1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 */ 7 8 #include <linux/ptrace.h> 9 #include <linux/module.h> 10 #include <linux/mm.h> 11 #include <linux/fs.h> 12 #include <linux/kdev_t.h> 13 #include <linux/proc_fs.h> 14 #include <linux/file.h> 15 #include <linux/sched/mm.h> 16 #include <linux/sched/debug.h> 17 18 #include <asm/arcregs.h> 19 #include <asm/irqflags.h> 20 21 /* 22 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) 23 * -Prints 3 regs per line and a CR. 24 * -To continue, callee regs right after scratch, special handling of CR 25 */ 26 static noinline void print_reg_file(long *reg_rev, int start_num) 27 { 28 unsigned int i; 29 char buf[512]; 30 int n = 0, len = sizeof(buf); 31 32 for (i = start_num; i < start_num + 13; i++) { 33 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", 34 i, (unsigned long)*reg_rev); 35 36 if (((i + 1) % 3) == 0) 37 n += scnprintf(buf + n, len - n, "\n"); 38 39 /* because pt_regs has regs reversed: r12..r0, r25..r13 */ 40 if (is_isa_arcv2() && start_num == 0) 41 reg_rev++; 42 else 43 reg_rev--; 44 } 45 46 if (start_num != 0) 47 n += scnprintf(buf + n, len - n, "\n\n"); 48 49 /* To continue printing callee regs on same line as scratch regs */ 50 if (start_num == 0) 51 pr_info("%s", buf); 52 else 53 pr_cont("%s\n", buf); 54 } 55 56 static void show_callee_regs(struct callee_regs *cregs) 57 { 58 print_reg_file(&(cregs->r13), 13); 59 } 60 61 static void print_task_path_n_nm(struct task_struct *tsk, char *buf) 62 { 63 char *path_nm = NULL; 64 struct mm_struct *mm; 65 struct file *exe_file; 66 67 mm = get_task_mm(tsk); 68 if (!mm) 69 goto done; 70 71 exe_file = get_mm_exe_file(mm); 72 mmput(mm); 73 74 if (exe_file) { 75 path_nm = file_path(exe_file, buf, 255); 76 fput(exe_file); 77 } 78 79 done: 80 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?"); 81 } 82 83 static void show_faulting_vma(unsigned long address, char *buf) 84 { 85 struct vm_area_struct *vma; 86 char *nm = buf; 87 struct mm_struct *active_mm = current->active_mm; 88 89 /* can't use print_vma_addr() yet as it doesn't check for 90 * non-inclusive vma 91 */ 92 down_read(&active_mm->mmap_sem); 93 vma = find_vma(active_mm, address); 94 95 /* check against the find_vma( ) behaviour which returns the next VMA 96 * if the container VMA is not found 97 */ 98 if (vma && (vma->vm_start <= address)) { 99 if (vma->vm_file) { 100 nm = file_path(vma->vm_file, buf, PAGE_SIZE - 1); 101 if (IS_ERR(nm)) 102 nm = "?"; 103 } 104 pr_info(" @off 0x%lx in [%s]\n" 105 " VMA: 0x%08lx to 0x%08lx\n", 106 vma->vm_start < TASK_UNMAPPED_BASE ? 107 address : address - vma->vm_start, 108 nm, vma->vm_start, vma->vm_end); 109 } else 110 pr_info(" @No matching VMA found\n"); 111 112 up_read(&active_mm->mmap_sem); 113 } 114 115 static void show_ecr_verbose(struct pt_regs *regs) 116 { 117 unsigned int vec, cause_code; 118 unsigned long address; 119 120 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 121 122 /* For Data fault, this is data address not instruction addr */ 123 address = current->thread.fault_address; 124 125 vec = regs->ecr_vec; 126 cause_code = regs->ecr_cause; 127 128 /* For DTLB Miss or ProtV, display the memory involved too */ 129 if (vec == ECR_V_DTLB_MISS) { 130 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 131 (cause_code == 0x01) ? "Read" : 132 ((cause_code == 0x02) ? "Write" : "EX"), 133 address, regs->ret); 134 } else if (vec == ECR_V_ITLB_MISS) { 135 pr_cont("Insn could not be fetched\n"); 136 } else if (vec == ECR_V_MACH_CHK) { 137 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ? 