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 static noinline void print_regs_scratch(struct pt_regs *regs)
  22 {
  23         pr_cont("BTA: 0x%08lx\n SP: 0x%08lx  FP: 0x%08lx BLK: %pS\n",
  24                 regs->bta, regs->sp, regs->fp, (void *)regs->blink);
  25         pr_cont("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
  26                 regs->lp_start, regs->lp_end, regs->lp_count);
  27
  28         pr_info("r00: 0x%08lx\tr01: 0x%08lx\tr02: 0x%08lx\n"    \
  29                 "r03: 0x%08lx\tr04: 0x%08lx\tr05: 0x%08lx\n"    \
  30                 "r06: 0x%08lx\tr07: 0x%08lx\tr08: 0x%08lx\n"    \
  31                 "r09: 0x%08lx\tr10: 0x%08lx\tr11: 0x%08lx\n"    \
  32                 "r12: 0x%08lx\t",
  33                 regs->r0, regs->r1, regs->r2,
  34                 regs->r3, regs->r4, regs->r5,
  35                 regs->r6, regs->r7, regs->r8,
  36                 regs->r9, regs->r10, regs->r11,
  37                 regs->r12);
  38 }
  39
  40 static void print_regs_callee(struct callee_regs *regs)
  41 {
  42         pr_cont("r13: 0x%08lx\tr14: 0x%08lx\n"                  \
  43                 "r15: 0x%08lx\tr16: 0x%08lx\tr17: 0x%08lx\n"    \
  44                 "r18: 0x%08lx\tr19: 0x%08lx\tr20: 0x%08lx\n"    \
  45                 "r21: 0x%08lx\tr22: 0x%08lx\tr23: 0x%08lx\n"    \
  46                 "r24: 0x%08lx\tr25: 0x%08lx\n",
  47                 regs->r13, regs->r14,
  48                 regs->r15, regs->r16, regs->r17,
  49                 regs->r18, regs->r19, regs->r20,
  50                 regs->r21, regs->r22, regs->r23,
  51                 regs->r24, regs->r25);
  52 }
  53
  54 static void print_task_path_n_nm(struct task_struct *tsk)
  55 {
  56         char *path_nm = NULL;
  57         struct mm_struct *mm;
  58         struct file *exe_file;
  59         char buf[ARC_PATH_MAX];
  60
  61         mm = get_task_mm(tsk);
  62         if (!mm)
  63                 goto done;
  64
  65         exe_file = get_mm_exe_file(mm);
  66         mmput(mm);
  67
  68         if (exe_file) {
  69                 path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
  70                 fput(exe_file);
  71         }
  72
  73 done:
  74         pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
  75 }
  76
  77 static void show_faulting_vma(unsigned long address)
  78 {
  79         struct vm_area_struct *vma;
  80         struct mm_struct *active_mm = current->active_mm;
  81
  82         /* can't use print_vma_addr() yet as it doesn't check for
  83          * non-inclusive vma
  84          */
  85         mmap_read_lock(active_mm);
  86         vma = vma_lookup(active_mm, address);
  87
  88         /* Lookup the vma at the address and report if the container VMA is not
  89          * found
  90          */
  91         if (vma) {
  92                 char buf[ARC_PATH_MAX];
  93                 char *nm = "anon";
  94
  95                 if (vma->vm_file) {
  96                         /* XXX: can we use %pD below and get rid of buf? */
  97                         nm = d_path(file_user_path(vma->vm_file), buf,
  98                                     ARC_PATH_MAX-1);
  99                         if (IS_ERR(nm))
 100                                 nm = "?";
 101                 }
 102                 pr_info("  @off 0x%lx in [%s]  VMA: 0x%08lx to 0x%08lx\n",
 103                         vma->vm_start < TASK_UNMAPPED_BASE ?
