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/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         struct inode *inode;
  87         unsigned long ino = 0;
  88         dev_t dev = 0;
  89         char *nm = buf;
  90         struct mm_struct *active_mm = current->active_mm;
  91
  92         /* can't use print_vma_addr() yet as it doesn't check for
  93          * non-inclusive vma
  94          */
  95         down_read(&active_mm->mmap_sem);
  96         vma = find_vma(active_mm, address);
  97
  98         /* check against the find_vma( ) behaviour which returns the next VMA
  99          * if the container VMA is not found
 100          */
 101         if (vma && (vma->vm_start <= address)) {
 102                 struct file *file = vma->vm_file;
 103                 if (file) {
 104                         nm = file_path(file, buf, PAGE_SIZE - 1);
 105                         inode = file_inode(vma->vm_file);
 106                         dev = inode->i_sb->s_dev;
 107                         ino = inode->i_ino;
 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                         pr_cont("Misaligned r/w from 0x%08lx\n", address);
 150                 else
 151                         pr_cont("%s access not allowed on page\n",
 152                                 (cause_code == 0x01) ? "Read" :
 153                                 ((cause_code == 0x02) ? "Write" : "EX"));
 154         } else if (vec == ECR_V_INSN_ERR) {
 155                 pr_cont("Illegal Insn\n");
 156 #ifdef CONFIG_ISA_ARCV2
 157         } else if (vec == ECR_V_MEM_ERR) {
 158                 if (cause_code == 0x00)
 159                         pr_cont("Bus Error from Insn Mem\n");
 160                 else if (cause_code == 0x10)
 161                         pr_cont("Bus Error from Data Mem\n");
 162                 else
 163                         pr_cont("Bus Error, check PRM\n");
 164 #endif
 165         } else if (vec == ECR_V_TRAP) {
 166                 if (regs->ecr_param == 5)
 167                         pr_cont("gcc generated __builtin_trap\n");
 168         } else {
 169                 pr_cont("Check Programmer's Manual\n");
 170         }
 171 }
 172
 173 /************************************************************************
 174  *  API called by rest of kernel
 175  ***********************************************************************/
 176
 177 void show_regs(struct pt_regs *regs)
 178 {
 179         struct task_struct *tsk = current;
 180         struct callee_regs *cregs;
 181         char *buf;
 182
 183         buf = (char *)__get_free_page(GFP_KERNEL);
 184         if (!buf)
 185                 return;
 186
 187         print_task_path_n_nm(tsk, buf);
 188         show_regs_print_info(KERN_INFO);
 189
 190         show_ecr_verbose(regs);
 191
 192         pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
 193                 current->thread.fault_address,
 194                 (void *)regs->blink, (void *)regs->ret);
 195
 196         if (user_mode(regs))
 197                 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
 198
 199         pr_info("[STAT32]: 0x%08lx", regs->status32);
 200
 201 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
 202
 203 #ifdef CONFIG_ISA_ARCOMPACT
 204         pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
 205                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 206                         STS_BIT(regs, DE), STS_BIT(regs, AE),
 207                         STS_BIT(regs, A2), STS_BIT(regs, A1),
 208                         STS_BIT(regs, E2), STS_BIT(regs, E1));
 209 #else
 210         pr_cont(" : %2s%2s%2s%2s\n",
 211                         STS_BIT(regs, IE),
 212                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 213                         STS_BIT(regs, DE), STS_BIT(regs, AE));
 214 #endif
 215         pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
 216                 regs->bta, regs->sp, regs->fp);
 217         pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
 218                regs->lp_start, regs->lp_end, regs->lp_count);
 219
 220         /* print regs->r0 thru regs->r12
 221          * Sequential printing was generating horrible code
 222          */
 223         print_reg_file(&(regs->r0), 0);
 224
 225         /* If Callee regs were saved, display them too */
 226         cregs = (struct callee_regs *)current->thread.callee_reg;
 227         if (cregs)
 228                 show_callee_regs(cregs);
 229
 230         free_page((unsigned long)buf);
 231 }
 232
 233 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
 234                             unsigned long address)
 235 {
 236         current->thread.fault_address = address;
 237
 238         /* Show fault description */
 239         pr_info("\n%s\n", str);
 240
 241         /* Caller and Callee regs */
 242         show_regs(regs);
 243
 244         /* Show stack trace if this Fatality happened in kernel mode */
 245         if (!user_mode(regs))
 246                 show_stacktrace(current, regs);
 247 }