mirror_zfs/lib/libuutil/uu_list.c
Brooks Davis 27d29946be
libuutil: deobfuscate internal pointers
uu_avl and uu_list stored internal next/prev pointers and parent
pointers (unused) obfuscated (byte swapped) to hide them from a long
forgotten leak checker (No one at the 2022 OpenZFS developers meeting
could recall the history.)  This would break on CHERI systems and adds
no obvious value.  Rename the members, use proper types rather than
uintptr_t, and eliminate the related macros.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes #14126
2022-11-03 09:57:05 -07:00

717 lines
17 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include "libuutil_common.h"
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#define ELEM_TO_NODE(lp, e) \
((uu_list_node_impl_t *)((uintptr_t)(e) + (lp)->ul_offset))
#define NODE_TO_ELEM(lp, n) \
((void *)((uintptr_t)(n) - (lp)->ul_offset))
/*
* uu_list_index_ts define a location for insertion. They are simply a
* pointer to the object after the insertion point. We store a mark
* in the low-bits of the index, to help prevent mistakes.
*
* When debugging, the index mark changes on every insert and delete, to
* catch stale references.
*/
#define INDEX_MAX (sizeof (uintptr_t) - 1)
#define INDEX_NEXT(m) (((m) == INDEX_MAX)? 1 : ((m) + 1) & INDEX_MAX)
#define INDEX_TO_NODE(i) ((uu_list_node_impl_t *)((i) & ~INDEX_MAX))
#define NODE_TO_INDEX(p, n) (((uintptr_t)(n) & ~INDEX_MAX) | (p)->ul_index)
#define INDEX_VALID(p, i) (((i) & INDEX_MAX) == (p)->ul_index)
#define INDEX_CHECK(i) (((i) & INDEX_MAX) != 0)
#define POOL_TO_MARKER(pp) ((void *)((uintptr_t)(pp) | 1))
static uu_list_pool_t uu_null_lpool = { &uu_null_lpool, &uu_null_lpool };
static pthread_mutex_t uu_lpool_list_lock = PTHREAD_MUTEX_INITIALIZER;
uu_list_pool_t *
uu_list_pool_create(const char *name, size_t objsize,
size_t nodeoffset, uu_compare_fn_t *compare_func, uint32_t flags)
{
uu_list_pool_t *pp, *next, *prev;
if (name == NULL ||
uu_check_name(name, UU_NAME_DOMAIN) == -1 ||
nodeoffset + sizeof (uu_list_node_t) > objsize) {
uu_set_error(UU_ERROR_INVALID_ARGUMENT);
return (NULL);
}
if (flags & ~UU_LIST_POOL_DEBUG) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
pp = uu_zalloc(sizeof (uu_list_pool_t));
if (pp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
(void) strlcpy(pp->ulp_name, name, sizeof (pp->ulp_name));
pp->ulp_nodeoffset = nodeoffset;
pp->ulp_objsize = objsize;
pp->ulp_cmp = compare_func;
if (flags & UU_LIST_POOL_DEBUG)
pp->ulp_debug = 1;
pp->ulp_last_index = 0;
(void) pthread_mutex_init(&pp->ulp_lock, NULL);
pp->ulp_null_list.ul_next = &pp->ulp_null_list;
pp->ulp_null_list.ul_prev = &pp->ulp_null_list;
(void) pthread_mutex_lock(&uu_lpool_list_lock);
pp->ulp_next = next = &uu_null_lpool;
pp->ulp_prev = prev = next->ulp_prev;
next->ulp_prev = pp;
prev->ulp_next = pp;
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
return (pp);
}
void
uu_list_pool_destroy(uu_list_pool_t *pp)
{
if (pp->ulp_debug) {
if (pp->ulp_null_list.ul_next != &pp->ulp_null_list ||
pp->ulp_null_list.ul_prev != &pp->ulp_null_list) {
uu_panic("uu_list_pool_destroy: Pool \"%.*s\" (%p) has "