 104                                 address : address - vma->vm_start,
 105                         nm, vma->vm_start, vma->vm_end);
 106         } else
 107                 pr_info("    @No matching VMA found\n");
 108
 109         mmap_read_unlock(active_mm);
 110 }
 111
 112 static void show_ecr_verbose(struct pt_regs *regs)
 113 {
 114         unsigned int vec, cause_code;
 115         unsigned long address;
 116
 117         /* For Data fault, this is data address not instruction addr */
 118         address = current->thread.fault_address;
 119
 120         vec = regs->ecr.vec;
 121         cause_code = regs->ecr.cause;
 122
 123         /* For DTLB Miss or ProtV, display the memory involved too */
 124         if (vec == ECR_V_DTLB_MISS) {
 125                 pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
 126                        (cause_code == 0x01) ? "Read" :
 127                        ((cause_code == 0x02) ? "Write" : "EX"),
 128                        address, (void *)regs->ret);
 129         } else if (vec == ECR_V_ITLB_MISS) {
 130                 pr_cont("Insn could not be fetched\n");
 131         } else if (vec == ECR_V_MACH_CHK) {
 132                 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
 133                                         "Double Fault" : "Other Fatal Err");
 134
 135         } else if (vec == ECR_V_PROTV) {
 136                 if (cause_code == ECR_C_PROTV_INST_FETCH)
 137                         pr_cont("Execute from Non-exec Page\n");
 138                 else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
 139                          IS_ENABLED(CONFIG_ISA_ARCOMPACT))
 140                         pr_cont("Misaligned r/w from 0x%08lx\n", address);
 141                 else
 142                         pr_cont("%s access not allowed on page\n",
 143                                 (cause_code == 0x01) ? "Read" :
 144                                 ((cause_code == 0x02) ? "Write" : "EX"));
 145         } else if (vec == ECR_V_INSN_ERR) {
 146                 pr_cont("Illegal Insn\n");
 147 #ifdef CONFIG_ISA_ARCV2
 148         } else if (vec == ECR_V_MEM_ERR) {
 149                 if (cause_code == 0x00)
 150                         pr_cont("Bus Error from Insn Mem\n");
 151                 else if (cause_code == 0x10)
 152                         pr_cont("Bus Error from Data Mem\n");
 153                 else
 154                         pr_cont("Bus Error, check PRM\n");
 155         } else if (vec == ECR_V_MISALIGN) {
 156                 pr_cont("Misaligned r/w from 0x%08lx\n", address);
 157 #endif
 158         } else if (vec == ECR_V_TRAP) {
 159                 if (regs->ecr.param == 5)
 160                         pr_cont("gcc generated __builtin_trap\n");
 161         } else {
 162                 pr_cont("Check Programmer's Manual\n");
 163         }
 164 }
 165
 166 /************************************************************************
 167  *  API called by rest of kernel
 168  ***********************************************************************/
 169
 170 void show_regs(struct pt_regs *regs)
 171 {
 172         struct task_struct *tsk = current;
 173         struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;
 174
 175         /*
 176          * generic code calls us with preemption disabled, but some calls
 177          * here could sleep, so re-enable to avoid lockdep splat
 178          */
 179         preempt_enable();
 180
 181         print_task_path_n_nm(tsk);
 182         show_regs_print_info(KERN_INFO);
 183
 184         show_ecr_verbose(regs);
 185
 186         if (user_mode(regs))
 187                 show_faulting_vma(regs->ret); /* faulting code, not data */
 188
 189         pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\n",
 190                 regs->ecr.full, current->thread.fault_address, regs->ret);
 191
 192         pr_info("STAT32: 0x%08lx", regs->status32);
 193
 194 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
 195
 196 #ifdef CONFIG_ISA_ARCOMPACT
 197         pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
 198                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 199                         STS_BIT(regs, DE), STS_BIT(regs, AE),
 200                         STS_BIT(regs, A2), STS_BIT(regs, A1),
 201                         STS_BIT(regs, E2), STS_BIT(regs, E1));
 202 #else
 203         pr_cont(" [%2s%2s%2s%2s]   ",
 204                         STS_BIT(regs, IE),
 205                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 206                         STS_BIT(regs, DE), STS_BIT(regs, AE));
 207 #endif
 208
 209         print_regs_scratch(regs);
 210         if (cregs)
 211                 print_regs_callee(cregs);
 212
 213         preempt_disable();
 214 }
 215
 216 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
 217                             unsigned long address)
 218 {
 219         current->thread.fault_address = address;
 220
 221         /* Show fault description */
 222         pr_info("\n%s\n", str);
 223
 224         /* Caller and Callee regs */
 225         show_regs(regs);
 226
 227         /* Show stack trace if this Fatality happened in kernel mode */
 228         if (!user_mode(regs))
 229                 show_stacktrace(current, regs, KERN_DEFAULT);
 230 }