138 "Double Fault" : "Other Fatal Err"); 139 140 } else if (vec == ECR_V_PROTV) { 141 if (cause_code == ECR_C_PROTV_INST_FETCH) 142 pr_cont("Execute from Non-exec Page\n"); 143 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 144 pr_cont("Misaligned r/w from 0x%08lx\n", address); 145 else 146 pr_cont("%s access not allowed on page\n", 147 (cause_code == 0x01) ? "Read" : 148 ((cause_code == 0x02) ? "Write" : "EX")); 149 } else if (vec == ECR_V_INSN_ERR) { 150 pr_cont("Illegal Insn\n"); 151 #ifdef CONFIG_ISA_ARCV2 152 } else if (vec == ECR_V_MEM_ERR) { 153 if (cause_code == 0x00) 154 pr_cont("Bus Error from Insn Mem\n"); 155 else if (cause_code == 0x10) 156 pr_cont("Bus Error from Data Mem\n"); 157 else 158 pr_cont("Bus Error, check PRM\n"); 159 #endif 160 } else if (vec == ECR_V_TRAP) { 161 if (regs->ecr_param == 5) 162 pr_cont("gcc generated __builtin_trap\n"); 163 } else { 164 pr_cont("Check Programmer's Manual\n"); 165 } 166 } 167 168 /************************************************************************ 169 * API called by rest of kernel 170 ***********************************************************************/ 171 172 void show_regs(struct pt_regs *regs) 173 { 174 struct task_struct *tsk = current; 175 struct callee_regs *cregs; 176 char *buf; 177 178 buf = (char *)__get_free_page(GFP_KERNEL); 179 if (!buf) 180 return; 181 182 print_task_path_n_nm(tsk, buf); 183 show_regs_print_info(KERN_INFO); 184 185 show_ecr_verbose(regs); 186 187 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 188 current->thread.fault_address, 189 (void *)regs->blink, (void *)regs->ret); 190 191 if (user_mode(regs)) 192 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 193 194 pr_info("[STAT32]: 0x%08lx", regs->status32); 195 196 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : "" 197 198 #ifdef CONFIG_ISA_ARCOMPACT 199 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n", 200 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 201 STS_BIT(regs, DE), STS_BIT(regs, AE), 202 STS_BIT(regs, A2), STS_BIT(regs, A1), 203 STS_BIT(regs, E2), STS_BIT(regs, E1)); 204 #else 205 pr_cont(" : %2s%2s%2s%2s\n", 206 STS_BIT(regs, IE), 207 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 208 STS_BIT(regs, DE), STS_BIT(regs, AE)); 209 #endif 210 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 211 regs->bta, regs->sp, regs->fp); 212 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 213 regs->lp_start, regs->lp_end, regs->lp_count); 214 215 /* print regs->r0 thru regs->r12 216 * Sequential printing was generating horrible code 217 */ 218 print_reg_file(&(regs->r0), 0); 219 220 /* If Callee regs were saved, display them too */ 221 cregs = (struct callee_regs *)current->thread.callee_reg; 222 if (cregs) 223 show_callee_regs(cregs); 224 225 free_page((unsigned long)buf); 226 } 227 228 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 229 unsigned long address) 230 { 231 current->thread.fault_address = address; 232 233 /* Show fault description */ 234 pr_info("\n%s\n", str); 235 236 /* Caller and Callee regs */ 237 show_regs(regs); 238 239 /* Show stack trace if this Fatality happened in kernel mode */ 240 if (!user_mode(regs)) 241 show_stacktrace(current, regs); 242 } 243