"outstanding lists, or is corrupt.\n",
(int)sizeof (pp->ulp_name), pp->ulp_name,
(void *)pp);
}
}
(void) pthread_mutex_lock(&uu_lpool_list_lock);
pp->ulp_next->ulp_prev = pp->ulp_prev;
pp->ulp_prev->ulp_next = pp->ulp_next;
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
pp->ulp_prev = NULL;
pp->ulp_next = NULL;
uu_free(pp);
}
void
uu_list_node_init(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
{
uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
if (pp->ulp_debug) {
uintptr_t offset = (uintptr_t)np - (uintptr_t)base;
if (offset + sizeof (*np) > pp->ulp_objsize) {
uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't fit in object (size %ld)\n",
base, (void *)np, (void *)pp, pp->ulp_name,
(long)offset, (long)pp->ulp_objsize);
}
if (offset != pp->ulp_nodeoffset) {
uu_panic("uu_list_node_init(%p, %p, %p (\"%s\")): "
"offset %ld doesn't match pool's offset (%ld)\n",
base, (void *)np, (void *)pp, pp->ulp_name,
(long)offset, (long)pp->ulp_objsize);
}
}
np->uln_next = POOL_TO_MARKER(pp);
np->uln_prev = NULL;
}
void
uu_list_node_fini(void *base, uu_list_node_t *np_arg, uu_list_pool_t *pp)
{
uu_list_node_impl_t *np = (uu_list_node_impl_t *)np_arg;
if (pp->ulp_debug) {
if (np->uln_next == NULL &&
np->uln_prev == NULL) {
uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
"node already finied\n",
base, (void *)np_arg, (void *)pp, pp->ulp_name);
}
if (np->uln_next != POOL_TO_MARKER(pp) ||
np->uln_prev != NULL) {
uu_panic("uu_list_node_fini(%p, %p, %p (\"%s\")): "
"node corrupt or on list\n",
base, (void *)np_arg, (void *)pp, pp->ulp_name);
}
}
np->uln_next = NULL;
np->uln_prev = NULL;
}
uu_list_t *
uu_list_create(uu_list_pool_t *pp, void *parent, uint32_t flags)
{
uu_list_t *lp, *next, *prev;
if (flags & ~(UU_LIST_DEBUG | UU_LIST_SORTED)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
if ((flags & UU_LIST_SORTED) && pp->ulp_cmp == NULL) {
if (pp->ulp_debug)
uu_panic("uu_list_create(%p, ...): requested "
"UU_LIST_SORTED, but pool has no comparison func\n",
(void *)pp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (NULL);
}
lp = uu_zalloc(sizeof (*lp));
if (lp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
lp->ul_pool = pp;
lp->ul_parent = parent;
lp->ul_offset = pp->ulp_nodeoffset;
lp->ul_debug = pp->ulp_debug || (flags & UU_LIST_DEBUG);
lp->ul_sorted = (flags & UU_LIST_SORTED);
lp->ul_numnodes = 0;
lp->ul_index = (pp->ulp_last_index = INDEX_NEXT(pp->ulp_last_index));
lp->ul_null_node.uln_next = &lp->ul_null_node;
lp->ul_null_node.uln_prev = &lp->ul_null_node;
lp->ul_null_walk.ulw_next = &lp->ul_null_walk;
lp->ul_null_walk.ulw_prev = &lp->ul_null_walk;
(void) pthread_mutex_lock(&pp->ulp_lock);
next = &pp->ulp_null_list;
prev = next->ul_prev;
lp->ul_next = next;
lp->ul_prev = prev;
next->ul_prev = lp;
prev->ul_next = lp;
(void) pthread_mutex_unlock(&pp->ulp_lock);
return (lp);
}
void
uu_list_destroy(uu_list_t *lp)
{
uu_list_pool_t *pp = lp->ul_pool;
if (lp->ul_debug) {
if (lp->ul_null_node.uln_next != &lp->ul_null_node ||
lp->ul_null_node.uln_prev != &lp->ul_null_node) {
uu_panic("uu_list_destroy(%p): list not empty\n",
