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x86: clean up after: move entry_64.S register saving out of the macros
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This add-on patch to x86: move entry_64.S register saving out
of the macros visually cleans up the appearance of the code by
introducing some basic helper macro's. It also adds some cfi
annotations which were missing.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Alexander van Heukelum authored and Ingo Molnar committed Nov 20, 2008
1 parent d99015b commit dcd072e
Showing 1 changed file with 112 additions and 108 deletions.
220 changes: 112 additions & 108 deletions arch/x86/kernel/entry_64.S
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Original file line number Diff line number Diff line change
Expand Up @@ -60,6 +60,23 @@
#define __AUDIT_ARCH_LE 0x40000000

.code64
/*
* Some macro's to hide the most frequently occuring CFI annotations.
*/
.macro CFI_PUSHQ reg
pushq \reg
CFI_ADJUST_CFA_OFFSET 8
.endm

.macro CFI_POPQ reg
popq \reg
CFI_ADJUST_CFA_OFFSET -8
.endm

.macro CFI_MOVQ reg offset=0
movq %\reg, \offset(%rsp)
CFI_REL_OFFSET \reg, \offset
.endm

#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
Expand Down Expand Up @@ -213,84 +230,84 @@ ENTRY(native_usergs_sysret64)
CFI_ADJUST_CFA_OFFSET -(6*8)
.endm

.macro CFI_DEFAULT_STACK start=1
/*
* initial frame state for interrupts (and exceptions without error code)
*/
.macro EMPTY_FRAME start=1 offset=0
.if \start
CFI_STARTPROC simple
CFI_STARTPROC simple
CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,SS+8
CFI_DEF_CFA rsp,8+\offset
.else
CFI_DEF_CFA_OFFSET SS+8
CFI_DEF_CFA_OFFSET 8+\offset
.endif
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
CFI_REL_OFFSET r11,R11
CFI_REL_OFFSET r10,R10
CFI_REL_OFFSET r9,R9
CFI_REL_OFFSET r8,R8
CFI_REL_OFFSET rax,RAX
CFI_REL_OFFSET rcx,RCX
CFI_REL_OFFSET rdx,RDX
CFI_REL_OFFSET rsi,RSI
CFI_REL_OFFSET rdi,RDI
CFI_REL_OFFSET rip,RIP
/*CFI_REL_OFFSET cs,CS*/
/*CFI_REL_OFFSET rflags,EFLAGS*/
CFI_REL_OFFSET rsp,RSP
/*CFI_REL_OFFSET ss,SS*/
.endm

/*
* initial frame state for interrupts and exceptions
* initial frame state for interrupts (and exceptions without error code)
*/
.macro _frame ref
CFI_STARTPROC simple
CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,SS+8-\ref
/*CFI_REL_OFFSET ss,SS-\ref*/
CFI_REL_OFFSET rsp,RSP-\ref
/*CFI_REL_OFFSET rflags,EFLAGS-\ref*/
/*CFI_REL_OFFSET cs,CS-\ref*/
CFI_REL_OFFSET rip,RIP-\ref
.macro INTR_FRAME start=1 offset=0
EMPTY_FRAME \start, (SS+8-RIP)+\offset
/*CFI_REL_OFFSET ss, SS-RIP+\offset*/
CFI_REL_OFFSET rsp, RSP-RIP+\offset
/*CFI_REL_OFFSET rflags, EFLAGS-RIP+\offset*/
/*CFI_REL_OFFSET cs, CS-RIP+\offset*/
CFI_REL_OFFSET rip, RIP-RIP+\offset
.endm

/*
* initial frame state for interrupts (and exceptions without error code)
*/
#define INTR_FRAME _frame RIP
/*
* initial frame state for exceptions with error code (and interrupts
* with vector already pushed)
*/
#define XCPT_FRAME _frame ORIG_RAX
.macro XCPT_FRAME start=1 offset=0
INTR_FRAME \start, (RIP-ORIG_RAX)+\offset
/*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/
.endm

/*
* frame that enables calling into C.
*/
.macro PARTIAL_FRAME start=1 offset=0
XCPT_FRAME \start, (ORIG_RAX-ARGOFFSET)+\offset
CFI_REL_OFFSET rdi, (RDI-ARGOFFSET)+\offset
CFI_REL_OFFSET rsi, (RSI-ARGOFFSET)+\offset
CFI_REL_OFFSET rdx, (RDX-ARGOFFSET)+\offset
CFI_REL_OFFSET rcx, (RCX-ARGOFFSET)+\offset
CFI_REL_OFFSET rax, (RAX-ARGOFFSET)+\offset
CFI_REL_OFFSET r8, (R8-ARGOFFSET)+\offset
CFI_REL_OFFSET r9, (R9-ARGOFFSET)+\offset
CFI_REL_OFFSET r10, (R10-ARGOFFSET)+\offset
CFI_REL_OFFSET r11, (R11-ARGOFFSET)+\offset
.endm

