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/fs_struct.h> 14 #include <linux/proc_fs.h> 15 #include <linux/file.h> 16 #include <asm/arcregs.h> 17 18 /* 19 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) 20 * -Prints 3 regs per line and a CR. 21 * -To continue, callee regs right after scratch, special handling of CR 22 */ 23 static noinline void print_reg_file(long *reg_rev, int start_num) 24 { 25 unsigned int i; 26 char buf[512]; 27 int n = 0, len = sizeof(buf); 28 29 /* weird loop because pt_regs regs rev r12..r0, r25..r13 */ 30 for (i = start_num; i < start_num + 13; i++) { 31 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", 32 i, (unsigned long)*reg_rev); 33 34 if (((i + 1) % 3) == 0) 35 n += scnprintf(buf + n, len - n, "\n"); 36 37 reg_rev--; 38 } 39 40 if (start_num != 0) 41 n += scnprintf(buf + n, len - n, "\n\n"); 42 43 pr_info("%s", buf); 44 } 45 46 static void show_callee_regs(struct callee_regs *cregs) 47 { 48 print_reg_file(&(cregs->r13), 13); 49 } 50 51 void print_task_path_n_nm(struct task_struct *tsk, char *buf) 52 { 53 struct path path; 54 char *path_nm = NULL; 55 struct mm_struct *mm; 56 struct file *exe_file; 57 58 mm = get_task_mm(tsk); 59 if (!mm) 60 goto done; 61 62 exe_file = get_mm_exe_file(mm); 63 mmput(mm); 64 65 if (exe_file) { 66 path = exe_file->f_path; 67 path_get(&exe_file->f_path); 68 fput(exe_file); 69 path_nm = d_path(&path, buf, 255); 70 path_put(&path); 71 } 72 73 done: 74 pr_info("%s, TGID %u\n", path_nm, tsk->tgid); 75 } 76 EXPORT_SYMBOL(print_task_path_n_nm); 77 78 static void show_faulting_vma(unsigned long address, char *buf) 79 { 80 struct vm_area_struct *vma; 81 struct inode *inode; 82 unsigned long ino = 0; 83 dev_t dev = 0; 84 char *nm = buf; 85 86 vma = find_vma(current->active_mm, address); 87 88 /* check against the find_vma( ) behaviour which returns the next VMA 89 * if the container VMA is not found 90 */ 91 if (vma && (vma->vm_start <= address)) { 92 struct file *file = vma->vm_file; 93 if (file) { 94 struct path *path = &file->f_path; 95 nm = d_path(path, buf, PAGE_SIZE - 1); 96 inode = vma->vm_file->f_path.dentry->d_inode; 97 dev = inode->i_sb->s_dev; 98 ino = inode->i_ino; 99 } 100 pr_info(" @off 0x%lx in [%s]\n" 101 " VMA: 0x%08lx to 0x%08lx\n\n", 102 address - vma->vm_start, nm, vma->vm_start, vma->vm_end); 103 } else 104 pr_info(" @No matching VMA found\n"); 105 } 106 107 static void show_ecr_verbose(struct pt_regs *regs) 108 { 109 unsigned int vec, cause_code, cause_reg; 110 unsigned long address; 111 112 cause_reg = current->thread.cause_code; 113 pr_info("\n[ECR]: 0x%08x => ", cause_reg); 114 115 /* For Data fault, this is data address not instruction addr */ 116 address = current->thread.fault_address; 117 118 vec = cause_reg >> 16; 119 cause_code = (cause_reg >> 8) & 0xFF; 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 @ 0x%08lx\n", 124 (cause_code == 0x01) ? "Read From" : 125 ((cause_code == 0x02) ? "Write to" : "EX"), 126 address, 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("%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_LOAD) 137 pr_cont("Read from Non-readable Page\n"); 138 else if (cause_code == ECR_C_PROTV_STORE) 139 pr_cont("Write to Non-writable Page\n"); 140 else if (cause_code == ECR_C_PROTV_XCHG) 141 pr_cont("Data exchange protection violation\n"); 142 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 143 pr_cont("Misaligned r/w from 0x%08lx\n", address); 144 } else if (vec == ECR_V_INSN_ERR) { 145 pr_cont("Illegal Insn\n"); 146 } else { 147 pr_cont("Check Programmer's Manual\n"); 148 } 149 } 150 151 /************************************************************************ 152 * API called by rest of kernel 153 ***********************************************************************/ 154 155 void show_regs(struct pt_regs *regs) 156 { 157 struct task_struct *tsk = current; 158 struct callee_regs *cregs; 159 char *buf; 160 161 buf = (char *)__get_free_page(GFP_TEMPORARY); 162 if (!buf) 163 return; 164 165 print_task_path_n_nm(tsk, buf); 166 167 if (current->thread.cause_code) 168 show_ecr_verbose(regs); 169 170 pr_info("[EFA]: 0x%08lx\n", current->thread.fault_address); 171 pr_info("[ERET]: 0x%08lx (PC of Faulting Instr)\n", regs->ret); 172 173 