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 #define ARC_PATH_MAX 256 22 23 /* 24 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) 25 * -Prints 3 regs per line and a CR. 26 * -To continue, callee regs right after scratch, special handling of CR 27 */ 28 static noinline void print_reg_file(long *reg_rev, int start_num) 29 { 30 unsigned int i; 31 char buf[512]; 32 int n = 0, len = sizeof(buf); 33 34 for (i = start_num; i < start_num + 13; i++) { 35 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", 36 i, (unsigned long)*reg_rev); 37 38 if (((i + 1) % 3) == 0) 39 n += scnprintf(buf + n, len - n, "\n"); 40 41 /* because pt_regs has regs reversed: r12..r0, r25..r13 */ 42 if (is_isa_arcv2() && start_num == 0) 43 reg_rev++; 44 else 45 reg_rev--; 46 } 47 48 if (start_num != 0) 49 n += scnprintf(buf + n, len - n, "\n\n"); 50 51 /* To continue printing callee regs on same line as scratch regs */ 52 if (start_num == 0) 53 pr_info("%s", buf); 54 else 55 pr_cont("%s\n", buf); 56 } 57 58 static void show_callee_regs(struct callee_regs *cregs) 59 { 60 print_reg_file(&(cregs->r13), 13); 61 } 62 63 static void print_task_path_n_nm(struct task_struct *tsk) 64 { 65 char *path_nm = NULL; 66 struct mm_struct *mm; 67 struct file *exe_file; 68 char buf[ARC_PATH_MAX]; 69 70 mm = get_task_mm(tsk); 71 if (!mm) 72 goto done; 73 74 exe_file = get_mm_exe_file(mm); 75 mmput(mm); 76 77 if (exe_file) { 78 path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1); 79 fput(exe_file); 80 } 81 82 done: 83 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?"); 84 } 85 86 static void show_faulting_vma(unsigned long address) 87 { 88 struct vm_area_struct *vma; 89 struct mm_struct *active_mm = current->active_mm; 90 91 /* can't use print_vma_addr() yet as it doesn't check for 92 * non-inclusive vma 93 */ 94 down_read(&active_mm->mmap_sem); 95 vma = find_vma(active_mm, address); 96 97 /* check against the find_vma( ) behaviour which returns the next VMA 98 * if the container VMA is not found 99 */ 100 if (vma && (vma->vm_start <= address)) { 101 char buf[ARC_PATH_MAX]; 102 char *nm = "?"; 103 104 if (vma->vm_file) { 105 nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1); 106 if (IS_ERR(nm)) 107 nm = "?"; 108 } 109 pr_info(" @off 0x%lx in [%s]\n" 110 " VMA: 0x%08lx to 0x%08lx\n", 111 vma->vm_start < TASK_UNMAPPED_BASE ? 112 address : address - vma->vm_start, 113 nm, vma->vm_start, vma->vm_end); 114 } else 115 pr_info(" @No matching VMA found\n"); 116 117 up_read(&active_mm->mmap_sem); 118 } 119 120 static void show_ecr_verbose(struct pt_regs *regs) 121 { 122 unsigned int vec, cause_code; 123 unsigned long address; 124 125 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 126 127 /* For Data fault, this is data address not instruction addr */ 128 address = current->thread.fault_address; 129 130 vec = regs->ecr_vec; 131 cause_code = regs->ecr_cause; 132 133 /* For DTLB Miss or ProtV, display the memory involved too */ 134 if (vec == ECR_V_DTLB_MISS) { 135 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 136 (cause_code == 0x01) ? "Read" : 137 ((cause_code == 0x02) ? "Write" : "EX"), 138 address, regs->ret); 139 } else if (vec == ECR_V_ITLB_MISS) { 140 pr_cont("Insn could not be fetched\n"); 141 } else if (vec == ECR_V_MACH_CHK) { 142 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ? 