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 /* Check per-task stack */ 97 if (in_task_stack(sp, task, info)) 98 goto recursion_check; 99 100 if (task != current) 101 goto unknown; 102 103 /* Check per-cpu stacks */ 104 if (!in_irq_stack(sp, info) && 105 !in_nodat_stack(sp, info) && 106 !in_restart_stack(sp, info)) 107 goto unknown; 108 109 recursion_check: 110 /* 111 * Make sure we don't iterate through any given stack more than once. 112 * If it comes up a second time then there's something wrong going on: 113 * just break out and report an unknown stack type. 114 */ 115 if (*visit_mask & (1UL << info->type)) 116 goto unknown; 117 *visit_mask |= 1UL << info->type; 118 return 0; 119 unknown: 120 info->type = STACK_TYPE_UNKNOWN; 121 return -EINVAL; 122 } 123 124 void show_stack(struct task_struct *task, unsigned long *stack) 125 { 126 struct unwind_state state; 127 128 printk("Call Trace:\n"); 129 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) 130 printk(state.reliable ? " [<%016lx>] %pSR \n" : 131 "([<%016lx>] %pSR)\n", 132 state.ip, (void *) state.ip); 133 debug_show_held_locks(task ? : current); 134 } 135 136 static void show_last_breaking_event(struct pt_regs *regs) 137 { 138 printk("Last Breaking-Event-Address:\n"); 139 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 140 } 141 142 void show_registers(struct pt_regs *regs) 143 { 144 struct psw_bits *psw = &psw_bits(regs->psw); 145 char *mode; 146 147 mode = user_mode(regs) ? "User" : "Krnl"; 148 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 149 if (!user_mode(regs)) 150 pr_cont(" (%pSR)", (void *)regs->psw.addr); 151 pr_cont("\n"); 152 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 153 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext, 154 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm); 155 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 156 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 157 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 158 printk(" %016lx %016lx %016lx %016lx\n", 159 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 160 printk(" %016lx %016lx %016lx %016lx\n", 161 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 162 printk(" %016lx %016lx %016lx %016lx\n", 163 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 164 show_code(regs); 165 } 166 167 void show_regs(struct pt_regs *regs) 168 { 169 show_regs_print_info(KERN_DEFAULT); 170 show_registers(regs); 171 /* Show stack backtrace if pt_regs is from kernel mode */ 172 if (!user_mode(regs)) 173 show_stack(NULL, (unsigned long *) regs->gprs[15]); 174 show_last_breaking_event(regs); 175 } 176 177 static DEFINE_SPINLOCK(die_lock); 178 179 void die(struct pt_regs *regs, const char *str) 180 { 181 static int die_counter; 182 183 oops_enter(); 184 lgr_info_log(); 185 debug_stop_all(); 186 console_verbose(); 187 spin_lock_irq(&die_lock); 188 bust_spinlocks(1); 189 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 190 regs->int_code >> 17, ++die_counter); 191 #ifdef CONFIG_PREEMPT 192 pr_cont("PREEMPT "); 193 #endif 194 pr_cont("SMP "); 195 if (debug_pagealloc_enabled()) 196 pr_cont("DEBUG_PAGEALLOC"); 197 pr_cont("\n"); 198 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 199 print_modules(); 200 show_regs(regs); 201 bust_spinlocks(0); 202 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 203 spin_unlock_irq(&die_lock); 204 if (in_interrupt()) 205 panic("Fatal exception in interrupt"); 206 if (panic_on_oops) 207 panic("Fatal exception: panic_on_oops"); 208 oops_exit(); 209 do_exit(SIGSEGV); 210 } 211