linux/arch/arc/kernel/troubleshoot.c
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   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
  21static 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
  40static 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
  54static 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
  73done:
  74        pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
  75}
  76
  77static 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 = "?";
  94
  95                if (vma->vm_file) {
  96                        nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
  97                        if (IS_ERR(nm))
  98                                nm = "?";
  99                }
 100                pr_info("  @off 0x%lx in [%s]  VMA: 0x%08lx to 0x%08lx\n",
 101                        vma->vm_start < TASK_UNMAPPED_BASE ?
 102                                address : address - vma->vm_start,
 103                        nm, vma->vm_start, vma->vm_end);
 104        } else
 105                pr_info("    @No matching VMA found\n");
 106
 107        mmap_read_unlock(active_mm);
 108}
 109
 110static void show_ecr_verbose(struct pt_regs *regs)
 111{
 112        unsigned int vec, cause_code;
 113        unsigned long address;
 114
 115        /* For Data fault, this is data address not instruction addr */
 116        address = current->thread.fault_address;
 117
 118        vec = regs->ecr_vec;
 119        cause_code = regs->ecr_cause;
 120
 121        /* For DTLB Miss or ProtV, display the memory involved too */
 122        if (vec == ECR_V_DTLB_MISS) {
 123                pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
 124                       (cause_code == 0x01) ? "Read" :
 125                       ((cause_code == 0x02) ? "Write" : "EX"),
 126                       address, (void *)regs->ret);
 127        } else if (vec == ECR_V_ITLB_MISS) {
 128                pr_cont("Insn could not be fetched\n");
 129        } else if (vec == ECR_V_MACH_CHK) {
 130                pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
 131                                        "Double Fault" : "Other Fatal Err");
 132
 133        } else if (vec == ECR_V_PROTV) {
 134                if (cause_code == ECR_C_PROTV_INST_FETCH)
 135                        pr_cont("Execute from Non-exec Page\n");
 136                else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
 137                         IS_ENABLED(CONFIG_ISA_ARCOMPACT))
 138                        pr_cont("Misaligned r/w from 0x%08lx\n", address);
 139                else
 140                        pr_cont("%s access not allowed on page\n",
 141                                (cause_code == 0x01) ? "Read" :
 142                                ((cause_code == 0x02) ? "Write" : "EX"));
 143        } else if (vec == ECR_V_INSN_ERR) {
 144                pr_cont("Illegal Insn\n");
 145#ifdef CONFIG_ISA_ARCV2
 146        } else if (vec == ECR_V_MEM_ERR) {
 147                if (cause_code == 0x00)
 148                        pr_cont("Bus Error from Insn Mem\n");
 149                else if (cause_code == 0x10)
 150                        pr_cont("Bus Error from Data Mem\n");
 151                else
 152                        pr_cont("Bus Error, check PRM\n");
 153        } else if (vec == ECR_V_MISALIGN) {
 154                pr_cont("Misaligned r/w from 0x%08lx\n", address);
 155#endif
 156        } else if (vec == ECR_V_TRAP) {
 157                if (regs->ecr_param == 5)
 158                        pr_cont("gcc generated __builtin_trap\n");
 159        } else {
 160                pr_cont("Check Programmer's Manual\n");
 161        }
 162}
 163
 164/************************************************************************
 165 *  API called by rest of kernel
 166 ***********************************************************************/
 167
 168void show_regs(struct pt_regs *regs)
 169{
 170        struct task_struct *tsk = current;
 171        struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;
 172
 173        /*
 174         * generic code calls us with preemption disabled, but some calls
 175         * here could sleep, so re-enable to avoid lockdep splat
 176         */
 177        preempt_enable();
 178
 179        print_task_path_n_nm(tsk);
 180        show_regs_print_info(KERN_INFO);
 181
 182        show_ecr_verbose(regs);
 183
 184        if (user_mode(regs))
 185                show_faulting_vma(regs->ret); /* faulting code, not data */
 186
 187        pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\nSTAT: 0x%08lx",
 188                regs->event, current->thread.fault_address, regs->ret,
 189                regs->status32);
 190
 191#define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
 192
 193#ifdef CONFIG_ISA_ARCOMPACT
 194        pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
 195                        (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 196                        STS_BIT(regs, DE), STS_BIT(regs, AE),
 197                        STS_BIT(regs, A2), STS_BIT(regs, A1),
 198                        STS_BIT(regs, E2), STS_BIT(regs, E1));
 199#else
 200        pr_cont(" [%2s%2s%2s%2s]   ",
 201                        STS_BIT(regs, IE),
 202                        (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
 203                        STS_BIT(regs, DE), STS_BIT(regs, AE));
 204#endif
 205
 206        print_regs_scratch(regs);
 207        if (cregs)
 208                print_regs_callee(cregs);
 209
 210        preempt_disable();
 211}
 212
 213void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
 214                            unsigned long address)
 215{
 216        current->thread.fault_address = address;
 217
 218        /* Show fault description */
 219        pr_info("\n%s\n", str);
 220
 221        /* Caller and Callee regs */
 222        show_regs(regs);
 223
 224        /* Show stack trace if this Fatality happened in kernel mode */
 225        if (!user_mode(regs))
 226                show_stacktrace(current, regs, KERN_DEFAULT);
 227}
 228