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x86_64: Merge (paranoid)?(zero|error)entry(_idt)?

PATCH New Andy Lutomirski 2 participants 7 messages May 21, 2014 x86

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#0 lore raw

cover x86_64: Merge (paranoid)?(zero|error)entry(_idt)?

Inspired by the RET vs IRET discussion, I thought about how much of a mess the current entry macros are and I shuddered at the thought of trying to modify them.

This little series merges them all into one idtentry macro that has arguments that specify all the various weird behaviors. It has a major
benefit: you can now look at the code and see how, say, the has_error_code and !has_error_code cases differ.

Andy Lutomirski (3):
x86_64: Add missing 'DEFAULT_FRAME 0' entry annotations
x86_64: Merge most 64-bit asm entry macros
x86_64: Merge paranoidzeroentry_ist into idtentry

 arch/x86/kernel/entry_64.S | 185 ++++++++++++++++++++-------------------------
 1 file changed, 80 insertions(+), 105 deletions(-)
Signature · 1 line
1.9.0
#1 lore raw

PATCH 1/3 x86_64: Add missing 'DEFAULT_FRAME 0' entry annotations

The paranoidzeroentry macros were missing them. I'm not at all convinced that these annotations are correct and/or necessary, but this makes the macros more consistent with each other.

---
 arch/x86/kernel/entry_64.S | 2 ++
 1 file changed, 2 insertions(+)
arch/x86/kernel/entry_64.S +2 -0
index 1e96c36..39372ec 100644
@@ -1230,6 +1230,7 @@ ENTRY(\sym)
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
 	call save_paranoid
+	DEFAULT_FRAME 0
 	TRACE_IRQS_OFF
 	movq %rsp,%rdi		/* pt_regs pointer */
 	xorl %esi,%esi		/* no error code */
@@ -1249,6 +1250,7 @@ ENTRY(\sym)
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
 	call save_paranoid
+	DEFAULT_FRAME 0
 	TRACE_IRQS_OFF_DEBUG
 	movq %rsp,%rdi		/* pt_regs pointer */
 	xorl %esi,%esi		/* no error code */
Signature · 1 line
1.9.0
#2 lore raw

[tip:x86/asm] x86_64, entry: Add missing 'DEFAULT_FRAME 0' entry annotations

x86_64, entry: Add missing 'DEFAULT_FRAME 0' entry annotations
Commit-ID:  1bd24efc8bd1e644b115cae51048c008bea76de1
Gitweb:     http://git.kernel.org/tip/1bd24efc8bd1e644b115cae51048c008bea76de1
Author:     Andy Lutomirski <[email protected]>
AuthorDate: Wed, 21 May 2014 15:07:07 -0700
Committer:  H. Peter Anvin <[email protected]>
CommitDate: Wed, 21 May 2014 16:22:51 -0700

x86_64, entry: Add missing 'DEFAULT_FRAME 0' entry annotations

The paranoidzeroentry macros were missing them. I'm not at all convinced that these annotations are correct and/or necessary, but this makes the macros more consistent with each other.

---
 arch/x86/kernel/entry_64.S | 2 ++
 1 file changed, 2 insertions(+)
arch/x86/kernel/entry_64.S +2 -0
index 1e96c36..39372ec 100644
@@ -1230,6 +1230,7 @@ ENTRY(\sym)
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
 	call save_paranoid
+	DEFAULT_FRAME 0
 	TRACE_IRQS_OFF
 	movq %rsp,%rdi		/* pt_regs pointer */
 	xorl %esi,%esi		/* no error code */
@@ -1249,6 +1250,7 @@ ENTRY(\sym)
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
 	call save_paranoid
+	DEFAULT_FRAME 0
 	TRACE_IRQS_OFF_DEBUG
 	movq %rsp,%rdi		/* pt_regs pointer */
 	xorl %esi,%esi		/* no error code */
#3 lore raw

PATCH 2/3 x86_64: Merge most 64-bit asm entry macros

In reply to Andy Lutomirski

I haven't touched the device interrupt code, which is different enough that it's probably not worth merging, and I haven't done anything about paranoidzeroentry_ist yet.