(void *)lp);
}
if (lp->ul_numnodes != 0) {
uu_panic("uu_list_destroy(%p): numnodes is nonzero, "
"but list is empty\n", (void *)lp);
}
if (lp->ul_null_walk.ulw_next != &lp->ul_null_walk ||
lp->ul_null_walk.ulw_prev != &lp->ul_null_walk) {
uu_panic("uu_list_destroy(%p): outstanding walkers\n",
(void *)lp);
}
}
(void) pthread_mutex_lock(&pp->ulp_lock);
lp->ul_next->ul_prev = lp->ul_prev;
lp->ul_prev->ul_next = lp->ul_next;
(void) pthread_mutex_unlock(&pp->ulp_lock);
lp->ul_prev = NULL;
lp->ul_next = NULL;
lp->ul_pool = NULL;
uu_free(lp);
}
static void
list_insert(uu_list_t *lp, uu_list_node_impl_t *np, uu_list_node_impl_t *prev,
uu_list_node_impl_t *next)
{
if (lp->ul_debug) {
if (next->uln_prev != prev || prev->uln_next != next)
uu_panic("insert(%p): internal error: %p and %p not "
"neighbors\n", (void *)lp, (void *)next,
(void *)prev);
if (np->uln_next != POOL_TO_MARKER(lp->ul_pool) ||
np->uln_prev != NULL) {
uu_panic("insert(%p): elem %p node %p corrupt, "
"not initialized, or already in a list.\n",
(void *)lp, NODE_TO_ELEM(lp, np), (void *)np);
}
/*
* invalidate outstanding uu_list_index_ts.
*/
lp->ul_index = INDEX_NEXT(lp->ul_index);
}
np->uln_next = next;
np->uln_prev = prev;
next->uln_prev = np;
prev->uln_next = np;
lp->ul_numnodes++;
}
void
uu_list_insert(uu_list_t *lp, void *elem, uu_list_index_t idx)
{
uu_list_node_impl_t *np;
np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_insert(%p, %p, %p): %s\n",
(void *)lp, elem, (void *)idx,
INDEX_CHECK(idx)? "outdated index" :
"invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_insert(%p, %p, %p): out-of-date "
"index\n", (void *)lp, elem, (void *)idx);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
}
void *
uu_list_find(uu_list_t *lp, void *elem, void *private, uu_list_index_t *out)
{
int sorted = lp->ul_sorted;
uu_compare_fn_t *func = lp->ul_pool->ulp_cmp;
uu_list_node_impl_t *np;
if (func == NULL) {
if (out != NULL)
*out = 0;
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (NULL);
}
for (np = lp->ul_null_node.uln_next; np != &lp->ul_null_node;
np = np->uln_next) {
void *ep = NODE_TO_ELEM(lp, np);
int cmp = func(ep, elem, private);
if (cmp == 0) {
if (out != NULL)
*out = NODE_TO_INDEX(lp, np);
return (ep);
}
if (sorted && cmp > 0) {
if (out != NULL)
*out = NODE_TO_INDEX(lp, np);
return (NULL);
}
}
if (out != NULL)
*out = NODE_TO_INDEX(lp, 0);
return (NULL);
}
void *
uu_list_nearest_next(uu_list_t *lp, uu_list_index_t idx)
{
uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_nearest_next(%p, %p): %s\n",
(void *)lp, (void *)idx,
INDEX_CHECK(idx)? "outdated index" :
"invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_nearest_next(%p, %p): out-of-date "
"index\n", (void *)lp, (void *)idx);
}
if (np == &lp->ul_null_node)
return (NULL);
else
return (NODE_TO_ELEM(lp, np));
}
void *
uu_list_nearest_prev(uu_list_t *lp, uu_list_index_t idx)
{
uu_list_node_impl_t *np = INDEX_TO_NODE(idx);
if (np == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (!INDEX_VALID(lp, idx))
uu_panic("uu_list_nearest_prev(%p, %p): %s\n",
(void *)lp, (void *)idx, INDEX_CHECK(idx)?
