diff options
Diffstat (limited to 'arch/arc/kernel/troubleshoot.c')
| -rw-r--r-- | arch/arc/kernel/troubleshoot.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c new file mode 100644 index 000000000000..7c10873c311f --- /dev/null +++ b/arch/arc/kernel/troubleshoot.c @@ -0,0 +1,322 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + */ + +#include <linux/ptrace.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/kdev_t.h> +#include <linux/fs_struct.h> +#include <linux/proc_fs.h> +#include <linux/file.h> +#include <asm/arcregs.h> + +/* + * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) + * -Prints 3 regs per line and a CR. + * -To continue, callee regs right after scratch, special handling of CR + */ +static noinline void print_reg_file(long *reg_rev, int start_num) +{ + unsigned int i; + char buf[512]; + int n = 0, len = sizeof(buf); + + /* weird loop because pt_regs regs rev r12..r0, r25..r13 */ + for (i = start_num; i < start_num + 13; i++) { + n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", + i, (unsigned long)*reg_rev); + + if (((i + 1) % 3) == 0) + n += scnprintf(buf + n, len - n, "\n"); + + reg_rev--; + } + + if (start_num != 0) + n += scnprintf(buf + n, len - n, "\n\n"); + + pr_info("%s", buf); +} + +static void show_callee_regs(struct callee_regs *cregs) +{ + print_reg_file(&(cregs->r13), 13); +} + +void print_task_path_n_nm(struct task_struct *tsk, char *buf) +{ + struct path path; + char *path_nm = NULL; + struct mm_struct *mm; + struct file *exe_file; + + mm = get_task_mm(tsk); + if (!mm) + goto done; + + exe_file = get_mm_exe_file(mm); + mmput(mm); + + if (exe_file) { + path = exe_file->f_path; + path_get(&exe_file->f_path); + fput(exe_file); + path_nm = d_path(&path, buf, 255); + path_put(&path); + } + +done: + pr_info("%s, TGID %u\n", path_nm, tsk->tgid); +} +EXPORT_SYMBOL(print_task_path_n_nm); + +static void show_faulting_vma(unsigned long address, char *buf) +{ + struct vm_area_struct *vma; + struct inode *inode; + unsigned long ino = 0; + dev_t dev = 0; + char *nm = buf; + + vma = find_vma(current->active_mm, address); + + /* check against the find_vma( ) behaviour which returns the next VMA + * if the container VMA is not found + */ + if (vma && (vma->vm_start <= address)) { + struct file *file = vma->vm_file; + if (file) { + struct path *path = &file->f_path; + nm = d_path(path, buf, PAGE_SIZE - 1); + inode = vma->vm_file->f_path.dentry->d_inode; + dev = inode->i_sb->s_dev; + ino = inode->i_ino; + } + pr_info(" @off 0x%lx in [%s]\n" + " VMA: 0x%08lx to 0x%08lx\n\n", + address - vma->vm_start, nm, vma->vm_start, vma->vm_end); + } else + pr_info(" @No matching VMA found\n"); +} + +static void show_ecr_verbose(struct pt_regs *regs) +{ + unsigned int vec, cause_code, cause_reg; + unsigned long address; + + cause_reg = current->thread.cause_code; + pr_info("\n[ECR]: 0x%08x => ", cause_reg); + + /* For Data fault, this is data address not instruction addr */ + address = current->thread.fault_address; + + vec = cause_reg >> 16; + cause_code = (cause_reg >> 8) & 0xFF; + + /* For DTLB Miss or ProtV, display the memory involved too */ + if (vec == ECR_V_DTLB_MISS) { + pr_cont("Invalid (%s) @ 0x%08lx by insn @ 0x%08lx\n", + (cause_code == 0x01) ? "Read From" : + ((cause_code == 0x02) ? "Write to" : "EX"), + address, regs->ret); + } else if (vec == ECR_V_ITLB_MISS) { + pr_cont("Insn could not be fetched\n"); + } else if (vec == ECR_V_MACH_CHK) { + pr_cont("%s\n", (cause_code == 0x0) ? + "Double Fault" : "Other Fatal Err"); + + } else if (vec == ECR_V_PROTV) { + if (cause_code == ECR_C_PROTV_INST_FETCH) + pr_cont("Execute from Non-exec Page\n"); + else if (cause_code == ECR_C_PROTV_LOAD) + pr_cont("Read from Non-readable Page\n"); + else if (cause_code == ECR_C_PROTV_STORE) + pr_cont("Write to Non-writable Page\n"); + else if (cause_code == ECR_C_PROTV_XCHG) + pr_cont("Data exchange protection violation\n"); + else if (cause_code == ECR_C_PROTV_MISALIG_DATA) + pr_cont("Misaligned r/w from 0x%08lx\n", address); + } else if (vec == ECR_V_INSN_ERR) { + pr_cont("Illegal Insn\n"); + } else { + pr_cont("Check Programmer's Manual\n"); + } +} + +/************************************************************************ + * API called by rest of kernel + ***********************************************************************/ + +void