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 174 175 /* can't use print_vma_addr() yet as it doesn't check for 176 * non-inclusive vma 177 */ 178 179 /* print special regs */ 180 pr_info("status32: 0x%08lx\n", regs->status32); 181 pr_info(" SP: 0x%08lx\tFP: 0x%08lx\n", regs->sp, regs->fp); 182 pr_info("BTA: 0x%08lx\tBLINK: 0x%08lx\n", 183 regs->bta, regs->blink); 184 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 185 regs->lp_start, regs->lp_end, regs->lp_count); 186 187 /* print regs->r0 thru regs->r12 188 * Sequential printing was generating horrible code 189 */ 190 print_reg_file(&(regs->r0), 0); 191 192 /* If Callee regs were saved, display them too */ 193 cregs = (struct callee_regs *)current->thread.callee_reg; 194 if (cregs) 195 show_callee_regs(cregs); 196 197 free_page((unsigned long)buf); 198 } 199 200 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 201 unsigned long address, unsigned long cause_reg) 202 { 203 current->thread.fault_address = address; 204 current->thread.cause_code = cause_reg; 205 206 /* Caller and Callee regs */ 207 show_regs(regs); 208 209 /* Show stack trace if this Fatality happened in kernel mode */ 210 if (!user_mode(regs)) 211 show_stacktrace(current, regs); 212 } 213 214 #ifdef CONFIG_DEBUG_FS 215 216 #include <linux/module.h> 217 #include <linux/fs.h> 218 #include <linux/mount.h> 219 #include <linux/pagemap.h> 220 #include <linux/init.h> 221 #include <linux/namei.h> 222 #include <linux/debugfs.h> 223 224 static struct dentry *test_dentry; 225 static struct dentry *test_dir; 226 static struct dentry *test_u32_dentry; 227 228 static u32 clr_on_read = 1; 229 230 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 231 u32 numitlb, numdtlb, num_pte_not_present; 232 233 static int fill_display_data(char *kbuf) 234 { 235 size_t num = 0; 236 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); 237 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); 238 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); 239 240 if (clr_on_read) 241 numitlb = numdtlb = num_pte_not_present = 0; 242 243 return num; 244 } 245 246 static int tlb_stats_open(struct inode *inode, struct file *file) 247 { 248 file->private_data = (void *)__get_free_page(GFP_KERNEL); 249 return 0; 250 } 251 252 /* called on user read(): display the couters */ 253 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ 254 char __user *user_buf, /* user buffer */ 255 size_t len, /* length of buffer */ 256 loff_t *offset) /* offset in the file */ 257 { 258 size_t num; 259 char *kbuf = (char *)file->private_data; 260 261 /* All of the data can he shoved in one iteration */ 262 if (*offset != 0) 263 return 0; 264 265 num = fill_display_data(kbuf); 266 267 /* simple_read_from_buffer() is helper for copy to user space 268 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset 269 @3 (offset) into the user space address starting at @1 (user_buf). 270 @5 (len) is max size of user buffer 271 */ 272 return simple_read_from_buffer(user_buf, num, offset, kbuf, len); 273 } 274 275 /* called on user write : clears the counters */ 276 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, 277 size_t length, loff_t *offset) 278 { 279 numitlb = numdtlb = num_pte_not_present = 0; 280 return length; 281 } 282 283 static int tlb_stats_close(struct inode *inode, struct file *file) 284 { 285 free_page((unsigned long)(file->private_data)); 286 return 0; 287 } 288 289 static const struct file_operations tlb_stats_file_ops = { 290 .read = tlb_stats_output, 291 .write = tlb_stats_clear, 292 .open = tlb_stats_open, 293 .release = tlb_stats_close 294 }; 295 #endif 296 297 static int __init arc_debugfs_init(void) 298 { 299 test_dir = debugfs_create_dir("arc", NULL); 300 301 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 302 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, 303 &tlb_stats_file_ops); 304 #endif 305 306 test_u32_dentry = 307 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); 308 309 return 0; 310 } 311 312 module_init(arc_debugfs_init); 313 314 static void __exit arc_debugfs_exit(void) 315 { 316 debugfs_remove(test_u32_dentry); 317 debugfs_remove(test_dentry); 318 debugfs_remove(test_dir); 319 } 320 module_exit(arc_debugfs_exit); 321 322 #endif 323