2 * Stack trace management functions
4 * Copyright IBM Corp. 2006
5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
8 #include <linux/sched.h>
9 #include <linux/stacktrace.h>
10 #include <linux/kallsyms.h>
11 #include <linux/module.h>
13 static unsigned long save_context_stack(struct stack_trace *trace,
19 struct stack_frame *sf;
24 if (sp < low || sp > high)
26 sf = (struct stack_frame *)sp;
30 trace->entries[trace->nr_entries++] = addr;
33 if (trace->nr_entries >= trace->max_entries)
39 if (sp <= low || sp > high - sizeof(*sf))
41 sf = (struct stack_frame *)sp;
43 /* Zero backchain detected, check for interrupt frame. */
44 sp = (unsigned long)(sf + 1);
45 if (sp <= low || sp > high - sizeof(*regs))
47 regs = (struct pt_regs *)sp;
48 addr = regs->psw.addr;
49 if (savesched || !in_sched_functions(addr)) {
51 trace->entries[trace->nr_entries++] = addr;
55 if (trace->nr_entries >= trace->max_entries)
62 static void __save_stack_trace(struct stack_trace *trace, unsigned long sp)
64 unsigned long new_sp, frame_size;
66 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
67 new_sp = save_context_stack(trace, sp,
68 S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
69 S390_lowcore.panic_stack + frame_size, 1);
70 new_sp = save_context_stack(trace, new_sp,
71 S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
72 S390_lowcore.async_stack + frame_size, 1);
73 save_context_stack(trace, new_sp,
74 S390_lowcore.thread_info,
75 S390_lowcore.thread_info + THREAD_SIZE, 1);
78 void save_stack_trace(struct stack_trace *trace)
80 register unsigned long r15 asm ("15");
84 __save_stack_trace(trace, sp);
85 if (trace->nr_entries < trace->max_entries)
86 trace->entries[trace->nr_entries++] = ULONG_MAX;
88 EXPORT_SYMBOL_GPL(save_stack_trace);
90 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
92 unsigned long sp, low, high;
96 /* Get current stack pointer. */
97 asm volatile("la %0,0(15)" : "=a" (sp));
99 low = (unsigned long) task_stack_page(tsk);
100 high = (unsigned long) task_pt_regs(tsk);
101 save_context_stack(trace, sp, low, high, 0);
102 if (trace->nr_entries < trace->max_entries)
103 trace->entries[trace->nr_entries++] = ULONG_MAX;
105 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
107 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
111 sp = kernel_stack_pointer(regs);
112 __save_stack_trace(trace, sp);
113 if (trace->nr_entries < trace->max_entries)
114 trace->entries[trace->nr_entries++] = ULONG_MAX;
116 EXPORT_SYMBOL_GPL(save_stack_trace_regs);