| /* |
| * kallsyms.c: in-kernel printing of symbolic oopses and stack traces. |
| * |
| * Rewritten and vastly simplified by Rusty Russell for in-kernel |
| * module loader: |
| * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation |
| * |
| * ChangeLog: |
| * |
| * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com> |
| * Changed the compression method from stem compression to "table lookup" |
| * compression (see scripts/kallsyms.c for a more complete description) |
| */ |
| #include <linux/kallsyms.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/seq_file.h> |
| #include <linux/fs.h> |
| #include <linux/err.h> |
| #include <linux/proc_fs.h> |
| #include <linux/sched.h> /* for cond_resched */ |
| #include <linux/mm.h> |
| #include <linux/ctype.h> |
| |
| #include <asm/sections.h> |
| |
| #ifdef CONFIG_KALLSYMS_ALL |
| #define all_var 1 |
| #else |
| #define all_var 0 |
| #endif |
| |
| /* These will be re-linked against their real values during the second link stage */ |
| extern const unsigned long kallsyms_addresses[] __attribute__((weak)); |
| extern const u8 kallsyms_names[] __attribute__((weak)); |
| |
| /* tell the compiler that the count isn't in the small data section if the arch |
| * has one (eg: FRV) |
| */ |
| extern const unsigned long kallsyms_num_syms |
| __attribute__((weak, section(".rodata"))); |
| |
| extern const u8 kallsyms_token_table[] __attribute__((weak)); |
| extern const u16 kallsyms_token_index[] __attribute__((weak)); |
| |
| extern const unsigned long kallsyms_markers[] __attribute__((weak)); |
| |
| static inline int is_kernel_inittext(unsigned long addr) |
| { |
| if (addr >= (unsigned long)_sinittext |
| && addr <= (unsigned long)_einittext) |
| return 1; |
| return 0; |
| } |
| |
| static inline int is_kernel_text(unsigned long addr) |
| { |
| if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) |
| return 1; |
| return in_gate_area_no_task(addr); |
| } |
| |
| static inline int is_kernel(unsigned long addr) |
| { |
| if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) |
| return 1; |
| return in_gate_area_no_task(addr); |
| } |
| |
| static int is_ksym_addr(unsigned long addr) |
| { |
| if (all_var) |
| return is_kernel(addr); |
| |
| return is_kernel_text(addr) || is_kernel_inittext(addr); |
| } |
| |
| /* expand a compressed symbol data into the resulting uncompressed string, |
| given the offset to where the symbol is in the compressed stream */ |
| static unsigned int kallsyms_expand_symbol(unsigned int off, char *result) |
| { |
| int len, skipped_first = 0; |
| const u8 *tptr, *data; |
| |
| /* get the compressed symbol length from the first symbol byte */ |
| data = &kallsyms_names[off]; |
| len = *data; |
| data++; |
| |
| /* update the offset to return the offset for the next symbol on |
| * the compressed stream */ |
| off += len + 1; |
| |
| /* for every byte on the compressed symbol data, copy the table |
| entry for that byte */ |
| while(len) { |
| tptr = &kallsyms_token_table[ kallsyms_token_index[*data] ]; |
| data++; |
| len--; |
| |
| while (*tptr) { |
| if(skipped_first) { |
| *result = *tptr; |
| result++; |
| } else |
| skipped_first = 1; |
| tptr++; |
| } |
| } |
| |
| *result = '\0'; |
| |
| /* return to offset to the next symbol */ |
| return off; |
| } |
| |
| /* get symbol type information. This is encoded as a single char at the |
| * begining of the symbol name */ |
| static char kallsyms_get_symbol_type(unsigned int off) |
| { |
| /* get just the first code, look it up in the token table, and return the |
| * first char from this token */ |
| return kallsyms_token_table[ kallsyms_token_index[ kallsyms_names[off+1] ] ]; |
| } |
| |
| |
| /* find the offset on the compressed stream given and index in the |
| * kallsyms array */ |
| static unsigned int get_symbol_offset(unsigned long pos) |
| { |
| const u8 *name; |
| int i; |
| |
| /* use the closest marker we have. We have markers every 256 positions, |
| * so that should be close enough */ |
| name = &kallsyms_names[ kallsyms_markers[pos>>8] ]; |
| |
| /* sequentially scan all the symbols up to the point we're searching for. |
| * Every symbol is stored in a [<len>][<len> bytes of data] format, so we |
| * just need to add the len to the current pointer for every symbol we |
| * wish to skip */ |
| for(i = 0; i < (pos&0xFF); i++) |
| name = name + (*name) + 1; |
