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#include <assert.h>
#include <backtrace.h>
#include <ccan/crypto/siphash24/siphash24.h>
#include <ccan/htable/htable.h>
#include <ccan/tal/tal.h>
#include <common/memleak.h>
#if DEVELOPER
static struct backtrace_state *backtrace_state;
static const void **notleaks;
static bool *notleak_children;
static size_t find_notleak(const tal_t *ptr)
{
size_t i, nleaks = tal_count(notleaks);
for (i = 0; i < nleaks; i++)
if (notleaks[i] == ptr)
return i;
abort();
}
static void notleak_change(tal_t *ctx,
enum tal_notify_type type,
void *info)
{
size_t i;
if (type == TAL_NOTIFY_FREE) {
i = find_notleak(ctx);
memmove(notleaks + i, notleaks + i + 1,
sizeof(*notleaks) * (tal_count(notleaks) - i - 1));
memmove(notleak_children + i, notleak_children + i + 1,
sizeof(*notleak_children)
* (tal_count(notleak_children) - i - 1));
tal_resize(&notleaks, tal_count(notleaks) - 1);
tal_resize(&notleak_children, tal_count(notleak_children) - 1);
} else if (type == TAL_NOTIFY_MOVE) {
i = find_notleak(info);
notleaks[i] = ctx;
}
}
void *notleak_(const void *ptr, bool plus_children)
{
size_t nleaks;
/* If we're not tracking, don't do anything. */
if (!notleaks)
return cast_const(void *, ptr);
nleaks = tal_count(notleaks);
tal_resize(&notleaks, nleaks+1);
tal_resize(&notleak_children, nleaks+1);
notleaks[nleaks] = ptr;
notleak_children[nleaks] = plus_children;
tal_add_notifier(ptr, TAL_NOTIFY_FREE|TAL_NOTIFY_MOVE, notleak_change);
return cast_const(void *, ptr);
}
/* This only works if all objects have tal_len() */
#ifndef CCAN_TAL_DEBUG
#error CCAN_TAL_DEBUG must be set
#endif
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 (p == exclude1 || p == exclude2)
continue;
if (name) {
/* Don't add backtrace objects. */
if (streq(name, "backtrace"))
continue;
/* Don't add tal_link objects */
if (strends(name, "struct link")
|| strends(name, "struct linkable"))
continue;
/* ccan/io allocates pollfd array. */
if (streq(name,
"ccan/ccan/io/poll.c:40:struct pollfd[]"))
continue;
}
htable_add(memtable, hash_ptr(i, NULL), i);
children_into_htable(exclude1, exclude2, 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);
tal_add_destructor(memtable, htable_clear);
return memtable;
}
static void scan_for_pointers(struct htable *memtable, const tal_t *p)
{
size_t i, n;
/* Search for (aligned) pointers. */
n = tal_len(p) / 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);
}
}
void memleak_scan_region(struct htable *memtable, const void *ptr)
{
pointer_referenced(memtable, ptr);
scan_for_pointers(memtable, ptr);
}
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)
{
size_t i;
/* Now delete the ones which are referenced. */
memleak_scan_region(memtable, root);
memleak_scan_region(memtable, notleaks);
/* Those who asked tal children to be removed, do so. */
for (i = 0; i < tal_count(notleaks); i++)
if (notleak_children[i])
remove_with_children(memtable, notleaks[i]);
/* notleak_children array is not a leak */
pointer_referenced(memtable, notleak_children);
/* Remove memtable itself */
pointer_referenced(memtable, memtable);
}
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, enum tal_notify_type type UNNEEDED,
void *child)
{
uintptr_t *bt = tal_alloc_arr_(child, sizeof(uintptr_t), 32, true, true,
"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);
}
void memleak_init(const tal_t *root, struct backtrace_state *bstate)
{
assert(!notleaks);
backtrace_state = bstate;
notleaks = tal_arr(NULL, const void *, 0);
notleak_children = tal_arr(notleaks, bool, 0);
if (backtrace_state)
tal_add_notifier(root, TAL_NOTIFY_ADD_CHILD, add_backtrace);
}
void memleak_cleanup(void)
{
notleaks = tal_free(notleaks);
}
#endif /* DEVELOPER */