x86/tcb: new tcb_trace function

This function dumps the stack trace of a thread from its TCB. In order to
do that, the base pointer is now included in the TCB, along with the stack
and instruction pointers.

3 files changed, 37 insertions, 21 deletions

diff --git a/arch/x86/machine/tcb.c b/arch/x86/machine/tcb.c
index 90f08b58..14d74c67 100644
--- a/arch/x86/machine/tcb.c
+++ b/arch/x86/machine/tcb.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 Richard Braun.
+ * Copyright (c) 2012, 2013 Richard Braun.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -19,6 +19,7 @@
 #include <kern/macros.h>
 #include <kern/param.h>
 #include <machine/cpu.h>
+#include <machine/strace.h>
 #include <machine/tcb.h>
 
 /*
@@ -32,6 +33,7 @@ tcb_init(struct tcb *tcb, void *stack, void (*fn)(void))
 {
     void **ptr;
 
+    tcb->bp = 0;
     tcb->sp = (unsigned long)stack + STACK_SIZE - sizeof(unsigned long);
     tcb->ip = (unsigned long)tcb_start;
 
@@ -49,6 +51,12 @@ tcb_load(struct tcb *tcb)
 }
 
 void
+tcb_trace(const struct tcb *tcb)
+{
+    strace_show(tcb->ip, tcb->bp);
+}
+
+void
 tcb_reschedule_intr(struct trap_frame *frame)
 {
     (void)frame;
diff --git a/arch/x86/machine/tcb.h b/arch/x86/machine/tcb.h
index 886237ee..bd0a793d 100644
--- a/arch/x86/machine/tcb.h
+++ b/arch/x86/machine/tcb.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 Richard Braun.
+ * Copyright (c) 2012, 2013 Richard Braun.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -31,6 +31,7 @@
  * Architecture specific thread data.
  */
 struct tcb {
+    unsigned long bp;
     unsigned long sp;
     unsigned long ip;
 };
@@ -82,6 +83,13 @@ tcb_switch(struct tcb *prev, struct tcb *next)
 }
 
 /*
+ * Dump the stack trace of a TCB.
+ *
+ * The thread associated to the TCB should not be running.
+ */
+void tcb_trace(const struct tcb *tcb);
+
+/*
  * Send a rescheduling interrupt to a remote processor.
  */
 static inline void
diff --git a/arch/x86/machine/tcb_asm.S b/arch/x86/machine/tcb_asm.S
index 815dc365..2089e939 100644
--- a/arch/x86/machine/tcb_asm.S
+++ b/arch/x86/machine/tcb_asm.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 Richard Braun.
+ * Copyright (c) 2012, 2013 Richard Braun.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -24,8 +24,9 @@
 #ifdef __LP64__
 
 ASM_ENTRY(tcb_context_load)
- movq 8(%rdi), %rax
- movq (%rdi), %rsp
+ movq (%rdi), %rbp
+ movq 8(%rdi), %rsp
+ movq 16(%rdi), %rax
  pushq $CPU_EFL_ONE
  popfq
  jmp *%rax
@@ -35,8 +36,9 @@ ASM_END(tcb_context_load)
 
 ASM_ENTRY(tcb_context_load)
  movl 4(%esp), %eax
- movl 4(%eax), %ecx
- movl (%eax), %esp
+ movl (%eax), %ebp
+ movl 4(%eax), %esp
+ movl 8(%eax), %ecx
  pushl $CPU_EFL_ONE
  popfl
  jmp *%ecx
@@ -50,7 +52,6 @@ ASM_END(tcb_context_load)
 
 ASM_ENTRY(tcb_start)
  popq %rax
- xorq %rbp, %rbp
  call *%rax
 
  /* Never reached */
@@ -60,15 +61,16 @@ ASM_END(tcb_start)
 ASM_ENTRY(tcb_context_switch)
  pushfq
  pushq %rbx
- pushq %rbp
  pushq %r12
  pushq %r13
  pushq %r14
  pushq %r15
- movq %rsp, (%rdi)
- movq $1f, 8(%rdi)
- movq (%rsi), %rsp
- movq 8(%rsi), %rax
+ movq %rbp, (%rdi)
+ movq %rsp, 8(%rdi)
+ movq $1f, 16(%rdi)
+ movq (%rsi), %rbp
+ movq 8(%rsi), %rsp
+ movq 16(%rsi), %rax
  jmp *%rax
 
 1:
@@ -76,7 +78,6 @@ ASM_ENTRY(tcb_context_switch)
  popq %r14
  popq %r13
  popq %r12
- popq %rbp
  popq %rbx
  popfq
  ret
@@ -86,7 +87,6 @@ ASM_END(tcb_context_switch)
 
 ASM_ENTRY(tcb_start)
  popl %eax
- xorl %ebp, %ebp
  call *%eax
 
  /* Never reached */
@@ -98,19 +98,19 @@ ASM_ENTRY(tcb_context_switch)
  movl 8(%esp), %ecx
  pushfl
  pushl %ebx
- pushl %ebp
  pushl %edi
  pushl %esi
- movl %esp, (%eax)
- movl $1f, 4(%eax)
- movl (%ecx), %esp
- movl 4(%ecx), %edx
+ movl %ebp, (%eax)
+ movl %esp, 4(%eax)
+ movl $1f, 8(%eax)
+ movl (%ecx), %ebp
+ movl 4(%ecx), %esp
+ movl 8(%ecx), %edx
  jmp *%edx
 
 1:
  popl %esi
  popl %edi
- popl %ebp
  popl %ebx
  popfl
  ret