/* * Kernel Debugger Architecture Independent Support Functions * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (c) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved. * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved. * 03/02/13    added new 2.5 kallsyms <xavier.bru@bull.net> */ #include <linux/types.h>#include <linux/sched.h>#include <linux/mm.h>#include <linux/kallsyms.h>#include <linux/stddef.h>#include <linux/vmalloc.h>#include <linux/ptrace.h>#include <linux/module.h>#include <linux/highmem.h>#include <linux/hardirq.h>#include <linux/delay.h>#include <linux/uaccess.h>#include <linux/kdb.h>#include <linux/slab.h>#include <linux/ctype.h>#include "kdb_private.h" /* * kdbgetsymval - Return the address of the given symbol. * * Parameters: *	symname	Character string containing symbol name *      symtab  Structure to receive results * Returns: *	0	Symbol not found, symtab zero filled *	1	Symbol mapped to module/symbol/section, data in symtab */int kdbgetsymval(const char *symname, kdb_symtab_t *symtab){	kdb_dbg_printf(AR, "symname=%s, symtab=%px\n", symname, symtab);	memset(symtab, 0, sizeof(*symtab));	symtab->sym_start = kallsyms_lookup_name(symname);	if (symtab->sym_start) {		kdb_dbg_printf(AR, "returns 1, symtab->sym_start=0x%lx\n",			       symtab->sym_start);		return 1;	}	kdb_dbg_printf(AR, "returns 0\n");	return 0;}EXPORT_SYMBOL(kdbgetsymval); /** * kdbnearsym() - Return the name of the symbol with the nearest address *                less than @addr. * @addr: Address to check for near symbol * @symtab: Structure to receive results * * WARNING: This function may return a pointer to a single statically * allocated buffer (namebuf). kdb's unusual calling context (single * threaded, all other CPUs halted) provides us sufficient locking for * this to be safe. The only constraint imposed by the static buffer is * that the caller must consume any previous reply prior to another call * to lookup a new symbol. * * Note that, strictly speaking, some architectures may re-enter the kdb * trap if the system turns out to be very badly damaged and this breaks * the single-threaded assumption above. In these circumstances successful * continuation and exit from the inner trap is unlikely to work and any * user attempting this receives a prominent warning before being allowed * to progress. In these circumstances we remain memory safe because * namebuf[KSYM_NAME_LEN-1] will never change from '\0' although we do * tolerate the possibility of garbled symbol display from the outer kdb * trap. * * Return: * * 0 - No sections contain this address, symtab zero filled * * 1 - Address mapped to module/symbol/section, data in symtab */int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab){	int ret = 0;	unsigned long symbolsize = 0;	unsigned long offset = 0;	static char namebuf[KSYM_NAME_LEN]; 	kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab);	memset(symtab, 0, sizeof(*symtab)); 	if (addr < 4096)		goto out; 	symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset,				(char **)(&symtab->mod_name), namebuf);	if (offset > 8*1024*1024) {		symtab->sym_name = NULL;		addr = offset = symbolsize = 0;	}	symtab->sym_start = addr - offset;	symtab->sym_end = symtab->sym_start + symbolsize;	ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; 	if (symtab->mod_name == NULL)		symtab->mod_name = "kernel";	kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, symtab->mod_name=%px, symtab->sym_name=%px (%s)\n",		       ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name);out:	return ret;} static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; /* * kallsyms_symbol_complete * * Parameters: *	prefix_name	prefix of a symbol name to lookup *	max_len		maximum length that can be returned * Returns: *	Number of symbols which match the given prefix. * Notes: *	prefix_name is changed to contain the longest unique prefix that *	starts with this prefix (tab completion). */int kallsyms_symbol_complete(char *prefix_name, int max_len){	loff_t pos = 0;	int prefix_len = strlen(prefix_name), prev_len = 0;	