| Message ID | 20240430-bpf-next-v2-2-140aa50f0f19@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | bpf_wq followup series | expand |
On Apr 30 2024, Benjamin Tissoires wrote: > If someone stores both a timer and a workqueue in a hash map, on free, we > would walk it twice. > Add a check in htab_free_malloced_timers_or_wq and free the timers > and workqueues if they are present. > > Fixes: 246331e3f1ea ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps") > Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> > > --- > > changes in v2: > - fix wq being not freed (and static call not used) > --- > kernel/bpf/hashtab.c | 49 +++++++++++++------------------------------------ > 1 file changed, 13 insertions(+), 36 deletions(-) > > diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c > index 0179183c543a..5eefadfc8ea9 100644 > --- a/kernel/bpf/hashtab.c > +++ b/kernel/bpf/hashtab.c > @@ -221,32 +221,11 @@ static bool htab_has_extra_elems(struct bpf_htab *htab) > return !htab_is_percpu(htab) && !htab_is_lru(htab); > } > > -static void htab_free_prealloced_timers(struct bpf_htab *htab) > +static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab) > { > u32 num_entries = htab->map.max_entries; > int i; > > - if (!btf_record_has_field(htab->map.record, BPF_TIMER)) > - return; > - if (htab_has_extra_elems(htab)) > - num_entries += num_possible_cpus(); > - > - for (i = 0; i < num_entries; i++) { > - struct htab_elem *elem; > - > - elem = get_htab_elem(htab, i); > - bpf_obj_free_timer(htab->map.record, elem->key + round_up(htab->map.key_size, 8)); > - cond_resched(); > - } > -} > - > -static void htab_free_prealloced_wq(struct bpf_htab *htab) > -{ > - u32 num_entries = htab->map.max_entries; > - int i; > - > - if (!btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) > - return; > if (htab_has_extra_elems(htab)) > num_entries += num_possible_cpus(); > > @@ -254,8 +233,12 @@ static void htab_free_prealloced_wq(struct bpf_htab *htab) > struct htab_elem *elem; > > elem = get_htab_elem(htab, i); > - bpf_obj_free_workqueue(htab->map.record, > - elem->key + round_up(htab->map.key_size, 8)); > + if (btf_record_has_field(htab->map.record, BPF_TIMER)) > + bpf_obj_free_timer(htab->map.record, > + elem->key + round_up(htab->map.key_size, 8)); > + else Sorry, this else above is wrong, it should be a check on BPF_WORKQUEUE instead. v3 is n its way (with the proper bpf-next suffix this time). Cheers, Benjamin > + bpf_obj_free_workqueue(htab->map.record, > + elem->key + round_up(htab->map.key_size, 8)); > cond_resched(); > } > } > @@ -1515,7 +1498,7 @@ static void delete_all_elements(struct bpf_htab *htab) > migrate_enable(); > } > > -static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer) > +static void htab_free_malloced_timers_and_wq(struct bpf_htab *htab) > { > int i; > > @@ -1527,10 +1510,10 @@ static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer > > hlist_nulls_for_each_entry(l, n, head, hash_node) { > /* We only free timer on uref dropping to zero */ > - if (is_timer) > + if (btf_record_has_field(htab->map.record, BPF_TIMER)) > bpf_obj_free_timer(htab->map.record, > l->key + round_up(htab->map.key_size, 8)); > - else > + if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) > bpf_obj_free_workqueue(htab->map.record, > l->key + round_up(htab->map.key_size, 8)); > } > @@ -1544,17 +1527,11 @@ static void htab_map_free_timers_and_wq(struct bpf_map *map) > struct bpf_htab *htab = container_of(map, struct bpf_htab, map); > > /* We only free timer and workqueue on uref dropping to zero */ > - if (btf_record_has_field(htab->map.record, BPF_TIMER)) { > - if (!htab_is_prealloc(htab)) > - htab_free_malloced_timers_or_wq(htab, true); > - else > - htab_free_prealloced_timers(htab); > - } > - if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) { > + if (btf_record_has_field(htab->map.record, BPF_TIMER | BPF_WORKQUEUE)) { > if (!htab_is_prealloc(htab)) > - htab_free_malloced_timers_or_wq(htab, false); > + htab_free_malloced_timers_and_wq(htab); > else > - htab_free_prealloced_wq(htab); > + htab_free_prealloced_timers_and_wq(htab); > } > } > > > -- > 2.44.0 >
