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_nm = file_path(exe_file, buf, 255); 75 fput(exe_file); 76 } 77 78 done: 79 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?"); 80 } 81 82 static void show_faulting_vma(unsigned long address, char *buf) 83 { 84 struct vm_area_struct *vma; 85 struct inode *inode; 86 unsigned long ino = 0; 87 dev_t dev = 0; 88 char *nm = buf; 89 struct mm_struct *active_mm = current->active_mm; 90 91 /* can't use print_vma_addr() yet as it doesn't check for 92 * non-inclusive vma 93 */ 94 down_read(&active_mm->mmap_sem); 95 vma = find_vma(active_mm, address); 96 97 /* check against the find_vma( ) behaviour which returns the next VMA 98 * if the container VMA is not found 99 */ 100 if (vma && (vma->vm_start <= address)) { 101 struct file *file = vma->vm_file; 102 if (file) { 103 nm = file_path(file, buf, PAGE_SIZE - 1); 104 inode = file_inode(vma->vm_file); 105 dev = inode->i_sb->s_dev; 106 ino = inode->i_ino; 107 } 108 pr_info(" @off 0x%lx in [%s]\n" 109 " VMA: 0x%08lx to 0x%08lx\n", 110 vma->vm_start < TASK_UNMAPPED_BASE ? 111 address : address - vma->vm_start, 112 nm, vma->vm_start, vma->vm_end); 113 } else 114 pr_info(" @No matching VMA found\n"); 115 116 up_read(&active_mm->mmap_sem); 117 } 118 119 static void show_ecr_verbose(struct pt_regs *regs) 120 { 121 unsigned int vec, cause_code; 122 unsigned long address; 123 124 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 125 126 /* For Data fault, this is data address not instruction addr */ 127 address = current->thread.fault_address; 128 129 vec = regs->ecr_vec; 130 cause_code = regs->ecr_cause; 131 132 /* For DTLB Miss or ProtV, display the memory involved too */ 133 if (vec == ECR_V_DTLB_MISS) { 134 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 135 (cause_code == 0x01) ? "Read" : 136 ((cause_code == 0x02) ? "Write" : "EX"), 137 address, regs->ret); 138 } else if (vec == ECR_V_ITLB_MISS) { 139 pr_cont("Insn could not be fetched\n"); 140 } else if (vec == ECR_V_MACH_CHK) { 141 pr_cont("%s\n", (cause_code == 0x0) ? 142 "Double Fault" : "Other Fatal Err"); 143 144 } else if (vec == ECR_V_PROTV) { 145 if (cause_code == ECR_C_PROTV_INST_FETCH) 146 pr_cont("Execute from Non-exec Page\n"); 147 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 148 pr_cont("Misaligned r/w from 0x%08lx\n", address); 149 else 150 pr_cont("%s access not allowed on page\n", 151 (cause_code == 0x01) ? "Read" : 152 ((cause_code == 0x02) ? "Write" : "EX")); 153 } else if (vec == ECR_V_INSN_ERR) { 154 pr_cont("Illegal Insn\n"); 155 #ifdef CONFIG_ISA_ARCV2 156 } else if (vec == ECR_V_MEM_ERR) { 157 if (cause_code == 0x00) 158 pr_cont("Bus Error from Insn Mem\n"); 159 else if (cause_code == 0x10) 160 pr_cont("Bus Error from Data Mem\n"); 161 else 162 pr_cont("Bus Error, check PRM\n"); 163 #endif 164 } else { 165 pr_cont("Check Programmer's Manual\n"); 166 } 167 } 168 169 /************************************************************************ 170 * API called by rest of kernel 171 ***********************************************************************/ 172 173 void show_regs(struct pt_regs *regs) 174 { 175 struct task_struct *tsk = current; 176 struct callee_regs *cregs; 177 char *buf; 178 179 buf = (char *)__get_free_page(GFP_TEMPORARY); 180 if (!buf) 181 return; 182 183 print_task_path_n_nm(tsk, buf); 184 show_regs_print_info(KERN_INFO); 185 186 show_ecr_verbose(regs); 187 188 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 189 current->thread.fault_address, 190 (void *)regs->blink, (void *)regs->ret); 191 192 if (user_mode(regs)) 193 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 194 195 pr_info("[STAT32]: 0x%08lx", regs->status32); 196 197 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : "" 198 199 #ifdef CONFIG_ISA_ARCOMPACT 200 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n", 201 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 202 STS_BIT(regs, DE), STS_BIT(regs, AE), 203 STS_BIT(regs, A2), STS_BIT(regs, A1), 204 STS_BIT(regs, E2), STS_BIT(regs, E1)); 205 #else 206 