From fe7cacc1c25e286872b878c5d46880b620cd1e2d Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 26 Jun 2006 13:57:44 +0200 Subject: [PATCH] [PATCH] i386: reliable stack trace support i386 entry.S To increase the usefulness of reliable stack unwinding, this adds CFI unwind annotations to many low-level i386 routines. Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/entry.S | 234 ++++++++++++++++++++++++++++++++++++-- include/asm-i386/dwarf2.h | 54 +++++++++ 2 files changed, 277 insertions(+), 11 deletions(-) create mode 100644 include/asm-i386/dwarf2.h diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index e802f3cac7e..e6e4506e749 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -48,6 +48,7 @@ #include #include #include +#include #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) testl $TF_MASK,EFLAGS(%esp) @@ -256,10 +341,12 @@ 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: @@ -273,6 +360,7 @@ iret_exc: .long 1b,iret_exc .previous + CFI_RESTORE_STATE ldt_ss: larl OLDSS(%esp), %eax jnz restore_nocheck @@ -285,11 +373,13 @@ 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 @@ -297,9 +387,11 @@ 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 @@ -329,8 +421,10 @@ work_notifysig: # deal with pending signals and work_notifysig_v86: #ifdef CONFIG_VM86 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 @@ -363,19 +457,21 @@ 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; \ @@ -387,16 +483,21 @@ 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 @@ -408,9 +509,14 @@ 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 @@ -424,60 +530,99 @@ 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) @@ -487,9 +632,12 @@ 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 @@ -514,16 +662,19 @@ label: \ pushl $sysenter_past_esp KPROBE_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 .previous .text /* * NMI is doubly nasty. It can happen _while_ we're handling @@ -534,14 +685,18 @@ 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. @@ -549,16 +704,19 @@ 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) @@ -574,97 +732,150 @@ nmi_debug_stack_check: 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 KPROBE_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 .previous .text 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 KPROBE_ENTRY(general_protection) + RING0_EC_FRAME pushl $do_general_protection + CFI_ADJUST_CFA_OFFSET 4 jmp error_code + CFI_ENDPROC .previous .text ENTRY(alignment_check) + RING0_EC_FRAME pushl $do_alignment_check + CFI_ADJUST_CFA_OFFSET 4 jmp error_code + CFI_ENDPROC KPROBE_ENTRY(page_fault) + RING0_EC_FRAME pushl $do_page_fault + CFI_ADJUST_CFA_OFFSET 4 jmp error_code + CFI_ENDPROC .previous .text #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 #ifdef CONFIG_STACK_UNWIND ENTRY(arch_unwind_init_running) + CFI_STARTPROC movl 4(%esp), %edx movl (%esp), %ecx leal 4(%esp), %eax @@ -689,6 +900,7 @@ ENTRY(arch_unwind_init_running) movl EBX(%edx), %ebx movl $__KERNEL_DS, OLDSS(%edx) jmpl *%eax + CFI_ENDPROC ENDPROC(arch_unwind_init_running) #endif diff --git a/include/asm-i386/dwarf2.h b/include/asm-i386/dwarf2.h new file mode 100644 index 00000000000..2280f6272f8 --- /dev/null +++ b/include/asm-i386/dwarf2.h @@ -0,0 +1,54 @@ +#ifndef _DWARF2_H +#define _DWARF2_H + +#include + +#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 -- 2.41.1