This appears to produce an entry_64.o file that differs only in the debug info line numbers.

---
 arch/x86/kernel/entry_64.S | 152 +++++++++++++++++++--------------------------
 1 file changed, 64 insertions(+), 88 deletions(-)
arch/x86/kernel/entry_64.S +64 -88
index 39372ec..eac9b81 100644
@@ -36,7 +36,7 @@
  * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
  * frame that is otherwise undefined after a SYSCALL
  * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
- * - errorentry/paranoidentry/zeroentry - Define exception entry points.
+ * - idtentry - Define exception entry points.
  */
 
 #include <linux/linkage.h>
@@ -1203,39 +1203,53 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-.macro zeroentry sym do_sym
+.macro idtentry sym do_sym has_error_code:req paranoid=0
 ENTRY(\sym)
+	.if \has_error_code
+	XCPT_FRAME
+	.else
 	INTR_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call error_entry
-	DEFAULT_FRAME 0
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
-	call \do_sym
-	jmp error_exit		/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
+	.endif
 
-.macro paranoidzeroentry sym do_sym
-ENTRY(\sym)
-	INTR_FRAME
 	ASM_CLAC
 	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
+
+	.ifeq \has_error_code
+	pushq_cfi $-1			/* ORIG_RAX: no syscall to restart */
+	.endif
+
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
+
+	.if \paranoid
 	call save_paranoid
+	.else
+	call error_entry
+	.endif
+
 	DEFAULT_FRAME 0
+
+	.if \paranoid
 	TRACE_IRQS_OFF
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
+	.endif
+
+	movq %rsp,%rdi			/* pt_regs pointer */
+
+	.if \has_error_code
+	movq ORIG_RAX(%rsp),%rsi	/* get error code */
+	movq $-1,ORIG_RAX(%rsp)		/* no syscall to restart */
+	.else
+	xorl %esi,%esi			/* no error code */
+	.endif
+
 	call \do_sym
-	jmp paranoid_exit	/* %ebx: no swapgs flag */
+
+	.if \paranoid
+	jmp paranoid_exit		/* %ebx: no swapgs flag */
+	.else
+	jmp error_exit			/* %ebx: no swapgs flag */
+	.endif
+
 	CFI_ENDPROC
 END(\sym)
 .endm
@@ -1262,68 +1276,30 @@ ENTRY(\sym)
 END(\sym)
 .endm
 
-.macro errorentry sym do_sym
-ENTRY(\sym)
-	XCPT_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	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 */
-	call \do_sym
-	jmp error_exit			/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
 #ifdef CONFIG_TRACING
-.macro trace_errorentry sym do_sym
-errorentry trace(\sym) trace(\do_sym)
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
+idtentry \sym \do_sym has_error_code=\has_error_code
 .endm
 #else
-.macro trace_errorentry sym do_sym
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry \sym \do_sym has_error_code=\has_error_code
 .endm
 #endif
 
