Commit 9d1ee8ce authored by Richard Weinberger's avatar Richard Weinberger

um: Rewrite show_stack()

Currently on UML stack traces are not very reliable and both
x86 and x86_64 have their on implementations.
This patch unifies both and adds support to outline unreliable
functions calls.
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 5e01dc7b
/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
* Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
*
* 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>
......@@ -9,58 +13,75 @@
#include <linux/sched.h>
#include <asm/sysrq.h>
/* Catch non-i386 SUBARCH's. */
#if !defined(CONFIG_UML_X86) || defined(CONFIG_64BIT)
void show_trace(struct task_struct *task, unsigned long * stack)
struct stack_frame {
struct stack_frame *next_frame;
unsigned long return_address;
};
static void print_stack_trace(unsigned long *sp, unsigned long bp)
{
int reliable;
unsigned long addr;
struct stack_frame *frame = (struct stack_frame *)bp;
if (!stack) {
stack = (unsigned long*) &stack;
WARN_ON(1);
}
printk(KERN_INFO "Call Trace: \n");
while (((long) stack & (THREAD_SIZE-1)) != 0) {
addr = *stack;
printk(KERN_INFO "Call Trace:\n");
while (((long) sp & (THREAD_SIZE-1)) != 0) {
addr = *sp;
if (__kernel_text_address(addr)) {
printk(KERN_INFO "%08lx: [<%08lx>]",
(unsigned long) stack, addr);
print_symbol(KERN_CONT " %s", addr);
reliable = 0;
if ((unsigned long) sp == bp + sizeof(long)) {
frame = frame ? frame->next_frame : NULL;
bp = (unsigned long)frame;
reliable = 1;
}
printk(KERN_INFO " [<%08lx>]", addr);
printk(KERN_CONT " %s", reliable ? "" : "? ");
print_symbol(KERN_CONT "%s", addr);
printk(KERN_CONT "\n");
}
stack++;
sp++;
}
printk(KERN_INFO "\n");
}
#endif
/*Stolen from arch/i386/kernel/traps.c */
static const int kstack_depth_to_print = 24;
/* This recently started being used in arch-independent code too, as in
* kernel/sched/core.c.*/
void show_stack(struct task_struct *task, unsigned long *esp)
static unsigned long get_frame_pointer(struct task_struct *task)
{
if (!task || task == current)
return current_bp();
else
return KSTK_EBP(task);
}
void show_stack(struct task_struct *task, unsigned long *stack)
{
unsigned long *stack;
unsigned long *sp = stack, bp = 0;
int i;
if (esp == NULL) {
if (task != current && task != NULL) {
esp = (unsigned long *) KSTK_ESP(task);
} else {
esp = (unsigned long *) &esp;
}
#ifdef CONFIG_FRAME_POINTER
bp = get_frame_pointer(task);
#endif
if (!stack) {
if (!task || task == current)
sp = current_sp();
else
sp = (unsigned long *)KSTK_ESP(task);
}
stack = esp;
printk(KERN_INFO "Stack:\n");
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (kstack_end(stack))
break;
if (i && ((i % 8) == 0))
printk(KERN_INFO " ");
printk(KERN_CONT "%08lx ", *stack++);
if (i && ((i % STACKSLOTS_PER_LINE) == 0))
printk(KERN_CONT "\n");
printk(KERN_CONT " %08lx", *stack++);
}
printk(KERN_CONT "\n");
show_trace(task, esp);
print_stack_trace(sp, bp);
}
......@@ -234,7 +234,6 @@ static int panic_exit(struct notifier_block *self, unsigned long unused1,
void *unused2)
{
bust_spinlocks(1);
show_regs(&(current->thread.regs));
bust_spinlocks(0);
uml_exitcode = 1;
os_dump_core();
......
......@@ -33,6 +33,8 @@ struct arch_thread {
.faultinfo = { 0, 0, 0 } \
}
#define STACKSLOTS_PER_LINE 8
static inline void arch_flush_thread(struct arch_thread *thread)
{
/* Clear any TLS still hanging */
......@@ -53,4 +55,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
#define current_text_addr() \
({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
#define current_sp() ({ void *sp; __asm__("movl %%esp, %0" : "=r" (sp) : ); sp; })
#define current_bp() ({ unsigned long bp; __asm__("movl %%ebp, %0" : "=r" (bp) : ); bp; })
#endif
......@@ -19,6 +19,8 @@ struct arch_thread {
.fs = 0, \
.faultinfo = { 0, 0, 0 } }
#define STACKSLOTS_PER_LINE 4
static inline void arch_flush_thread(struct arch_thread *thread)
{
}
......@@ -32,4 +34,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
#define current_text_addr() \
({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })
#define current_sp() ({ void *sp; __asm__("movq %%rsp, %0" : "=r" (sp) : ); sp; })
#define current_bp() ({ unsigned long bp; __asm__("movq %%rbp, %0" : "=r" (bp) : ); bp; })
#endif
......@@ -30,70 +30,4 @@ void show_regs(struct pt_regs *regs)
printk(" DS: %04lx ES: %04lx\n",
0xffff & PT_REGS_DS(regs),
0xffff & PT_REGS_ES(regs));
show_trace(NULL, (unsigned long *) &regs);
}
/* Copied from i386. */
static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
return p > (void *)tinfo &&
p < (void *)tinfo + THREAD_SIZE - 3;
}
/* Adapted from i386 (we also print the address we read from). */
static inline unsigned long print_context_stack(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);
printk("%08lx: [<%08lx>]", ebp + 4, addr);
print_symbol(" %s", addr);
printk("\n");
ebp = *(unsigned long *)ebp;
}
#else
while (valid_stack_ptr(tinfo, stack)) {
addr = *stack;
if (__kernel_text_address(addr)) {
printk("%08lx: [<%08lx>]", (unsigned long) stack, addr);
print_symbol(" %s", addr);
printk("\n");
}
stack++;
}
#endif
return ebp;
}
void show_trace(struct task_struct* task, unsigned long * stack)
{
unsigned long ebp;
struct thread_info *context;
/* Turn this into BUG_ON if possible. */
if (!stack) {
stack = (unsigned long*) &stack;
printk("show_trace: got NULL stack, implicit assumption task == current");
WARN_ON(1);
}
if (!task)
task = current;
if (task != current) {
ebp = (unsigned long) KSTK_EBP(task);
} else {
asm ("movl %%ebp, %0" : "=r" (ebp) : );
}
context = (struct thread_info *)
((unsigned long)stack & (~(THREAD_SIZE - 1)));
print_context_stack(context, stack, ebp);
printk("\n");
}
......@@ -12,7 +12,7 @@
#include <asm/ptrace.h>
#include <asm/sysrq.h>
void __show_regs(struct pt_regs *regs)
void show_regs(struct pt_regs *regs)
{
printk("\n");
print_modules();
......@@ -33,9 +33,3 @@ void __show_regs(struct pt_regs *regs)
printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
PT_REGS_R13(regs), PT_REGS_R14(regs), PT_REGS_R15(regs));
}
void show_regs(struct pt_regs *regs)
{
__show_regs(regs);
show_trace(current, (unsigned long *) &regs);
}
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