[PATCH] i386 CFI annotations

[PATCH] i386 CFI annotations

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 17569 bytes --]

(Note: Patch also attached because the inline version is certain to get
line wrapped.)

As a foundation for reliable stack unwinding, this adds CFI unwind
annotations to many low-level i386 routines, plus a config option
(available to all architectures) to enable them as well as the
compiler
producing similar information for all C sources.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff -Npru 2.6.13/arch/i386/kernel/entry.S
2.6.13-i386-cfi/arch/i386/kernel/entry.S
--- 2.6.13/arch/i386/kernel/entry.S	2005-08-29 01:41:01.000000000
+0200
+++ 2.6.13-i386-cfi/arch/i386/kernel/entry.S	2005-09-07
16:21:51.000000000 +0200
@@ -48,6 +48,7 @@
 #include <asm/smp.h>
 #include <asm/page.h>
 #include <asm/desc.h>
+#include <asm/dwarf2.h>
 #include "irq_vectors.h"
 
 #define nr_syscalls ((syscall_table_size)/4)
@@ -85,31 +86,67 @@ VM_MASK		= 0x00020000
 #define SAVE_ALL \
 	cld; \
 	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;
 
 #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;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	/*CFI_RESTORE es;*/\
 .section .fixup,"ax";	\
 3:	movl $0,(%esp);	\
 	jmp 1b;		\
@@ -122,13 +159,43 @@ VM_MASK		= 0x00020000
 	.long 2b,4b;	\
 .previous
 
+#define RING0_INT_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, 3*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_EC_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, 4*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_PTREGS_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, OLDESP-EBX;\
+	/*CFI_OFFSET cs, CS-OLDESP;*/\
+	CFI_OFFSET eip, EIP-OLDESP;\
+	/*CFI_OFFSET es, ES-OLDESP;*/\
+	/*CFI_OFFSET ds, DS-OLDESP;*/\
+	CFI_OFFSET eax, EAX-OLDESP;\
+	CFI_OFFSET ebp, EBP-OLDESP;\
+	CFI_OFFSET edi, EDI-OLDESP;\
+	CFI_OFFSET esi, ESI-OLDESP;\
+	CFI_OFFSET edx, EDX-OLDESP;\
+	CFI_OFFSET ecx, ECX-OLDESP;\
+	CFI_OFFSET ebx, EBX-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
 	jmp syscall_exit
+	CFI_ENDPROC
 
 /*
  * Return to user mode is not as complex as all this looks,
@@ -139,6 +206,7 @@ ENTRY(ret_from_fork)
 
 	# userspace resumption stub bypassing syscall exit tracing
 	ALIGN
+	RING0_PTREGS_FRAME
 ret_from_exception:
 	preempt_stop
 ret_from_intr:
@@ -171,20 +239,33 @@ need_resched:
 	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)
+	CFI_STARTPROC simple
+	CFI_DEF_CFA esp, 0
+	CFI_REGISTER esp, ebp
 	movl TSS_sysenter_esp0(%esp),%esp
 sysenter_past_esp:
 	sti
 	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*/
 	pushl $SYSENTER_RETURN
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eip, 0
 
 /*
  * Load the potential sixth argument from user stack.
@@ -199,6 +280,7 @@ sysenter_past_esp:
 .previous
 
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
 
@@ -219,11 +301,14 @@ sysenter_past_esp:
 	xorl %ebp,%ebp
 	sti
 	sysexit
+	CFI_ENDPROC
 
 
 	# 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)
 					# system call tracing in
operation
@@ -252,10 +337,12 @@ restore_all:
 	movb CS(%esp), %al
 	andl $(VM_MASK | (4 << 8) | 3), %eax
 	cmpl $((4 << 8) | 3), %eax
+	CFI_REMEMBER_STATE
 	je ldt_ss			# returning to user-space with
LDT SS
 restore_nocheck:
 	RESTORE_REGS
 	addl $4, %esp
+	CFI_ADJUST_CFA_OFFSET -4
 1:	iret
 .section .fixup,"ax"
 iret_exc:
@@ -269,6 +356,7 @@ iret_exc:
 	.long 1b,iret_exc
 .previous
 