-	/* error code is on the stack already */
-.macro paranoiderrorentry sym do_sym
-ENTRY(\sym)
-	XCPT_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call save_paranoid
-	DEFAULT_FRAME 0
-	TRACE_IRQS_OFF
-	movq %rsp,%rdi			/* pt_regs pointer */
-	movq ORIG_RAX(%rsp),%rsi	/* get error code */
-	movq $-1,ORIG_RAX(%rsp)		/* no syscall to restart */
-	call \do_sym
-	jmp paranoid_exit		/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
-zeroentry divide_error do_divide_error
-zeroentry overflow do_overflow
-zeroentry bounds do_bounds
-zeroentry invalid_op do_invalid_op
-zeroentry device_not_available do_device_not_available
-paranoiderrorentry double_fault do_double_fault
-zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun
-errorentry invalid_TSS do_invalid_TSS
-errorentry segment_not_present do_segment_not_present
-zeroentry spurious_interrupt_bug do_spurious_interrupt_bug
-zeroentry coprocessor_error do_coprocessor_error
-errorentry alignment_check do_alignment_check
-zeroentry simd_coprocessor_error do_simd_coprocessor_error
+idtentry divide_error do_divide_error has_error_code=0
+idtentry overflow do_overflow has_error_code=0
+idtentry bounds do_bounds has_error_code=0
+idtentry invalid_op do_invalid_op has_error_code=0
+idtentry device_not_available do_device_not_available has_error_code=0
+idtentry double_fault do_double_fault has_error_code=1 paranoid=1
+idtentry coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0
+idtentry invalid_TSS do_invalid_TSS has_error_code=1
+idtentry segment_not_present do_segment_not_present has_error_code=1
+idtentry spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0
+idtentry coprocessor_error do_coprocessor_error has_error_code=0
+idtentry alignment_check do_alignment_check has_error_code=1
+idtentry simd_coprocessor_error do_simd_coprocessor_error has_error_code=0
 
 
 	/* Reload gs selector with exception handling */
@@ -1373,7 +1349,7 @@ ENTRY(do_softirq_own_stack)
 END(do_softirq_own_stack)
 
 #ifdef CONFIG_XEN
-zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
+idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
 
 /*
  * A note on the "critical region" in our callback handler.
@@ -1486,19 +1462,19 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
 
 paranoidzeroentry_ist debug do_debug DEBUG_STACK
 paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
-paranoiderrorentry stack_segment do_stack_segment
+idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
 #ifdef CONFIG_XEN
-zeroentry xen_debug do_debug
-zeroentry xen_int3 do_int3
-errorentry xen_stack_segment do_stack_segment
+idtentry xen_debug do_debug has_error_code=0
+idtentry xen_int3 do_int3 has_error_code=0
+idtentry xen_stack_segment do_stack_segment has_error_code=1
 #endif
-errorentry general_protection do_general_protection
-trace_errorentry page_fault do_page_fault
+idtentry general_protection do_general_protection has_error_code=1
+trace_idtentry page_fault do_page_fault has_error_code=1
 #ifdef CONFIG_KVM_GUEST
-errorentry async_page_fault do_async_page_fault
+idtentry async_page_fault do_async_page_fault has_error_code=1
 #endif
 #ifdef CONFIG_X86_MCE
-paranoidzeroentry machine_check *machine_check_vector(%rip)
+idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
 #endif
 
 	/*
Signature · 1 line
1.9.0
#4 lore raw

[tip:x86/asm] x86_64, entry: Merge most 64-bit asm entry macros

x86_64, entry: Merge most 64-bit asm entry macros
Commit-ID:  cb5dd2c5eed155919f626684691cf525234ecda1
Gitweb:     http://git.kernel.org/tip/cb5dd2c5eed155919f626684691cf525234ecda1
Author:     Andy Lutomirski <[email protected]>
AuthorDate: Wed, 21 May 2014 15:07:08 -0700
Committer:  H. Peter Anvin <[email protected]>
CommitDate: Wed, 21 May 2014 16:22:57 -0700

x86_64, entry: Merge most 64-bit asm entry macros

I haven't touched the device interrupt code, which is different enough that it's probably not worth merging, and I haven't done anything about paranoidzeroentry_ist yet.

This appears to produce an entry_64.o file that differs only in the debug info line numbers.

---
 arch/x86/kernel/entry_64.S | 152 +++++++++++++++++++--------------------------
 1 file changed, 64 insertions(+), 88 deletions(-)
arch/x86/kernel/entry_64.S +64 -88
index 39372ec..eac9b81 100644
@@ -36,7 +36,7 @@
  * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
  * frame that is otherwise undefined after a SYSCALL
  * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
- * - errorentry/paranoidentry/zeroentry - Define exception entry points.
+ * - idtentry - Define exception entry points.
  */
 
