arch/arc/kernel/troubleshoot.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   4  */
   5
   6 #include <linux/ptrace.h>
   7 #include <linux/module.h>
   8 #include <linux/mm.h>
   9 #include <linux/fs.h>
  10 #include <linux/kdev_t.h>
  11 #include <linux/proc_fs.h>
  12 #include <linux/file.h>
  13 #include <linux/sched/mm.h>
  14 #include <linux/sched/debug.h>
  15
  16 #include <asm/arcregs.h>
  17 #include <asm/irqflags.h>
  18
  19 #define ARC_PATH_MAX    256
  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)
  62 {
  63         char *path_nm = NULL;
  64         struct mm_struct *mm;
  65         struct file *exe_file;
  66         char buf[ARC_PATH_MAX];
  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, ARC_PATH_MAX-1);
  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)
  85 {
  86         struct vm_area_struct *vma;
  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                 char buf[ARC_PATH_MAX];
 100                 char *nm = "?";
 101
 102                 if (vma->vm_file) {
 103                         nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
 104                         if (IS_ERR(nm))
 105                                 nm = "?";
 106                 }
 107                 pr_info("  @off 0x%lx in [%s]  VMA: 0x%08lx to 0x%08lx\n",
 108                         vma->vm_start < TASK_UNMAPPED_BASE ?
 109                                 address : address - vma->vm_start,
 110                         nm, vma->vm_start, vma->vm_end);
 111         } else
 112                 pr_info("    @No matching VMA found\n");
 113
 114         up_read(&active_mm->mmap_sem);
 115 }
 116
 117 static void show_ecr_verbose(struct pt_regs *regs)
 118 {
 119         unsigned int vec, cause_code;
 120         unsigned long address;
 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 @ %pS\n",
 131                        (cause_code == 0x01) ? "Read" :
 132                        ((cause_code == 0x02) ? "Write" : "EX"),
 133                        address, (void *)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                          IS_ENABLED(CONFIG_ISA_ARCOMPACT))
 145                         pr_cont("Misaligned r/w from 0x%08lx\n", address);
 146                 else
 147                         pr_cont("%s access not allowed on page\n",
 148                                 (cause_code == 0x01) ? "Read" :
 149                                 ((cause_code == 0x02) ? "Write" : "EX"));
 150         } else if (vec == ECR_V_INSN_ERR) {
 151                 pr_cont("Illegal Insn\n");
 152 #ifdef CONFIG_ISA_ARCV2
 153         } else if (vec == ECR_V_MEM_ERR) {
 154                 if (cause_code == 0x00)
 155                         pr_cont("Bus Error from Insn Mem\n");
 156                 else if (cause_code == 0x10)
 157                         pr_cont("Bus Error from Data Mem\n");
 158                 else
 159                         pr_cont("Bus Error, check PRM\n");
 160         } else if (vec == ECR_V_MISALIGN) {
 161                 pr_cont("Misaligned r/w from 0x%08lx\n", address);
 162 #endif
 163         } else if (vec == ECR_V_TRAP) {
 164                 if (regs->ecr_param == 5)
 165                         pr_cont("gcc generated __builtin_trap\n");
 166         } else {
 167                 pr_cont("Check Programmer's Manual\n");
 168         }
 169 }
 170
 171 /************************************************************************
 172  *  API called by rest of kernel
 173  ***********************************************************************/
 174
 175 void show_regs(struct pt_regs *regs)
 176 {
 177         struct task_struct *tsk = current;
 178         struct callee_regs *cregs;
 179
 180         /*
 181          * generic code calls us with preemption disabled, but some calls
 182          * here could sleep, so re-enable to avoid lockdep splat
 183          */
 184         preempt_enable();
 185
 186         print_task_path_n_nm(tsk);
 187         show_regs_print_info(KERN_INFO);
 188
 189         show_ecr_verbose(regs);
 190
 191         if (user_mode(regs))
 192                 show_faulting_vma(regs->ret); /* faulting code, not data */
 193
 194         pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\nSTAT: 0x%08lx",
 195                 regs->event, current->thread.fault_address, regs->ret,
 196                 regs->status32);
 197
 198 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
 199
 200 #ifdef CONFIG_ISA_ARCOMPACT
 201         pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
 202                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 203                         STS_BIT(regs, DE), STS_BIT(regs, AE),
 204                         STS_BIT(regs, A2), STS_BIT(regs, A1),
 205                         STS_BIT(regs, E2), STS_BIT(regs, E1));
 206 #else
 207         pr_cont(" [%2s%2s%2s%2s]",
 208                         STS_BIT(regs, IE),
 209                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 210                         STS_BIT(regs, DE), STS_BIT(regs, AE));
 211 #endif
 212         pr_cont("  BTA: 0x%08lx\n  SP: 0x%08lx  FP: 0x%08lx BLK: %pS\n",
 213                 regs->bta, regs->sp, regs->fp, (void *)regs->blink);
 214         pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
 215                 regs->lp_start, regs->lp_end, regs->lp_count);
 216
 217         /* print regs->r0 thru regs->r12
 218          * Sequential printing was generating horrible code
 219          */
 220         print_reg_file(&(regs->r0), 0);
 221
 222         /* If Callee regs were saved, display them too */
 223         cregs = (struct callee_regs *)current->thread.callee_reg;
 224         if (cregs)
 225                 show_callee_regs(cregs);
 226
 227         preempt_disable();
 228 }
 229
 230 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
 231                             unsigned long address)
 232 {
 233         current->thread.fault_address = address;
 234
 235         /* Show fault description */
 236         pr_info("\n%s\n", str);
 237
 238         /* Caller and Callee regs */
 239         show_regs(regs);
 240
 241         /* Show stack trace if this Fatality happened in kernel mode */
 242         if (!user_mode(regs))
 243                 show_stacktrace(current, regs);
 244 }