int i, number = 0;	const char *name; 	while ((name = kdb_walk_kallsyms(&pos))) {		if (strncmp(name, prefix_name, prefix_len) == 0) {			strscpy(ks_namebuf, name, sizeof(ks_namebuf));			/* Work out the longest name that matches the prefix */			if (++number == 1) {				prev_len = min_t(int, max_len-1,						 strlen(ks_namebuf));				memcpy(ks_namebuf_prev, ks_namebuf, prev_len);				ks_namebuf_prev[prev_len] = '\0';				continue;			}			for (i = 0; i < prev_len; i++) {				if (ks_namebuf[i] != ks_namebuf_prev[i]) {					prev_len = i;					ks_namebuf_prev[i] = '\0';					break;				}			}		}	}	if (prev_len > prefix_len)		memcpy(prefix_name, ks_namebuf_prev, prev_len+1);	return number;} /* * kallsyms_symbol_next * * Parameters: *	prefix_name	prefix of a symbol name to lookup *	flag	0 means search from the head, 1 means continue search. *	buf_size	maximum length that can be written to prefix_name *			buffer * Returns: *	1 if a symbol matches the given prefix. *	0 if no string found */int kallsyms_symbol_next(char *prefix_name, int flag, int buf_size){	int prefix_len = strlen(prefix_name);	static loff_t pos;	const char *name; 	if (!flag)		pos = 0; 	while ((name = kdb_walk_kallsyms(&pos))) {		if (!strncmp(name, prefix_name, prefix_len))			return strscpy(prefix_name, name, buf_size);	}	return 0;} /* * kdb_symbol_print - Standard method for printing a symbol name and offset. * Inputs: *	addr	Address to be printed. *	symtab	Address of symbol data, if NULL this routine does its *		own lookup. *	punc	Punctuation for string, bit field. * Remarks: *	The string and its punctuation is only printed if the address *	is inside the kernel, except that the value is always printed *	when requested. */void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p,		      unsigned int punc){	kdb_symtab_t symtab, *symtab_p2;	if (symtab_p) {		symtab_p2 = (kdb_symtab_t *)symtab_p;	} else {		symtab_p2 = &symtab;		kdbnearsym(addr, symtab_p2);	}	if (!(symtab_p2->sym_name || (punc & KDB_SP_VALUE)))		return;	if (punc & KDB_SP_SPACEB)		kdb_printf(" ");	if (punc & KDB_SP_VALUE)		kdb_printf(kdb_machreg_fmt0, addr);	if (symtab_p2->sym_name) {		if (punc & KDB_SP_VALUE)			kdb_printf(" ");		if (punc & KDB_SP_PAREN)			kdb_printf("(");		if (strcmp(symtab_p2->mod_name, "kernel"))			kdb_printf("[%s]", symtab_p2->mod_name);		kdb_printf("%s", symtab_p2->sym_name);		if (addr != symtab_p2->sym_start)			kdb_printf("+0x%lx", addr - symtab_p2->sym_start);		if (punc & KDB_SP_SYMSIZE)			kdb_printf("/0x%lx",				   symtab_p2->sym_end - symtab_p2->sym_start);		if (punc & KDB_SP_PAREN)			kdb_printf(")");	}	if (punc & KDB_SP_SPACEA)		kdb_printf(" ");	if (punc & KDB_SP_NEWLINE)		kdb_printf("\n");} /* * kdb_strdup - kdb equivalent of strdup, for disasm code. * Inputs: *	str	The string to duplicate. *	type	Flags to kmalloc for the new string. * Returns: *	Address of the new string, NULL if storage could not be allocated. * Remarks: *	This is not in lib/string.c because it uses kmalloc which is not *	available when string.o is used in boot loaders. */char *kdb_strdup(const char *str, gfp_t type){	int n = strlen(str)+1;	char *s = kmalloc(n, type);	if (!s)		return NULL;	return strcpy(s, str);} /* * kdb_getarea_size - Read an area of data.  The kdb equivalent of *	copy_from_user, with kdb messages for invalid addresses. * Inputs: *	res	Pointer to the area to receive the result. *	addr	Address of the area to copy. *	size	Size of the area. * Returns: *	0 for success, < 0 for error. */int kdb_getarea_size(void *res, unsigned long addr, size_t size){	int ret = copy_from_kernel_nofault((char *)res, (char *)addr, size);	if (ret) {		if (!KDB_STATE(SUPPRESS)) {			kdb_func_printf("Bad address 0x%lx\n", addr);			KDB_STATE_SET(SUPPRESS);		}		ret = KDB_BADADDR;	} else {		KDB_STATE_CLEAR(SUPPRESS);	}	return ret;} /* * kdb_putarea_size - Write an area of data.  