Jan Beulich
2007-Mar-05 11:13 UTC
[Xen-devel] [PATCH 1/10] linux 2.6.18: assembly annotations
This adds (or moves to the proper place) annotations paralleling those
added in native code in 2.6.18. To make this look less guly, it
required moving around a few things.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: head-2007-02-27/arch/i386/kernel/entry-xen.S
==================================================================---
head-2007-02-27.orig/arch/i386/kernel/entry-xen.S 2007-03-05 10:00:18.000000000
+0100
+++ head-2007-02-27/arch/i386/kernel/entry-xen.S 2007-03-01 17:49:29.000000000
+0100
@@ -368,6 +368,7 @@ sysexit_scrit: /**** START OF SYSEXIT CR
movl ESI(%esp), %esi
sysexit
14: __DISABLE_INTERRUPTS
+ TRACE_IRQS_OFF
sysexit_ecrit: /**** END OF SYSEXIT CRITICAL REGION ****/
push %esp
call evtchn_do_upcall
@@ -427,11 +428,13 @@ restore_nocheck:
restore_nocheck:
movl EFLAGS(%esp), %eax
testl $(VM_MASK|NMI_MASK), %eax
+ CFI_REMEMBER_STATE
jnz hypervisor_iret
shr $9, %eax # EAX[0] == IRET_EFLAGS.IF
GET_VCPU_INFO
andb evtchn_upcall_mask(%esi),%al
andb $1,%al # EAX[0] == IRET_EFLAGS.IF & event_mask
+ CFI_REMEMBER_STATE
jnz restore_all_enable_events # != 0 => enable event delivery
#endif
TRACE_IRQS_IRET
@@ -455,8 +458,8 @@ iret_exc:
.long 1b,iret_exc
.previous
-#ifndef CONFIG_XEN
CFI_RESTORE_STATE
+#ifndef CONFIG_XEN
ldt_ss:
larl OLDSS(%esp), %eax
jnz restore_nocheck
@@ -485,14 +488,36 @@ ldt_ss:
.align 4
.long 1b,iret_exc
.previous
- CFI_ENDPROC
#else
+ ALIGN
+restore_all_enable_events:
+ TRACE_IRQS_ON
+ __ENABLE_INTERRUPTS
+scrit: /**** START OF CRITICAL REGION ****/
+ __TEST_PENDING
+ jnz 14f # process more events if necessary...
+ RESTORE_REGS
+ addl $4, %esp
+ CFI_ADJUST_CFA_OFFSET -4
+1: iret
+.section __ex_table,"a"
+ .align 4
+ .long 1b,iret_exc
+.previous
+14: __DISABLE_INTERRUPTS
+ TRACE_IRQS_OFF
+ jmp 11f
+ecrit: /**** END OF CRITICAL REGION ****/
+
+ CFI_RESTORE_STATE
hypervisor_iret:
andl $~NMI_MASK, EFLAGS(%esp)
RESTORE_REGS
addl $4, %esp
+ CFI_ADJUST_CFA_OFFSET -4
jmp hypercall_page + (__HYPERVISOR_iret * 32)
#endif
+ CFI_ENDPROC
# perform work that needs to be done immediately before resumption
ALIGN
@@ -736,7 +761,9 @@ error_code:
# critical region we know that the entire frame is present and correct
# so we can simply throw away the new one.
ENTRY(hypervisor_callback)
+ RING0_INT_FRAME
pushl %eax
+ CFI_ADJUST_CFA_OFFSET 4
SAVE_ALL
movl EIP(%esp),%eax
cmpl $scrit,%eax
@@ -749,26 +776,13 @@ ENTRY(hypervisor_callback)
ja 11f
addl $OLDESP,%esp # Remove eflags...ebx from stack frame.
11: push %esp
+ CFI_ADJUST_CFA_OFFSET 4
call evtchn_do_upcall
add $4,%esp
+ CFI_ADJUST_CFA_OFFSET -4
jmp ret_from_intr
+ CFI_ENDPROC
- ALIGN
-restore_all_enable_events:
- __ENABLE_INTERRUPTS
-scrit: /**** START OF CRITICAL REGION ****/
- __TEST_PENDING
- jnz 14f # process more events if necessary...