+	CFI_RESTORE_STATE
 ldt_ss:
 	larl OLDSS(%esp), %eax
 	jnz restore_nocheck
@@ -281,11 +369,13 @@ ldt_ss:
 	 * CPUs, which we can try to work around to make
 	 * dosemu and wine happy. */
 	subl $8, %esp		# reserve space for switch16 pointer
+	CFI_ADJUST_CFA_OFFSET 8
 	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
+	CFI_ADJUST_CFA_OFFSET -8	# frame has moved
 	RESTORE_REGS
 	lss 20+4(%esp), %esp	# switch to 16bit stack
 1:	iret
@@ -293,9 +383,11 @@ ldt_ss:
 	.align 4
 	.long 1b,iret_exc
 .previous
+	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
@@ -324,8 +416,10 @@ work_notifysig:				# deal
with pending s
 	ALIGN
 work_notifysig_v86:
 	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
 	xorl %edx, %edx
 	call do_notify_resume
@@ -354,19 +448,21 @@ syscall_exit_work:
 	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)
 	jmp resume_userspace
 
-	ALIGN
 syscall_badsys:
 	movl $-ENOSYS,EAX(%esp)
 	jmp resume_userspace
+	CFI_ENDPROC
 
 #define FIXUP_ESPFIX_STACK \
 	movl %esp, %eax; \
@@ -378,16 +474,21 @@ syscall_badsys:
 	movl %eax, %esp;
 #define UNWIND_ESPFIX_STACK \
 	pushl %eax; \
+	CFI_ADJUST_CFA_OFFSET 4; \
 	movl %ss, %eax; \
 	/* see if on 16bit stack */ \
 	cmpw $__ESPFIX_SS, %ax; \
-	jne 28f; \
-	movl $__KERNEL_DS, %edx; \
-	movl %edx, %ds; \
-	movl %edx, %es; \
+	je 28f; \
+27:	popl %eax; \
+	CFI_ADJUST_CFA_OFFSET -4; \
+.section .fixup,"ax"; \
+28:	movl $__KERNEL_DS, %eax; \
+	movl %eax, %ds; \
+	movl %eax, %es; \
 	/* switch to 32bit stack */ \
-	FIXUP_ESPFIX_STACK \
-28:	popl %eax;
+	FIXUP_ESPFIX_STACK; \
+	jmp 27b; \
+.previous
 
 /*
  * Build the entry stubs and pointer table with
@@ -399,9 +500,14 @@ ENTRY(interrupt)
 
 vector=0
 ENTRY(irq_entries_start)
+	RING0_INT_FRAME
 .rept NR_IRQS
 	ALIGN
+ .if vector
+	CFI_ADJUST_CFA_OFFSET -4
+ .endif
 1:	pushl $vector-256
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp common_interrupt
 .data
 	.long 1b
@@ -415,60 +521,99 @@ common_interrupt:
 	movl %esp,%eax
 	call do_IRQ
 	jmp ret_from_intr
+	CFI_ENDPROC
 
 #define BUILD_INTERRUPT(name, nr)	\
 ENTRY(name)				\
+	RING0_INT_FRAME;		\
 	pushl $nr-256;			\
-	SAVE_ALL			\
+	CFI_ADJUST_CFA_OFFSET 4;	\
+	SAVE_ALL;			\
 	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)
+	RING0_INT_FRAME
 	pushl $0			# no error code
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_divide_error
+	CFI_ADJUST_CFA_OFFSET 4
 	ALIGN
 error_code:
 	pushl %ds
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET ds, 0*/
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eax, 0
 	xorl %eax, %eax
 	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
 	decl %eax			# eax = -1
 	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
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET es, 0*/
 	UNWIND_ESPFIX_STACK
 	popl %ecx
+	CFI_ADJUST_CFA_OFFSET -4
+	/*CFI_REGISTER es, 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_REL_OFFSET es, 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
 
 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
 	testl $0x4, %eax		# EM (math emulation bit)
@@ -478,9 +623,12 @@ ENTRY(device_not_available)
 	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
@@ -505,16 +653,19 @@
label:						\
 	pushl $sysenter_past_esp
 
 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
+	CFI_ENDPROC
 
 /*
  * NMI is doubly nasty. It can happen _while_ we're handling
@@ -525,14 +676,18 @@ debug_stack_correct:
  * fault happened on the sysenter path.
  */
 ENTRY(nmi)
+	RING0_INT_FRAME
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	movl %ss, %eax
 	cmpw $__ESPFIX_SS, %ax
 	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4
 	je nmi_16bit_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.
@@ -540,16 +695,19 @@ 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:
 	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
+	CFI_ENDPROC
 
 nmi_stack_fixup:
 	FIX_STACK(12,nmi_stack_correct, 1)
@@ -566,91 +724,143 @@ nmi_debug_stack_fixup:
 	jmp nmi_stack_correct
 
 nmi_16bit_stack:
+	RING0_INT_FRAME
 	/* create the pointer to lss back */
 	pushl %ss
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl %esp
+	CFI_ADJUST_CFA_OFFSET 4
 	movzwl %sp, %esp
 	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
+	CFI_ADJUST_CFA_OFFSET -20	# the frame has now moved
 	xorl %edx,%edx			# zero error code
 	call do_nmi
 	RESTORE_REGS
 	lss 12+4(%esp), %esp		# back to 16bit stack
 1:	iret
+	CFI_ENDPROC
 .section __ex_table,"a"
 	.align 4
 	.long 1b,iret_exc
 .previous
 