"outdated index" : "invalid index");
if (np->uln_prev == NULL)
uu_panic("uu_list_nearest_prev(%p, %p): out-of-date "
"index\n", (void *)lp, (void *)idx);
}
if ((np = np->uln_prev) == &lp->ul_null_node)
return (NULL);
else
return (NODE_TO_ELEM(lp, np));
}
static void
list_walk_init(uu_list_walk_t *wp, uu_list_t *lp, uint32_t flags)
{
uu_list_walk_t *next, *prev;
int robust = (flags & UU_WALK_ROBUST);
int direction = (flags & UU_WALK_REVERSE)? -1 : 1;
(void) memset(wp, 0, sizeof (*wp));
wp->ulw_list = lp;
wp->ulw_robust = robust;
wp->ulw_dir = direction;
if (direction > 0)
wp->ulw_next_result = lp->ul_null_node.uln_next;
else
wp->ulw_next_result = lp->ul_null_node.uln_prev;
if (lp->ul_debug || robust) {
/*
* Add this walker to the list's list of walkers so
* uu_list_remove() can advance us if somebody tries to
* remove ulw_next_result.
*/
wp->ulw_next = next = &lp->ul_null_walk;
wp->ulw_prev = prev = next->ulw_prev;
next->ulw_prev = wp;
prev->ulw_next = wp;
}
}
static uu_list_node_impl_t *
list_walk_advance(uu_list_walk_t *wp, uu_list_t *lp)
{
uu_list_node_impl_t *np = wp->ulw_next_result;
uu_list_node_impl_t *next;
if (np == &lp->ul_null_node)
return (NULL);
next = (wp->ulw_dir > 0)? np->uln_next : np->uln_prev;
wp->ulw_next_result = next;
return (np);
}
static void
list_walk_fini(uu_list_walk_t *wp)
{
/* GLXXX debugging? */
if (wp->ulw_next != NULL) {
wp->ulw_next->ulw_prev = wp->ulw_prev;
wp->ulw_prev->ulw_next = wp->ulw_next;
wp->ulw_next = NULL;
wp->ulw_prev = NULL;
}
wp->ulw_list = NULL;
wp->ulw_next_result = NULL;
}
uu_list_walk_t *
uu_list_walk_start(uu_list_t *lp, uint32_t flags)
{
uu_list_walk_t *wp;
if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (NULL);
}
wp = uu_zalloc(sizeof (*wp));
if (wp == NULL) {
uu_set_error(UU_ERROR_NO_MEMORY);
return (NULL);
}
list_walk_init(wp, lp, flags);
return (wp);
}
void *
uu_list_walk_next(uu_list_walk_t *wp)
{
uu_list_t *lp = wp->ulw_list;
uu_list_node_impl_t *np = list_walk_advance(wp, lp);
if (np == NULL)
return (NULL);
return (NODE_TO_ELEM(lp, np));
}
void
uu_list_walk_end(uu_list_walk_t *wp)
{
list_walk_fini(wp);
uu_free(wp);
}
int
uu_list_walk(uu_list_t *lp, uu_walk_fn_t *func, void *private, uint32_t flags)
{
uu_list_node_impl_t *np;
int status = UU_WALK_NEXT;
int robust = (flags & UU_WALK_ROBUST);
int reverse = (flags & UU_WALK_REVERSE);
if (flags & ~(UU_WALK_ROBUST | UU_WALK_REVERSE)) {
uu_set_error(UU_ERROR_UNKNOWN_FLAG);
return (-1);
}
if (lp->ul_debug || robust) {
uu_list_walk_t my_walk;
void *e;
list_walk_init(&my_walk, lp, flags);
while (status == UU_WALK_NEXT &&
(e = uu_list_walk_next(&my_walk)) != NULL)
status = (*func)(e, private);
list_walk_fini(&my_walk);
} else {
if (!reverse) {
for (np = lp->ul_null_node.uln_next;
status == UU_WALK_NEXT && np != &lp->ul_null_node;
np = np->uln_next) {
status = (*func)(NODE_TO_ELEM(lp, np), private);
}
} else {
for (np = lp->ul_null_node.uln_prev;
status == UU_WALK_NEXT && np != &lp->ul_null_node;
np = np->uln_prev) {
status = (*func)(NODE_TO_ELEM(lp, np), private);
}
}
}
if (status >= 0)
return (0);
uu_set_error(UU_ERROR_CALLBACK_FAILED);
return (-1);
}
void
uu_list_remove(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, elem);
uu_list_walk_t *wp;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_remove(%p, %p): elem not on list\n",
(void *)lp, elem);
/*
* invalidate outstanding uu_list_index_ts.
