Few patches that should have been there from day 1.
Anyway, they are coming now.
Signed-off-by: Benjamin Tissoires bentiss@kernel.org --- Changes in v2: - fix wq in hashtabs not being freed (and static call not being used) - Link to v1: https://lore.kernel.org/r/20240425-bpf-next-v1-0-1d8330e6c643@kernel.org
--- Benjamin Tissoires (3): bpf: do not walk twice the map on free bpf: do not walk twice the hash map on free selftests/bpf: drop an unused local variable
kernel/bpf/arraymap.c | 15 ++++----- kernel/bpf/hashtab.c | 49 ++++++++--------------------- tools/testing/selftests/bpf/prog_tests/wq.c | 2 -- 3 files changed, 21 insertions(+), 45 deletions(-) --- base-commit: 1bba3b3d373dbafae891e7cb06b8c82c8d62aba1 change-id: 20240425-bpf-next-2114350587e3
Best regards,
If someone stores both a timer and a workqueue in a map, on free we would walk it twice. Add a check in array_map_free_timers_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
---
no changes in v2 --- kernel/bpf/arraymap.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 580d07b15471..feabc0193852 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -436,13 +436,14 @@ static void array_map_free_timers_wq(struct bpf_map *map) /* We don't reset or free fields other than timer and workqueue * on uref dropping to zero. */ - if (btf_record_has_field(map->record, BPF_TIMER)) - for (i = 0; i < array->map.max_entries; i++) - bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i)); - - if (btf_record_has_field(map->record, BPF_WORKQUEUE)) - for (i = 0; i < array->map.max_entries; i++) - bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i)); + if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE)) { + for (i = 0; i < array->map.max_entries; i++) { + if (btf_record_has_field(map->record, BPF_TIMER)) + bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i)); + if (btf_record_has_field(map->record, BPF_WORKQUEUE)) + bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i)); + } + } }
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
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 + 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); } }
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;@@ -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));} @@ -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);elsehtab_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);
htab_free_prealloced_wq(htab);
htab_free_prealloced_timers_and_wq(htab);}
-- 2.44.0
Some copy/paste leftover, this is never used
Fixes: e3d9eac99afd ("selftests/bpf: wq: add bpf_wq_init() checks") Signed-off-by: Benjamin Tissoires bentiss@kernel.org
---
no changes in v2 --- tools/testing/selftests/bpf/prog_tests/wq.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/wq.c b/tools/testing/selftests/bpf/prog_tests/wq.c index c4bacd3160e1..99e438fe12ac 100644 --- a/tools/testing/selftests/bpf/prog_tests/wq.c +++ b/tools/testing/selftests/bpf/prog_tests/wq.c @@ -36,7 +36,5 @@ void serial_test_wq(void)
void serial_test_failures_wq(void) { - LIBBPF_OPTS(bpf_test_run_opts, topts); - RUN_TESTS(wq_failures); }
linux-kselftest-mirror@lists.linaro.org
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Benjamin Tissoires