pr_cont(" : %2s%2s%2s%2s\n", 207 STS_BIT(regs, IE), 208 (regs->status32 & STATUS_U_MASK) ? "U " : "K ", 209 STS_BIT(regs, DE), STS_BIT(regs, AE)); 210 #endif 211 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 212 regs->bta, regs->sp, regs->fp); 213 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 214 regs->lp_start, regs->lp_end, regs->lp_count); 215 216 /* print regs->r0 thru regs->r12 217 * Sequential printing was generating horrible code 218 */ 219 print_reg_file(&(regs->r0), 0); 220 221 /* If Callee regs were saved, display them too */ 222 cregs = (struct callee_regs *)current->thread.callee_reg; 223 if (cregs) 224 show_callee_regs(cregs); 225 226 free_page((unsigned long)buf); 227 } 228 229 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 230 unsigned long address) 231 { 232 current->thread.fault_address = address; 233 234 /* Caller and Callee regs */ 235 show_regs(regs); 236 237 /* Show stack trace if this Fatality happened in kernel mode */ 238 if (!user_mode(regs)) 239 show_stacktrace(current, regs); 240 } 241 242 #ifdef CONFIG_DEBUG_FS 243 244 #include <linux/module.h> 245 #include <linux/fs.h> 246 #include <linux/mount.h> 247 #include <linux/pagemap.h> 248 #include <linux/init.h> 249 #include <linux/namei.h> 250 #include <linux/debugfs.h> 251 252 static struct dentry *test_dentry; 253 static struct dentry *test_dir; 254 static struct dentry *test_u32_dentry; 255 256 static u32 clr_on_read = 1; 257 258 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 259 u32 numitlb, numdtlb, num_pte_not_present; 260 261 static int fill_display_data(char *kbuf) 262 { 263 size_t num = 0; 264 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); 265 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); 266 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); 267 268 if (clr_on_read) 269 numitlb = numdtlb = num_pte_not_present = 0; 270 271 return num; 272 } 273 274 static int tlb_stats_open(struct inode *inode, struct file *file) 275 { 276 file->private_data = (void *)__get_free_page(GFP_KERNEL); 277 return 0; 278 } 279 280 /* called on user read(): display the couters */ 281 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ 282 char __user *user_buf, /* user buffer */ 283 size_t len, /* length of buffer */ 284 loff_t *offset) /* offset in the file */ 285 { 286 size_t num; 287 char *kbuf = (char *)file->private_data; 288 289 /* All of the data can he shoved in one iteration */ 290 if (*offset != 0) 291 return 0; 292 293 num = fill_display_data(kbuf); 294 295 /* simple_read_from_buffer() is helper for copy to user space 296 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset 297 @3 (offset) into the user space address starting at @1 (user_buf). 298 @5 (len) is max size of user buffer 299 */ 300 return simple_read_from_buffer(user_buf, num, offset, kbuf, len); 301 } 302 303 /* called on user write : clears the counters */ 304 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, 305 size_t length, loff_t *offset) 306 { 307 numitlb = numdtlb = num_pte_not_present = 0; 308 return length; 309 } 310 311 static int tlb_stats_close(struct inode *inode, struct file *file) 312 { 313 free_page((unsigned long)(file->private_data)); 314 return 0; 315 } 316 317 static const struct file_operations tlb_stats_file_ops = { 318 .read = tlb_stats_output, 319 .write = tlb_stats_clear, 320 .open = tlb_stats_open, 321 .release = tlb_stats_close 322 }; 323 #endif 324 325 static int __init arc_debugfs_init(void) 326 { 327 test_dir = debugfs_create_dir("arc", NULL); 328 329 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 330 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, 331 &tlb_stats_file_ops); 332 #endif 333 334 test_u32_dentry = 335 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); 336 337 return 0; 338 } 339 340 module_init(arc_debugfs_init); 341 342 static void __exit arc_debugfs_exit(void) 343 { 344 debugfs_remove(test_u32_dentry); 345 debugfs_remove(test_dentry); 346 debugfs_remove(test_dir); 347 } 348 module_exit(arc_debugfs_exit); 349 350 #endif 351