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 for (i = start_num; i < start_num + 13; i++) { 30 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", 31 i, (unsigned long)*reg_rev); 32 33 if (((i + 1) % 3) == 0) 34 n += scnprintf(buf + n, len - n, "\n"); 35 36 /* because pt_regs has regs reversed: r12..r0, r25..r13 */ 37 reg_rev--; 38 } 39 40 if (start_num != 0) 41 n += scnprintf(buf + n, len - n, "\n\n"); 42 43 /* To continue printing callee regs on same line as scratch regs */ 44 if (start_num == 0) 45 pr_info("%s", buf); 46 else 47 pr_cont("%s\n", buf); 48 } 49 50 static void show_callee_regs(struct callee_regs *cregs) 51 { 52 print_reg_file(&(cregs->r13), 13); 53 } 54 55 void print_task_path_n_nm(struct task_struct *tsk, char *buf) 56 { 57 struct path path; 58 char *path_nm = NULL; 59 struct mm_struct *mm; 60 struct file *exe_file; 61 62 mm = get_task_mm(tsk); 63 if (!mm) 64 goto done; 65 66 exe_file = get_mm_exe_file(mm); 67 mmput(mm); 68 69 if (exe_file) { 70 path = exe_file->f_path; 71 path_get(&exe_file->f_path); 72 fput(exe_file); 73 path_nm = d_path(&path, buf, 255); 74 path_put(&path); 75 } 76 77 done: 78 pr_info("Path: %s\n", path_nm); 79 } 80 EXPORT_SYMBOL(print_task_path_n_nm); 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 struct path *path = &file->f_path; 104 nm = d_path(path, buf, PAGE_SIZE - 1); 105 inode = file_inode(vma->vm_file); 106 dev = inode->i_sb->s_dev; 107 ino = inode->i_ino; 108 } 109 pr_info(" @off 0x%lx in [%s]\n" 110 " VMA: 0x%08lx to 0x%08lx\n", 111 vma->vm_start < TASK_UNMAPPED_BASE ? 112 address : address - vma->vm_start, 113 nm, vma->vm_start, vma->vm_end); 114 } else 115 pr_info(" @No matching VMA found\n"); 116 117 up_read(&active_mm->mmap_sem); 118 } 119 120 static void show_ecr_verbose(struct pt_regs *regs) 121 { 122 unsigned int vec, cause_code; 123 unsigned long address; 124 125 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 126 127 /* For Data fault, this is data address not instruction addr */ 128 address = current->thread.fault_address; 129 130 vec = regs->ecr_vec; 131 cause_code = regs->ecr_cause; 132 133 /* For DTLB Miss or ProtV, display the memory involved too */ 134 if (vec == ECR_V_DTLB_MISS) { 135 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 136 (cause_code == 0x01) ? "Read" : 137 ((cause_code == 0x02) ? "Write" : "EX"), 138 address, regs->ret); 139 } else if (vec == ECR_V_ITLB_MISS) { 140 pr_cont("Insn could not be fetched\n"); 141 } else if (vec == ECR_V_MACH_CHK) { 142 pr_cont("%s\n", (cause_code == 0x0) ? 143 "Double Fault" : "Other Fatal Err"); 144 145 } else if (vec == ECR_V_PROTV) { 146 if (cause_code == ECR_C_PROTV_INST_FETCH) 147 pr_cont("Execute from Non-exec Page\n"); 148 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 149 pr_cont("Misaligned r/w from 0x%08lx\n", address); 150 else 151 pr_cont("%s access not allowed on page\n", 152 (cause_code == 0x01) ? "Read" : 153 ((cause_code == 0x02) ? "Write" : "EX")); 154 } else if (vec == ECR_V_INSN_ERR) { 155 pr_cont("Illegal Insn\n"); 156 } else { 157 pr_cont("Check Programmer's Manual\n"); 158 } 159 } 160 161 /************************************************************************ 162 * API called by rest of kernel 163 ***********************************************************************/ 164 165 void show_regs(struct pt_regs *regs) 166 { 167 struct task_struct *tsk = current; 168 struct callee_regs *cregs; 169 char *buf; 170 171 buf = (char *)__get_free_page(GFP_TEMPORARY); 172 if (!buf) 173 return; 174 175 print_task_path_n_nm(tsk, buf); 176 show_regs_print_info(KERN_INFO); 177 178 show_ecr_verbose(regs); 179 180 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 181 current->thread.fault_address, 182 (void *)regs->blink, (void *)regs->ret); 183 184 if (user_mode(regs)) 185 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 186 187 pr_info("[STAT32]: 0x%08lx", regs->status32); 188 189 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit : "" 190 if (!user_mode(regs)) 191 pr_cont(" : %2s %2s %2s %2s %2s\n", 192 STS_BIT(regs, AE), STS_BIT(regs, A2), STS_BIT(regs, A1), 193 STS_BIT(regs, E2), STS_BIT(regs, E1)); 194 195 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 196 regs->bta, regs->sp, regs->fp); 197 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 198 regs->lp_start, regs->lp_end, regs->lp_count); 199 200 /* print regs->r0 thru regs->r12 201 * Sequential printing was generating horrible code 202 */ 203 print_reg_file(&(regs->r0), 0); 204 205 /* If Callee regs were saved, display them too */ 206 cregs = (struct callee_regs *)current->thread.callee_reg; 207 if (cregs) 208 show_callee_regs(cregs); 209 210 free_page((unsigned long)buf); 211 } 212 213 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 214 unsigned long address) 215 { 216 current->thread.fault_address = address; 217 218 /* Caller and Callee regs */ 219 show_regs(regs); 220 221 /* Show stack trace if this Fatality happened in kernel mode */ 222 if (!user_mode(regs)) 223 show_stacktrace(current, regs); 224 } 225 226 #ifdef CONFIG_DEBUG_FS 227 228 #include <linux/module.h> 229 #include <linux/fs.h> 230 #include <linux/mount.h> 231 #include <linux/pagemap.h> 232 #include <linux/init.h> 233 #include <linux/namei.h> 234 #include <linux/debugfs.h> 235 236 static struct dentry *test_dentry; 237 static struct dentry *test_dir; 238 static struct dentry *test_u32_dentry; 239 240 static u32 clr_on_read = 1; 241 242 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 243 u32 numitlb, numdtlb, num_pte_not_present; 244 245 static int fill_display_data(char *kbuf) 246 { 247 size_t num = 0; 248 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); 249 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); 250 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); 251 252 if (clr_on_read) 253 numitlb = numdtlb = num_pte_not_present = 0; 254 255 return num; 256 } 257 258 static int tlb_stats_open(struct inode *inode, struct file *file) 259 { 260 file->private_data = (void *)__get_free_page(GFP_KERNEL); 261 return 0; 262 } 263 264 /* called on user read(): display the couters */ 265 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ 266 char __user *user_buf, /* user buffer */ 267 size_t len, /* length of buffer */ 268 loff_t *offset) /* offset in the file */ 269 { 270 size_t num; 271 char *kbuf = (char *)file->private_data; 272 273 /* All of the data can he shoved in one iteration */ 274 if (*offset != 0) 275 return 0; 276 277 num = fill_display_data(kbuf); 278 279 /* simple_read_from_buffer() is helper for copy to user space 280 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset 281 @3 (offset) into the user space address starting at @1 (user_buf). 282 @5 (len) is max size of user buffer 283 */ 284 return simple_read_from_buffer(user_buf, num, offset, kbuf, len); 285 } 286 287 /* called on user write : clears the counters */ 288 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, 289 size_t length, loff_t *offset) 290 { 291 numitlb = numdtlb = num_pte_not_present = 0; 292 return length; 293 } 294 295 static int tlb_stats_close(struct inode *inode, struct file *file) 296 { 297 free_page((unsigned long)(file->private_data)); 298 return 0; 299 } 300 301 static const struct file_operations tlb_stats_file_ops = { 302 .read = tlb_stats_output, 303 .write = tlb_stats_clear, 304 .open = tlb_stats_open, 305 .release = tlb_stats_close 306 }; 307 #endif 308 309 static int __init arc_debugfs_init(void) 310 { 311 test_dir = debugfs_create_dir("arc", NULL); 312 313 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 314 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, 315 &tlb_stats_file_ops); 316 #endif 317 318 test_u32_dentry = 319 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); 320 321 return 0; 322 } 323 324 module_init(arc_debugfs_init); 325 326 static void __exit arc_debugfs_exit(void) 327 { 328 debugfs_remove(test_u32_dentry); 329 debugfs_remove(test_dentry); 330 debugfs_remove(test_dir); 331 } 332 module_exit(arc_debugfs_exit); 333 334 #endif 335