The kdb equivalent of *	copy_to_user, with kdb messages for invalid addresses. * Inputs: *	addr	Address of the area to write to. *	res	Pointer to the area holding the data. *	size	Size of the area. * Returns: *	0 for success, < 0 for error. */int kdb_putarea_size(unsigned long addr, void *res, size_t size){	int ret = copy_from_kernel_nofault((char *)addr, (char *)res, size);	if (ret) {		if (!KDB_STATE(SUPPRESS)) {			kdb_func_printf("Bad address 0x%lx\n", addr);			KDB_STATE_SET(SUPPRESS);		}		ret = KDB_BADADDR;	} else {		KDB_STATE_CLEAR(SUPPRESS);	}	return ret;} /* * kdb_getphys - Read data from a physical address. Validate the * 	address is in range, use kmap_atomic() to get data * 	similar to kdb_getarea() - but for phys addresses * Inputs: * 	res	Pointer to the word to receive the result * 	addr	Physical address of the area to copy * 	size	Size of the area * Returns: *	0 for success, < 0 for error. */static int kdb_getphys(void *res, unsigned long addr, size_t size){	unsigned long pfn;	void *vaddr;	struct page *page; 	pfn = (addr >> PAGE_SHIFT);	if (!pfn_valid(pfn))		return 1;	page = pfn_to_page(pfn);	vaddr = kmap_atomic(page);	memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size);	kunmap_atomic(vaddr); 	return 0;} /* * kdb_getphysword * Inputs: *	word	Pointer to the word to receive the result. *	addr	Address of the area to copy. *	size	Size of the area. * Returns: *	0 for success, < 0 for error. */int kdb_getphysword(unsigned long *word, unsigned long addr, size_t size){	int diag;	__u8  w1;	__u16 w2;	__u32 w4;	__u64 w8;	*word = 0;	/* Default value if addr or size is invalid */ 	switch (size) {	case 1:		diag = kdb_getphys(&w1, addr, sizeof(w1));		if (!diag)			*word = w1;		break;	case 2:		diag = kdb_getphys(&w2, addr, sizeof(w2));		if (!diag)			*word = w2;		break;	case 4:		diag = kdb_getphys(&w4, addr, sizeof(w4));		if (!diag)			*word = w4;		break;	case 8:		if (size <= sizeof(*word)) {			diag = kdb_getphys(&w8, addr, sizeof(w8));			if (!diag)				*word = w8;			break;		}		fallthrough;	default:		diag = KDB_BADWIDTH;		kdb_func_printf("bad width %zu\n", size);	}	return diag;} /* * kdb_getword - Read a binary value.  Unlike kdb_getarea, this treats *	data as numbers. * Inputs: *	word	Pointer to the word to receive the result. *	addr	Address of the area to copy. *	size	Size of the area. * Returns: *	0 for success, < 0 for error. */int kdb_getword(unsigned long *word, unsigned long addr, size_t size){	int diag;	__u8  w1;	__u16 w2;	__u32 w4;	__u64 w8;	*word = 0;	/* Default value if addr or size is invalid */	switch (size) {	case 1:		diag = kdb_getarea(w1, addr);		if (!diag)			*word = w1;		break;	case 2:		diag = kdb_getarea(w2, addr);		if (!diag)			*word = w2;		break;	case 4:		diag = kdb_getarea(w4, addr);		if (!diag)			*word = w4;		break;	case 8:		if (size <= sizeof(*word)) {			diag = kdb_getarea(w8, addr);			if (!diag)				*word = w8;			break;		}		fallthrough;	default:		diag = KDB_BADWIDTH;		kdb_func_printf("bad width %zu\n", size);	}	return diag;} /* * kdb_putword - Write a binary value.  Unlike kdb_putarea, this *	treats data as numbers. * Inputs: *	addr	Address of the area to write to.. *	word	The value to set. *	size	Size of the area. * Returns: *	0 for success, < 0 for error. */int kdb_putword(unsigned long addr, unsigned long word, size_t size){	int diag;	__u8  w1;	__u16 w2;	__u32 w4;	__u64 w8;	switch (size) {	case 1:		w1 = word;		diag = kdb_putarea(addr, w1);		break;	case 2:		w2 = word;		diag = kdb_putarea(addr, w2);		break;	case 4:		w4 = word;		diag = kdb_putarea(addr, w4);		break;	case 8:		if (size <= sizeof(word)) {			w8 = word;			diag = kdb_putarea(addr, w8);			break;		}		fallthrough;	default:		diag = KDB_BADWIDTH;		kdb_func_printf("bad width %zu\n", size);	}	return diag;}   /* * kdb_task_state_char - Return the character that represents the task state. * Inputs: *	p	struct task for the process * Returns: *	One character to represent the task state. */char kdb_task_state_char (const struct task_struct *p){	unsigned long tmp;	char state;	int cpu; 	if (!p ||	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))		return 'E'; 	state = task_state_to_char((struct task_struct *) p); 	if (is_idle_task(p)) {		/* Idle task.  Is it really idle, apart from the kdb		 * interrupt? */

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