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Commit 5bdc9b44 authored by Heiko Carstens's avatar Heiko Carstens Committed by Linus Torvalds
Browse files

[PATCH] lockdep: stacktrace subsystem, s390 support 



stacktrace interface for s390 as needed by lock validator.

[clg@fr.ibm.com: build fix]
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 21b32bbf

arch/s390/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -7,6 +7,10 @@ config MMU 
	bool

	default y



config STACKTRACE_SUPPORT

	bool

	default y



config RWSEM_GENERIC_SPINLOCK

	bool

arch/s390/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ obj-$(CONFIG_COMPAT) += compat_linux.o compat_signal.o \ 
obj-$(CONFIG_BINFMT_ELF32)	+= binfmt_elf32.o



obj-$(CONFIG_VIRT_TIMER)	+= vtime.o

obj-$(CONFIG_STACKTRACE)	+= stacktrace.o



# Kexec part

S390_KEXEC_OBJS := machine_kexec.o crash.o

arch/s390/kernel/stacktrace.c

0 → 100644
+90 −0
Original line number Diff line number Diff line 
/*

 * 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, int all_contexts,

		      unsigned int skip)

{

	register unsigned long sp asm ("15");

	unsigned long orig_sp;



	sp &= PSW_ADDR_INSN;

	orig_sp = sp;



	sp = save_context_stack(trace, &skip, sp,

				S390_lowcore.panic_stack - PAGE_SIZE,

				S390_lowcore.panic_stack);

	if ((sp != orig_sp) && !all_contexts)

		return;

	sp = save_context_stack(trace, &skip, sp,

				S390_lowcore.async_stack - ASYNC_SIZE,

				S390_lowcore.async_stack);

	if ((sp != orig_sp) && !all_contexts)

		return;

	if (task)

		save_context_stack(trace, &skip, sp,

				   (unsigned long) task_stack_page(task),

				   (unsigned long) task_stack_page(task) + THREAD_SIZE);

	else

		save_context_stack(trace, &skip, sp, S390_lowcore.thread_info,

				   S390_lowcore.thread_info + THREAD_SIZE);

	return;

}