
1292		-
1293		-ENTRY(xen_do_upcall)
1294		-1: mov %esp, %eax
1295		- call xen_evtchn_do_upcall
1296		-#ifndef CONFIG_PREEMPT
1297		- call xen_maybe_preempt_hcall
1298		-#endif
1299		- jmp ret_from_intr
1300		-ENDPROC(xen_hypervisor_callback)
1301		-
1302		-/*
1303		- * Hypervisor uses this for application faults while it executes.
1304		- * We get here for two reasons:
1305		- * 1. Fault while reloading DS, ES, FS or GS
1306		- * 2. Fault while executing IRET
1307		- * Category 1 we fix up by reattempting the load, and zeroing the segment
1308		- * register if the load fails.
1309		- * Category 2 we fix up by jumping to do_iret_error. We cannot use the
1310		- * normal Linux return path in this case because if we use the IRET hypercall
1311		- * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
1312		- * We distinguish between categories by maintaining a status value in EAX.
1313		- */
1314		-ENTRY(xen_failsafe_callback)
1315		- pushl %eax
1316		- movl $1, %eax
1317		-1: mov 4(%esp), %ds
1318		-2: mov 8(%esp), %es
1319		-3: mov 12(%esp), %fs
1320		-4: mov 16(%esp), %gs
1321		- /* EAX == 0 => Category 1 (Bad segment)
1322		- EAX != 0 => Category 2 (Bad IRET) */
1323		- testl %eax, %eax
1324		- popl %eax
1325		- lea 16(%esp), %esp
1326		- jz 5f
1327		- jmp iret_exc
1328		-5: pushl $-1 /* orig_ax = -1 => not a system call */
1329		- SAVE_ALL
1330		- ENCODE_FRAME_POINTER
1331		- jmp ret_from_exception
1332		-
1333		-.section .fixup, "ax"
1334		-6: xorl %eax, %eax
1335		- movl %eax, 4(%esp)
1336		- jmp 1b
1337		-7: xorl %eax, %eax
1338		- movl %eax, 8(%esp)
1339		- jmp 2b
1340		-8: xorl %eax, %eax
1341		- movl %eax, 12(%esp)
1342		- jmp 3b
1343		-9: xorl %eax, %eax
1344		- movl %eax, 16(%esp)
1345		- jmp 4b
1346		-.previous
1347		- _ASM_EXTABLE(1b, 6b)
1348		- _ASM_EXTABLE(2b, 7b)
1349		- _ASM_EXTABLE(3b, 8b)
1350		- _ASM_EXTABLE(4b, 9b)
1351		-ENDPROC(xen_failsafe_callback)
1352		-
1353		-BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR,
1354		- xen_evtchn_do_upcall)
1355		-
1356		-#endif /* CONFIG_XEN */
1357		-
1358		-#if IS_ENABLED(CONFIG_HYPERV)
1359		-
1360		-BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR,
1361		- hyperv_vector_handler)
1362		-
1363		-BUILD_INTERRUPT3(hyperv_reenlightenment_vector, HYPERV_REENLIGHTENMENT_VECTOR,
1364		- hyperv_reenlightenment_intr)
1365		-
1366		-BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR,
1367		- hv_stimer0_vector_handler)
1368		-
1369		-#endif /* CONFIG_HYPERV */
1370		-
1371		-ENTRY(page_fault)
1372		- ASM_CLAC
1373		- pushl $do_page_fault
1374		- ALIGN
1375		- jmp common_exception
1376		-END(page_fault)
1377		-
1378		-common_exception:
	1150	+SYM_CODE_START_LOCAL_NOALIGN(handle_exception)
1379	1151	/* the function address is in %gs's slot on the stack */
1380		- pushl %fs
1381		- pushl %es
1382		- pushl %ds
1383		- pushl %eax
1384		- movl $(__USER_DS), %eax
1385		- movl %eax, %ds
1386		- movl %eax, %es
1387		- movl $(__KERNEL_PERCPU), %eax
1388		- movl %eax, %fs
1389		- pushl %ebp
1390		- pushl %edi
1391		- pushl %esi
1392		- pushl %edx
1393		- pushl %ecx
1394		- pushl %ebx
1395		- SWITCH_TO_KERNEL_STACK
	1152	+ SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1
1396	1153	ENCODE_FRAME_POINTER
1397		- cld
1398		- UNWIND_ESPFIX_STACK
	1154	+
	1155	+ /* fixup %gs */
1399	1156	GS_TO_REG %ecx
1400	1157	movl PT_GS(%esp), %edi # get the function address
1401		- movl PT_ORIG_EAX(%esp), %edx # get the error code
1402		- movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
1403	1158	REG_TO_PTGS %ecx
1404	1159	SET_KERNEL_GS %ecx
1405		- TRACE_IRQS_OFF
1406		- movl %esp, %eax # pt_regs pointer
1407		- CALL_NOSPEC %edi
1408		- jmp ret_from_exception
1409		-END(common_exception)
1410	1160
1411		-ENTRY(debug)
	1161	+ /* fixup orig %eax */
	1162	+ movl PT_ORIG_EAX(%esp), %edx # get the error code
	1163	+ movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
	1164	+
	1165	+ movl %esp, %eax # pt_regs pointer
	1166	+ CALL_NOSPEC edi
	1167	+
	1168	+handle_exception_return:
	1169	+#ifdef CONFIG_VM86
	1170	+ movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
	1171	+ movb PT_CS(%esp), %al
	1172	+ andl $(X86_EFLAGS_VM \| SEGMENT_RPL_MASK), %eax
	1173	+#else
1412	1174	/*
1413		- * Entry from sysenter is now handled in common_exception
	1175	+ * We can be coming here from child spawned by kernel_thread().