| |
| return name - kallsyms_names; |
| } |
| |
| /* Lookup the address for this symbol. Returns 0 if not found. */ |
| unsigned long kallsyms_lookup_name(const char *name) |
| { |
| char namebuf[KSYM_NAME_LEN]; |
| unsigned long i; |
| unsigned int off; |
| |
| for (i = 0, off = 0; i < kallsyms_num_syms; i++) { |
| off = kallsyms_expand_symbol(off, namebuf); |
| |
| if (strcmp(namebuf, name) == 0) |
| return kallsyms_addresses[i]; |
| } |
| return module_kallsyms_lookup_name(name); |
| } |
| |
| static unsigned long get_symbol_pos(unsigned long addr, |
| unsigned long *symbolsize, |
| unsigned long *offset) |
| { |
| unsigned long symbol_start = 0, symbol_end = 0; |
| unsigned long i, low, high, mid; |
| |
| /* This kernel should never had been booted. */ |
| BUG_ON(!kallsyms_addresses); |
| |
| /* do a binary search on the sorted kallsyms_addresses array */ |
| low = 0; |
| high = kallsyms_num_syms; |
| |
| while (high - low > 1) { |
| mid = (low + high) / 2; |
| if (kallsyms_addresses[mid] <= addr) |
| low = mid; |
| else |
| high = mid; |
| } |
| |
| /* |
| * search for the first aliased symbol. Aliased |
| * symbols are symbols with the same address |
| */ |
| while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low]) |
| --low; |
| |
| symbol_start = kallsyms_addresses[low]; |
| |
| /* Search for next non-aliased symbol */ |
| for (i = low + 1; i < kallsyms_num_syms; i++) { |
| if (kallsyms_addresses[i] > symbol_start) { |
| symbol_end = kallsyms_addresses[i]; |
| break; |
| } |
| } |
| |
| /* if we found no next symbol, we use the end of the section */ |
| if (!symbol_end) { |
| if (is_kernel_inittext(addr)) |
| symbol_end = (unsigned long)_einittext; |
| else if (all_var) |
| symbol_end = (unsigned long)_end; |
| else |
| symbol_end = (unsigned long)_etext; |
| } |
| |
| if (symbolsize) |
| *symbolsize = symbol_end - symbol_start; |
| if (offset) |
| *offset = addr - symbol_start; |
| |
| return low; |
| } |
| |
| /* |
| * Lookup an address but don't bother to find any names. |
| */ |
| int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, |
| unsigned long *offset) |
| { |
| char namebuf[KSYM_NAME_LEN]; |
| if (is_ksym_addr(addr)) |
| return !!get_symbol_pos(addr, symbolsize, offset); |
| |
| return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); |
| } |
| |
| /* |
| * Lookup an address |
| * - modname is set to NULL if it's in the kernel |
| * - we guarantee that the returned name is valid until we reschedule even if |
| * it resides in a module |
| * - we also guarantee that modname will be valid until rescheduled |
| */ |
| const char *kallsyms_lookup(unsigned long addr, |
| unsigned long *symbolsize, |
| unsigned long *offset, |
| char **modname, char *namebuf) |
| { |
| namebuf[KSYM_NAME_LEN - 1] = 0; |
| namebuf[0] = 0; |
| |
| if (is_ksym_addr(addr)) { |
| unsigned long pos; |
| |
| pos = get_symbol_pos(addr, symbolsize, offset); |
| /* Grab name */ |
| kallsyms_expand_symbol(get_symbol_offset(pos), namebuf); |
| if (modname) |
| *modname = NULL; |
| return namebuf; |
| } |
| |
| /* see if it's in a module */ |
| return module_address_lookup(addr, symbolsize, offset, modname, |
| namebuf); |
| return NULL; |
| } |
| |
| int lookup_symbol_name(unsigned long addr, char *symname) |
| { |
| symname[0] = '\0'; |
| symname[KSYM_NAME_LEN - 1] = '\0'; |
| |
| if (is_ksym_addr(addr)) { |
| unsigned long pos; |
| |
| pos = get_symbol_pos(addr, NULL, NULL); |
| /* Grab name */ |
| kallsyms_expand_symbol(get_symbol_offset(pos), symname); |
| return 0; |
| } |
| /* see if it's in a module */ |
| return lookup_module_symbol_name(addr, symname); |
| } |
| |
| int lookup_symbol_attrs(unsigned long addr, unsigned long *size, |
| unsigned long *offset, char *modname, char *name) |
| { |
| name[0] = '\0'; |
| name[KSYM_NAME_LEN - 1] = '\0'; |
| |
| if (is_ksym_addr(addr)) { |
| unsigned long pos; |
| |
| pos = get_symbol_pos(addr, size, offset); |
| /* Grab name */ |
| kallsyms_expand_symbol(get_symbol_offset(pos), name); |
| modname[0] = '\0'; |
| return 0; |
| } |
| /* see if it's in a module */ |
| return lookup_module_symbol_attrs(addr, size, offset, modname, name); |
| } |
| |
| /* Look up a kernel symbol and return it in a text buffer. */ |
| int sprint_symbol(char *buffer, unsigned long address) |
| { |
| char *modname; |
| const char *name; |
| unsigned long offset, size; |
