[PATCH for review] [113/145] i386: Do stacktracer conversion too

Andi Kleen
2006-08-10T19:56:04Z

r

Following x86-64 patches. Reuses code from them in fact.

Convert the standard backtracer to do all output using
callbacks. Use the x86-64 stack tracer implementation
that uses these callbacks to implement the stacktrace interface.

This allows to use the new dwarf2 unwinder for stacktrace
and get better backtraces.

Cc: mingo@elte.hu

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/i386/kernel/Makefile | 1
arch/i386/kernel/stacktrace.c | 93 ------------------------------------
arch/i386/kernel/traps.c | 108 +++++++++++++++++++++++++++++++-----------
include/asm-i386/stacktrace.h | 1
4 files changed, 83 insertions(+), 120 deletions(-)

Index: linux/arch/i386/kernel/Makefile
===================================================================
--- linux.orig/arch/i386/kernel/Makefile
+++ linux/arch/i386/kernel/Makefile
@@ -82,4 +82,5 @@ $(obj)/vsyscall-syms.o: $(src)/vsyscall.
$(call if_changed,syscall)

k8-y += ../../x86_64/kernel/k8.o
+stacktrace-y += ../../x86_64/kernel/stacktrace.o

Index: linux/arch/i386/kernel/stacktrace.c
===================================================================
--- linux.orig/arch/i386/kernel/stacktrace.c
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * arch/i386/kernel/stacktrace.c
- *
- * Stack trace management functions
- *
- * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- */
-#include <linux/sched.h>
-#include <linux/stacktrace.h>
-
-static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
-{
- return p > (void *)tinfo &&
- p < (void *)tinfo + THREAD_SIZE - 3;
-}
-
-/*
- * Save stack-backtrace addresses into a stack_trace buffer:
- */
-static inline unsigned long
-save_context_stack(struct stack_trace *trace, unsigned int skip,
- struct thread_info *tinfo, unsigned long *stack,
- unsigned long ebp)
-{
- unsigned long addr;
-
-#ifdef CONFIG_FRAME_POINTER
- while (valid_stack_ptr(tinfo, (void *)ebp)) {
- addr = *(unsigned long *)(ebp + 4);
- if (!skip)
- trace->entries[trace->nr_entries++] = addr;
- else
- skip--;
- if (trace->nr_entries >= trace->max_entries)
- break;
- /*
- * break out of recursive entries (such as
- * end_of_stack_stop_unwind_function):
- */
- if (ebp == *(unsigned long *)ebp)
- break;
-
- ebp = *(unsigned long *)ebp;
- }
-#else
- while (valid_stack_ptr(tinfo, stack)) {
- addr = *stack++;
- if (__kernel_text_address(addr)) {
- if (!skip)
- trace->entries[trace->nr_entries++] = addr;
- else
- skip--;
- if (trace->nr_entries >= trace->max_entries)
- break;
- }
- }
-#endif
-
- return ebp;
-}
-
-/*
- * Save stack-backtrace addresses into a stack_trace buffer.
- */
-void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
-{
- unsigned long ebp;
- unsigned long *stack = &ebp;
-
- WARN_ON(trace->nr_entries || !trace->max_entries);
-
- if (!task || task == current) {
- /* Grab ebp right from our regs: */
- asm ("movl %%ebp, %0" : "=r" (ebp));
- } else {
- /* ebp is the last reg pushed by switch_to(): */
- ebp = *(unsigned long *) task->thread.esp;
- }
-
- while (1) {
- struct thread_info *context = (struct thread_info *)
- ((unsigned long)stack & (~(THREAD_SIZE - 1)));
-
- ebp = save_context_stack(trace, trace->skip, context, stack, ebp);
- stack = (unsigned long *)context->previous_esp;
- if (!stack || trace->nr_entries >= trace->max_entries)
- break;
- trace->entries[trace->nr_entries++] = ULONG_MAX;
- if (trace->nr_entries >= trace->max_entries)
- break;
- }
-}
-
Index: linux/arch/i386/kernel/traps.c
===================================================================
--- linux.orig/arch/i386/kernel/traps.c
+++ linux/arch/i386/kernel/traps.c
@@ -51,6 +51,7 @@
#include <asm/smp.h>
#include <asm/arch_hooks.h>
#include <asm/kdebug.h>
+#include <asm/stacktrace.h>

#include <linux/module.h>

@@ -114,26 +115,16 @@ static inline int valid_stack_ptr(struct
p < (void *)tinfo + THREAD_SIZE - 3;
}

-/*
- * Print one address/symbol entries per line.
- */
-static inline void print_addr_and_symbol(unsigned long addr, char *log_lvl)
-{
- printk(" [<%08lx>] ", addr);
-
- print_symbol("%s\n", addr);
-}
-
static inline unsigned long print_context_stack(struct thread_info *tinfo,
unsigned long *stack, unsigned long ebp,
- char *log_lvl)
+ struct stacktrace_ops *ops, void *data)
{
unsigned long addr;

