This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / s390 / kernel / stacktrace.c

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
new file mode 100644 (file)
index 0000000..d9428a0
--- /dev/null
+++ b/arch/s390/kernel/stacktrace.c
@@ -0,0 +1,89 @@
+/*
+ * 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;
+
+       sp &= PSW_ADDR_INSN;
+       orig_sp = sp;
+
+       sp = save_context_stack(trace, &trace->skip, sp,
+                               S390_lowcore.panic_stack - PAGE_SIZE,
+                               S390_lowcore.panic_stack);
+       if ((sp != orig_sp) && !trace->all_contexts)
+               return;
+       sp = save_context_stack(trace, &trace->skip, sp,
+                               S390_lowcore.async_stack - ASYNC_SIZE,
+                               S390_lowcore.async_stack);
+       if ((sp != orig_sp) && !trace->all_contexts)
+               return;
+       if (task)
+               save_context_stack(trace, &trace->skip, sp,
+                                  (unsigned long) task_stack_page(task),
+                                  (unsigned long) task_stack_page(task) + THREAD_SIZE);
+       else
+               save_context_stack(trace, &trace->skip, sp,
+                                  S390_lowcore.thread_info,
+                                  S390_lowcore.thread_info + THREAD_SIZE);
+       return;
+}