 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
+	CFI_ENDPROC
 
 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
 
 ENTRY(general_protection)
+	RING0_EC_FRAME
 	pushl $do_general_protection
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(alignment_check)
+	RING0_EC_FRAME
 	pushl $do_alignment_check
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(page_fault)
+	RING0_EC_FRAME
 	pushl $do_page_fault
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	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
 
 #include "syscall_table.S"
 
diff -Npru 2.6.13/include/asm-i386/dwarf2.h
2.6.13-i386-cfi/include/asm-i386/dwarf2.h
--- 2.6.13/include/asm-i386/dwarf2.h	1970-01-01 01:00:00.000000000
+0100
+++ 2.6.13-i386-cfi/include/asm-i386/dwarf2.h	2005-06-30
14:43:06.000000000 +0200
@@ -0,0 +1,54 @@
+#ifndef _DWARF2_H
+#define _DWARF2_H
+
+#include <linux/config.h>
+
+#ifndef __ASSEMBLY__
+#warning "asm/dwarf2.h should be only included in pure assembly
files"
+#endif
+
+/*
+   Macros for dwarf2 CFI unwind table entries.
+   See "as.info" for details on these pseudo ops. Unfortunately
+   they are only supported in very new binutils, so define them
+   away for older version.
+ */
+
+#ifdef CONFIG_UNWIND_INFO
+
+#define CFI_STARTPROC .cfi_startproc
+#define CFI_ENDPROC .cfi_endproc
+#define CFI_DEF_CFA .cfi_def_cfa
+#define CFI_DEF_CFA_REGISTER .cfi_def_cfa_register
+#define CFI_DEF_CFA_OFFSET .cfi_def_cfa_offset
+#define CFI_ADJUST_CFA_OFFSET .cfi_adjust_cfa_offset
+#define CFI_OFFSET .cfi_offset
+#define CFI_REL_OFFSET .cfi_rel_offset
+#define CFI_REGISTER .cfi_register
+#define CFI_RESTORE .cfi_restore
+#define CFI_REMEMBER_STATE .cfi_remember_state
+#define CFI_RESTORE_STATE .cfi_restore_state
+
+#else
+
+/* Due to the structure of pre-exisiting code, don't use assembler
line
+   comment character # to ignore the arguments. Instead, use a dummy
macro. */
+.macro ignore a=0, b=0, c=0, d=0
+.endm
+
+#define CFI_STARTPROC	ignore
+#define CFI_ENDPROC	ignore
+#define CFI_DEF_CFA	ignore
+#define CFI_DEF_CFA_REGISTER	ignore
+#define CFI_DEF_CFA_OFFSET	ignore
+#define CFI_ADJUST_CFA_OFFSET	ignore
+#define CFI_OFFSET	ignore
+#define CFI_REL_OFFSET	ignore
+#define CFI_REGISTER	ignore
+#define CFI_RESTORE	ignore
+#define CFI_REMEMBER_STATE ignore
+#define CFI_RESTORE_STATE ignore
+
+#endif
+
+#endif
diff -Npru 2.6.13/lib/Kconfig.debug 2.6.13-i386-cfi/lib/Kconfig.debug
--- 2.6.13/lib/Kconfig.debug	2005-08-29 01:41:01.000000000 +0200
+++ 2.6.13-i386-cfi/lib/Kconfig.debug	2005-09-07 13:26:18.000000000
+0200
@@ -159,3 +159,12 @@ config FRAME_POINTER
 	  If you don't debug the kernel, you can say N, but we may not
be able
 	  to solve problems without frame pointers.
 