#ifdef CONFIG_FRAME_POINTER
while (valid_stack_ptr(tinfo, (void *)ebp)) {
addr = *(unsigned long *)(ebp + 4);
- print_addr_and_symbol(addr, log_lvl);
+ ops->address(data, addr);
/*
* break out of recursive entries (such as
* end_of_stack_stop_unwind_function):
@@ -146,28 +137,35 @@ static inline unsigned long print_contex
while (valid_stack_ptr(tinfo, stack)) {
addr = *stack++;
if (__kernel_text_address(addr))
- print_addr_and_symbol(addr, log_lvl);
+ ops->address(data, addr);
}
#endif
return ebp;
}

+struct ops_and_data {
+ struct stacktrace_ops *ops;
+ void *data;
+};
+
static asmlinkage int
-show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
+dump_trace_unwind(struct unwind_frame_info *info, void *data)
{
+ struct ops_and_data *oad = (struct ops_and_data *)data;
int n = 0;

while (unwind(info) == 0 && UNW_PC(info)) {
n++;
- print_addr_and_symbol(UNW_PC(info), log_lvl);
+ oad->ops->address(oad->data, UNW_PC(info));
if (arch_unw_user_mode(info))
break;
}
return n;
}

-static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, char *log_lvl)
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *stack,
+ struct stacktrace_ops *ops, void *data)
{
unsigned long ebp;

@@ -177,34 +175,42 @@ static void show_trace_log_lvl(struct ta
if (call_trace >= 0) {
int unw_ret = 0;
struct unwind_frame_info info;
+ struct ops_and_data oad = { .ops = ops, .data = data };

if (regs) {
if (unwind_init_frame_info(&info, task, regs) == 0)
- unw_ret = show_trace_unwind(&info, log_lvl);
+ unw_ret = dump_trace_unwind(&info, &oad);
} else if (task == current)
- unw_ret = unwind_init_running(&info, show_trace_unwind, log_lvl);
+ unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
else {
if (unwind_init_blocked(&info, task) == 0)
- unw_ret = show_trace_unwind(&info, log_lvl);
+ unw_ret = dump_trace_unwind(&info, &oad);
}
if (unw_ret > 0 && !arch_unw_user_mode(&info)) {
#ifdef CONFIG_STACK_UNWIND
- print_symbol("DWARF2 unwinder stuck at %s\n",
+ ops->warning_symbol(data, "DWARF2 unwinder stuck at %s",
UNW_PC(&info));
if (call_trace == 1) {
- printk("Leftover inexact backtrace:\n");
+ ops->warning(data, "Leftover inexact backtrace:");
if (UNW_SP(&info))
stack = (void *)UNW_SP(&info);
} else if (call_trace > 1)
return;
else
- printk("Full inexact backtrace again:\n");
+ ops->warning(data, "Full inexact backtrace again:");
#else
- printk("Inexact backtrace:\n");
+ ops->warning(data, "Inexact backtrace:");
#endif
}
}

+ if (!stack) {
+ unsigned long dummy;
+ stack = &dummy;
+ if (task && task != current)
+ stack = (unsigned long *)task->thread.esp;
+ }
+
if (task == current) {
/* Grab ebp right from our regs */
asm ("movl %%ebp, %0" : "=r" (ebp) : );
@@ -217,15 +223,63 @@ static void show_trace_log_lvl(struct ta
struct thread_info *context;
context = (struct thread_info *)
((unsigned long)stack & (~(THREAD_SIZE - 1)));
- ebp = print_context_stack(context, stack, ebp, log_lvl);
+ ebp = print_context_stack(context, stack, ebp, ops, data);
+ /* Should be after the line below, but somewhere
+ in early boot context comes out corrupted and we
+ can't reference it -AK */
+ if (ops->stack(data, "IRQ") < 0)
+ break;
stack = (unsigned long*)context->previous_esp;
if (!stack)
break;
- printk("%s =======================\n", log_lvl);
}
}
+EXPORT_SYMBOL(dump_trace);
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+ printk(data);
+ print_symbol(msg, symbol);
+ printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+ printk("%s%s\n", (char *)data, msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+ return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr)
+{
+ printk("%s [<%08lx>] ", (char *)data, addr);
+ print_symbol("%s\n", addr);
+}
+
+static struct stacktrace_ops print_trace_ops = {
+ .warning = print_trace_warning,
+ .warning_symbol = print_trace_warning_symbol,
+ .stack = print_trace_stack,
+ .address = print_trace_address,
+};
+
+static void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long * stack, char *log_lvl)
+{
+ dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
+ printk("%s =======================\n", log_lvl);
+}

-void show_trace(struct task_struct *task, struct pt_regs *regs, unsigned long * stack)
+void show_trace(struct task_struct *task, struct pt_regs *regs,
+ unsigned long * stack)
{
show_trace_log_lvl(task, regs, stack, "");
}
Index: linux/include/asm-i386/stacktrace.h
===================================================================
--- /dev/null
+++ linux/include/asm-i386/stacktrace.h
@@ -0,0 +1 @@
+#include <asm-x86_64/stacktrace.h>