kernel_optimize_test/arch/um/kernel/stacktrace.c
Daniel Walter 970e51fead um: Add support for CONFIG_STACKTRACE
Add stacktrace support for User Mode Linux

Signed-off-by: Daniel Walter <dwalter@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2014-10-13 21:46:25 +02:00

81 lines
2.0 KiB
C

/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright (C) 2013 Richard Weinberger <richard@nod.at>
* Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kallsyms.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/stacktrace.h>
void dump_trace(struct task_struct *tsk,
const struct stacktrace_ops *ops,
void *data)
{
int reliable = 0;
unsigned long *sp, bp, addr;
struct pt_regs *segv_regs = tsk->thread.segv_regs;
struct stack_frame *frame;
bp = get_frame_pointer(tsk, segv_regs);
sp = get_stack_pointer(tsk, segv_regs);
frame = (struct stack_frame *)bp;
while (((long) sp & (THREAD_SIZE-1)) != 0) {
addr = *sp;
if (__kernel_text_address(addr)) {
reliable = 0;
if ((unsigned long) sp == bp + sizeof(long)) {
frame = frame ? frame->next_frame : NULL;
bp = (unsigned long)frame;
reliable = 1;
}
ops->address(data, addr, reliable);
}
sp++;
}
}
static void save_addr(void *data, unsigned long address, int reliable)
{
struct stack_trace *trace = data;
if (!reliable)
return;
if (trace->nr_entries >= trace->max_entries)
return;
trace->entries[trace->nr_entries++] = address;
}
static const struct stacktrace_ops dump_ops = {
.address = save_addr
};
static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace)
{
dump_trace(tsk, &dump_ops, trace);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace(struct stack_trace *trace)
{
__save_stack_trace(current, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
__save_stack_trace(tsk, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);