+config UNWIND_INFO
+	bool "Compile the kernel with frame unwind information" if
!IA64
+	default DEBUG_KERNEL && !IA64
+	help
+	  If you say Y here the resulting kernel image will be slightly
larger
+	  but not slower, and it will give very useful debugging
information.
+	  If you don't debug the kernel, you can say N, but we may not
be able
+	  to solve problems without frame unwind information or frame
pointers.
+
diff -Npru 2.6.13/Makefile 2.6.13-i386-cfi/Makefile
--- 2.6.13/Makefile	2005-08-29 01:41:01.000000000 +0200
+++ 2.6.13-i386-cfi/Makefile	2005-09-07 13:25:54.000000000 +0200
@@ -517,6 +517,10 @@ CFLAGS		+= $(call
add-align,CONFIG_CC_AL
 CFLAGS		+= $(call
add-align,CONFIG_CC_ALIGN_LOOPS,-loops)
 CFLAGS		+= $(call
add-align,CONFIG_CC_ALIGN_JUMPS,-jumps)
 
+ifdef CONFIG_UNWIND_INFO
+CFLAGS		+= -fasynchronous-unwind-tables
+endif
+
 ifdef CONFIG_FRAME_POINTER
 CFLAGS		+= -fno-omit-frame-pointer $(call
cc-option,-fno-optimize-sibling-calls,)
 else


[-- Attachment #2: linux-2.6.13-i386-cfi.patch --]
[-- Type: application/octet-stream, Size: 17568 bytes --]

(Note: Patch also attached because the inline version is certain to get
line wrapped.)

As a foundation for reliable stack unwinding, this adds CFI unwind
annotations to many low-level i386 routines, plus a config option
(available to all architectures) to enable them as well as the compiler
producing similar information for all C sources.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff -Npru 2.6.13/arch/i386/kernel/entry.S 2.6.13-i386-cfi/arch/i386/kernel/entry.S
--- 2.6.13/arch/i386/kernel/entry.S	2005-08-29 01:41:01.000000000 +0200
+++ 2.6.13-i386-cfi/arch/i386/kernel/entry.S	2005-09-07 16:21:51.000000000 +0200
@@ -48,6 +48,7 @@
 #include <asm/smp.h>
 #include <asm/page.h>
 #include <asm/desc.h>
+#include <asm/dwarf2.h>
 #include "irq_vectors.h"
 
 #define nr_syscalls ((syscall_table_size)/4)
@@ -85,31 +86,67 @@ VM_MASK		= 0x00020000
 #define SAVE_ALL \
 	cld; \
 	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;
 
 #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;	\
+	CFI_ADJUST_CFA_OFFSET -4;\
+	/*CFI_RESTORE es;*/\
 .section .fixup,"ax";	\
 3:	movl $0,(%esp);	\
 	jmp 1b;		\
@@ -122,13 +159,43 @@ VM_MASK		= 0x00020000
 	.long 2b,4b;	\
 .previous
 
+#define RING0_INT_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, 3*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_EC_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, 4*4;\
+	/*CFI_OFFSET cs, -2*4;*/\
+	CFI_OFFSET eip, -3*4
+
+#define RING0_PTREGS_FRAME \
+	CFI_STARTPROC simple;\
+	CFI_DEF_CFA esp, OLDESP-EBX;\
+	/*CFI_OFFSET cs, CS-OLDESP;*/\
+	CFI_OFFSET eip, EIP-OLDESP;\
+	/*CFI_OFFSET es, ES-OLDESP;*/\
+	/*CFI_OFFSET ds, DS-OLDESP;*/\
+	CFI_OFFSET eax, EAX-OLDESP;\
+	CFI_OFFSET ebp, EBP-OLDESP;\
+	CFI_OFFSET edi, EDI-OLDESP;\
+	CFI_OFFSET esi, ESI-OLDESP;\
+	CFI_OFFSET edx, EDX-OLDESP;\
+	CFI_OFFSET ecx, ECX-OLDESP;\
+	CFI_OFFSET ebx, EBX-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
 	jmp syscall_exit
+	CFI_ENDPROC
 
 /*
  * Return to user mode is not as complex as all this looks,
@@ -139,6 +206,7 @@ ENTRY(ret_from_fork)
 
 	# userspace resumption stub bypassing syscall exit tracing
 	ALIGN
+	RING0_PTREGS_FRAME
 ret_from_exception:
 	preempt_stop
 ret_from_intr:
@@ -171,20 +239,33 @@ need_resched:
 	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)
+	CFI_STARTPROC simple
+	CFI_DEF_CFA esp, 0
+	CFI_REGISTER esp, ebp
 	movl TSS_sysenter_esp0(%esp),%esp
 sysenter_past_esp:
 	sti
 	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*/
 	pushl $SYSENTER_RETURN
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eip, 0
 
 /*
  * Load the potential sixth argument from user stack.
@@ -199,6 +280,7 @@ sysenter_past_esp:
 .previous
 
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	SAVE_ALL
 	GET_THREAD_INFO(%ebp)
 
@@ -219,11 +301,14 @@ sysenter_past_esp:
 	xorl %ebp,%ebp
 	sti
 	sysexit
+	CFI_ENDPROC
 