show_regs(struct pt_regs *regs) +{ + struct task_struct *tsk = current; + struct callee_regs *cregs; + char *buf; + + buf = (char *)__get_free_page(GFP_TEMPORARY); + if (!buf) + return; + + print_task_path_n_nm(tsk, buf); + + if (current->thread.cause_code) + show_ecr_verbose(regs); + + pr_info("[EFA]: 0x%08lx\n", current->thread.fault_address); + pr_info("[ERET]: 0x%08lx (PC of Faulting Instr)\n", regs->ret); + + show_faulting_vma(regs->ret, buf); /* faulting code, not data */ + + /* can't use print_vma_addr() yet as it doesn't check for + * non-inclusive vma + */ + + /* print special regs */ + pr_info("status32: 0x%08lx\n", regs->status32); + pr_info(" SP: 0x%08lx\tFP: 0x%08lx\n", regs->sp, regs->fp); + pr_info("BTA: 0x%08lx\tBLINK: 0x%08lx\n", + regs->bta, regs->blink); + pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", + regs->lp_start, regs->lp_end, regs->lp_count); + + /* print regs->r0 thru regs->r12 + * Sequential printing was generating horrible code + */ + print_reg_file(&(regs->r0), 0); + + /* If Callee regs were saved, display them too */ + cregs = (struct callee_regs *)current->thread.callee_reg; + if (cregs) + show_callee_regs(cregs); + + free_page((unsigned long)buf); +} + +void show_kernel_fault_diag(const char *str, struct pt_regs *regs, + unsigned long address, unsigned long cause_reg) +{ + current->thread.fault_address = address; + current->thread.cause_code = cause_reg; + + /* Caller and Callee regs */ + show_regs(regs); + + /* Show stack trace if this Fatality happened in kernel mode */ + if (!user_mode(regs)) + show_stacktrace(current, regs); +} + +#ifdef CONFIG_DEBUG_FS + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/pagemap.h> +#include <linux/init.h> +#include <linux/namei.h> +#include <linux/debugfs.h> + +static struct dentry *test_dentry; +static struct dentry *test_dir; +static struct dentry *test_u32_dentry; + +static u32 clr_on_read = 1; + +#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT +u32 numitlb, numdtlb, num_pte_not_present; + +static int fill_display_data(char *kbuf) +{ + size_t num = 0; + num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); + num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); + num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); + + if (clr_on_read) + numitlb = numdtlb = num_pte_not_present = 0; + + return num; +} + +static int tlb_stats_open(struct inode *inode, struct file *file) +{ + file->private_data = (void *)__get_free_page(GFP_KERNEL); + return 0; +} + +/* called on user read(): display the couters */ +static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ + char __user *user_buf, /* user buffer */ + size_t len, /* length of buffer */ + loff_t *offset) /* offset in the file */ +{ + size_t num; + char *kbuf = (char *)file->private_data; + + /* All of the data can he shoved in one iteration */ + if (*offset != 0) + return 0; + + num = fill_display_data(kbuf); + + /* simple_read_from_buffer() is helper for copy to user space + It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset + @3 (offset) into the user space address starting at @1 (user_buf). + @5 (len) is max size of user buffer + */ + return simple_read_from_buffer(user_buf, num, offset, kbuf, len); +} + +/* called on user write : clears the counters */ +static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, + size_t length, loff_t *offset) +{ + numitlb = numdtlb = num_pte_not_present = 0; + return length; +} + +static int tlb_stats_close(struct inode *inode, struct file *file) +{ + free_page((unsigned long)(file->private_data)); + return 0; +} + +static const struct file_operations tlb_stats_file_ops = { + .read = tlb_stats_output, + .write = tlb_stats_clear, + .open = tlb_stats_open, + .release = tlb_stats_close +}; +#endif + +static int __init arc_debugfs_init(void) +{ + test_dir = debugfs_create_dir("arc", NULL); + +#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT + test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, + &tlb_stats_file_ops); +#endif + + test_u32_dentry = + debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); + + return 0; +} + +module_init(arc_debugfs_init); + +static void __exit arc_debugfs_exit(void) +{ + debugfs_remove(test_u32_dentry); + debugfs_remove(test_dentry); + debugfs_remove(test_dir); +} +module_exit(arc_debugfs_exit); + +#endif |