1414	1176	*/
1415		- ASM_CLAC
1416		- pushl $-1 # mark this as an int
1417		- pushl $do_debug
1418		- jmp common_exception
1419		-END(debug)
	1177	+ movl PT_CS(%esp), %eax
	1178	+ andl $SEGMENT_RPL_MASK, %eax
	1179	+#endif
	1180	+ cmpl $USER_RPL, %eax # returning to v8086 or userspace ?
	1181	+ jnb ret_to_user
	1182	+
	1183	+ PARANOID_EXIT_TO_KERNEL_MODE
	1184	+ BUG_IF_WRONG_CR3
	1185	+ RESTORE_REGS 4
	1186	+ jmp .Lirq_return
	1187	+
	1188	+ret_to_user:
	1189	+ movl %esp, %eax
	1190	+ jmp restore_all_switch_stack
	1191	+SYM_CODE_END(handle_exception)
	1192	+
	1193	+SYM_CODE_START(asm_exc_double_fault)
	1194	+1:
	1195	+ /*
	1196	+ * This is a task gate handler, not an interrupt gate handler.
	1197	+ * The error code is on the stack, but the stack is otherwise
	1198	+ * empty. Interrupts are off. Our state is sane with the following
	1199	+ * exceptions:
	1200	+ *
	1201	+ * - CR0.TS is set. "TS" literally means "task switched".
	1202	+ * - EFLAGS.NT is set because we're a "nested task".
	1203	+ * - The doublefault TSS has back_link set and has been marked busy.
	1204	+ * - TR points to the doublefault TSS and the normal TSS is busy.
	1205	+ * - CR3 is the normal kernel PGD. This would be delightful, except
	1206	+ * that the CPU didn't bother to save the old CR3 anywhere. This
	1207	+ * would make it very awkward to return back to the context we came
	1208	+ * from.
	1209	+ *
	1210	+ * The rest of EFLAGS is sanitized for us, so we don't need to
	1211	+ * worry about AC or DF.
	1212	+ *
	1213	+ * Don't even bother popping the error code. It's always zero,
	1214	+ * and ignoring it makes us a bit more robust against buggy
	1215	+ * hypervisor task gate implementations.
	1216	+ *
	1217	+ * We will manually undo the task switch instead of doing a
	1218	+ * task-switching IRET.
	1219	+ */
	1220	+
	1221	+ clts /* clear CR0.TS */
	1222	+ pushl $X86_EFLAGS_FIXED
	1223	+ popfl /* clear EFLAGS.NT */
	1224	+
	1225	+ call doublefault_shim
	1226	+
	1227	+ /* We don't support returning, so we have no IRET here. */
	1228	+1:
	1229	+ hlt
	1230	+ jmp 1b
	1231	+SYM_CODE_END(asm_exc_double_fault)
1420	1232
1421	1233	/*
1422	1234	* NMI is doubly nasty. It can happen on the first instruction of
..	..	@@ -1425,10 +1237,14 @@
1425	1237	* switched stacks. We handle both conditions by simply checking whether we
1426	1238	* interrupted kernel code running on the SYSENTER stack.
1427	1239	*/
1428		-ENTRY(nmi)
	1240	+SYM_CODE_START(asm_exc_nmi)
1429	1241	ASM_CLAC
1430	1242
1431	1243	#ifdef CONFIG_X86_ESPFIX32
	1244	+ /*
	1245	+ * ESPFIX_SS is only ever set on the return to user path
	1246	+ * after we've switched to the entry stack.
