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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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struct codetag_type { struct list_head link; unsigned int count; struct idr mod_idr; /* * protects mod_idr, next_mod_seq, * iter->mod_seq and cmod->mod_seq */ struct rw_semaphore mod_lock; struct codetag_type_desc desc; /* generates unique sequence number for module load */ unsigned long next_mod_seq;};
struct codetag_range { struct codetag *start; struct codetag *stop;};
struct codetag_module { struct module *mod; struct codetag_range range; unsigned long mod_seq;};
static DEFINE_MUTEX(codetag_lock);static LIST_HEAD(codetag_types);
void codetag_lock_module_list(struct codetag_type *cttype){ down_read(&cttype->mod_lock);}
bool codetag_trylock_module_list(struct codetag_type *cttype){ return down_read_trylock(&cttype->mod_lock) != 0;}
void codetag_unlock_module_list(struct codetag_type *cttype){ up_read(&cttype->mod_lock);}
struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype){ struct codetag_iterator iter = { .cttype = cttype, .cmod = NULL, .mod_id = 0, .ct = NULL, .mod_seq = 0, };
return iter;}
static inline struct codetag *get_first_module_ct(struct codetag_module *cmod){ return cmod->range.start < cmod->range.stop ? cmod->range.start : NULL;}
static inlinestruct codetag *get_next_module_ct(struct codetag_iterator *iter){ struct codetag *res = (struct codetag *) ((char *)iter->ct + iter->cttype->desc.tag_size);
return res < iter->cmod->range.stop ? res : NULL;}
struct codetag *codetag_next_ct(struct codetag_iterator *iter){ struct codetag_type *cttype = iter->cttype; struct codetag_module *cmod; struct codetag *ct;
lockdep_assert_held(&cttype->mod_lock);
if (unlikely(idr_is_empty(&cttype->mod_idr))) return NULL;
ct = NULL; while (true) { cmod = idr_find(&cttype->mod_idr, iter->mod_id);
/* If module was removed move to the next one */ if (!cmod) cmod = idr_get_next_ul(&cttype->mod_idr, &iter->mod_id);
/* Exit if no more modules */ if (!cmod) break;
if (!iter->cmod || iter->mod_seq != cmod->mod_seq) { iter->cmod = cmod; iter->mod_seq = cmod->mod_seq; ct = get_first_module_ct(cmod); } else { ct = get_next_module_ct(iter); }
if (ct) break;
iter->mod_id++; }
iter->ct = ct; return ct;}
void codetag_to_text(struct seq_buf *out, struct codetag *ct){ if (ct->modname) seq_buf_printf(out, "%s:%u [%s] func:%s", ct->filename, ct->lineno, ct->modname, ct->function); else seq_buf_printf(out, "%s:%u func:%s", ct->filename, ct->lineno, ct->function);}
static inline size_t range_size(const struct codetag_type *cttype, const struct codetag_range *range){ return ((char *)range->stop - (char *)range->start) / cttype->desc.tag_size;}
static void *get_symbol(struct module *mod, const char *prefix, const char *name){ DECLARE_SEQ_BUF(sb, KSYM_NAME_LEN); const char *buf; void *ret;
seq_buf_printf(&sb, "%s%s", prefix, name); if (seq_buf_has_overflowed(&sb)) return NULL;
buf = seq_buf_str(&sb); preempt_disable(); ret = mod ? (void *)find_kallsyms_symbol_value(mod, buf) : (void *)kallsyms_lookup_name(buf); preempt_enable();
return ret;}
static struct codetag_range get_section_range(struct module *mod, const char *section){ return (struct codetag_range) { get_symbol(mod, CODETAG_SECTION_START_PREFIX, section), get_symbol(mod, CODETAG_SECTION_STOP_PREFIX, section), };}
static const char *get_mod_name(__maybe_unused struct module *mod){#ifdef CONFIG_MODULES if (mod) return mod->name;#endif return "(built-in)";}
static int codetag_module_init(struct codetag_type *cttype, struct module *mod){ struct codetag_range range; struct codetag_module *cmod; int mod_id; int err;
range = get_section_range(mod, cttype->desc.section); if (!range.start || !range.stop) { pr_warn("Failed to load code tags of type %s from the module %s\n", cttype->desc.section, get_mod_name(mod)); return -EINVAL; }
/* Ignore empty ranges */ if (range.start == range.stop) return 0;
BUG_ON(range.start > range.stop);
cmod = kmalloc_obj(*cmod); if (unlikely(!cmod)) return -ENOMEM;
cmod->mod = mod; cmod->range = range;
down_write(&cttype->mod_lock); cmod->mod_seq = ++cttype->next_mod_seq; mod_id = idr_alloc(&cttype->mod_idr, cmod, 0, 0, GFP_KERNEL); if (mod_id >= 0) { if (cttype->desc.module_load) { err = cttype->desc.module_load(mod, range.start, range.stop); if (!err) cttype->count += range_size(cttype, &range); else idr_remove(&cttype->mod_idr, mod_id); } else { cttype->count += range_size(cttype, &range); err = 0; } } else { err = mod_id; } up_write(&cttype->mod_lock);
if (err < 0) { kfree(cmod); return err; }
return 0;}
#ifdef CONFIG_MODULES#define CODETAG_SECTION_PREFIX ".codetag."