 #include <linux/linkage.h>
@@ -1203,39 +1203,53 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-.macro zeroentry sym do_sym
+.macro idtentry sym do_sym has_error_code:req paranoid=0
 ENTRY(\sym)
+	.if \has_error_code
+	XCPT_FRAME
+	.else
 	INTR_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call error_entry
-	DEFAULT_FRAME 0
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
-	call \do_sym
-	jmp error_exit		/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
+	.endif
 
-.macro paranoidzeroentry sym do_sym
-ENTRY(\sym)
-	INTR_FRAME
 	ASM_CLAC
 	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
+
+	.ifeq \has_error_code
+	pushq_cfi $-1			/* ORIG_RAX: no syscall to restart */
+	.endif
+
 	subq $ORIG_RAX-R15, %rsp
 	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
+
+	.if \paranoid
 	call save_paranoid
+	.else
+	call error_entry
+	.endif
+
 	DEFAULT_FRAME 0
+
+	.if \paranoid
 	TRACE_IRQS_OFF
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
+	.endif
+
+	movq %rsp,%rdi			/* pt_regs pointer */
+
+	.if \has_error_code
+	movq ORIG_RAX(%rsp),%rsi	/* get error code */
+	movq $-1,ORIG_RAX(%rsp)		/* no syscall to restart */
+	.else
+	xorl %esi,%esi			/* no error code */
+	.endif
+
 	call \do_sym
-	jmp paranoid_exit	/* %ebx: no swapgs flag */
+
+	.if \paranoid
+	jmp paranoid_exit		/* %ebx: no swapgs flag */
+	.else
+	jmp error_exit			/* %ebx: no swapgs flag */
+	.endif
+
 	CFI_ENDPROC
 END(\sym)
 .endm
@@ -1262,68 +1276,30 @@ ENTRY(\sym)
 END(\sym)
 .endm
 
-.macro errorentry sym do_sym
-ENTRY(\sym)
-	XCPT_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	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 */
-	call \do_sym
-	jmp error_exit			/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
 #ifdef CONFIG_TRACING
-.macro trace_errorentry sym do_sym
-errorentry trace(\sym) trace(\do_sym)
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
+idtentry \sym \do_sym has_error_code=\has_error_code
 .endm
 #else
-.macro trace_errorentry sym do_sym
-errorentry \sym \do_sym
+.macro trace_idtentry sym do_sym has_error_code:req
+idtentry \sym \do_sym has_error_code=\has_error_code
 .endm
 #endif
 
-	/* error code is on the stack already */
-.macro paranoiderrorentry sym do_sym
-ENTRY(\sym)
-	XCPT_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call save_paranoid
-	DEFAULT_FRAME 0
-	TRACE_IRQS_OFF
-	movq %rsp,%rdi			/* pt_regs pointer */
-	movq ORIG_RAX(%rsp),%rsi	/* get error code */
-	movq $-1,ORIG_RAX(%rsp)		/* no syscall to restart */
-	call \do_sym
-	jmp paranoid_exit		/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
-zeroentry divide_error do_divide_error
-zeroentry overflow do_overflow
-zeroentry bounds do_bounds
-zeroentry invalid_op do_invalid_op
-zeroentry device_not_available do_device_not_available
-paranoiderrorentry double_fault do_double_fault
-zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun
-errorentry invalid_TSS do_invalid_TSS
-errorentry segment_not_present do_segment_not_present
-zeroentry spurious_interrupt_bug do_spurious_interrupt_bug
-zeroentry coprocessor_error do_coprocessor_error
-errorentry alignment_check do_alignment_check
-zeroentry simd_coprocessor_error do_simd_coprocessor_error
+idtentry divide_error do_divide_error has_error_code=0
+idtentry overflow do_overflow has_error_code=0
+idtentry bounds do_bounds has_error_code=0
+idtentry invalid_op do_invalid_op has_error_code=0
+idtentry device_not_available do_device_not_available has_error_code=0
+idtentry double_fault do_double_fault has_error_code=1 paranoid=1
+idtentry coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0
+idtentry invalid_TSS do_invalid_TSS has_error_code=1
+idtentry segment_not_present do_segment_not_present has_error_code=1
+idtentry spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0
+idtentry coprocessor_error do_coprocessor_error has_error_code=0
+idtentry alignment_check do_alignment_check has_error_code=1
+idtentry simd_coprocessor_error do_simd_coprocessor_error has_error_code=0
 
