1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Stack dumping functions 4 * 5 * Copyright IBM Corp. 1999, 2013 6 */ 7 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> 15 #include <linux/mm.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> 22 #include <asm/dis.h> 23 #include <asm/ipl.h> 24 #include <asm/unwind.h> 25 26 const char *stack_type_name(enum stack_type type) 27 { 28 switch (type) { 29 case STACK_TYPE_TASK: 30 return "task"; 31 case STACK_TYPE_IRQ: 32 return "irq"; 33 case STACK_TYPE_NODAT: 34 return "nodat"; 35 case STACK_TYPE_RESTART: 36 return "restart"; 37 default: 38 return "unknown"; 39 } 40 } 41 EXPORT_SYMBOL_GPL(stack_type_name); 42 43 static inline bool in_stack(unsigned long sp, struct stack_info *info, 44 enum stack_type type, unsigned long low, 45 unsigned long high) 46 { 47 if (sp < low || sp >= high) 48 return false; 49 info->type = type; 50 info->begin = low; 51 info->end = high; 52 return true; 53 } 54 55 static bool in_task_stack(unsigned long sp, struct task_struct *task, 56 struct stack_info *info) 57 { 58 unsigned long stack; 59 60 stack = (unsigned long) task_stack_page(task); 61 return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE); 62 } 63 64 static bool in_irq_stack(unsigned long sp, struct stack_info *info) 65 { 66 unsigned long frame_size, top; 67 68 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 69 top = S390_lowcore.async_stack + frame_size; 70 return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top); 71 } 72 73 static bool in_nodat_stack(unsigned long sp, struct stack_info *info) 74 { 75 unsigned long frame_size, top; 76 77 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 78 top = S390_lowcore.nodat_stack + frame_size; 79 return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top); 80 } 81 82 static bool in_restart_stack(unsigned long sp, struct stack_info *info) 83 { 84 unsigned long frame_size, top; 85 86 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 87 top = S390_lowcore.restart_stack + frame_size; 88 return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top); 89 } 90 91 int get_stack_info(unsigned long sp, struct task_struct *task, 92 struct stack_info *info, unsigned long *visit_mask) 93 { 94 if (!sp) 95 goto unknown; 96 97 /* Check per-task stack */ 98 if (in_task_stack(sp, task, info)) 99 goto recursion_check; 100 101 if (task != current) 102 goto unknown; 103 104 /* Check per-cpu stacks */ 105 if (!in_irq_stack(sp, info) && 106 !in_nodat_stack(sp, info) && 107 !in_restart_stack(sp, info)) 108 goto unknown; 109 110 recursion_check: 111 /* 112 * Make sure we don't iterate through any given stack more than once. 113 * If it comes up a second time then there's something wrong going on: 114 * just break out and report an unknown stack type. 115 */ 116 if (*visit_mask & (1UL << info->type)) 117 goto unknown; 118 *visit_mask |= 1UL << info->type; 119 return 0; 120 unknown: 121 info->type = STACK_TYPE_UNKNOWN; 122 return -EINVAL; 123 } 124 125 void show_stack(struct task_struct *task, unsigned long *stack) 126 { 127 struct unwind_state state; 128 129 printk("Call Trace:\n"); 130 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) 131 printk(state.reliable ? " [<%016lx>] %pSR \n" : 132 "([<%016lx>] %pSR)\n", 133 state.ip, (void *) state.ip); 134 debug_show_held_locks(task ? : current); 135 } 136 137 static void show_last_breaking_event(struct pt_regs *regs) 138 { 139 printk("Last Breaking-Event-Address:\n"); 140 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 141 } 142 143 void show_registers(struct pt_regs *regs) 144 { 145 struct psw_bits *psw = &psw_bits(regs->psw); 146 char *mode; 147 148 mode = user_mode(regs) ? "User" : "Krnl"; 149 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 150 if (!user_mode(regs)) 151 pr_cont(" (%pSR)", (void *)regs->psw.addr); 152 pr_cont("\n"); 153 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 154 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext, 155 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm); 156 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 157 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 158 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 159 printk(" %016lx %016lx %016lx %016lx\n", 160 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 161 printk(" %016lx %016lx %016lx %016lx\n", 162 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 163 printk(" %016lx %016lx %016lx %016lx\n", 164 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 165 show_code(regs); 166 } 167 168 void show_regs(struct pt_regs *regs) 169 { 170 show_regs_print_info(KERN_DEFAULT); 171 show_registers(regs); 172 /* Show stack backtrace if pt_regs is from kernel mode */ 173 if (!user_mode(regs)) 174 show_stack(NULL, (unsigned long *) regs->gprs[15]); 175 show_last_breaking_event(regs); 176 } 177 178 static DEFINE_SPINLOCK(die_lock); 179 180 void die(struct pt_regs *regs, const char *str) 181 { 182 static int die_counter; 183 184 oops_enter(); 185 lgr_info_log(); 186 debug_stop_all(); 187 console_verbose(); 188 spin_lock_irq(&die_lock); 189 bust_spinlocks(1); 190 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 191 regs->int_code >> 17, ++die_counter); 192 #ifdef CONFIG_PREEMPT 193 pr_cont("PREEMPT "); 194 #endif 195 pr_cont("SMP "); 196 if (debug_pagealloc_enabled()) 197 pr_cont("DEBUG_PAGEALLOC"); 198 pr_cont("\n"); 199 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 200 print_modules(); 201 show_regs(regs); 202 bust_spinlocks(0); 203 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 204 spin_unlock_irq(&die_lock); 205 if (in_interrupt()) 206 panic("Fatal exception in interrupt"); 207 if (panic_on_oops) 208 panic("Fatal exception: panic_on_oops"); 209 oops_exit(); 210 do_exit(SIGSEGV); 211 } 212