 
 	# 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)
 					# system call tracing in operation
@@ -252,10 +337,12 @@ restore_all:
 	movb CS(%esp), %al
 	andl $(VM_MASK | (4 << 8) | 3), %eax
 	cmpl $((4 << 8) | 3), %eax
+	CFI_REMEMBER_STATE
 	je ldt_ss			# returning to user-space with LDT SS
 restore_nocheck:
 	RESTORE_REGS
 	addl $4, %esp
+	CFI_ADJUST_CFA_OFFSET -4
 1:	iret
 .section .fixup,"ax"
 iret_exc:
@@ -269,6 +356,7 @@ iret_exc:
 	.long 1b,iret_exc
 .previous
 
+	CFI_RESTORE_STATE
 ldt_ss:
 	larl OLDSS(%esp), %eax
 	jnz restore_nocheck
@@ -281,11 +369,13 @@ ldt_ss:
 	 * CPUs, which we can try to work around to make
 	 * dosemu and wine happy. */
 	subl $8, %esp		# reserve space for switch16 pointer
+	CFI_ADJUST_CFA_OFFSET 8
 	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
+	CFI_ADJUST_CFA_OFFSET -8	# frame has moved
 	RESTORE_REGS
 	lss 20+4(%esp), %esp	# switch to 16bit stack
 1:	iret
@@ -293,9 +383,11 @@ ldt_ss:
 	.align 4
 	.long 1b,iret_exc
 .previous
+	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
@@ -324,8 +416,10 @@ work_notifysig:				# deal with pending s
 	ALIGN
 work_notifysig_v86:
 	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
 	xorl %edx, %edx
 	call do_notify_resume
@@ -354,19 +448,21 @@ syscall_exit_work:
 	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)
 	jmp resume_userspace
 
-	ALIGN
 syscall_badsys:
 	movl $-ENOSYS,EAX(%esp)
 	jmp resume_userspace
+	CFI_ENDPROC
 
 #define FIXUP_ESPFIX_STACK \
 	movl %esp, %eax; \
@@ -378,16 +474,21 @@ syscall_badsys:
 	movl %eax, %esp;
 #define UNWIND_ESPFIX_STACK \
 	pushl %eax; \
+	CFI_ADJUST_CFA_OFFSET 4; \
 	movl %ss, %eax; \
 	/* see if on 16bit stack */ \
 	cmpw $__ESPFIX_SS, %ax; \
-	jne 28f; \
-	movl $__KERNEL_DS, %edx; \
-	movl %edx, %ds; \
-	movl %edx, %es; \
+	je 28f; \
+27:	popl %eax; \
+	CFI_ADJUST_CFA_OFFSET -4; \
+.section .fixup,"ax"; \
+28:	movl $__KERNEL_DS, %eax; \
+	movl %eax, %ds; \
+	movl %eax, %es; \
 	/* switch to 32bit stack */ \
-	FIXUP_ESPFIX_STACK \
-28:	popl %eax;
+	FIXUP_ESPFIX_STACK; \
+	jmp 27b; \
+.previous
 
 /*
  * Build the entry stubs and pointer table with
@@ -399,9 +500,14 @@ ENTRY(interrupt)
 
 vector=0
 ENTRY(irq_entries_start)
+	RING0_INT_FRAME
 .rept NR_IRQS
 	ALIGN
+ .if vector
+	CFI_ADJUST_CFA_OFFSET -4
+ .endif
 1:	pushl $vector-256
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp common_interrupt
 .data
 	.long 1b
@@ -415,60 +521,99 @@ common_interrupt:
 	movl %esp,%eax
 	call do_IRQ
 	jmp ret_from_intr
+	CFI_ENDPROC
 
 #define BUILD_INTERRUPT(name, nr)	\
 ENTRY(name)				\
+	RING0_INT_FRAME;		\
 	pushl $nr-256;			\
-	SAVE_ALL			\
+	CFI_ADJUST_CFA_OFFSET 4;	\
+	SAVE_ALL;			\
 	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)
+	RING0_INT_FRAME
 	pushl $0			# no error code
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl $do_divide_error
+	CFI_ADJUST_CFA_OFFSET 4
 	ALIGN
 error_code:
 	pushl %ds
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET ds, 0*/
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET eax, 0
 	xorl %eax, %eax
 	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
 	decl %eax			# eax = -1
 	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
+	CFI_ADJUST_CFA_OFFSET 4
+	/*CFI_REL_OFFSET es, 0*/
 	UNWIND_ESPFIX_STACK
 	popl %ecx
+	CFI_ADJUST_CFA_OFFSET -4
+	/*CFI_REGISTER es, 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_REL_OFFSET es, 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
 
