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#include <assert.h>
#include <backtrace.h>
#include <ccan/crypto/siphash24/siphash24.h>
#include <ccan/htable/htable.h>
#include <ccan/intmap/intmap.h>
#include <common/daemon.h>
#include <common/memleak.h>
#include <common/utils.h>
struct backtrace_state *backtrace_state;
#if DEVELOPER
static bool memleak_track;
struct memleak_notleak {
bool plus_children;
};
struct memleak_helper {
void (*cb)(struct htable *memtable, const tal_t *);
};
void *notleak_(const void *ptr, bool plus_children)
{
struct memleak_notleak *notleak;
/* If we're not tracking, don't do anything. */
if (!memleak_track)
return cast_const(void *, ptr);
notleak = tal(ptr, struct memleak_notleak);
notleak->plus_children = plus_children;
return cast_const(void *, ptr);
}
static size_t hash_ptr(const void *elem, void *unused UNNEEDED)
{
static struct siphash_seed seed;
return siphash24(&seed, &elem, sizeof(elem));
}
static bool pointer_referenced(struct htable *memtable, const void *p)
{
return htable_del(memtable, hash_ptr(p, NULL), p);
}
static void children_into_htable(const void *exclude1, const void *exclude2,
struct htable *memtable, const tal_t *p)
{
const tal_t *i;
for (i = tal_first(p); i; i = tal_next(i)) {
const char *name = tal_name(i);
if (i == exclude1 || i == exclude2)
return;
if (name) {
/* Don't add backtrace objects. */
if (streq(name, "backtrace"))
continue;
/* Don't add our own memleak_helpers or notleak() */
if (strends(name, "struct memleak_helper")
|| strends(name, "struct memleak_notleak"))
continue;
/* Don't add tal_link objects */
if (strends(name, "struct link")
|| strends(name, "struct linkable"))
continue;
/* ccan/io allocates pollfd array, always array. */
if (strends(name, "struct pollfd[]") && !tal_parent(i))
continue;
if (strends(name, "struct io_plan *[]") && !tal_parent(i))
continue;
/* Other notleak internals. */
if (strends(name, "_notleak"))
continue;
/* Don't add tmpctx. */
if (streq(name, "tmpctx"))
continue;
}
htable_add(memtable, hash_ptr(i, NULL), i);
children_into_htable(exclude1, exclude2, memtable, i);
}
}
static void scan_for_pointers(struct htable *memtable,
const tal_t *p, size_t bytelen)
{
size_t i, n;
/* Search for (aligned) pointers. */
n = bytelen / sizeof(void *);
for (i = 0; i < n; i++) {
void *ptr;
memcpy(&ptr, (char *)p + i * sizeof(void *), sizeof(ptr));
if (pointer_referenced(memtable, ptr))
scan_for_pointers(memtable, ptr, tal_bytelen(ptr));
}
}
void memleak_scan_region(struct htable *memtable,
const void *ptr, size_t bytelen)
{
pointer_referenced(memtable, ptr);
scan_for_pointers(memtable, ptr, bytelen);
}
static void remove_with_children(struct htable *memtable, const tal_t *p)
{
const tal_t *i;
pointer_referenced(memtable, p);
for (i = tal_first(p); i; i = tal_next(i))
remove_with_children(memtable, i);
}
void memleak_remove_referenced(struct htable *memtable, const void *root)
{
/* Now delete the ones which are referenced. */
memleak_scan_region(memtable, root, tal_bytelen(root));
/* Remove memtable itself */
pointer_referenced(memtable, memtable);
}
/* memleak can't see inside hash tables, so do them manually */
void memleak_remove_htable(struct htable *memtable, const struct htable *ht)
{
struct htable_iter i;
const void *p;
for (p = htable_first(ht, &i); p; p = htable_next(ht, &i))
