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/asm-offsets.h> 21 #include <asm/processor.h> 22 #include <asm/debug.h> 23 #include <asm/dis.h> 24 #include <asm/ipl.h> 25 #include <asm/unwind.h> 26 27 const char *stack_type_name(enum stack_type type) 28 { 29 switch (type) { 30 case STACK_TYPE_TASK: 31 return "task"; 32 case STACK_TYPE_IRQ: 33 return "irq"; 34 case STACK_TYPE_NODAT: 35 return "nodat"; 36 case STACK_TYPE_RESTART: 37 return "restart"; 38 default: 39 return "unknown"; 40 } 41 } 42 EXPORT_SYMBOL_GPL(stack_type_name); 43 44 static inline bool in_stack(unsigned long sp, struct stack_info *info, 45 enum stack_type type, unsigned long stack) 46 { 47 if (sp < stack || sp >= stack + THREAD_SIZE) 48 return false; 49 info->type = type; 50 info->begin = stack; 51 info->end = stack + THREAD_SIZE; 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 = (unsigned long)task_stack_page(task); 59 60 return in_stack(sp, info, STACK_TYPE_TASK, stack); 61 } 62 63 static bool in_irq_stack(unsigned long sp, struct stack_info *info) 64 { 65 unsigned long stack = get_lowcore()->async_stack - STACK_INIT_OFFSET; 66 67 return in_stack(sp, info, STACK_TYPE_IRQ, stack); 68 } 69 70 static bool in_nodat_stack(unsigned long sp, struct stack_info *info) 71 { 72 unsigned long stack = get_lowcore()->nodat_stack - STACK_INIT_OFFSET; 73 74 return in_stack(sp, info, STACK_TYPE_NODAT, stack); 75 } 76 77 static bool in_mcck_stack(unsigned long sp, struct stack_info *info) 78 { 79 unsigned long stack = get_lowcore()->mcck_stack - STACK_INIT_OFFSET; 80 81 return in_stack(sp, info, STACK_TYPE_MCCK, stack); 82 } 83 84 static bool in_restart_stack(unsigned long sp, struct stack_info *info) 85 { 86 unsigned long stack = get_lowcore()->restart_stack - STACK_INIT_OFFSET; 87 88 return in_stack(sp, info, STACK_TYPE_RESTART, stack); 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 /* Sanity check: ABI requires SP to be aligned 8 bytes. */ 98 if (sp & 0x7) 99 goto unknown; 100 101 /* Check per-task stack */ 102 if (in_task_stack(sp, task, info)) 103 goto recursion_check; 104 105 if (task != current) 106 goto unknown; 107 108 /* Check per-cpu stacks */ 109 if (!in_irq_stack(sp, info) && 110 !in_nodat_stack(sp, info) && 111 !in_restart_stack(sp, info) && 112 !in_mcck_stack(sp, info)) 113 goto unknown; 114 115 recursion_check: 116 /* 117 * Make sure we don't iterate through any given stack more than once. 118 * If it comes up a second time then there's something wrong going on: 119 * just break out and report an unknown stack type. 120 */ 121 if (*visit_mask & (1UL << info->type)) 122 goto unknown; 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 const char *loglvl) 132 { 133 struct unwind_state state; 134 135 printk("%sCall Trace:\n", loglvl); 136 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) 137 printk(state.reliable ? "%s [<%016lx>] %pSR \n" : 138 "%s([<%016lx>] %pSR)\n", 139 loglvl, state.ip, (void *) state.ip); 140 debug_show_held_locks(task ? : current); 141 } 142 143 static void show_last_breaking_event(struct pt_regs *regs) 144 { 145 printk("Last Breaking-Event-Address:\n"); 146 printk(" [<%016lx>] ", regs->last_break); 147 if (user_mode(regs)) { 148 print_vma_addr(KERN_CONT, regs->last_break); 149 pr_cont("\n"); 150 } else { 151 pr_cont("%pSR\n", (void *)regs->last_break); 152 } 153 } 154 155 void show_registers(struct pt_regs *regs) 156 { 157 struct psw_bits *psw = &psw_bits(regs->psw); 158 unsigned long pswaddr; 159 char *mode; 160 161 pswaddr = regs->psw.addr; 162 if (test_pt_regs_flag(regs, PIF_PSW_ADDR_ADJUSTED)) 163 pswaddr = __forward_psw(regs->psw, regs->int_code >> 16); 164 mode = user_mode(regs) ? "User" : "Krnl"; 165 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)pswaddr); 166 if (!user_mode(regs)) 167 pr_cont(" (%pSR)", (void *)pswaddr); 168 pr_cont("\n"); 169 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 170 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext, 171 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm); 172 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 173 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 174 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 175 printk(" %016lx %016lx %016lx %016lx\n", 176 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 177 printk(" %016lx %016lx %016lx %016lx\n", 178 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 179 printk(" %016lx %016lx %016lx %016lx\n", 180 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 181 show_code(regs); 182 } 183 184 void show_regs(struct pt_regs *regs) 185 { 186 show_regs_print_info(KERN_DEFAULT); 187 show_registers(regs); 188 /* Show stack backtrace if pt_regs is from kernel mode */ 189 if (!user_mode(regs)) 190 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT); 191 show_last_breaking_event(regs); 192 } 193 194 static DEFINE_SPINLOCK(die_lock); 195 196 void __noreturn die(struct pt_regs *regs, const char *str) 197 { 198 static int die_counter; 199 200 oops_enter(); 201 lgr_info_log(); 202 debug_stop_all(); 203 console_verbose(); 204 spin_lock_irq(&die_lock); 205 bust_spinlocks(1); 206 printk("%s: %04x ilc:%d [#%d]", str, regs->int_code & 0xffff, 207 regs->int_code >> 17, ++die_counter); 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