Subject: DWARF2 EH-frame based stack unwinding
From: jbeulich@novell.com
Patch-mainline: no
This includes reverting f1883f86dea84fe47a71a39fc1afccc005915ed8.
Update Jan 17 2009 jeffm:
- Something in 2.6.29-rc1 tweaked the frame pointer code somehow, so I fixed
that up.
Update Jul 02 2010 jbeulich:
- fix after upstream commit 9e565292270a2d55524be38835104c564ac8f795
Update Sep 15 2011 jbeulich:
- add support for DW_CFA_def_cfa_expression (needed by x86-64)
Automatically created from "patches.suse/stack-unwind" by xen-port-patches.py
--- head.orig/arch/x86/kernel/entry_32-xen.S 2012-04-11 13:26:23.000000000 +0200
+++ head/arch/x86/kernel/entry_32-xen.S 2012-04-04 13:33:12.000000000 +0200
@@ -1228,6 +1228,41 @@ END(fixup_4gb_segment)
*/
.popsection
+#ifdef CONFIG_STACK_UNWIND
+ENTRY(arch_unwind_init_running)
+ CFI_STARTPROC
+ movl 4(%esp), %edx
+ movl (%esp), %ecx
+ leal 4(%esp), %eax
+ movl %ebx, PT_EBX(%edx)
+ xorl %ebx, %ebx
+ movl %ebx, PT_ECX(%edx)
+ movl %ebx, PT_EDX(%edx)
+ movl %esi, PT_ESI(%edx)
+ movl %edi, PT_EDI(%edx)
+ movl %ebp, PT_EBP(%edx)
+ movl %ebx, PT_EAX(%edx)
+ movl $__USER_DS, PT_DS(%edx)
+ movl $__USER_DS, PT_ES(%edx)
+ movl $__KERNEL_PERCPU, PT_FS(%edx)
+ movl $__KERNEL_STACK_CANARY, PT_GS(%edx)
+ movl %eax, PT_OLDESP(%edx)
+ movl 16(%esp), %eax
+ movl %ebx, PT_ORIG_EAX(%edx)
+ movl %ecx, PT_EIP(%edx)
+ movl 12(%esp), %ecx
+ movl $__KERNEL_CS, PT_CS(%edx)
+ movl %eax, 12(%esp)
+ movl 8(%esp), %eax
+ movl %ecx, 8(%esp)
+ movl %ebx, PT_EFLAGS(%edx)
+ movl PT_EBX(%edx), %ebx
+ movl $__KERNEL_DS, PT_OLDSS(%edx)
+ jmpl *%eax
+ CFI_ENDPROC
+ENDPROC(arch_unwind_init_running)
+#endif
+
ENTRY(kernel_thread_helper)
pushl $0 # fake return address for unwinder
CFI_STARTPROC
--- head.orig/arch/x86/kernel/entry_64-xen.S 2012-04-11 13:26:23.000000000 +0200
+++ head/arch/x86/kernel/entry_64-xen.S 2012-04-11 16:59:09.000000000 +0200
@@ -1185,6 +1185,40 @@ ENTRY(call_softirq)
CFI_ENDPROC
END(call_softirq)
+#ifdef CONFIG_STACK_UNWIND
+ENTRY(arch_unwind_init_running)
+ CFI_STARTPROC
+ movq %r15, R15(%rdi)
+ movq %r14, R14(%rdi)
+ xchgq %rsi, %rdx
+ movq %r13, R13(%rdi)
+ movq %r12, R12(%rdi)
+ xorl %eax, %eax
+ movq %rbp, RBP(%rdi)
+ movq %rbx, RBX(%rdi)
+ movq (%rsp), %r9
+ xchgq %rdx, %rcx
+ movq %rax, R11(%rdi)
+ movq %rax, R10(%rdi)
+ movq %rax, R9(%rdi)
+ movq %rax, R8(%rdi)
+ movq %rax, RAX(%rdi)
+ movq %rax, RCX(%rdi)
+ movq %rax, RDX(%rdi)
+ movq %rax, RSI(%rdi)
+ movq %rax, RDI(%rdi)
+ movq %rax, ORIG_RAX(%rdi)
+ movq %r9, RIP(%rdi)
+ leaq 8(%rsp), %r9
+ movq $__KERNEL_CS, CS(%rdi)
+ movq %rax, EFLAGS(%rdi)
+ movq %r9, RSP(%rdi)
+ movq $__KERNEL_DS, SS(%rdi)
+ jmpq *%rcx
+ CFI_ENDPROC
+END(arch_unwind_init_running)
+#endif
+
/*
* Some functions should be protected against kprobes
*/