/* Some codetag types need a separate module section */bool codetag_needs_module_section(struct module *mod, const char *name, unsigned long size){ const char *type_name; struct codetag_type *cttype; bool ret = false;
if (strncmp(name, CODETAG_SECTION_PREFIX, strlen(CODETAG_SECTION_PREFIX))) return false;
type_name = name + strlen(CODETAG_SECTION_PREFIX); mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { if (strcmp(type_name, cttype->desc.section) == 0) { if (!cttype->desc.needs_section_mem) break;
down_write(&cttype->mod_lock); ret = cttype->desc.needs_section_mem(mod, size); up_write(&cttype->mod_lock); break; } } mutex_unlock(&codetag_lock);
return ret;}
void *codetag_alloc_module_section(struct module *mod, const char *name, unsigned long size, unsigned int prepend, unsigned long align){ const char *type_name = name + strlen(CODETAG_SECTION_PREFIX); struct codetag_type *cttype; void *ret = ERR_PTR(-EINVAL);
mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { if (strcmp(type_name, cttype->desc.section) == 0) { if (WARN_ON(!cttype->desc.alloc_section_mem)) break;
down_write(&cttype->mod_lock); ret = cttype->desc.alloc_section_mem(mod, size, prepend, align); up_write(&cttype->mod_lock); break; } } mutex_unlock(&codetag_lock);
return ret;}
void codetag_free_module_sections(struct module *mod){ struct codetag_type *cttype;
mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { if (!cttype->desc.free_section_mem) continue;
down_write(&cttype->mod_lock); cttype->desc.free_section_mem(mod, false); up_write(&cttype->mod_lock); } mutex_unlock(&codetag_lock);}
void codetag_module_replaced(struct module *mod, struct module *new_mod){ struct codetag_type *cttype;
mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { if (!cttype->desc.module_replaced) continue;
down_write(&cttype->mod_lock); cttype->desc.module_replaced(mod, new_mod); up_write(&cttype->mod_lock); } mutex_unlock(&codetag_lock);}
int codetag_load_module(struct module *mod){ struct codetag_type *cttype; int ret = 0;
if (!mod) return 0;
mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { ret = codetag_module_init(cttype, mod); if (ret) break; } mutex_unlock(&codetag_lock);
return ret;}
void codetag_unload_module(struct module *mod){ struct codetag_type *cttype;
if (!mod) return;
/* await any module's kfree_rcu() operations to complete */ kvfree_rcu_barrier();
mutex_lock(&codetag_lock); list_for_each_entry(cttype, &codetag_types, link) { struct codetag_module *found = NULL; struct codetag_module *cmod; unsigned long mod_id, tmp;
down_write(&cttype->mod_lock); idr_for_each_entry_ul(&cttype->mod_idr, cmod, tmp, mod_id) { if (cmod->mod && cmod->mod == mod) { found = cmod; break; } } if (found) { if (cttype->desc.module_unload) cttype->desc.module_unload(cmod->mod, cmod->range.start, cmod->range.stop);
cttype->count -= range_size(cttype, &cmod->range); idr_remove(&cttype->mod_idr, mod_id); kfree(cmod); } up_write(&cttype->mod_lock); if (found && cttype->desc.free_section_mem) cttype->desc.free_section_mem(mod, true); } mutex_unlock(&codetag_lock);}#endif /* CONFIG_MODULES */
struct codetag_type *codetag_register_type(const struct codetag_type_desc *desc){ struct codetag_type *cttype; int err;
BUG_ON(desc->tag_size <= 0);
cttype = kzalloc_obj(*cttype); if (unlikely(!cttype)) return ERR_PTR(-ENOMEM);
cttype->desc = *desc; idr_init(&cttype->mod_idr); init_rwsem(&cttype->mod_lock);
err = codetag_module_init(cttype, NULL); if (unlikely(err)) { kfree(cttype); return ERR_PTR(err); }
mutex_lock(&codetag_lock); list_add_tail(&cttype->link, &codetag_types); mutex_unlock(&codetag_lock);
return cttype;}