Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752475AbdCMKnL (ORCPT ); Mon, 13 Mar 2017 06:43:11 -0400 Received: from mga02.intel.com ([134.134.136.20]:2291 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751521AbdCMKnC (ORCPT ); Mon, 13 Mar 2017 06:43:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,158,1486454400"; d="scan'208";a="1107833443" From: Elena Reshetova To: shli@kernel.org Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH] drivers, md: convert stripe_head.count from atomic_t to refcount_t Date: Mon, 13 Mar 2017 12:42:51 +0200 Message-Id: <1489401771-31169-1-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12756 Lines: 352 refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- drivers/md/raid5-cache.c | 8 +++--- drivers/md/raid5.c | 68 +++++++++++++++++++++++++----------------------- drivers/md/raid5.h | 3 ++- 3 files changed, 41 insertions(+), 38 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 3f307be..6c05e12 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -979,7 +979,7 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) * don't delay. */ clear_bit(STRIPE_DELAYED, &sh->state); - atomic_inc(&sh->count); + refcount_inc(&sh->count); mutex_lock(&log->io_mutex); /* meta + data */ @@ -1321,7 +1321,7 @@ static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh) assert_spin_locked(&conf->device_lock); list_del_init(&sh->lru); - atomic_inc(&sh->count); + refcount_inc(&sh->count); set_bit(STRIPE_HANDLE, &sh->state); atomic_inc(&conf->active_stripes); @@ -1424,7 +1424,7 @@ static void r5c_do_reclaim(struct r5conf *conf) */ if (!list_empty(&sh->lru) && !test_bit(STRIPE_HANDLE, &sh->state) && - atomic_read(&sh->count) == 0) { + refcount_read(&sh->count) == 0) { r5c_flush_stripe(conf, sh); if (count++ >= R5C_RECLAIM_STRIPE_GROUP) break; @@ -2650,7 +2650,7 @@ r5c_cache_data(struct r5l_log *log, struct stripe_head *sh, * don't delay. */ clear_bit(STRIPE_DELAYED, &sh->state); - atomic_inc(&sh->count); + refcount_inc(&sh->count); mutex_lock(&log->io_mutex); /* meta + data */ diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2ce23b0..7e3913a 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -296,7 +296,7 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh, static void __release_stripe(struct r5conf *conf, struct stripe_head *sh, struct list_head *temp_inactive_list) { - if (atomic_dec_and_test(&sh->count)) + if (refcount_dec_and_test(&sh->count)) do_release_stripe(conf, sh, temp_inactive_list); } @@ -388,7 +388,7 @@ void raid5_release_stripe(struct stripe_head *sh) /* Avoid release_list until the last reference. */ - if (atomic_add_unless(&sh->count, -1, 1)) + if (refcount_dec_not_one(&sh->count)) return; if (unlikely(!conf->mddev->thread) || @@ -401,7 +401,7 @@ void raid5_release_stripe(struct stripe_head *sh) slow_path: local_irq_save(flags); /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */ - if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) { + if (refcount_dec_and_lock(&sh->count, &conf->device_lock)) { INIT_LIST_HEAD(&list); hash = sh->hash_lock_index; do_release_stripe(conf, sh, &list); @@ -491,7 +491,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) struct r5conf *conf = sh->raid_conf; int i, seq; - BUG_ON(atomic_read(&sh->count) != 0); + BUG_ON(refcount_read(&sh->count) != 0); BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); BUG_ON(stripe_operations_active(sh)); BUG_ON(sh->batch_head); @@ -668,11 +668,11 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector, &conf->cache_state); } else { init_stripe(sh, sector, previous); - atomic_inc(&sh->count); + refcount_inc(&sh->count); } - } else if (!atomic_inc_not_zero(&sh->count)) { + } else if (!refcount_inc_not_zero(&sh->count)) { spin_lock(&conf->device_lock); - if (!atomic_read(&sh->count)) { + if (!refcount_read(&sh->count)) { if (!test_bit(STRIPE_HANDLE, &sh->state)) atomic_inc(&conf->active_stripes); BUG_ON(list_empty(&sh->lru) && @@ -688,7 +688,7 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector, sh->group = NULL; } } - atomic_inc(&sh->count); + refcount_inc(&sh->count); spin_unlock(&conf->device_lock); } } while (sh == NULL); @@ -752,9 +752,9 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh hash = stripe_hash_locks_hash(head_sector); spin_lock_irq(conf->hash_locks + hash); head = __find_stripe(conf, head_sector, conf->generation); - if (head && !atomic_inc_not_zero(&head->count)) { + if (head && !refcount_inc_not_zero(&head->count)) { spin_lock(&conf->device_lock); - if (!atomic_read(&head->count)) { + if (!refcount_read(&head->count)) { if (!test_bit(STRIPE_HANDLE, &head->state)) atomic_inc(&conf->active_stripes); BUG_ON(list_empty(&head->lru) && @@ -770,7 +770,7 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh head->group = NULL; } } - atomic_inc(&head->count); + refcount_inc(&head->count); spin_unlock(&conf->device_lock); } spin_unlock_irq(conf->hash_locks + hash); @@ -833,7 +833,7 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh sh->batch_head->bm_seq = seq; } - atomic_inc(&sh->count); + refcount_inc(&sh->count); unlock_out: unlock_two_stripes(head, sh); out: @@ -1036,9 +1036,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) pr_debug("%s: for %llu schedule op %d on disc %d\n", __func__, (unsigned long long)sh->sector, bi->bi_opf, i); - atomic_inc(&sh->count); + refcount_inc(&sh->count); if (sh != head_sh) - atomic_inc(&head_sh->count); + refcount_inc(&head_sh->count); if (use_new_offset(conf, sh)) bi->bi_iter.bi_sector = (sh->sector + rdev->new_data_offset); @@ -1097,9 +1097,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) "replacement disc %d\n", __func__, (unsigned long long)sh->sector, rbi->bi_opf, i); - atomic_inc(&sh->count); + refcount_inc(&sh->count); if (sh != head_sh) - atomic_inc(&head_sh->count); + refcount_inc(&head_sh->count); if (use_new_offset(conf, sh)) rbi->bi_iter.bi_sector = (sh->sector + rrdev->new_data_offset); @@ -1275,7 +1275,7 @@ static void ops_run_biofill(struct stripe_head *sh) } } - atomic_inc(&sh->count); + refcount_inc(&sh->count); init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL); async_trigger_callback(&submit); } @@ -1353,7 +1353,7 @@ ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) if (i != target) xor_srcs[count++] = sh->dev[i].page; - atomic_inc(&sh->count); + refcount_inc(&sh->count); init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL, ops_complete_compute, sh, to_addr_conv(sh, percpu, 0)); @@ -1441,7 +1441,7 @@ ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu) BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags)); dest = tgt->page; - atomic_inc(&sh->count); + refcount_inc(&sh->count); if (target == qd_idx) { count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL); @@ -1516,7 +1516,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) pr_debug("%s: stripe: %llu faila: %d failb: %d\n", __func__, (unsigned long long)sh->sector, faila, failb); - atomic_inc(&sh->count); + refcount_inc(&sh->count); if (failb == syndrome_disks+1) { /* Q disk is one of the missing disks */ @@ -1784,7 +1784,7 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, break; } if (i >= sh->disks) { - atomic_inc(&sh->count); + refcount_inc(&sh->count); set_bit(R5_Discard, &sh->dev[pd_idx].flags); ops_complete_reconstruct(sh); return; @@ -1825,7 +1825,7 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, flags = ASYNC_TX_ACK | (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST); - atomic_inc(&head_sh->count); + refcount_inc(&head_sh->count); init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh, to_addr_conv(sh, percpu, j)); } else { @@ -1867,7 +1867,7 @@ ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, break; } if (i >= sh->disks) { - atomic_inc(&sh->count); + refcount_inc(&sh->count); set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags); set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags); ops_complete_reconstruct(sh); @@ -1891,7 +1891,7 @@ ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu, struct stripe_head, batch_list) == head_sh; if (last_stripe) { - atomic_inc(&head_sh->count); + refcount_inc(&head_sh->count); init_async_submit(&submit, txflags, tx, ops_complete_reconstruct, head_sh, to_addr_conv(sh, percpu, j)); } else @@ -1948,7 +1948,7 @@ static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &sh->ops.zero_sum_result, &submit); - atomic_inc(&sh->count); + refcount_inc(&sh->count); init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL); tx = async_trigger_callback(&submit); } @@ -1967,7 +1967,7 @@ static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu if (!checkp) srcs[count] = NULL; - atomic_inc(&sh->count); + refcount_inc(&sh->count); init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check, sh, to_addr_conv(sh, percpu, 0)); async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, @@ -2057,7 +2057,7 @@ static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp, INIT_LIST_HEAD(&sh->lru); INIT_LIST_HEAD(&sh->r5c); INIT_LIST_HEAD(&sh->log_list); - atomic_set(&sh->count, 1); + refcount_set(&sh->count, 1); sh->log_start = MaxSector; for (i = 0; i < disks; i++) { struct r5dev *dev = &sh->dev[i]; @@ -2354,7 +2354,7 @@ static int drop_one_stripe(struct r5conf *conf) spin_unlock_irq(conf->hash_locks + hash); if (!sh) return 0; - BUG_ON(atomic_read(&sh->count)); + BUG_ON(refcount_read(&sh->count)); shrink_buffers(sh); kmem_cache_free(conf->slab_cache, sh); atomic_dec(&conf->active_stripes); @@ -2386,7 +2386,7 @@ static void raid5_end_read_request(struct bio * bi) break; pr_debug("end_read_request %llu/%d, count: %d, error %d.\n", - (unsigned long long)sh->sector, i, atomic_read(&sh->count), + (unsigned long long)sh->sector, i, refcount_read(&sh->count), bi->bi_error); if (i == disks) { bio_reset(bi); @@ -2523,7 +2523,7 @@ static void raid5_end_write_request(struct bio *bi) } } pr_debug("end_write_request %llu/%d, count %d, error: %d.\n", - (unsigned long long)sh->sector, i, atomic_read(&sh->count), + (unsigned long long)sh->sector, i, refcount_read(&sh->count), bi->bi_error); if (i == disks) { bio_reset(bi); @@ -4545,7 +4545,7 @@ static void handle_stripe(struct stripe_head *sh) pr_debug("handling stripe %llu, state=%#lx cnt=%d, " "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n", (unsigned long long)sh->sector, sh->state, - atomic_read(&sh->count), sh->pd_idx, sh->qd_idx, + refcount_read(&sh->count), sh->pd_idx, sh->qd_idx, sh->check_state, sh->reconstruct_state); analyse_stripe(sh, &s); @@ -4924,7 +4924,7 @@ static void activate_bit_delay(struct r5conf *conf, struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru); int hash; list_del_init(&sh->lru); - atomic_inc(&sh->count); + refcount_inc(&sh->count); hash = sh->hash_lock_index; __release_stripe(conf, sh, &temp_inactive_list[hash]); } @@ -5240,7 +5240,9 @@ static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group) sh->group = NULL; } list_del_init(&sh->lru); - BUG_ON(atomic_inc_return(&sh->count) != 1); + BUG_ON(refcount_read(&sh->count) != 0); + refcount_set(&sh->count, 1); + return sh; } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 4bb27b9..a1ed351 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -3,6 +3,7 @@ #include #include +#include /* * @@ -207,7 +208,7 @@ struct stripe_head { short ddf_layout;/* use DDF ordering to calculate Q */ short hash_lock_index; unsigned long state; /* state flags */ - atomic_t count; /* nr of active thread/requests */ + refcount_t count; /* nr of active thread/requests */ int bm_seq; /* sequence number for bitmap flushes */ int disks; /* disks in stripe */ int overwrite_disks; /* total overwrite disks in stripe, -- 2.7.4