 
 	/* Reload gs selector with exception handling */
@@ -1373,7 +1349,7 @@ ENTRY(do_softirq_own_stack)
 END(do_softirq_own_stack)
 
 #ifdef CONFIG_XEN
-zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
+idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
 
 /*
  * A note on the "critical region" in our callback handler.
@@ -1486,19 +1462,19 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
 
 paranoidzeroentry_ist debug do_debug DEBUG_STACK
 paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
-paranoiderrorentry stack_segment do_stack_segment
+idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
 #ifdef CONFIG_XEN
-zeroentry xen_debug do_debug
-zeroentry xen_int3 do_int3
-errorentry xen_stack_segment do_stack_segment
+idtentry xen_debug do_debug has_error_code=0
+idtentry xen_int3 do_int3 has_error_code=0
+idtentry xen_stack_segment do_stack_segment has_error_code=1
 #endif
-errorentry general_protection do_general_protection
-trace_errorentry page_fault do_page_fault
+idtentry general_protection do_general_protection has_error_code=1
+trace_idtentry page_fault do_page_fault has_error_code=1
 #ifdef CONFIG_KVM_GUEST
-errorentry async_page_fault do_async_page_fault
+idtentry async_page_fault do_async_page_fault has_error_code=1
 #endif
 #ifdef CONFIG_X86_MCE
-paranoidzeroentry machine_check *machine_check_vector(%rip)
+idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
 #endif
 
 	/*
#5 lore raw

PATCH 3/3 x86_64: Merge paranoidzeroentry_ist into idtentry

In reply to Andy Lutomirski

One more specialized entry function is now gone. Again, this seems to only change line numbers in entry_64.o.

---
 arch/x86/kernel/entry_64.S | 47 ++++++++++++++++++++++------------------------
 1 file changed, 22 insertions(+), 25 deletions(-)
arch/x86/kernel/entry_64.S +22 -25
index eac9b81..be846d2 100644
@@ -1203,8 +1203,15 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-.macro idtentry sym do_sym has_error_code:req paranoid=0
+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
+
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
 ENTRY(\sym)
+	/* Sanity check */
+	.if \shift_ist != -1 && \paranoid == 0
+	.error "using shift_ist requires paranoid=1"
+	.endif
+
 	.if \has_error_code
 	XCPT_FRAME
 	.else
@@ -1230,8 +1237,12 @@ ENTRY(\sym)
 	DEFAULT_FRAME 0
 
 	.if \paranoid
+	.if \shift_ist != -1
+	TRACE_IRQS_OFF_DEBUG		/* reload IDT in case of recursion */
+	.else
 	TRACE_IRQS_OFF
 	.endif
+	.endif
 
 	movq %rsp,%rdi			/* pt_regs pointer */
 
@@ -1242,8 +1253,16 @@ ENTRY(\sym)
 	xorl %esi,%esi			/* no error code */
 	.endif
 
+	.if \shift_ist != -1
+	subq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	.endif
+
 	call \do_sym
 
+	.if \shift_ist != -1
+	addq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	.endif
+
 	.if \paranoid
 	jmp paranoid_exit		/* %ebx: no swapgs flag */
 	.else
@@ -1254,28 +1273,6 @@ ENTRY(\sym)
 END(\sym)
 .endm
 
-#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
-.macro paranoidzeroentry_ist sym do_sym ist
-ENTRY(\sym)
-	INTR_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call save_paranoid
-	DEFAULT_FRAME 0
-	TRACE_IRQS_OFF_DEBUG
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
-	subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-	call \do_sym
-	addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-	jmp paranoid_exit	/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
 #ifdef CONFIG_TRACING
 .macro trace_idtentry sym do_sym has_error_code:req
 idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
@@ -1460,8 +1457,8 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
  */
 	.pushsection .kprobes.text, "ax"
 