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 0179183c543a..5eefadfc8ea9 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -221,32 +221,11 @@ static bool htab_has_extra_elems(struct bpf_htab *htab) return !htab_is_percpu(htab) && !htab_is_lru(htab); } -static void htab_free_prealloced_timers(struct bpf_htab *htab) +static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab) { u32 num_entries = htab->map.max_entries; int i; - if (!btf_record_has_field(htab->map.record, BPF_TIMER)) - return; - if (htab_has_extra_elems(htab)) - num_entries += num_possible_cpus(); - - for (i = 0; i < num_entries; i++) { - struct htab_elem *elem; - - elem = get_htab_elem(htab, i); - bpf_obj_free_timer(htab->map.record, elem->key + round_up(htab->map.key_size, 8)); - cond_resched(); - } -} - -static void htab_free_prealloced_wq(struct bpf_htab *htab) -{ - u32 num_entries = htab->map.max_entries; - int i; - - if (!btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) - return; if (htab_has_extra_elems(htab)) num_entries += num_possible_cpus(); @@ -254,8 +233,12 @@ static void htab_free_prealloced_wq(struct bpf_htab *htab) struct htab_elem *elem; elem = get_htab_elem(htab, i); - bpf_obj_free_workqueue(htab->map.record, - elem->key + round_up(htab->map.key_size, 8)); + if (btf_record_has_field(htab->map.record, BPF_TIMER)) + bpf_obj_free_timer(htab->map.record, + elem->key + round_up(htab->map.key_size, 8)); + else + bpf_obj_free_workqueue(htab->map.record, + elem->key + round_up(htab->map.key_size, 8)); cond_resched(); } } @@ -1515,7 +1498,7 @@ static void delete_all_elements(struct bpf_htab *htab) migrate_enable(); } -static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer) +static void htab_free_malloced_timers_and_wq(struct bpf_htab *htab) { int i; @@ -1527,10 +1510,10 @@ static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer hlist_nulls_for_each_entry(l, n, head, hash_node) { /* We only free timer on uref dropping to zero */ - if (is_timer) + if (btf_record_has_field(htab->map.record, BPF_TIMER)) bpf_obj_free_timer(htab->map.record, l->key + round_up(htab->map.key_size, 8)); - else + if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) bpf_obj_free_workqueue(htab->map.record, l->key + round_up(htab->map.key_size, 8)); } @@ -1544,17 +1527,11 @@ static void htab_map_free_timers_and_wq(struct bpf_map *map) struct bpf_htab *htab = container_of(map, struct bpf_htab, map); /* We only free timer and workqueue on uref dropping to zero */ - if (btf_record_has_field(htab->map.record, BPF_TIMER)) { - if (!htab_is_prealloc(htab)) - htab_free_malloced_timers_or_wq(htab, true); - else - htab_free_prealloced_timers(htab); - } - if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) { + if (btf_record_has_field(htab->map.record, BPF_TIMER | BPF_WORKQUEUE)) { if (!htab_is_prealloc(htab)) - htab_free_malloced_timers_or_wq(htab, false); + htab_free_malloced_timers_and_wq(htab); else - htab_free_prealloced_wq(htab); + htab_free_prealloced_timers_and_wq(htab); } }
If someone stores both a timer and a workqueue in a hash map, on free, we would walk it twice. Add a check in htab_free_malloced_timers_or_wq and free the timers and workqueues if they are present. Fixes: 246331e3f1ea ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps") Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> --- changes in v2: - fix wq being not freed (and static call not used) --- kernel/bpf/hashtab.c | 49 +++++++++++++------------------------------------ 1 file changed, 13 insertions(+), 36 deletions(-)