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 stack) 45 { 46 if (sp < stack || sp >= stack + THREAD_SIZE) 47 return false; 48 info->type = type; 49 info->begin = stack; 50 info->end = stack + THREAD_SIZE; 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 = (unsigned long)task_stack_page(task); 58 59 return in_stack(sp, info, STACK_TYPE_TASK, stack); 60 } 61 62 static bool in_irq_stack(unsigned long sp, struct stack_info *info) 63 { 64 unsigned long stack = get_lowcore()->async_stack - STACK_INIT_OFFSET; 65 66 return in_stack(sp, info, STACK_TYPE_IRQ, stack); 67 } 68 69 static bool in_nodat_stack(unsigned long sp, struct stack_info *info) 70 { 71 unsigned long stack = get_lowcore()->nodat_stack - STACK_INIT_OFFSET; 72 73 return in_stack(sp, info, STACK_TYPE_NODAT, stack); 74 } 75 76 static bool in_mcck_stack(unsigned long sp, struct stack_info *info) 77 { 78 unsigned long stack = get_lowcore()->mcck_stack - STACK_INIT_OFFSET; 79 80 return in_stack(sp, info, STACK_TYPE_MCCK, stack); 81 } 82 83 static bool in_restart_stack(unsigned long sp, struct stack_info *info) 84 { 85 unsigned long stack = get_lowcore()->restart_stack - STACK_INIT_OFFSET; 86 87 return in_stack(sp, info, STACK_TYPE_RESTART, stack); 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 /* Sanity check: ABI requires SP to be aligned 8 bytes. */ 97 if (sp & 0x7) 98 goto unknown; 99 100 /* Check per-task stack */ 101 if (in_task_stack(sp, task, info)) 102 goto recursion_check; 103 104 if (task != current) 105 goto unknown; 106 107 /* Check per-cpu stacks */ 108 if (!in_irq_stack(sp, info) && 109 !in_nodat_stack(sp, info) && 110 !in_restart_stack(sp, info) && 111 !in_mcck_stack(sp, info)) 112 goto unknown; 113 114 recursion_check: 115 /* 116 * Make sure we don't iterate through any given stack more than once. 117 * If it comes up a second time then there's something wrong going on: 118 * just break out and report an unknown stack type. 119 */ 120 if (*visit_mask & (1UL << info->type)) 121 goto unknown; 122 *visit_mask |= 1UL << info->type; 123 return 0; 124 unknown: 125 info->type = STACK_TYPE_UNKNOWN; 126 return -EINVAL; 127 } 128 129 void show_stack(struct task_struct *task, unsigned long *stack, 130 const char *loglvl) 131 { 132 struct unwind_state state; 133 134 printk("%sCall Trace:\n", loglvl); 135 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) 136 printk(state.reliable ? "%s [<%016lx>] %pSR \n" : 137 "%s([<%016lx>] %pSR)\n", 138 loglvl, state.ip, (void *) state.ip); 139 debug_show_held_locks(task ? : current); 140 } 141 142 static void show_last_breaking_event(struct pt_regs *regs) 143 { 144 printk("Last Breaking-Event-Address:\n"); 145 printk(" [<%016lx>] ", regs->last_break); 146 if (user_mode(regs)) { 147 print_vma_addr(KERN_CONT, regs->last_break); 148 pr_cont("\n"); 149 } else { 150 pr_cont("%pSR\n", (void *)regs->last_break); 151 } 152 } 153 154 void show_registers(struct pt_regs *regs) 155 { 156 struct psw_bits *psw = &psw_bits(regs->psw); 157 char *mode; 158 159 mode = user_mode(regs) ? "User" : "Krnl"; 160 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 161 if (!user_mode(regs)) 162 pr_cont(" (%pSR)", (void *)regs->psw.addr); 163 pr_cont("\n"); 164 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 165 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext, 166 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm); 167 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 168 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 169 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 170 printk(" %016lx %016lx %016lx %016lx\n", 171 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 172 printk(" %016lx %016lx %016lx %016lx\n", 173 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 174 printk(" %016lx %016lx %016lx %016lx\n", 175 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 176 show_code(regs); 177 } 178 179 void show_regs(struct pt_regs *regs) 180 { 181 show_regs_print_info(KERN_DEFAULT); 182 show_registers(regs); 183 /* Show stack backtrace if pt_regs is from kernel mode */ 184 if (!user_mode(regs)) 185 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT); 186 show_last_breaking_event(regs); 187 } 188 189 static DEFINE_SPINLOCK(die_lock); 190 191 void __noreturn die(struct pt_regs *regs, const char *str) 192 { 193 static int die_counter; 194 195 oops_enter(); 196 lgr_info_log(); 197 debug_stop_all(); 198 console_verbose(); 199 spin_lock_irq(&die_lock); 200 bust_spinlocks(1); 201 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 202 regs->int_code >> 17, ++die_counter); 203 #ifdef CONFIG_PREEMPT 204 pr_cont("PREEMPT "); 205 #elif defined(CONFIG_PREEMPT_RT) 206 pr_cont("PREEMPT_RT "); 207 #endif 208 pr_cont("SMP "); 209 if (debug_pagealloc_enabled()) 210 pr_cont("DEBUG_PAGEALLOC"); 211 pr_cont("\n"); 212 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 213 print_modules(); 214 show_regs(regs); 215 bust_spinlocks(0); 216 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 217 spin_unlock_irq(&die_lock); 218 if (in_interrupt()) 219 panic("Fatal exception in interrupt"); 220 if (panic_on_oops) 221 panic("Fatal exception: panic_on_oops"); 222 oops_exit(); 223 make_task_dead(SIGSEGV); 224 } 225