memleak_scan_region(memtable, p, tal_bytelen(p));
}
/* FIXME: If uintmap used tal, this wouldn't be necessary! */
void memleak_remove_intmap_(struct htable *memtable, const struct intmap *m)
{
void *p;
intmap_index_t i;
for (p = intmap_first_(m, &i); p; p = intmap_after_(m, &i))
memleak_scan_region(memtable, p, tal_bytelen(p));
}
static bool ptr_match(const void *candidate, void *ptr)
{
return candidate == ptr;
}
const void *memleak_get(struct htable *memtable, const uintptr_t **backtrace)
{
struct htable_iter it;
const tal_t *i, *p;
i = htable_first(memtable, &it);
if (!i)
return NULL;
/* Delete from table (avoids parenting loops) */
htable_delval(memtable, &it);
/* Find ancestor, which is probably source of leak. */
for (p = tal_parent(i);
htable_get(memtable, hash_ptr(p, NULL), ptr_match, p);
i = p, p = tal_parent(i));
/* Delete all children */
remove_with_children(memtable, i);
/* Does it have a child called "backtrace"? */
for (*backtrace = tal_first(i);
*backtrace;
*backtrace = tal_next(*backtrace)) {
if (tal_name(*backtrace)
&& streq(tal_name(*backtrace), "backtrace"))
break;
}
return i;
}
static int append_bt(void *data, uintptr_t pc)
{
uintptr_t *bt = data;
if (bt[0] == 32)
return 1;
bt[bt[0]++] = pc;
return 0;
}
static void add_backtrace(tal_t *parent UNUSED, enum tal_notify_type type UNNEEDED,
void *child)
{
uintptr_t *bt = tal_arrz_label(child, uintptr_t, 32, "backtrace");
/* First serves as counter. */
bt[0] = 1;
backtrace_simple(backtrace_state, 2, append_bt, NULL, bt);
tal_add_notifier(child, TAL_NOTIFY_ADD_CHILD, add_backtrace);
}
static void add_backtrace_notifiers(const tal_t *root)
{
tal_add_notifier(root, TAL_NOTIFY_ADD_CHILD, add_backtrace);
for (tal_t *i = tal_first(root); i; i = tal_next(i))
add_backtrace_notifiers(i);
}
void memleak_add_helper_(const tal_t *p,
void (*cb)(struct htable *memtable, const tal_t *))
{
struct memleak_helper *mh = tal(p, struct memleak_helper);
mh->cb = cb;
}
/* Handle allocations marked with helpers or notleak() */
static void call_memleak_helpers(struct htable *memtable, const tal_t *p)
{
const tal_t *i;
for (i = tal_first(p); i; i = tal_next(i)) {
const char *name = tal_name(i);
if (name && strends(name, "struct memleak_helper")) {
const struct memleak_helper *mh = i;
mh->cb(memtable, p);
} else if (name && strends(name, "struct memleak_notleak")) {
const struct memleak_notleak *notleak = i;
if (notleak->plus_children)
remove_with_children(memtable, p);
else
pointer_referenced(memtable, p);
memleak_scan_region(memtable, p, tal_bytelen(p));
} else {
call_memleak_helpers(memtable, i);
}
}
}
struct htable *memleak_enter_allocations(const tal_t *ctx,
const void *exclude1,
const void *exclude2)
{
struct htable *memtable = tal(ctx, struct htable);
htable_init(memtable, hash_ptr, NULL);
/* First, add all pointers off NULL to table. */
children_into_htable(exclude1, exclude2, memtable, NULL);
/* Iterate and call helpers to eliminate hard-to-get references. */
call_memleak_helpers(memtable, NULL);
tal_add_destructor(memtable, htable_clear);
return memtable;
}
void memleak_init(void)
{
memleak_track = true;
if (backtrace_state)
add_backtrace_notifiers(NULL);
}
#else /* !DEVELOPER */
void *notleak_(const void *ptr, bool plus_children UNNEEDED)
{
return cast_const(void *, ptr);
}
#endif /* !DEVELOPER */