arch/arc/kernel/troubleshoot.c

   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/fs_struct.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/file.h>
  16 #include <linux/sched/mm.h>
  17 #include <linux/sched/debug.h>
  18
  19 #include <asm/arcregs.h>
  20 #include <asm/irqflags.h>
  21
  22 /*
  23  * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
  24  *   -Prints 3 regs per line and a CR.
  25  *   -To continue, callee regs right after scratch, special handling of CR
  26  */
  27 static noinline void print_reg_file(long *reg_rev, int start_num)
  28 {
  29         unsigned int i;
  30         char buf[512];
  31         int n = 0, len = sizeof(buf);
  32
  33         for (i = start_num; i < start_num + 13; i++) {
  34                 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
  35                                i, (unsigned long)*reg_rev);
  36
  37                 if (((i + 1) % 3) == 0)
  38                         n += scnprintf(buf + n, len - n, "\n");
  39
  40                 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
  41                 if (is_isa_arcv2() && start_num == 0)
  42                         reg_rev++;
  43                 else
  44                         reg_rev--;
  45         }
  46
  47         if (start_num != 0)
  48                 n += scnprintf(buf + n, len - n, "\n\n");
  49
  50         /* To continue printing callee regs on same line as scratch regs */
  51         if (start_num == 0)
  52                 pr_info("%s", buf);
  53         else
  54                 pr_cont("%s\n", buf);
  55 }
  56
  57 static void show_callee_regs(struct callee_regs *cregs)
  58 {
  59         print_reg_file(&(cregs->r13), 13);
  60 }
  61
  62 static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
  63 {
  64         char *path_nm = NULL;
  65         struct mm_struct *mm;
  66         struct file *exe_file;
  67
  68         mm = get_task_mm(tsk);
  69         if (!mm)
  70                 goto done;
  71
  72         exe_file = get_mm_exe_file(mm);
  73         mmput(mm);
  74
  75         if (exe_file) {
  76                 path_nm = file_path(exe_file, buf, 255);
  77                 fput(exe_file);
  78         }
  79
  80 done:
  81         pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
  82 }
  83
  84 static void show_faulting_vma(unsigned long address, char *buf)
  85 {
  86         struct vm_area_struct *vma;
  87         struct inode *inode;
  88         unsigned long ino = 0;
  89         dev_t dev = 0;
  90         char *nm = buf;
  91         struct mm_struct *active_mm = current->active_mm;
  92
  93         /* can't use print_vma_addr() yet as it doesn't check for
  94          * non-inclusive vma
  95          */
  96         down_read(&active_mm->mmap_sem);
  97         vma = find_vma(active_mm, address);
  98
  99         /* check against the find_vma( ) behaviour which returns the next VMA
 100          * if the container VMA is not found
 101          */
 102         if (vma && (vma->vm_start <= address)) {
 103                 struct file *file = vma->vm_file;
 104                 if (file) {
 105                         nm = file_path(file, buf, PAGE_SIZE - 1);
 106                         inode = file_inode(vma->vm_file);
 107                         dev = inode->i_sb->s_dev;
 108                         ino = inode->i_ino;
 109                 }
 110                 pr_info("    @off 0x%lx in [%s]\n"
 111                         "    VMA: 0x%08lx to 0x%08lx\n",
 112                         vma->vm_start < TASK_UNMAPPED_BASE ?
 113                                 address : address - vma->vm_start,
 114                         nm, vma->vm_start, vma->vm_end);
 115         } else
 116                 pr_info("    @No matching VMA found\n");
 117
 118         up_read(&active_mm->mmap_sem);
 119 }
 120
 121 static void show_ecr_verbose(struct pt_regs *regs)
 122 {
 123         unsigned int vec, cause_code;
 124         unsigned long address;
 125
 126         pr_info("\n[ECR   ]: 0x%08lx => ", regs->event);
 127
 128         /* For Data fault, this is data address not instruction addr */
 129         address = current->thread.fault_address;
 130
 131         vec = regs->ecr_vec;
 132         cause_code = regs->ecr_cause;
 133
 134         /* For DTLB Miss or ProtV, display the memory involved too */
 135         if (vec == ECR_V_DTLB_MISS) {
 136                 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
 137                        (cause_code == 0x01) ? "Read" :
 138                        ((cause_code == 0x02) ? "Write" : "EX"),
 139                        address, regs->ret);
 140         } else if (vec == ECR_V_ITLB_MISS) {
 141                 pr_cont("Insn could not be fetched\n");
 142         } else if (vec == ECR_V_MACH_CHK) {
 143                 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
 144                                         "Double Fault" : "Other Fatal Err");
 145
 146         } else if (vec == ECR_V_PROTV) {
 147                 if (cause_code == ECR_C_PROTV_INST_FETCH)
 148                         pr_cont("Execute from Non-exec Page\n");
 149                 else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
 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 #endif
 166         } else if (vec == ECR_V_TRAP) {
 167                 if (regs->ecr_param == 5)
 168                         pr_cont("gcc generated __builtin_trap\n");
 169         } else {
 170                 pr_cont("Check Programmer's Manual\n");
 171         }
 172 }
 173
 174 /************************************************************************
 175  *  API called by rest of kernel
 176  ***********************************************************************/
 177
 178 void show_regs(struct pt_regs *regs)
 179 {
 180         struct task_struct *tsk = current;
 181         struct callee_regs *cregs;
 182         char *buf;
 183
 184         buf = (char *)__get_free_page(GFP_KERNEL);
 185         if (!buf)
 186                 return;
 187
 188         print_task_path_n_nm(tsk, buf);
 189         show_regs_print_info(KERN_INFO);
 190
 191         show_ecr_verbose(regs);
 192
 193         pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
 194                 current->thread.fault_address,
 195                 (void *)regs->blink, (void *)regs->ret);
 196
 197         if (user_mode(regs))
 198                 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
 199
 200         pr_info("[STAT32]: 0x%08lx", regs->status32);
 201
 202 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
 203
 204 #ifdef CONFIG_ISA_ARCOMPACT
 205         pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
 206                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 207                         STS_BIT(regs, DE), STS_BIT(regs, AE),
 208                         STS_BIT(regs, A2), STS_BIT(regs, A1),
 209                         STS_BIT(regs, E2), STS_BIT(regs, E1));
 210 #else
 211         pr_cont(" : %2s%2s%2s%2s\n",
 212                         STS_BIT(regs, IE),
 213                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 214                         STS_BIT(regs, DE), STS_BIT(regs, AE));
 215 #endif
 216         pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
 217                 regs->bta, regs->sp, regs->fp);
 218         pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
 219                regs->lp_start, regs->lp_end, regs->lp_count);
 220
 221         /* print regs->r0 thru regs->r12
 222          * Sequential printing was generating horrible code
 223          */
 224         print_reg_file(&(regs->r0), 0);
 225
 226         /* If Callee regs were saved, display them too */
 227         cregs = (struct callee_regs *)current->thread.callee_reg;
 228         if (cregs)
 229                 show_callee_regs(cregs);
 230
 231         free_page((unsigned long)buf);
 232 }
 233
 234 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
 235                             unsigned long address)
 236 {
 237         current->thread.fault_address = address;
 238
 239         /* Show fault description */
 240         pr_info("\n%s\n", str);
 241
 242         /* Caller and Callee regs */
 243         show_regs(regs);
 244
 245         /* Show stack trace if this Fatality happened in kernel mode */
 246         if (!user_mode(regs))
 247                 show_stacktrace(current, regs);
 248 }