*/
lp->ul_index = INDEX_NEXT(lp->ul_index);
}
/*
* robust walkers must be advanced. In debug mode, non-robust
* walkers are also on the list. If there are any, it's an error.
*/
for (wp = lp->ul_null_walk.ulw_next; wp != &lp->ul_null_walk;
wp = wp->ulw_next) {
if (wp->ulw_robust) {
if (np == wp->ulw_next_result)
(void) list_walk_advance(wp, lp);
} else if (wp->ulw_next_result != NULL) {
uu_panic("uu_list_remove(%p, %p): active non-robust "
"walker\n", (void *)lp, elem);
}
}
np->uln_next->uln_prev = np->uln_prev;
np->uln_prev->uln_next = np->uln_next;
lp->ul_numnodes--;
np->uln_next = POOL_TO_MARKER(lp->ul_pool);
np->uln_prev = NULL;
}
void *
uu_list_teardown(uu_list_t *lp, void **cookie)
{
void *ep;
/*
* XXX: disable list modification until list is empty
*/
if (lp->ul_debug && *cookie != NULL)
uu_panic("uu_list_teardown(%p, %p): unexpected cookie\n",
(void *)lp, (void *)cookie);
ep = uu_list_first(lp);
if (ep)
uu_list_remove(lp, ep);
return (ep);
}
int
uu_list_insert_before(uu_list_t *lp, void *target, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
if (target == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_insert_before(%p, %p, %p): %p is "
"not currently on a list\n",
(void *)lp, target, elem, target);
}
if (lp->ul_sorted) {
if (lp->ul_debug)
uu_panic("uu_list_insert_before(%p, ...): list is "
"UU_LIST_SORTED\n", (void *)lp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (-1);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np->uln_prev, np);
return (0);
}
int
uu_list_insert_after(uu_list_t *lp, void *target, void *elem)
{
uu_list_node_impl_t *np = ELEM_TO_NODE(lp, target);
if (target == NULL)
np = &lp->ul_null_node;
if (lp->ul_debug) {
if (np->uln_prev == NULL)
uu_panic("uu_list_insert_after(%p, %p, %p): %p is "
"not currently on a list\n",
(void *)lp, target, elem, target);
}
if (lp->ul_sorted) {
if (lp->ul_debug)
uu_panic("uu_list_insert_after(%p, ...): list is "
"UU_LIST_SORTED\n", (void *)lp);
uu_set_error(UU_ERROR_NOT_SUPPORTED);
return (-1);
}
list_insert(lp, ELEM_TO_NODE(lp, elem), np, np->uln_next);
return (0);
}
size_t
uu_list_numnodes(uu_list_t *lp)
{
return (lp->ul_numnodes);
}
void *
uu_list_first(uu_list_t *lp)
{
uu_list_node_impl_t *n = lp->ul_null_node.uln_next;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_last(uu_list_t *lp)
{
uu_list_node_impl_t *n = lp->ul_null_node.uln_prev;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_next(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
n = n->uln_next;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
void *
uu_list_prev(uu_list_t *lp, void *elem)
{
uu_list_node_impl_t *n = ELEM_TO_NODE(lp, elem);
n = n->uln_prev;
if (n == &lp->ul_null_node)
return (NULL);
return (NODE_TO_ELEM(lp, n));
}
/*
* called from uu_lockup() and uu_release(), as part of our fork1()-safety.
*/
void
uu_list_lockup(void)
{
uu_list_pool_t *pp;
(void) pthread_mutex_lock(&uu_lpool_list_lock);
for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
pp = pp->ulp_next)
(void) pthread_mutex_lock(&pp->ulp_lock);
}
void
uu_list_release(void)
{
uu_list_pool_t *pp;
for (pp = uu_null_lpool.ulp_next; pp != &uu_null_lpool;
pp = pp->ulp_next)
(void) pthread_mutex_unlock(&pp->ulp_lock);
(void) pthread_mutex_unlock(&uu_lpool_list_lock);
}