| char namebuf[KSYM_NAME_LEN]; |
| |
| name = kallsyms_lookup(address, &size, &offset, &modname, namebuf); |
| if (!name) |
| return sprintf(buffer, "0x%lx", address); |
| |
| if (modname) |
| return sprintf(buffer, "%s+%#lx/%#lx [%s]", name, offset, |
| size, modname); |
| else |
| return sprintf(buffer, "%s+%#lx/%#lx", name, offset, size); |
| } |
| |
| /* Look up a kernel symbol and print it to the kernel messages. */ |
| void __print_symbol(const char *fmt, unsigned long address) |
| { |
| char buffer[KSYM_SYMBOL_LEN]; |
| |
| sprint_symbol(buffer, address); |
| |
| printk(fmt, buffer); |
| } |
| |
| /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ |
| struct kallsym_iter |
| { |
| loff_t pos; |
| unsigned long value; |
| unsigned int nameoff; /* If iterating in core kernel symbols */ |
| char type; |
| char name[KSYM_NAME_LEN]; |
| char module_name[MODULE_NAME_LEN]; |
| int exported; |
| }; |
| |
| static int get_ksymbol_mod(struct kallsym_iter *iter) |
| { |
| if (module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value, |
| &iter->type, iter->name, iter->module_name, |
| &iter->exported) < 0) |
| return 0; |
| return 1; |
| } |
| |
| /* Returns space to next name. */ |
| static unsigned long get_ksymbol_core(struct kallsym_iter *iter) |
| { |
| unsigned off = iter->nameoff; |
| |
| iter->module_name[0] = '\0'; |
| iter->value = kallsyms_addresses[iter->pos]; |
| |
| iter->type = kallsyms_get_symbol_type(off); |
| |
| off = kallsyms_expand_symbol(off, iter->name); |
| |
| return off - iter->nameoff; |
| } |
| |
| static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) |
| { |
| iter->name[0] = '\0'; |
| iter->nameoff = get_symbol_offset(new_pos); |
| iter->pos = new_pos; |
| } |
| |
| /* Returns false if pos at or past end of file. */ |
| static int update_iter(struct kallsym_iter *iter, loff_t pos) |
| { |
| /* Module symbols can be accessed randomly. */ |
| if (pos >= kallsyms_num_syms) { |
| iter->pos = pos; |
| return get_ksymbol_mod(iter); |
| } |
| |
| /* If we're not on the desired position, reset to new position. */ |
| if (pos != iter->pos) |
| reset_iter(iter, pos); |
| |
| iter->nameoff += get_ksymbol_core(iter); |
| iter->pos++; |
| |
| return 1; |
| } |
| |
| static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
| { |
| (*pos)++; |
| |
| if (!update_iter(m->private, *pos)) |
| return NULL; |
| return p; |
| } |
| |
| static void *s_start(struct seq_file *m, loff_t *pos) |
| { |
| if (!update_iter(m->private, *pos)) |
| return NULL; |
| return m->private; |
| } |
| |
| static void s_stop(struct seq_file *m, void *p) |
| { |
| } |
| |
| static int s_show(struct seq_file *m, void *p) |
| { |
| struct kallsym_iter *iter = m->private; |
| |
| /* Some debugging symbols have no name. Ignore them. */ |
| if (!iter->name[0]) |
| return 0; |
| |
| if (iter->module_name[0]) { |
| char type; |
| |
| /* Label it "global" if it is exported, |
| * "local" if not exported. */ |
| type = iter->exported ? toupper(iter->type) : |
| tolower(iter->type); |
| seq_printf(m, "%0*lx %c %s\t[%s]\n", |
| (int)(2*sizeof(void*)), |
| iter->value, type, iter->name, iter->module_name); |
| } else |
| seq_printf(m, "%0*lx %c %s\n", |
| (int)(2*sizeof(void*)), |
| iter->value, iter->type, iter->name); |
| return 0; |
| } |
| |
| static const struct seq_operations kallsyms_op = { |
| .start = s_start, |
| .next = s_next, |
| .stop = s_stop, |
| .show = s_show |
| }; |
| |
| static int kallsyms_open(struct inode *inode, struct file *file) |
| { |
| /* We keep iterator in m->private, since normal case is to |
| * s_start from where we left off, so we avoid doing |
| * using get_symbol_offset for every symbol */ |
| struct kallsym_iter *iter; |
| int ret; |
| |
| iter = kmalloc(sizeof(*iter), GFP_KERNEL); |
| if (!iter) |
| return -ENOMEM; |
| reset_iter(iter, 0); |
| |
| ret = seq_open(file, &kallsyms_op); |
| if (ret == 0) |
| ((struct seq_file *)file->private_data)->private = iter; |
| else |
| kfree(iter); |
| return ret; |
| } |
| |
| static const struct file_operations kallsyms_operations = { |
| .open = kallsyms_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static int __init kallsyms_init(void) |
| { |
| proc_create("kallsyms", 0444, NULL, &kallsyms_operations); |
| return 0; |
| } |
| __initcall(kallsyms_init); |
| |
| EXPORT_SYMBOL(__print_symbol); |
| EXPORT_SYMBOL_GPL(sprint_symbol); |