 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
 	testl $0x4, %eax		# EM (math emulation bit)
@@ -478,9 +623,12 @@ ENTRY(device_not_available)
 	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
@@ -505,16 +653,19 @@ label:						\
 	pushl $sysenter_past_esp
 
 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
+	CFI_ENDPROC
 
 /*
  * NMI is doubly nasty. It can happen _while_ we're handling
@@ -525,14 +676,18 @@ debug_stack_correct:
  * fault happened on the sysenter path.
  */
 ENTRY(nmi)
+	RING0_INT_FRAME
 	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
 	movl %ss, %eax
 	cmpw $__ESPFIX_SS, %ax
 	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4
 	je nmi_16bit_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.
@@ -540,16 +695,19 @@ 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:
 	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
+	CFI_ENDPROC
 
 nmi_stack_fixup:
 	FIX_STACK(12,nmi_stack_correct, 1)
@@ -566,91 +724,143 @@ nmi_debug_stack_fixup:
 	jmp nmi_stack_correct
 
 nmi_16bit_stack:
+	RING0_INT_FRAME
 	/* create the pointer to lss back */
 	pushl %ss
+	CFI_ADJUST_CFA_OFFSET 4
 	pushl %esp
+	CFI_ADJUST_CFA_OFFSET 4
 	movzwl %sp, %esp
 	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
+	CFI_ADJUST_CFA_OFFSET -20	# the frame has now moved
 	xorl %edx,%edx			# zero error code
 	call do_nmi
 	RESTORE_REGS
 	lss 12+4(%esp), %esp		# back to 16bit stack
 1:	iret
+	CFI_ENDPROC
 .section __ex_table,"a"
 	.align 4
 	.long 1b,iret_exc
 .previous
 
 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
+	CFI_ENDPROC
 
 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
 
 ENTRY(general_protection)
+	RING0_EC_FRAME
 	pushl $do_general_protection
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(alignment_check)
+	RING0_EC_FRAME
 	pushl $do_alignment_check
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	CFI_ENDPROC
 
 ENTRY(page_fault)
+	RING0_EC_FRAME
 	pushl $do_page_fault
+	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
+	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
 
 #include "syscall_table.S"
 
diff -Npru 2.6.13/include/asm-i386/dwarf2.h 2.6.13-i386-cfi/include/asm-i386/dwarf2.h
--- 2.6.13/include/asm-i386/dwarf2.h	1970-01-01 01:00:00.000000000 +0100
+++ 2.6.13-i386-cfi/include/asm-i386/dwarf2.h	2005-06-30 14:43:06.000000000 +0200
@@ -0,0 +1,54 @@
+#ifndef _DWARF2_H
+#define _DWARF2_H
+
+#include <linux/config.h>
+
+#ifndef __ASSEMBLY__
+#warning "asm/dwarf2.h should be only included in pure assembly files"
+#endif
+
+/*
+   Macros for dwarf2 CFI unwind table entries.
+   See "as.info" for details on these pseudo ops. Unfortunately
+   they are only supported in very new binutils, so define them
+   away for older version.
+ */
+
+#ifdef CONFIG_UNWIND_INFO
+
+#define CFI_STARTPROC .cfi_startproc
+#define CFI_ENDPROC .cfi_endproc
+#define CFI_DEF_CFA .cfi_def_cfa
+#define CFI_DEF_CFA_REGISTER .cfi_def_cfa_register
+#define CFI_DEF_CFA_OFFSET .cfi_def_cfa_offset
+#define CFI_ADJUST_CFA_OFFSET .cfi_adjust_cfa_offset
+#define CFI_OFFSET .cfi_offset
+#define CFI_REL_OFFSET .cfi_rel_offset
+#define CFI_REGISTER .cfi_register
+#define CFI_RESTORE .cfi_restore
+#define CFI_REMEMBER_STATE .cfi_remember_state
+#define CFI_RESTORE_STATE .cfi_restore_state
+
+#else
+
+/* Due to the structure of pre-exisiting code, don't use assembler line
+   comment character # to ignore the arguments. Instead, use a dummy macro. */
+.macro ignore a=0, b=0, c=0, d=0
+.endm
+
+#define CFI_STARTPROC	ignore
+#define CFI_ENDPROC	ignore
+#define CFI_DEF_CFA	ignore
+#define CFI_DEF_CFA_REGISTER	ignore
+#define CFI_DEF_CFA_OFFSET	ignore
+#define CFI_ADJUST_CFA_OFFSET	ignore
+#define CFI_OFFSET	ignore
+#define CFI_REL_OFFSET	ignore
+#define CFI_REGISTER	ignore
+#define CFI_RESTORE	ignore
+#define CFI_REMEMBER_STATE ignore
+#define CFI_RESTORE_STATE ignore
+
+#endif
+
+#endif
diff -Npru 2.6.13/lib/Kconfig.debug 2.6.13-i386-cfi/lib/Kconfig.debug
--- 2.6.13/lib/Kconfig.debug	2005-08-29 01:41:01.000000000 +0200
+++ 2.6.13-i386-cfi/lib/Kconfig.debug	2005-09-07 13:26:18.000000000 +0200
@@ -159,3 +159,12 @@ config FRAME_POINTER
 	  If you don't debug the kernel, you can say N, but we may not be able
 	  to solve problems without frame pointers.
 
