kernel-fxtec-pro1x/arch/s390/kernel/stacktrace.c
Christian Borntraeger 75e9de18f0 [S390] stacktrace bug.
The latest kernel 2.6.19-rc1 triggers a bug in the s390 specific stack
trace code when compiled with gcc 3.4.
This patch fixes the latest lock dependency validator code (2.6.19-rc1)
on s390 gcc 3.4. The variable sp was fixed to r15 (which is the stack
pointer in the s390 abi) and assigned new values to r15. Therefore,
gcc 3.4 assigns a new value to r15 and does not restore it on exit (r15
is supposed to be call save) - the kernel stack is broken. Avoid trouble
by not assigning any new value to sp (r15).

Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-10-11 15:31:52 +02:00

88 lines
2.3 KiB
C

/*
* arch/s390/kernel/stacktrace.c
*
* Stack trace management functions
*
* Copyright (C) IBM Corp. 2006
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/kallsyms.h>
static inline unsigned long save_context_stack(struct stack_trace *trace,
unsigned int *skip,
unsigned long sp,
unsigned long low,
unsigned long high)
{
struct stack_frame *sf;
struct pt_regs *regs;
unsigned long addr;
while(1) {
sp &= PSW_ADDR_INSN;
if (sp < low || sp > high)
return sp;
sf = (struct stack_frame *)sp;
while(1) {
addr = sf->gprs[8] & PSW_ADDR_INSN;
if (!(*skip))
trace->entries[trace->nr_entries++] = addr;
else
(*skip)--;
if (trace->nr_entries >= trace->max_entries)
return sp;
low = sp;
sp = sf->back_chain & PSW_ADDR_INSN;
if (!sp)
break;
if (sp <= low || sp > high - sizeof(*sf))
return sp;
sf = (struct stack_frame *)sp;
}
/* Zero backchain detected, check for interrupt frame. */
sp = (unsigned long)(sf + 1);
if (sp <= low || sp > high - sizeof(*regs))
return sp;
regs = (struct pt_regs *)sp;
addr = regs->psw.addr & PSW_ADDR_INSN;
if (!(*skip))
trace->entries[trace->nr_entries++] = addr;
else
(*skip)--;
if (trace->nr_entries >= trace->max_entries)
return sp;
low = sp;
sp = regs->gprs[15];
}
}
void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
{
register unsigned long sp asm ("15");
unsigned long orig_sp, new_sp;
orig_sp = sp & PSW_ADDR_INSN;
new_sp = save_context_stack(trace, &trace->skip, orig_sp,
S390_lowcore.panic_stack - PAGE_SIZE,
S390_lowcore.panic_stack);
if ((new_sp != orig_sp) && !trace->all_contexts)
return;
new_sp = save_context_stack(trace, &trace->skip, new_sp,
S390_lowcore.async_stack - ASYNC_SIZE,
S390_lowcore.async_stack);
if ((new_sp != orig_sp) && !trace->all_contexts)
return;
if (task)
save_context_stack(trace, &trace->skip, new_sp,
(unsigned long) task_stack_page(task),
(unsigned long) task_stack_page(task) + THREAD_SIZE);
else
save_context_stack(trace, &trace->skip, new_sp,
S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE);
return;
}