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 #include <asm/irqflags.h> 18 19 /* 20 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) 21 * -Prints 3 regs per line and a CR. 22 * -To continue, callee regs right after scratch, special handling of CR 23 */ 24 static noinline void print_reg_file(long *reg_rev, int start_num) 25 { 26 unsigned int i; 27 char buf[512]; 28 int n = 0, len = sizeof(buf); 29 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 /* because pt_regs has regs reversed: r12..r0, r25..r13 */ 38 if (is_isa_arcv2() && start_num == 0) 39 reg_rev++; 40 else 41 reg_rev--; 42 } 43 44 if (start_num != 0) 45 n += scnprintf(buf + n, len - n, "\n\n"); 46 47 /* To continue printing callee regs on same line as scratch regs */ 48 if (start_num == 0) 49 pr_info("%s", buf); 50 else 51 pr_cont("%s\n", buf); 52 } 53 54 static void show_callee_regs(struct callee_regs *cregs) 55 { 56 print_reg_file(&(cregs->r13), 13); 57 } 58 59 static void print_task_path_n_nm(struct task_struct *tsk, char *buf) 60 { 61 struct path path; 62 char *path_nm = NULL; 63 struct mm_struct *mm; 64 struct file *exe_file; 65 66 mm = get_task_mm(tsk); 67 if (!mm) 68 goto done; 69 70 exe_file = get_mm_exe_file(mm); 71 mmput(mm); 72 73 if (exe_file) { 74 path = exe_file->f_path; 75 path_get(&exe_file->f_path); 76 fput(exe_file); 77 path_nm = d_path(&path, buf, 255); 78 path_put(&path); 79 } 80 81 done: 82 pr_info("Path: %s\n", path_nm); 83 } 84 85 static void show_faulting_vma(unsigned long address, char *buf) 86 { 87 struct vm_area_struct *vma; 88 struct inode *inode; 89 unsigned long ino = 0; 90 dev_t dev = 0; 91 char *nm = buf; 92 struct mm_struct *active_mm = current->active_mm; 93 94 /* can't use print_vma_addr() yet as it doesn't check for 95 * non-inclusive vma 96 */ 97 down_read(&active_mm->mmap_sem); 98 vma = find_vma(active_mm, address); 99 100 /* check against the find_vma( ) behaviour which returns the next VMA 101 * if the container VMA is not found 102 */ 103 if (vma && (vma->vm_start <= address)) { 104 struct file *file = vma->vm_file; 105 if (file) { 106 struct path *path = &file->f_path; 107 nm = d_path(path, buf, PAGE_SIZE - 1); 108 inode = file_inode(vma->vm_file); 109 dev = inode->i_sb->s_dev; 110 ino = inode->i_ino; 111 } 112 pr_info(" @off 0x%lx in [%s]\n" 113 " VMA: 0x%08lx to 0x%08lx\n", 114 vma->vm_start < TASK_UNMAPPED_BASE ? 115 address : address - vma->vm_start, 116 nm, vma->vm_start, vma->vm_end); 117 } else 118 pr_info(" @No matching VMA found\n"); 119 120 up_read(&active_mm->mmap_sem); 121 } 122 123 static void show_ecr_verbose(struct pt_regs *regs) 124 { 125 unsigned int vec, cause_code; 126 unsigned long address; 127 128 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 129 130 /* For Data fault, this is data address not instruction addr */ 131 address = current->thread.fault_address; 132 133 vec = regs->ecr_vec; 134 cause_code = regs->ecr_cause; 135 136 /* For DTLB Miss or ProtV, display the memory involved too */ 137 if (vec == ECR_V_DTLB_MISS) { 138 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 139 (cause_code == 0x01) ? "Read" : 140 ((cause_code == 0x02) ? "Write" : "EX"), 141 address, regs->ret); 142 } else if (vec == ECR_V_ITLB_MISS) { 143 pr_cont("Insn could not be fetched\n"); 144 } else if (vec == ECR_V_MACH_CHK) { 145 pr_cont("%s\n", (cause_code == 0x0) ? 146 "Double Fault" : "Other Fatal Err"); 147 148 } else if (vec == ECR_V_PROTV) { 149 if (cause_code == ECR_C_PROTV_INST_FETCH) 150 pr_cont("Execute from Non-exec Page\n"); 151 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 152 pr_cont("Misaligned r/w from 0x%08lx\n", address); 153 else 154 pr_cont("%s access not allowed on page\n", 155 (cause_code == 0x01) ? "Read" : 156 ((cause_code == 0x02) ? "Write" : "EX")); 157 } else if (vec == ECR_V_INSN_ERR) { 158 pr_cont("Illegal Insn\n"); 159 #ifdef CONFIG_ISA_ARCV2 160 } else if (vec == ECR_V_MEM_ERR) { 161 if (cause_code == 0x00) 162 pr_cont("Bus Error from Insn Mem\n"); 163 else if (cause_code == 0x10) 164 pr_cont("Bus Error from Data Mem\n"); 165 else 166 pr_cont("Bus Error, check PRM\n"); 167 #endif 168 } else { 169 pr_cont("Check Programmer's Manual\n"); 170 } 171 } 172 173 /************************************************************************ 174 * API called by rest of kernel 175 ***********************************************************************/ 176 177 void show_regs(struct pt_regs *regs) 178 { 179 struct task_struct *tsk = current; 180 struct callee_regs *cregs; 181 char *buf; 182 183 buf = (char *)__get_free_page(GFP_TEMPORARY); 184 if (!buf) 185 return; 186 187 print_task_path_n_nm(tsk, buf); 