-paranoidzeroentry_ist debug do_debug DEBUG_STACK
-paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
+idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
 idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
 #ifdef CONFIG_XEN
 idtentry xen_debug do_debug has_error_code=0
Signature · 1 line
1.9.0
#6 lore raw

[tip:x86/asm] x86_64, entry: Merge paranoidzeroentry_ist into idtentry

x86_64, entry: Merge paranoidzeroentry_ist into idtentry
Commit-ID:  577ed45ec56e9c43269df1c4a05c59ed19ea8e6a
Gitweb:     http://git.kernel.org/tip/577ed45ec56e9c43269df1c4a05c59ed19ea8e6a
Author:     Andy Lutomirski <[email protected]>
AuthorDate: Wed, 21 May 2014 15:07:09 -0700
Committer:  H. Peter Anvin <[email protected]>
CommitDate: Wed, 21 May 2014 16:23:02 -0700

x86_64, entry: Merge paranoidzeroentry_ist into idtentry

One more specialized entry function is now gone. Again, this seems to only change line numbers in entry_64.o.

---
 arch/x86/kernel/entry_64.S | 47 ++++++++++++++++++++++------------------------
 1 file changed, 22 insertions(+), 25 deletions(-)
arch/x86/kernel/entry_64.S +22 -25
index eac9b81..be846d2 100644
@@ -1203,8 +1203,15 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-.macro idtentry sym do_sym has_error_code:req paranoid=0
+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
+
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
 ENTRY(\sym)
+	/* Sanity check */
+	.if \shift_ist != -1 && \paranoid == 0
+	.error "using shift_ist requires paranoid=1"
+	.endif
+
 	.if \has_error_code
 	XCPT_FRAME
 	.else
@@ -1230,8 +1237,12 @@ ENTRY(\sym)
 	DEFAULT_FRAME 0
 
 	.if \paranoid
+	.if \shift_ist != -1
+	TRACE_IRQS_OFF_DEBUG		/* reload IDT in case of recursion */
+	.else
 	TRACE_IRQS_OFF
 	.endif
+	.endif
 
 	movq %rsp,%rdi			/* pt_regs pointer */
 
@@ -1242,8 +1253,16 @@ ENTRY(\sym)
 	xorl %esi,%esi			/* no error code */
 	.endif
 
+	.if \shift_ist != -1
+	subq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	.endif
+
 	call \do_sym
 
+	.if \shift_ist != -1
+	addq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	.endif
+
 	.if \paranoid
 	jmp paranoid_exit		/* %ebx: no swapgs flag */
 	.else
@@ -1254,28 +1273,6 @@ ENTRY(\sym)
 END(\sym)
 .endm
 
-#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
-.macro paranoidzeroentry_ist sym do_sym ist
-ENTRY(\sym)
-	INTR_FRAME
-	ASM_CLAC
-	PARAVIRT_ADJUST_EXCEPTION_FRAME
-	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */
-	subq $ORIG_RAX-R15, %rsp
-	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-	call save_paranoid
-	DEFAULT_FRAME 0
-	TRACE_IRQS_OFF_DEBUG
-	movq %rsp,%rdi		/* pt_regs pointer */
-	xorl %esi,%esi		/* no error code */
-	subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-	call \do_sym
-	addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-	jmp paranoid_exit	/* %ebx: no swapgs flag */
-	CFI_ENDPROC
-END(\sym)
-.endm
-
 #ifdef CONFIG_TRACING
 .macro trace_idtentry sym do_sym has_error_code:req
 idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
@@ -1460,8 +1457,8 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
  */
 	.pushsection .kprobes.text, "ax"
 
-paranoidzeroentry_ist debug do_debug DEBUG_STACK
-paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
+idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
 idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
 #ifdef CONFIG_XEN
 idtentry xen_debug do_debug has_error_code=0