linux-stable/arch/h8300/kernel/traps.c
Tejun Heo 196779b9b4 dump_stack: consolidate dump_stack() implementations and unify their behaviors
Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00

166 lines
3.9 KiB
C

/*
* linux/arch/h8300/boot/traps.c -- general exception handling code
* H8/300 support Yoshinori Sato <ysato@users.sourceforge.jp>
*
* Cloned from Linux/m68k.
*
* No original Copyright holder listed,
* Probable original (C) Roman Zippel (assigned DJD, 1999)
*
* Copyright 1999-2000 D. Jeff Dionne, <jeff@rt-control.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/bug.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/page.h>
static DEFINE_SPINLOCK(die_lock);
/*
* this must be called very early as the kernel might
* use some instruction that are emulated on the 060
*/
void __init base_trap_init(void)
{
}
void __init trap_init (void)
{
}
asmlinkage void set_esp0 (unsigned long ssp)
{
current->thread.esp0 = ssp;
}
/*
* Generic dumping code. Used for panic and debug.
*/
static void dump(struct pt_regs *fp)
{
unsigned long *sp;
unsigned char *tp;
int i;
printk("\nCURRENT PROCESS:\n\n");
printk("COMM=%s PID=%d\n", current->comm, current->pid);
if (current->mm) {
printk("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
(int) current->mm->start_code,
(int) current->mm->end_code,
(int) current->mm->start_data,
(int) current->mm->end_data,
(int) current->mm->end_data,
(int) current->mm->brk);
printk("USER-STACK=%08x KERNEL-STACK=%08lx\n\n",
(int) current->mm->start_stack,
(int) PAGE_SIZE+(unsigned long)current);
}
show_regs(fp);
printk("\nCODE:");
tp = ((unsigned char *) fp->pc) - 0x20;
for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) {
if ((i % 0x10) == 0)
printk("\n%08x: ", (int) (tp + i));
printk("%08x ", (int) *sp++);
}
printk("\n");
printk("\nKERNEL STACK:");
tp = ((unsigned char *) fp) - 0x40;
for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
if ((i % 0x10) == 0)
printk("\n%08x: ", (int) (tp + i));
printk("%08x ", (int) *sp++);
}
printk("\n");
if (STACK_MAGIC != *(unsigned long *)((unsigned long)current+PAGE_SIZE))
printk("(Possibly corrupted stack page??)\n");
printk("\n\n");
}
void die(const char *str, struct pt_regs *fp, unsigned long err)
{
static int diecount;
oops_enter();
console_verbose();
spin_lock_irq(&die_lock);
report_bug(fp->pc, fp);
printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++diecount);
dump(fp);
spin_unlock_irq(&die_lock);
do_exit(SIGSEGV);
}
extern char _start, _etext;
#define check_kernel_text(addr) \
((addr >= (unsigned long)(&_start)) && \
(addr < (unsigned long)(&_etext)))
static int kstack_depth_to_print = 24;
void show_stack(struct task_struct *task, unsigned long *esp)
{
unsigned long *stack, addr;
int i;
if (esp == NULL)
esp = (unsigned long *) &esp;
stack = esp;
printk("Stack from %08lx:", (unsigned long)stack);
for (i = 0; i < kstack_depth_to_print; i++) {
if (((unsigned long)stack & (THREAD_SIZE - 1)) == 0)
break;
if (i % 8 == 0)
printk("\n ");
printk(" %08lx", *stack++);
}
printk("\nCall Trace:");
i = 0;
stack = esp;
while (((unsigned long)stack & (THREAD_SIZE - 1)) != 0) {
addr = *stack++;
/*
* If the address is either in the text segment of the
* kernel, or in the region which contains vmalloc'ed
* memory, it *may* be the address of a calling
* routine; if so, print it so that someone tracing
* down the cause of the crash will be able to figure
* out the call path that was taken.
*/
if (check_kernel_text(addr)) {
if (i % 4 == 0)
printk("\n ");
printk(" [<%08lx>]", addr);
i++;
}
}
printk("\n");
}
void show_trace_task(struct task_struct *tsk)
{
show_stack(tsk,(unsigned long *)tsk->thread.esp0);
}