- RESTORE_REGS
- addl $4, %esp
-1: iret
-.section __ex_table,"a"
- .align 4
- .long 1b,iret_exc
-.previous
-14: __DISABLE_INTERRUPTS
- jmp 11b
-ecrit: /**** END OF CRITICAL REGION ****/
# [How we do the fixup]. We want to merge the current stack frame with the
# just-interrupted frame. How we do this depends on where in the critical
# region the interrupted handler was executing, and so how many saved
@@ -835,6 +849,7 @@ ENTRY(failsafe_callback)
addl $16,%esp # EAX != 0 => Category 2 (Bad IRET)
jmp iret_exc
5: addl $16,%esp # EAX == 0 => Category 1 (Bad segment)
+ RING0_INT_FRAME
pushl $0
SAVE_ALL
jmp ret_from_exception
@@ -860,6 +875,7 @@ ENTRY(failsafe_callback)
.long 4b,9b; \
.previous
#endif
+ CFI_ENDPROC
ENTRY(coprocessor_error)
RING0_INT_FRAME
@@ -1187,8 +1203,11 @@ ENDPROC(arch_unwind_init_running)
#endif
ENTRY(fixup_4gb_segment)
+ RING0_EC_FRAME
pushl $do_fixup_4gb_segment
+ CFI_ADJUST_CFA_OFFSET 4
jmp error_code
+ CFI_ENDPROC
.section .rodata,"a"
.align 4
Index: head-2007-02-27/arch/i386/kernel/head-xen.S
==================================================================---
head-2007-02-27.orig/arch/i386/kernel/head-xen.S 2007-03-05 10:00:18.000000000
+0100
+++ head-2007-02-27/arch/i386/kernel/head-xen.S 2007-03-02 15:33:04.000000000
+0100
@@ -9,6 +9,7 @@
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
+#include <asm/dwarf2.h>
#include <xen/interface/xen.h>
#include <xen/interface/elfnote.h>
@@ -72,7 +73,9 @@ ENTRY(startup_32)
#define HYPERCALL_PAGE_OFFSET 0x1000
.org HYPERCALL_PAGE_OFFSET
ENTRY(hypercall_page)
+ CFI_STARTPROC
.skip 0x1000
+ CFI_ENDPROC
/*
* Real beginning of normal "text" segment
Index: head-2007-02-27/arch/x86_64/kernel/entry-xen.S
==================================================================---
head-2007-02-27.orig/arch/x86_64/kernel/entry-xen.S 2007-03-05
10:00:18.000000000 +0100
+++ head-2007-02-27/arch/x86_64/kernel/entry-xen.S 2007-03-02 16:37:46.000000000
+0100
@@ -116,19 +116,21 @@ NMI_MASK = 0x80000000
CFI_ADJUST_CFA_OFFSET -(6*8)
.endm
- .macro CFI_DEFAULT_STACK start=1
+ .macro CFI_DEFAULT_STACK start=1,adj=0
.if \start
CFI_STARTPROC simple
- CFI_DEF_CFA rsp,SS+8
+ CFI_DEF_CFA rsp,SS+8-(\adj*ARGOFFSET)
.else
- CFI_DEF_CFA_OFFSET SS+8
+ CFI_DEF_CFA_OFFSET SS+8-(\adj*ARGOFFSET)
.endif
+ .if \adj == 0
CFI_REL_OFFSET r15,R15
CFI_REL_OFFSET r14,R14
CFI_REL_OFFSET r13,R13
CFI_REL_OFFSET r12,R12
CFI_REL_OFFSET rbp,RBP
CFI_REL_OFFSET rbx,RBX
+ .endif
CFI_REL_OFFSET r11,R11
CFI_REL_OFFSET r10,R10
CFI_REL_OFFSET r9,R9
@@ -363,8 +365,8 @@ ENTRY(int_ret_from_sys_call)
CFI_REL_OFFSET r9,R9-ARGOFFSET
CFI_REL_OFFSET r10,R10-ARGOFFSET
CFI_REL_OFFSET r11,R11-ARGOFFSET
- TRACE_IRQS_OFF
XEN_BLOCK_EVENTS(%rsi)
+ TRACE_IRQS_OFF
testb $3,CS-ARGOFFSET(%rsp)
jnz 1f
/* Need to set the proper %ss (not NULL) for ring 3 iretq */
@@ -534,7 +536,7 @@ END(stub_rt_sigreturn)
*/
retint_check:
- CFI_DEFAULT_STACK
+ CFI_DEFAULT_STACK adj=1
movl threadinfo_flags(%rcx),%edx
andl %edi,%edx
CFI_REMEMBER_STATE
@@ -838,6 +840,7 @@ ENTRY(error_entry)
CFI_REL_OFFSET r15,R15
#if 0
cmpl $__KERNEL_CS,CS(%rsp)
+ CFI_REMEMBER_STATE
je error_kernelspace
#endif
error_call_handler:
@@ -864,7 +867,7 @@ error_exit:
TRACE_IRQS_IRETQ
jmp retint_restore_args
-error_kernelspace:
+#if 0
/*
* We need to re-write the logic here because we don''t do
iretq to
* to return to user mode. It''s still possible that we get
trap/fault
@@ -872,7 +875,8 @@ error_kernelspace:
* for example).