143 "Double Fault" : "Other Fatal Err"); 144 145 } else if (vec == ECR_V_PROTV) { 146 if (cause_code == ECR_C_PROTV_INST_FETCH) 147 pr_cont("Execute from Non-exec Page\n"); 148 else if (cause_code == ECR_C_PROTV_MISALIG_DATA && 149 IS_ENABLED(CONFIG_ISA_ARCOMPACT)) 150 pr_cont("Misaligned r/w from 0x%08lx\n", address); 151 else 152 pr_cont("%s access not allowed on page\n", 153 (cause_code == 0x01) ? "Read" : 154 ((cause_code == 0x02) ? "Write" : "EX")); 155 } else if (vec == ECR_V_INSN_ERR) { 156 pr_cont("Illegal Insn\n"); 157 #ifdef CONFIG_ISA_ARCV2 158 } else if (vec == ECR_V_MEM_ERR) { 159 if (cause_code == 0x00) 160 pr_cont("Bus Error from Insn Mem\n"); 161 else if (cause_code == 0x10) 162 pr_cont("Bus Error from Data Mem\n"); 163 else 164 pr_cont("Bus Error, check PRM\n"); 165 } else if (vec == ECR_V_MISALIGN) { 166 pr_cont("Misaligned r/w from 0x%08lx\n", address); 167 #endif 168 } else if (vec == ECR_V_TRAP) { 169 if (regs->ecr_param == 5) 170 pr_cont("gcc generated __builtin_trap\n"); 171 } else { 172 pr_cont("Check Programmer's Manual\n"); 173 } 174 } 175 176 /************************************************************************ 177 * API called by rest of kernel 178 ***********************************************************************/ 179 180 void show_regs(struct pt_regs *regs) 181 { 182 struct task_struct *tsk = current; 183 struct callee_regs *cregs; 184 185 /* 186 * generic code calls us with preemption disabled, but some calls 187 * here could sleep, so re-enable to avoid lockdep splat 188 */ 189 preempt_enable(); 190 191 print_task_path_n_nm(tsk); 192 show_regs_print_info(KERN_INFO); 193 194 show_ecr_verbose(regs); 195 196 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 197 current->thread.fault_address, 198 (void *)regs->blink, (void *)regs->ret); 199 200 if (user_mode(regs)) 201 show_faulting_vma(regs->ret); /* faulting code, not data */ 202 203 pr_info("[STAT32]: 0x%08lx", regs->status32); 204 205 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : "" 206 207 #ifdef CONFIG_ISA_ARCOMPACT 208 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n", 209 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 210 STS_BIT(regs, DE), STS_BIT(regs, AE), 211 STS_BIT(regs, A2), STS_BIT(regs, A1), 212 STS_BIT(regs, E2), STS_BIT(regs, E1)); 213 #else 214 pr_cont(" : %2s%2s%2s%2s\n", 215 STS_BIT(regs, IE), 216 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 217 STS_BIT(regs, DE), STS_BIT(regs, AE)); 218 #endif 219 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 220 regs->bta, regs->sp, regs->fp); 221 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 222 regs->lp_start, regs->lp_end, regs->lp_count); 223 224 /* print regs->r0 thru regs->r12 225 * Sequential printing was generating horrible code 226 */ 227 print_reg_file(&(regs->r0), 0); 228 229 /* If Callee regs were saved, display them too */ 230 cregs = (struct callee_regs *)current->thread.callee_reg; 231 if (cregs) 232 show_callee_regs(cregs); 233 234 preempt_disable(); 235 } 236 237 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 238 unsigned long address) 239 { 240 current->thread.fault_address = address; 241 242 /* Show fault description */ 243 pr_info("\n%s\n", str); 244 245 /* Caller and Callee regs */ 246 show_regs(regs); 247 248 /* Show stack trace if this Fatality happened in kernel mode */ 249 if (!user_mode(regs)) 250 show_stacktrace(current, regs); 251 } 252