+config UNWIND_INFO
+	bool "Compile the kernel with frame unwind information" if !IA64
+	default DEBUG_KERNEL && !IA64
+	help
+	  If you say Y here the resulting kernel image will be slightly larger
+	  but not slower, and it will give very useful debugging information.
+	  If you don't debug the kernel, you can say N, but we may not be able
+	  to solve problems without frame unwind information or frame pointers.
+
diff -Npru 2.6.13/Makefile 2.6.13-i386-cfi/Makefile
--- 2.6.13/Makefile	2005-08-29 01:41:01.000000000 +0200
+++ 2.6.13-i386-cfi/Makefile	2005-09-07 13:25:54.000000000 +0200
@@ -517,6 +517,10 @@ CFLAGS		+= $(call add-align,CONFIG_CC_AL
 CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_LOOPS,-loops)
 CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_JUMPS,-jumps)
 
+ifdef CONFIG_UNWIND_INFO
+CFLAGS		+= -fasynchronous-unwind-tables
+endif
+
 ifdef CONFIG_FRAME_POINTER
 CFLAGS		+= -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
 else

Re: [PATCH] i386 CFI annotations

[Tom Rini]

On Thu, Sep 08, 2005 at 05:10:29PM +0200, Jan Beulich wrote:

> As a foundation for reliable stack unwinding, this adds CFI unwind
> annotations to many low-level i386 routines, plus a config option
> (available to all architectures) to enable them as well as the
> compiler
> producing similar information for all C sources.
> 
> Signed-off-by: Jan Beulich <jbeulich@novell.com>

x86_64 has proper CFI annotations on things, and just depends on
DEBUG_INFO.  Perhaps that would be a slightly easier path to use for
pushing this along?

> +	CFI_ADJUST_CFA_OFFSET 4;\
> +	/*CFI_REL_OFFSET es, 0;*/\
>  	pushl %ds; \
> +	CFI_ADJUST_CFA_OFFSET 4;\
> +	/*CFI_REL_OFFSET ds, 0;*/\

Adding new commented out code never wins new friends. :)

> diff -Npru 2.6.13/include/asm-i386/dwarf2.h
[snip]
> +#ifdef CONFIG_UNWIND_INFO
[snip]
> +#else
[snip]
> +#define CFI_STARTPROC	ignore

Why not just empty defines?

-- 
Tom Rini
http://gate.crashing.org/~trini/

Re: [PATCH] i386 CFI annotations

[Jan Beulich]

>>> Tom Rini <trini@kernel.crashing.org> 08.09.05 18:13:34 >>>
>On Thu, Sep 08, 2005 at 05:57:55PM +0200, Jan Beulich wrote:
>
>> >> +	CFI_ADJUST_CFA_OFFSET 4;\
>> >> +	/*CFI_REL_OFFSET es, 0;*/\
>> >>  	pushl %ds; \
>> >> +	CFI_ADJUST_CFA_OFFSET 4;\
>> >> +	/*CFI_REL_OFFSET ds, 0;*/\
>> >
>> >Adding new commented out code never wins new friends. :)
>> 
>> I know. But how would you indicate functionality belonging there
but
>> just not provided by the translating utilities. If that's really a
>> problem, then I would need to teach the respective macros to ignore
>> certain operands.
>
>Not provided by binutils or ?

Not provided for even by the spec; if it was just binutils missing them
I'd have added this already.

>> >> diff -Npru 2.6.13/include/asm-i386/dwarf2.h
>> >[snip]
>> >> +#ifdef CONFIG_UNWIND_INFO
>> >[snip]
>> >> +#else
>> >[snip]
>> >> +#define CFI_STARTPROC	ignore
>> >
>> >Why not just empty defines?
>> 
>> Because they aren't function-like macros, but can have arguments
>> (assembler syntax style); these arguments would then remain
standalone
>> on the line, and the assembly would fail.
>
>Take a look at
>http://marc.theaimsgroup.com/?l=linux-kernel&m=112267822014301&w=2 
>
>I think we have slightly different approaches to the same problem, but
I
>found doing the cfi macros as cpp macros instead of gas macros was
>cleaner & easier in the end.