*
*/
-#if 0
+ CFI_RESTORE_STATE
+error_kernelspace:
incl %ebx
/* There are two places in the kernel that can potentially fault with
usergs. Handle them here. The exception handlers after
@@ -888,11 +892,13 @@ error_kernelspace:
cmpq $gs_change,RIP(%rsp)
je error_swapgs
jmp error_sti
-#endif
+#endif
+ CFI_ENDPROC
END(error_entry)
ENTRY(hypervisor_callback)
zeroentry do_hypervisor_callback
+END(hypervisor_callback)
/*
* Copied from arch/xen/i386/kernel/entry.S
@@ -909,48 +915,66 @@ ENTRY(hypervisor_callback)
# existing activation in its critical region -- if so, we pop the current
# activation and restart the handler using the previous one.
ENTRY(do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
+ CFI_STARTPROC
# Since we don''t modify %rdi, evtchn_do_upall(struct *pt_regs) will
# see the correct pointer to the pt_regs
movq %rdi, %rsp # we don''t return, adjust the stack frame
-11: movq %gs:pda_irqstackptr,%rax
- incl %gs:pda_irqcount
- cmovzq %rax,%rsp
- pushq %rdi
+ CFI_ENDPROC
+ CFI_DEFAULT_STACK
+11: incl %gs:pda_irqcount
+ movq %rsp,%rbp
+ CFI_DEF_CFA_REGISTER rbp
+ cmovzq %gs:pda_irqstackptr,%rsp
+ pushq %rbp # backlink for old unwinder
call evtchn_do_upcall
popq %rsp
+ CFI_DEF_CFA_REGISTER rsp
decl %gs:pda_irqcount
jmp error_exit
+ CFI_ENDPROC
+END(do_hypervisor_callback)
#ifdef CONFIG_X86_LOCAL_APIC
KPROBE_ENTRY(nmi)
zeroentry do_nmi_callback
ENTRY(do_nmi_callback)
+ CFI_STARTPROC
addq $8, %rsp
+ CFI_ENDPROC
+ CFI_DEFAULT_STACK
call do_nmi
orl $NMI_MASK,EFLAGS(%rsp)
RESTORE_REST
XEN_BLOCK_EVENTS(%rsi)
+ TRACE_IRQS_OFF
GET_THREAD_INFO(%rcx)
jmp retint_restore_args
+ CFI_ENDPROC
.previous .text
+END(nmi)
#endif
ALIGN
restore_all_enable_events:
+ CFI_DEFAULT_STACK adj=1
+ TRACE_IRQS_ON
XEN_UNBLOCK_EVENTS(%rsi) # %rsi is already set up...
scrit: /**** START OF CRITICAL REGION ****/
XEN_TEST_PENDING(%rsi)
+ CFI_REMEMBER_STATE
jnz 14f # process more events if necessary...
XEN_PUT_VCPU_INFO(%rsi)
RESTORE_ARGS 0,8,0
HYPERVISOR_IRET 0
+ CFI_RESTORE_STATE
14: XEN_LOCKED_BLOCK_EVENTS(%rsi)
XEN_PUT_VCPU_INFO(%rsi)
