[PATCH] x86_64: reliable stack trace support (x86-64)

These are the x86_64-specific pieces to enable reliable stack traces. The
only restriction with this is that it currently cannot unwind across the
interrupt->normal stack boundary, as that transition is lacking proper
annotation.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 9999d703b6c4..6c68beec51b3 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -1089,3 +1089,36 @@ ENTRY(call_softirq)
         ret
         CFI_ENDPROC
 ENDPROC(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), %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    %rcx, RIP(%rdi)
+        leaq    8(%rsp), %rcx
+        movq    $__KERNEL_CS, CS(%rdi)
+        movq    %rax, EFLAGS(%rdi)
+        movq    %rcx, RSP(%rdi)
+        movq    $__KERNEL_DS, SS(%rdi)
+        jmpq    *%rdx
+        CFI_ENDPROC
+ENDPROC(arch_unwind_init_running)
+#endif