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