/*
* frame that enables passing a complete pt_regs to a C function.
*/
.macro DEFAULT_FRAME start=1 offset=0
PARTIAL_FRAME \start, (R11-R15)+\offset
CFI_REL_OFFSET rbx, RBX+\offset
CFI_REL_OFFSET rbp, RBP+\offset
CFI_REL_OFFSET r12, R12+\offset
CFI_REL_OFFSET r13, R13+\offset
CFI_REL_OFFSET r14, R14+\offset
CFI_REL_OFFSET r15, R15+\offset
.endm

/* save partial stack frame */
ENTRY(save_args)
XCPT_FRAME
cld
movq %rdi, 8*8+16(%rsp)
CFI_REL_OFFSET rdi, 8*8+16
movq %rsi, 7*8+16(%rsp)
CFI_REL_OFFSET rsi, 7*8+16
movq %rdx, 6*8+16(%rsp)
CFI_REL_OFFSET rdx, 6*8+16
movq %rcx, 5*8+16(%rsp)
CFI_REL_OFFSET rcx, 5*8+16
movq %rax, 4*8+16(%rsp)
CFI_REL_OFFSET rax, 4*8+16
movq %r8, 3*8+16(%rsp)
CFI_REL_OFFSET r8, 3*8+16
movq %r9, 2*8+16(%rsp)
CFI_REL_OFFSET r9, 2*8+16
movq %r10, 1*8+16(%rsp)
CFI_REL_OFFSET r10, 1*8+16
movq %r11, 0*8+16(%rsp)
CFI_REL_OFFSET r11, 0*8+16
CFI_MOVQ rdi, (RDI-ARGOFFSET)+16
CFI_MOVQ rsi, (RSI-ARGOFFSET)+16
CFI_MOVQ rdx, (RDX-ARGOFFSET)+16
CFI_MOVQ rcx, (RCX-ARGOFFSET)+16
CFI_MOVQ rax, (RAX-ARGOFFSET)+16
CFI_MOVQ r8, (R8-ARGOFFSET)+16
CFI_MOVQ r9, (R9-ARGOFFSET)+16
CFI_MOVQ r10, (R10-ARGOFFSET)+16
CFI_MOVQ r11, (R11-ARGOFFSET)+16
leaq -ARGOFFSET+16(%rsp),%rdi /* arg1 for handler */
movq %rbp, 8(%rsp) /* push %rbp */
CFI_MOVQ rbp, 8 /* push %rbp */
leaq 8(%rsp), %rbp /* mov %rsp, %ebp */
testl $3, CS(%rdi)
je 1f
Expand All @@ -303,9 +320,10 @@ ENTRY(save_args)
*/
1: incl %gs:pda_irqcount
jne 2f
pop %rax /* move return address... */
CFI_POPQ %rax /* move return address... */
mov %gs:pda_irqstackptr,%rsp
push %rax /* ... to the new stack */
EMPTY_FRAME 0
CFI_PUSHQ %rax /* ... to the new stack */
/*
* We entered an interrupt context - irqs are off:
*/
Expand All @@ -319,7 +337,7 @@ END(save_args)
*/
/* rdi: prev */
ENTRY(ret_from_fork)
CFI_DEFAULT_STACK
DEFAULT_FRAME
push kernel_eflags(%rip)
CFI_ADJUST_CFA_OFFSET 8
popf # reset kernel eflags
Expand Down Expand Up @@ -732,6 +750,7 @@ END(interrupt)
subq $10*8, %rsp
CFI_ADJUST_CFA_OFFSET 10*8
call save_args
PARTIAL_FRAME 0
call \func
.endm

