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         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 }