mirror of
https://github.com/torvalds/linux.git
synced 2024-12-23 11:21:33 +00:00
75e9de18f0
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>
89 lines
2.3 KiB
C
89 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;
|
|
}
|