SAVE_REST
movq %rsp,%rdi # set the argument again
jmp 11b
+ CFI_ENDPROC
ecrit: /**** END OF CRITICAL REGION ****/
# At this point, unlike on x86-32, we don''t do the fixup to simplify
the
# code and the stack frame is more complex on x86-64.
@@ -970,8 +994,12 @@ ecrit: /**** END OF CRITICAL REGION ***
# We distinguish between categories by comparing each saved segment register
# with its current contents: any discrepancy means we in category 1.
ENTRY(failsafe_callback)
+ _frame (RIP-0x30)
+ CFI_REL_OFFSET rcx, 0
+ CFI_REL_OFFSET r11, 8
movw %ds,%cx
cmpw %cx,0x10(%rsp)
+ CFI_REMEMBER_STATE
jne 1f
movw %es,%cx
cmpw %cx,0x18(%rsp)
@@ -984,17 +1012,26 @@ ENTRY(failsafe_callback)
jne 1f
/* All segments match their saved values => Category 2 (Bad IRET). */
movq (%rsp),%rcx
+ CFI_RESTORE rcx
movq 8(%rsp),%r11
+ CFI_RESTORE r11
addq $0x30,%rsp
+ CFI_ADJUST_CFA_OFFSET -0x30
movq $11,%rdi /* SIGSEGV */
jmp do_exit
+ CFI_RESTORE_STATE
1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
movq (%rsp),%rcx
+ CFI_RESTORE rcx
movq 8(%rsp),%r11
+ CFI_RESTORE r11
addq $0x30,%rsp
+ CFI_ADJUST_CFA_OFFSET -0x30
pushq $0
+ CFI_ADJUST_CFA_OFFSET 8
SAVE_ALL
jmp error_exit
+ CFI_ENDPROC
#if 0
.section __ex_table,"a"
.align 8
@@ -1117,12 +1154,12 @@ END(device_not_available)
/* runs on exception stack */
KPROBE_ENTRY(debug)
- INTR_FRAME
-/* pushq $0
+/* INTR_FRAME
+ pushq $0
CFI_ADJUST_CFA_OFFSET 8 */
zeroentry do_debug
-/* paranoid_exit */
- CFI_ENDPROC
+/* paranoidexit
+ CFI_ENDPROC */
END(debug)
.previous .text
@@ -1144,12 +1181,12 @@ END(nmi)
#endif
KPROBE_ENTRY(int3)
- INTR_FRAME
-/* pushq $0
+/* INTR_FRAME
+ pushq $0
CFI_ADJUST_CFA_OFFSET 8 */
zeroentry do_int3
-/* jmp paranoid_exit1 */
- CFI_ENDPROC
+/* jmp paranoid_exit1
+ CFI_ENDPROC */
END(int3)
.previous .text
@@ -1193,9 +1230,11 @@ END(segment_not_present)
/* runs on exception stack */
ENTRY(stack_segment)
- XCPT_FRAME
+/* XCPT_FRAME
+ paranoidentry do_stack_segment */
errorentry do_stack_segment
- CFI_ENDPROC
+/* jmp paranoid_exit1
+ CFI_ENDPROC */
END(stack_segment)
KPROBE_ENTRY(general_protection)
Index: head-2007-02-27/arch/x86_64/kernel/head-xen.S
==================================================================---
head-2007-02-27.orig/arch/x86_64/kernel/head-xen.S 2007-03-05 10:00:18.000000000
+0100
+++ head-2007-02-27/arch/x86_64/kernel/head-xen.S 2007-03-02 15:47:16.000000000
+0100
@@ -22,7 +22,7 @@
#include <asm/page.h>
#include <asm/msr.h>
#include <asm/cache.h>
-
+#include <asm/dwarf2.h>
#include <xen/interface/elfnote.h>
#define _PAGE_PRESENT 0x1
@@ -42,6 +42,7 @@ ENTRY(_start)
/* rsi is pointer to startup info structure.
pass it to C */
movq %rsi,%rdi
+ pushq $0 # fake return address
jmp x86_64_start_kernel
ENTRY(stext)
@@ -82,7 +83,25 @@ NEXT_PAGE(level2_kernel_pgt)
.fill 512,8,0
NEXT_PAGE(hypercall_page)
- .fill 512,8,0
+ CFI_STARTPROC
+ .rept 0x1000 / 0x20
+ .skip 1 /* push %rcx */
+ CFI_ADJUST_CFA_OFFSET 8
+ CFI_REL_OFFSET rcx,0
+ .skip 2 /* push %r11 */
+ CFI_ADJUST_CFA_OFFSET 8
+ CFI_REL_OFFSET rcx,0
+ .skip 5 /* mov $#,%eax */
+ .skip 2 /* syscall */
+ .skip 2 /* pop %r11 */
+ CFI_ADJUST_CFA_OFFSET -8
+ CFI_RESTORE r11
+ .skip 1 /* pop %rcx */
+ CFI_ADJUST_CFA_OFFSET -8
+ CFI_RESTORE rcx
+ .align 0x20,0 /* ret */
+ .endr
+ CFI_ENDPROC
#undef NEXT_PAGE
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