Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 22066a6..03a6758 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -664,26 +664,23 @@
struct htab_elem *l = container_of(head, struct htab_elem, rcu);
struct bpf_htab *htab = l->htab;
- /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
- * we're calling kfree, otherwise deadlock is possible if kprobes
- * are placed somewhere inside of slub
- */
- preempt_disable();
- __this_cpu_inc(bpf_prog_active);
htab_elem_free(htab, l);
- __this_cpu_dec(bpf_prog_active);
- preempt_enable();
+}
+
+static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
+{
+ struct bpf_map *map = &htab->map;
+ void *ptr;
+
+ if (map->ops->map_fd_put_ptr) {
+ ptr = fd_htab_map_get_ptr(map, l);
+ map->ops->map_fd_put_ptr(ptr);
+ }
}
static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
{
- struct bpf_map *map = &htab->map;
-
- if (map->ops->map_fd_put_ptr) {
- void *ptr = fd_htab_map_get_ptr(map, l);
-
- map->ops->map_fd_put_ptr(ptr);
- }
+ htab_put_fd_value(htab, l);
if (htab_is_prealloc(htab)) {
__pcpu_freelist_push(&htab->freelist, &l->fnode);
@@ -712,6 +709,32 @@
}
}
+static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr,
+ void *value, bool onallcpus)
+{
+ /* When using prealloc and not setting the initial value on all cpus,
+ * zero-fill element values for other cpus (just as what happens when
+ * not using prealloc). Otherwise, bpf program has no way to ensure
+ * known initial values for cpus other than current one
+ * (onallcpus=false always when coming from bpf prog).
+ */
+ if (htab_is_prealloc(htab) && !onallcpus) {
+ u32 size = round_up(htab->map.value_size, 8);
+ int current_cpu = raw_smp_processor_id();
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu == current_cpu)
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value,
+ size);
+ else
+ memset(per_cpu_ptr(pptr, cpu), 0, size);
+ }
+ } else {
+ pcpu_copy_value(htab, pptr, value, onallcpus);
+ }
+}
+
static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
{
return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
@@ -735,6 +758,7 @@
*/
pl_new = this_cpu_ptr(htab->extra_elems);
l_new = *pl_new;
+ htab_put_fd_value(htab, old_elem);
*pl_new = old_elem;
} else {
struct pcpu_freelist_node *l;
@@ -781,7 +805,7 @@
}
}
- pcpu_copy_value(htab, pptr, value, onallcpus);
+ pcpu_init_value(htab, pptr, value, onallcpus);
if (!prealloc)
htab_elem_set_ptr(l_new, key_size, pptr);
@@ -1077,7 +1101,7 @@
pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
value, onallcpus);
} else {
- pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
+ pcpu_init_value(htab, htab_elem_get_ptr(l_new, key_size),
value, onallcpus);
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
l_new = NULL;