1 // SPDX-License-Identifier: GPL-2.0
3 * Stack dumping functions
5 * Copyright IBM Corp. 1999, 2013
8 #include <linux/kallsyms.h>
9 #include <linux/hardirq.h>
10 #include <linux/kprobes.h>
11 #include <linux/utsname.h>
12 #include <linux/export.h>
13 #include <linux/kdebug.h>
14 #include <linux/ptrace.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/sched/debug.h>
19 #include <linux/sched/task_stack.h>
20 #include <asm/processor.h>
21 #include <asm/debug.h>
24 #include <asm/unwind.h>
26 const char *stack_type_name(enum stack_type type)
33 case STACK_TYPE_NODAT:
35 case STACK_TYPE_RESTART:
42 static inline bool in_stack(unsigned long sp, struct stack_info *info,
43 enum stack_type type, unsigned long low,
46 if (sp < low || sp >= high)
54 static bool in_task_stack(unsigned long sp, struct task_struct *task,
55 struct stack_info *info)
59 stack = (unsigned long) task_stack_page(task);
60 return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
63 static bool in_irq_stack(unsigned long sp, struct stack_info *info)
65 unsigned long frame_size, top;
67 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
68 top = S390_lowcore.async_stack + frame_size;
69 return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
72 static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
74 unsigned long frame_size, top;
76 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
77 top = S390_lowcore.nodat_stack + frame_size;
78 return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
81 static bool in_restart_stack(unsigned long sp, struct stack_info *info)
83 unsigned long frame_size, top;
85 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
86 top = S390_lowcore.restart_stack + frame_size;
87 return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
90 int get_stack_info(unsigned long sp, struct task_struct *task,
91 struct stack_info *info, unsigned long *visit_mask)
96 task = task ? : current;
98 /* Check per-task stack */
99 if (in_task_stack(sp, task, info))
100 goto recursion_check;
105 /* Check per-cpu stacks */
106 if (!in_irq_stack(sp, info) &&
107 !in_nodat_stack(sp, info) &&
108 !in_restart_stack(sp, info))
113 * Make sure we don't iterate through any given stack more than once.
114 * If it comes up a second time then there's something wrong going on:
115 * just break out and report an unknown stack type.
117 if (*visit_mask & (1UL << info->type)) {
118 printk_deferred_once(KERN_WARNING
119 "WARNING: stack recursion on stack type %d\n",
123 *visit_mask |= 1UL << info->type;
126 info->type = STACK_TYPE_UNKNOWN;
130 void show_stack(struct task_struct *task, unsigned long *stack)
132 struct unwind_state state;
134 printk("Call Trace:\n");
137 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
138 printk(state.reliable ? " [<%016lx>] %pSR \n" :
139 "([<%016lx>] %pSR)\n",
140 state.ip, (void *) state.ip);
141 debug_show_held_locks(task ? : current);
144 static void show_last_breaking_event(struct pt_regs *regs)
146 printk("Last Breaking-Event-Address:\n");
147 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
150 void show_registers(struct pt_regs *regs)
152 struct psw_bits *psw = &psw_bits(regs->psw);
155 mode = user_mode(regs) ? "User" : "Krnl";
156 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
157 if (!user_mode(regs))
158 pr_cont(" (%pSR)", (void *)regs->psw.addr);
160 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
161 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
162 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
163 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
164 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
165 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
166 printk(" %016lx %016lx %016lx %016lx\n",
167 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
168 printk(" %016lx %016lx %016lx %016lx\n",
169 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
170 printk(" %016lx %016lx %016lx %016lx\n",
171 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
175 void show_regs(struct pt_regs *regs)
177 show_regs_print_info(KERN_DEFAULT);
178 show_registers(regs);
179 /* Show stack backtrace if pt_regs is from kernel mode */
180 if (!user_mode(regs))
181 show_stack(NULL, (unsigned long *) regs->gprs[15]);
182 show_last_breaking_event(regs);
185 static DEFINE_SPINLOCK(die_lock);
187 void die(struct pt_regs *regs, const char *str)
189 static int die_counter;
195 spin_lock_irq(&die_lock);
197 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
198 regs->int_code >> 17, ++die_counter);
199 #ifdef CONFIG_PREEMPT
203 if (debug_pagealloc_enabled())
204 pr_cont("DEBUG_PAGEALLOC");
206 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
210 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
211 spin_unlock_irq(&die_lock);
213 panic("Fatal exception in interrupt");
215 panic("Fatal exception: panic_on_oops");