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 42 static inline bool in_stack(unsigned long sp, struct stack_info *info, 43 enum stack_type type, unsigned long low, 44 unsigned long high) 45 { 46 if (sp < low || sp >= high) 47 return false; 48 info->type = type; 49 info->begin = low; 50 info->end = high; 51 return true; 52 } 53 54 static bool in_task_stack(unsigned long sp, struct task_struct *task, 55 struct stack_info *info) 56 { 57 unsigned long stack; 58 59 stack = (unsigned long) task_stack_page(task); 60 return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE); 61 } 62 63 static bool in_irq_stack(unsigned long sp, struct stack_info *info) 64 { 65 unsigned long frame_size, top; 66 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); 70 } 71 72 static bool in_nodat_stack(unsigned long sp, struct stack_info *info) 73 { 74 unsigned long frame_size, top; 75 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); 79 } 80 81 static bool in_restart_stack(unsigned long sp, struct stack_info *info) 82 { 83 unsigned long frame_size, top; 84 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); 88 } 89 90 int get_stack_info(unsigned long sp, struct task_struct *task, 91 struct stack_info *info, unsigned long *visit_mask) 92 { 93 if (!sp) 94 goto unknown; 95 96 task = task ? : current; 97 98 /* Check per-task stack */ 99 if (in_task_stack(sp, task, info)) 100 goto recursion_check; 101 102 if (task != current) 103 goto unknown; 104 105 /* Check per-cpu stacks */ 106 if (!in_irq_stack(sp, info) && 107 !in_nodat_stack(sp, info) && 108 !in_restart_stack(sp, info)) 109 goto unknown; 110 111 recursion_check: 112 /* 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. 116 */ 117 if (*visit_mask & (1UL << info->type)) { 118 printk_deferred_once(KERN_WARNING 119 "WARNING: stack recursion on stack type %d\n", 120 info->type); 121 goto unknown; 122 } 123 *visit_mask |= 1UL << info->type; 124 return 0; 125 unknown: 126 info->type = STACK_TYPE_UNKNOWN; 127 return -EINVAL; 128 } 129 130 void show_stack(struct task_struct *task, unsigned long *stack) 131 { 132 struct unwind_state state; 133 134 printk("Call Trace:\n"); 135 if (!task) 136 task = current; 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); 142 } 143 144 static void show_last_breaking_event(struct pt_regs *regs) 145 { 146 printk("Last Breaking-Event-Address:\n"); 147 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 148 } 149 150 void show_registers(struct pt_regs *regs) 151 { 152 struct psw_bits *psw = &psw_bits(regs->psw); 153 char *mode; 154 155 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); 159 pr_cont("\n"); 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]); 172 show_code(regs); 173 } 174 175 void show_regs(struct pt_regs *regs) 176 { 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); 183 } 184 185 static DEFINE_SPINLOCK(die_lock); 186 187 void die(struct pt_regs *regs, const char *str) 188 { 189 static int die_counter; 190 191 oops_enter(); 192 lgr_info_log(); 193 debug_stop_all(); 194 console_verbose(); 195 spin_lock_irq(&die_lock); 196 bust_spinlocks(1); 197 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 198 regs->int_code >> 17, ++die_counter); 199 #ifdef CONFIG_PREEMPT 200 pr_cont("PREEMPT "); 201 #endif 202 #ifdef CONFIG_SMP 203 pr_cont("SMP "); 204 #endif 205 if (debug_pagealloc_enabled()) 206 pr_cont("DEBUG_PAGEALLOC"); 207 pr_cont("\n"); 208 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 209 print_modules(); 210 show_regs(regs); 211 bust_spinlocks(0); 212 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 213 spin_unlock_irq(&die_lock); 214 if (in_interrupt()) 215 panic("Fatal exception in interrupt"); 216 if (panic_on_oops) 217 panic("Fatal exception: panic_on_oops"); 218 oops_exit(); 219 do_exit(SIGSEGV); 220 } 221