| /* |
| * 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 |
| * Stem compression by Andi Kleen. |
| */ |
| #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> |
| |
| /* These will be re-linked against their real values during the second link stage */ |
| extern unsigned long kallsyms_addresses[] __attribute__((weak)); |
| extern unsigned long kallsyms_num_syms __attribute__((weak)); |
| extern char kallsyms_names[] __attribute__((weak)); |
| |
| /* Defined by the linker script. */ |
| extern char _stext[], _etext[], _sinittext[], _einittext[]; |
| |
| 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 0; |
| } |
| |
| /* Lookup an address. modname is set to NULL if it's in the kernel. */ |
| const char *kallsyms_lookup(unsigned long addr, |
| unsigned long *symbolsize, |
| unsigned long *offset, |
| char **modname, char *namebuf) |
| { |
| unsigned long i, best = 0; |
| |
| /* This kernel should never had been booted. */ |
| BUG_ON(!kallsyms_addresses); |
| |
| namebuf[127] = 0; |
| namebuf[0] = 0; |
| |
| if (is_kernel_text(addr) || is_kernel_inittext(addr)) { |
| unsigned long symbol_end; |
| char *name = kallsyms_names; |
| |
| /* They're sorted, we could be clever here, but who cares? */ |
| for (i = 0; i < kallsyms_num_syms; i++) { |
| if (kallsyms_addresses[i] > kallsyms_addresses[best] && |
| kallsyms_addresses[i] <= addr) |
| best = i; |
| } |
| |
| /* Grab name */ |
| for (i = 0; i <= best; i++) { |
| unsigned prefix = *name++; |
| strncpy(namebuf + prefix, name, 127 - prefix); |
| name += strlen(name) + 1; |
| } |
| |
| /* Base symbol size on next symbol. */ |
| if (best + 1 < kallsyms_num_syms) |
| symbol_end = kallsyms_addresses[best + 1]; |
| else if (is_kernel_inittext(addr)) |
| symbol_end = (unsigned long)_einittext; |
| else |
| symbol_end = (unsigned long)_etext; |
| |
| *symbolsize = symbol_end - kallsyms_addresses[best]; |
| *modname = NULL; |
| *offset = addr - kallsyms_addresses[best]; |
| return namebuf; |
| } |
| |
| return module_address_lookup(addr, symbolsize, offset, modname); |
| } |
| |
| /* Replace "%s" in format with address, or returns -errno. */ |
| void __print_symbol(const char *fmt, unsigned long address) |
| { |
| char *modname; |
| const char *name; |
| unsigned long offset, size; |
| char namebuf[128]; |
| |
| name = kallsyms_lookup(address, &size, &offset, &modname, namebuf); |
| |
| if (!name) { |
| char addrstr[sizeof("0x%lx") + (BITS_PER_LONG*3/10)]; |
| |
| sprintf(addrstr, "0x%lx", address); |
| printk(fmt, addrstr); |
| return; |
| } |
| |
| if (modname) { |
| /* This is pretty small. */ |
| char buffer[sizeof("%s+%#lx/%#lx [%s]") |
| + strlen(name) + 2*(BITS_PER_LONG*3/10) |
| + strlen(modname)]; |
| |
| sprintf(buffer, "%s+%#lx/%#lx [%s]", |
| name, offset, size, modname); |
| printk(fmt, buffer); |
| } else { |
| char buffer[sizeof("%s+%#lx/%#lx") |
| + strlen(name) + 2*(BITS_PER_LONG*3/10)]; |
| |
| sprintf(buffer, "%s+%#lx/%#lx", name, offset, size); |
| printk(fmt, buffer); |
| } |
| } |
| |
| /* To avoid O(n^2) iteration, we carry prefix along. */ |
| struct kallsym_iter |
| { |
| loff_t pos; |
| struct module *owner; |
| unsigned long value; |
| unsigned int nameoff; /* If iterating in core kernel symbols */ |
| char type; |
| char name[128]; |
| }; |
| |
| /* Only label it "global" if it is exported. */ |
| static void upcase_if_global(struct kallsym_iter *iter) |
| { |
| if (is_exported(iter->name, iter->owner)) |
| iter->type += 'A' - 'a'; |
| } |
| |
| static int get_ksymbol_mod(struct kallsym_iter *iter) |
| { |
| iter->owner = module_get_kallsym(iter->pos - kallsyms_num_syms, |
| &iter->value, |
| &iter->type, iter->name); |
| if (iter->owner == NULL) |
| return 0; |
| |
| upcase_if_global(iter); |
| return 1; |
| } |
| |
| static void get_ksymbol_core(struct kallsym_iter *iter) |
| { |
| unsigned stemlen; |
| |
| /* First char of each symbol name indicates prefix length |
| shared with previous name (stem compression). */ |
| stemlen = kallsyms_names[iter->nameoff++]; |
| |
| strlcpy(iter->name+stemlen, kallsyms_names+iter->nameoff, 128-stemlen); |
| iter->nameoff += strlen(kallsyms_names + iter->nameoff) + 1; |
| iter->owner = NULL; |
| iter->value = kallsyms_addresses[iter->pos]; |
| iter->type = 't'; |
| |
| upcase_if_global(iter); |
| } |
| |
| static void reset_iter(struct kallsym_iter *iter) |
| { |
| iter->name[0] = '\0'; |
| iter->nameoff = 0; |
| iter->pos = 0; |
| } |
| |
| /* 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 past the desired position, reset to start. */ |
| if (pos < iter->pos) |
| reset_iter(iter); |
| |
| /* We need to iterate through the previous symbols: can be slow */ |
| for (; iter->pos != pos; iter->pos++) { |
| get_ksymbol_core(iter); |
| cond_resched(); |
| } |
| 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->owner) |
| seq_printf(m, "%0*lx %c %s\t[%s]\n", |
| (int)(2*sizeof(void*)), |
| iter->value, iter->type, iter->name, |
| module_name(iter->owner)); |
| else |
| seq_printf(m, "%0*lx %c %s\n", |
| (int)(2*sizeof(void*)), |
| iter->value, iter->type, iter->name); |
| return 0; |
| } |
| |
| 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 O(N^2). */ |
| struct kallsym_iter *iter; |
| int ret; |
| |
| iter = kmalloc(sizeof(*iter), GFP_KERNEL); |
| if (!iter) |
| return -ENOMEM; |
| reset_iter(iter); |
| |
| ret = seq_open(file, &kallsyms_op); |
| if (ret == 0) |
| ((struct seq_file *)file->private_data)->private = iter; |
| else |
| kfree(iter); |
| return ret; |
| } |
| |
| static int kallsyms_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *m = (struct seq_file *)file->private_data; |
| kfree(m->private); |
| return seq_release(inode, file); |
| } |
| |
| static struct file_operations kallsyms_operations = { |
| .open = kallsyms_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = kallsyms_release, |
| }; |
| |
| int __init kallsyms_init(void) |
| { |
| struct proc_dir_entry *entry; |
| |
| entry = create_proc_entry("kallsyms", 0444, NULL); |
| if (entry) |
| entry->proc_fops = &kallsyms_operations; |
| return 0; |
| } |
| __initcall(kallsyms_init); |
| |
| EXPORT_SYMBOL(kallsyms_lookup); |
| EXPORT_SYMBOL(__print_symbol); |