I don't like this better, I actually started from the x86-64 approach.
Specifically, if working around the above mentioned commented-out-code
problem should be necessary, then using assembler macros is likely to
provide for an easier solution.

Jan

Re: [PATCH] i386 CFI annotations

[Richard Henderson]

On Fri, Sep 09, 2005 at 08:51:57AM +0200, Jan Beulich wrote:
> >>> Tom Rini <trini@kernel.crashing.org> 08.09.05 18:13:34 >>>
> >On Thu, Sep 08, 2005 at 05:57:55PM +0200, Jan Beulich wrote:
> >
> >> >> +	CFI_ADJUST_CFA_OFFSET 4;\
> >> >> +	/*CFI_REL_OFFSET es, 0;*/\
> >> >>  	pushl %ds; \
> >> >> +	CFI_ADJUST_CFA_OFFSET 4;\
> >> >> +	/*CFI_REL_OFFSET ds, 0;*/\
> >> >
> >> >Adding new commented out code never wins new friends. :)
> >> 
> >> I know. But how would you indicate functionality belonging there
> but
> >> just not provided by the translating utilities. If that's really a
> >> problem, then I would need to teach the respective macros to ignore
> >> certain operands.
> >
> >Not provided by binutils or ?
> 
> Not provided for even by the spec; if it was just binutils missing them
> I'd have added this already.

You know this is just convention, right?  And that binutils allows
you to put any column numbers you like?  So all you have to do it
match whatever debugger you're planning to use.  Make something up.


r~

Re: [PATCH] i386 CFI annotations

[Jan Beulich]

>>> Richard Henderson <rth@twiddle.net> 10.09.05 07:58:36 >>>
>On Fri, Sep 09, 2005 at 08:51:57AM +0200, Jan Beulich wrote:
>> >>> Tom Rini <trini@kernel.crashing.org> 08.09.05 18:13:34 >>>
>> >On Thu, Sep 08, 2005 at 05:57:55PM +0200, Jan Beulich wrote:
>> >
>> >> >> +	CFI_ADJUST_CFA_OFFSET 4;\
>> >> >> +	/*CFI_REL_OFFSET es, 0;*/\
>> >> >>  	pushl %ds; \
>> >> >> +	CFI_ADJUST_CFA_OFFSET 4;\
>> >> >> +	/*CFI_REL_OFFSET ds, 0;*/\
>> >> >
>> >> >Adding new commented out code never wins new friends. :)
>> >> 
>> >> I know. But how would you indicate functionality belonging there
>> but
>> >> just not provided by the translating utilities. If that's really
a
>> >> problem, then I would need to teach the respective macros to
ignore
>> >> certain operands.
>> >
>> >Not provided by binutils or ?
>> 
>> Not provided for even by the spec; if it was just binutils missing
them
>> I'd have added this already.
>
>You know this is just convention, right?  And that binutils allows
>you to put any column numbers you like?  So all you have to do it
>match whatever debugger you're planning to use.  Make something up.

I know. But I don't like the idea of 'putting something in' that later
might turn out incompatible with something else. The minimum support
from the Dwarf spec I'd expect here would be an equivalent to IA64's
.unwabi. But truly I think the processor-specific pieces of Dwarf's
frame unwind spec should provide numbering for the complete set of
registers.

Jan

Re: [PATCH] i386 CFI annotations

[Richard Henderson]

On Mon, Sep 12, 2005 at 09:04:12AM +0200, Jan Beulich wrote:
> But truly I think the processor-specific pieces of Dwarf's
> frame unwind spec should provide numbering for the complete set of
> registers.

Except there is no standards body for this.  So *someone* will
have to make it up.

Make it up and put it in gas and gdb: that will make it a defacto standard.


r~

Re: [PATCH] i386 CFI annotations

[Daniel Jacobowitz]

On Mon, Sep 12, 2005 at 12:49:14AM -0700, Richard Henderson wrote:
> On Mon, Sep 12, 2005 at 09:04:12AM +0200, Jan Beulich wrote:
> > But truly I think the processor-specific pieces of Dwarf's
> > frame unwind spec should provide numbering for the complete set of
> > registers.
> 
> Except there is no standards body for this.  So *someone* will
> have to make it up.
> 
> Make it up and put it in gas and gdb: that will make it a defacto standard.

Agreed.  If it makes you feel better, we could ask the DWARF committee to
maintain a repository of processor-specific documents.

-- 
Daniel Jacobowitz
CodeSourcery, LLC