Expand Down Expand Up @@ -949,11 +968,11 @@ END(spurious_interrupt)
.macro zeroentry sym
INTR_FRAME
PARAVIRT_ADJUST_EXCEPTION_FRAME
pushq $-1 /* ORIG_RAX: no syscall to restart */
CFI_ADJUST_CFA_OFFSET 8
CFI_PUSHQ $-1 /* ORIG_RAX: no syscall to restart */
subq $15*8,%rsp
CFI_ADJUST_CFA_OFFSET 15*8
call error_entry
DEFAULT_FRAME 0
movq %rsp,%rdi /* pt_regs pointer */
xorl %esi,%esi /* no error code */
call \sym
Expand All @@ -967,6 +986,7 @@ END(spurious_interrupt)
subq $15*8,%rsp
CFI_ADJUST_CFA_OFFSET 15*8
call error_entry
DEFAULT_FRAME 0
movq %rsp,%rdi /* pt_regs pointer */
movq ORIG_RAX(%rsp),%rsi /* get error code */
movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */
Expand Down Expand Up @@ -1079,40 +1099,25 @@ paranoid_schedule\trace:
* returns in "no swapgs flag" in %ebx.
*/
KPROBE_ENTRY(error_entry)
_frame RDI
XCPT_FRAME
CFI_ADJUST_CFA_OFFSET 15*8
/* oldrax contains error code */
cld
movq %rdi,14*8+8(%rsp)
CFI_REL_OFFSET rdi,RDI+8
movq %rsi,13*8+8(%rsp)
CFI_REL_OFFSET rsi,RSI+8
movq %rdx,12*8+8(%rsp)
CFI_REL_OFFSET rdx,RDX+8
movq %rcx,11*8+8(%rsp)
CFI_REL_OFFSET rcx,RCX+8
movq %rax,10*8+8(%rsp)
CFI_REL_OFFSET rax,RAX+8
movq %r8, 9*8+8(%rsp)
CFI_REL_OFFSET r8,R8+8
movq %r9, 8*8+8(%rsp)
CFI_REL_OFFSET r9,R9+8
movq %r10,7*8+8(%rsp)
CFI_REL_OFFSET r10,R10+8
movq %r11,6*8+8(%rsp)
CFI_REL_OFFSET r11,R11+8
movq %rbx,5*8+8(%rsp)
CFI_REL_OFFSET rbx,RBX+8
movq %rbp,4*8+8(%rsp)
CFI_REL_OFFSET rbp,RBP+8
movq %r12,3*8+8(%rsp)
CFI_REL_OFFSET r12,R12+8
movq %r13,2*8+8(%rsp)
CFI_REL_OFFSET r13,R13+8
movq %r14,1*8+8(%rsp)
CFI_REL_OFFSET r14,R14+8
movq %r15,0*8+8(%rsp)
CFI_REL_OFFSET r15,R15+8
CFI_MOVQ rdi, RDI+8
CFI_MOVQ rsi, RSI+8
CFI_MOVQ rdx, RDX+8
CFI_MOVQ rcx, RCX+8
CFI_MOVQ rax, RAX+8
CFI_MOVQ r8, R8+8
CFI_MOVQ r9, R9+8
CFI_MOVQ r10, R10+8
CFI_MOVQ r11, R11+8
CFI_MOVQ rbx, RBX+8
CFI_MOVQ rbp, RBP+8
CFI_MOVQ r12, R12+8
CFI_MOVQ r13, R13+8
CFI_MOVQ r14, R14+8
CFI_MOVQ r15, R15+8
xorl %ebx,%ebx
testl $3,CS+8(%rsp)
je error_kernelspace
Expand Down Expand Up @@ -1146,7 +1151,7 @@ KPROBE_END(error_entry)

/* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */
KPROBE_ENTRY(error_exit)
_frame R15
DEFAULT_FRAME
movl %ebx,%eax
RESTORE_REST
DISABLE_INTERRUPTS(CLBR_NONE)
Expand Down Expand Up @@ -1455,7 +1460,7 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
see the correct pointer to the pt_regs */
movq %rdi, %rsp # we don't return, adjust the stack frame
CFI_ENDPROC
CFI_DEFAULT_STACK
DEFAULT_FRAME
11: incl %gs:pda_irqcount
movq %rsp,%rbp
CFI_DEF_CFA_REGISTER rbp
Expand Down Expand Up @@ -1483,10 +1488,13 @@ END(do_hypervisor_callback)
# with its current contents: any discrepancy means we in category 1.
*/
ENTRY(xen_failsafe_callback)
framesz = (RIP-0x30) /* workaround buggy gas */
_frame framesz
CFI_REL_OFFSET rcx, 0
CFI_REL_OFFSET r11, 8
INTR_FRAME 1 (6*8)
/*CFI_REL_OFFSET gs,GS*/
/*CFI_REL_OFFSET fs,FS*/
/*CFI_REL_OFFSET es,ES*/
/*CFI_REL_OFFSET ds,DS*/
CFI_REL_OFFSET r11,8
CFI_REL_OFFSET rcx,0
movw %ds,%cx
cmpw %cx,0x10(%rsp)
CFI_REMEMBER_STATE
Expand All @@ -1507,12 +1515,9 @@ ENTRY(xen_failsafe_callback)
CFI_RESTORE r11
addq $0x30,%rsp
CFI_ADJUST_CFA_OFFSET -0x30
pushq $0
CFI_ADJUST_CFA_OFFSET 8
pushq %r11
CFI_ADJUST_CFA_OFFSET 8
pushq %rcx
CFI_ADJUST_CFA_OFFSET 8
CFI_PUSHQ $0 /* RIP */
CFI_PUSHQ %r11
CFI_PUSHQ %rcx
jmp general_protection
CFI_RESTORE_STATE
1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
Expand All @@ -1522,8 +1527,7 @@ ENTRY(xen_failsafe_callback)
CFI_RESTORE r11
addq $0x30,%rsp
CFI_ADJUST_CFA_OFFSET -0x30
pushq $0
CFI_ADJUST_CFA_OFFSET 8
CFI_PUSHQ $0
SAVE_ALL
jmp error_exit
CFI_ENDPROC
Expand Down

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