	1247	+ */
1432	1248	pushl %eax
1433	1249	movl %ss, %eax
1434	1250	cmpw $__ESPFIX_SS, %ax
..	..	@@ -1450,7 +1266,7 @@
1450	1266	jb .Lnmi_from_sysenter_stack
1451	1267
1452	1268	/* Not on SYSENTER stack. */
1453		- call do_nmi
	1269	+ call exc_nmi
1454	1270	jmp .Lnmi_return
1455	1271
1456	1272	.Lnmi_from_sysenter_stack:
..	..	@@ -1460,10 +1276,15 @@
1460	1276	*/
1461	1277	movl %esp, %ebx
1462	1278	movl PER_CPU_VAR(cpu_current_top_of_stack), %esp
1463		- call do_nmi
	1279	+ call exc_nmi
1464	1280	movl %ebx, %esp
1465	1281
1466	1282	.Lnmi_return:
	1283	+#ifdef CONFIG_X86_ESPFIX32
	1284	+ testl $CS_FROM_ESPFIX, PT_CS(%esp)
	1285	+ jnz .Lnmi_from_espfix
	1286	+#endif
	1287	+
1467	1288	CHECK_AND_APPLY_ESPFIX
1468	1289	RESTORE_ALL_NMI cr3_reg=%edi pop=4
1469	1290	jmp .Lirq_return
..	..	@@ -1471,55 +1292,48 @@
1471	1292	#ifdef CONFIG_X86_ESPFIX32
1472	1293	.Lnmi_espfix_stack:
1473	1294	/*
1474		- * create the pointer to lss back
	1295	+ * Create the pointer to LSS back
1475	1296	*/
1476	1297	pushl %ss
1477	1298	pushl %esp
1478	1299	addl $4, (%esp)
1479		- /* copy the iret frame of 12 bytes */
1480		- .rept 3
1481		- pushl 16(%esp)
1482		- .endr
1483		- pushl %eax
1484		- SAVE_ALL_NMI cr3_reg=%edi
1485		- ENCODE_FRAME_POINTER
1486		- FIXUP_ESPFIX_STACK # %eax == %esp
1487		- xorl %edx, %edx # zero error code
1488		- call do_nmi
1489		- RESTORE_ALL_NMI cr3_reg=%edi
1490		- lss 12+4(%esp), %esp # back to espfix stack
1491		- jmp .Lirq_return
1492		-#endif
1493		-END(nmi)
1494	1300
1495		-ENTRY(int3)
1496		- ASM_CLAC
1497		- pushl $-1 # mark this as an int
	1301	+ /* Copy the (short) IRET frame */
	1302	+ pushl 4*4(%esp) # flags
	1303	+ pushl 4*4(%esp) # cs
	1304	+ pushl 4*4(%esp) # ip
1498	1305
1499		- SAVE_ALL switch_stacks=1
	1306	+ pushl %eax # orig_ax
	1307	+
	1308	+ SAVE_ALL_NMI cr3_reg=%edi unwind_espfix=1
1500	1309	ENCODE_FRAME_POINTER
1501		- TRACE_IRQS_OFF
	1310	+
	1311	+ /* clear CS_FROM_KERNEL, set CS_FROM_ESPFIX */
	1312	+ xorl $(CS_FROM_ESPFIX \| CS_FROM_KERNEL), PT_CS(%esp)
	1313	+
1502	1314	xorl %edx, %edx # zero error code
1503	1315	movl %esp, %eax # pt_regs pointer
1504		- call do_int3
1505		- jmp ret_from_exception
1506		-END(int3)
	1316	+ jmp .Lnmi_from_sysenter_stack
1507	1317
1508		-ENTRY(general_protection)
1509		- ASM_CLAC
1510		- pushl $do_general_protection
1511		- jmp common_exception
1512		-END(general_protection)
1513		-
1514		-#ifdef CONFIG_KVM_GUEST
1515		-ENTRY(async_page_fault)
1516		- ASM_CLAC
1517		- pushl $do_async_page_fault
1518		- jmp common_exception
1519		-END(async_page_fault)
	1318	+.Lnmi_from_espfix:
	1319	+ RESTORE_ALL_NMI cr3_reg=%edi
	1320	+ /*
	1321	+ * Because we cleared CS_FROM_KERNEL, IRET_FRAME 'forgot' to
	1322	+ * fix up the gap and long frame:
	1323	+ *
	1324	+ * 3 - original frame (exception)
	1325	+ * 2 - ESPFIX block (above)
	1326	+ * 6 - gap (FIXUP_FRAME)
	1327	+ * 5 - long frame (FIXUP_FRAME)
	1328	+ * 1 - orig_ax
	1329	+ */
	1330	+ lss (1+5+6)*4(%esp), %esp # back to espfix stack
	1331	+ jmp .Lirq_return
1520	1332	#endif
	1333	+SYM_CODE_END(asm_exc_nmi)
1521	1334
1522		-ENTRY(rewind_stack_do_exit)
	1335	+.pushsection .text, "ax"
	1336	+SYM_CODE_START(rewind_stack_do_exit)
1523	1337	/* Prevent any naive code from trying to unwind to our caller. */
1524	1338	xorl %ebp, %ebp
1525	1339
..	..	@@ -1528,4 +1342,5 @@
1528	1342
1529	1343	call do_exit
1530	1344	1: jmp 1b
1531		-END(rewind_stack_do_exit)
	1345	+SYM_CODE_END(rewind_stack_do_exit)
	1346	+.popsection