188 show_regs_print_info(KERN_INFO); 189 190 show_ecr_verbose(regs); 191 192 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 193 current->thread.fault_address, 194 (void *)regs->blink, (void *)regs->ret); 195 196 if (user_mode(regs)) 197 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 198 199 pr_info("[STAT32]: 0x%08lx", regs->status32); 200 201 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : "" 202 203 #ifdef CONFIG_ISA_ARCOMPACT 204 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n", 205 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 206 STS_BIT(regs, DE), STS_BIT(regs, AE), 207 STS_BIT(regs, A2), STS_BIT(regs, A1), 208 STS_BIT(regs, E2), STS_BIT(regs, E1)); 209 #else 210 pr_cont(" : %2s%2s%2s%2s\n", 211 STS_BIT(regs, IE), 212 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 213 STS_BIT(regs, DE), STS_BIT(regs, AE)); 214 #endif 215 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 216 regs->bta, regs->sp, regs->fp); 217 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 218 regs->lp_start, regs->lp_end, regs->lp_count); 219 220 /* print regs->r0 thru regs->r12 221 * Sequential printing was generating horrible code 222 */ 223 print_reg_file(&(regs->r0), 0); 224 225 /* If Callee regs were saved, display them too */ 226 cregs = (struct callee_regs *)current->thread.callee_reg; 227 if (cregs) 228 show_callee_regs(cregs); 229 230 free_page((unsigned long)buf); 231 } 232 233 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 234 unsigned long address) 235 { 236 current->thread.fault_address = address; 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 } 245 246 #ifdef CONFIG_DEBUG_FS 247 248 #include <linux/module.h> 249 #include <linux/fs.h> 250 #include <linux/mount.h> 251 #include <linux/pagemap.h> 252 #include <linux/init.h> 253 #include <linux/namei.h> 254 #include <linux/debugfs.h> 255 256 static struct dentry *test_dentry; 257 static struct dentry *test_dir; 258 static struct dentry *test_u32_dentry; 259 260 static u32 clr_on_read = 1; 261 262 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 263 u32 numitlb, numdtlb, num_pte_not_present; 264 265 static int fill_display_data(char *kbuf) 266 { 267 size_t num = 0; 268 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); 269 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); 270 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); 271 272 if (clr_on_read) 273 numitlb = numdtlb = num_pte_not_present = 0; 274 275 return num; 276 } 277 278 static int tlb_stats_open(struct inode *inode, struct file *file) 279 { 280 file->private_data = (void *)__get_free_page(GFP_KERNEL); 281 return 0; 282 } 283 284 /* called on user read(): display the couters */ 285 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ 286 char __user *user_buf, /* user buffer */ 287 size_t len, /* length of buffer */ 288 loff_t *offset) /* offset in the file */ 289 { 290 size_t num; 291 char *kbuf = (char *)file->private_data; 292 293 /* All of the data can he shoved in one iteration */ 294 if (*offset != 0) 295 return 0; 296 297 num = fill_display_data(kbuf); 298 299 /* simple_read_from_buffer() is helper for copy to user space 300 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset 301 @3 (offset) into the user space address starting at @1 (user_buf). 302 @5 (len) is max size of user buffer 303 */ 304 return simple_read_from_buffer(user_buf, num, offset, kbuf, len); 305 } 306 307 /* called on user write : clears the counters */ 308 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, 309 size_t length, loff_t *offset) 310 { 311 numitlb = numdtlb = num_pte_not_present = 0; 312 return length; 313 } 314 315 static int tlb_stats_close(struct inode *inode, struct file *file) 316 { 317 free_page((unsigned long)(file->private_data)); 318 return 0; 319 } 320 321 static const struct file_operations tlb_stats_file_ops = { 322 .read = tlb_stats_output, 323 .write = tlb_stats_clear, 324 .open = tlb_stats_open, 325 .release = tlb_stats_close 326 }; 327 #endif 328 329 static int __init arc_debugfs_init(void) 330 { 331 test_dir = debugfs_create_dir("arc", NULL); 332 333 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 334 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, 335 &tlb_stats_file_ops); 336 #endif 337 338 test_u32_dentry = 339 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); 340 341 return 0; 342 } 343 344 module_init(arc_debugfs_init); 345 346 static void __exit arc_debugfs_exit(void) 347 { 348 debugfs_remove(test_u32_dentry); 349 debugfs_remove(test_dentry); 350 debugfs_remove(test_dir); 351 } 352 module_exit(arc_debugfs_exit); 353 354 #endif 355