Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-07 14:32:23 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

bpf: Limit up to 512 bytes for bpf_global_percpu_ma allocation

Browse Source 
For percpu data structure allocation with bpf_global_percpu_ma,
the maximum data size is 4K. But for a system with large
number of cpus, bigger data size (e.g., 2K, 4K) might consume
a lot of memory. For example, the percpu memory consumption
with unit size 2K and 1024 cpus will be 2K * 1K * 1k = 2GB
memory.

We should discourage such usage. Let us limit the maximum data
size to be 512 for bpf_global_percpu_ma allocation.

Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231222031801.1290841-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Yonghong Song 2023-12-21 19:18:01 -08:00 committed by Alexei Starovoitov
parent 0e2ba9f96f
commit 5c1a376532
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
kernel/bpf/verifier.c
View File

@ -195,6 +195,8 @@ struct bpf_verifier_stack_elem {
POISON_POINTER_DELTA))
#define BPF_MAP_PTR(X) ((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV))
#define BPF_GLOBAL_PERCPU_MA_MAX_SIZE 512
static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx);
static int release_reference(struct bpf_verifier_env *env, int ref_obj_id);
static void invalidate_non_owning_refs(struct bpf_verifier_env *env);
@ -12160,6 +12162,12 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
}
if (meta.func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
if (ret_t->size > BPF_GLOBAL_PERCPU_MA_MAX_SIZE) {
verbose(env, "bpf_percpu_obj_new type size (%d) is greater than %d\n",
ret_t->size, BPF_GLOBAL_PERCPU_MA_MAX_SIZE);
return -EINVAL;
}
if (!bpf_global_percpu_ma_set) {
mutex_lock(&bpf_percpu_ma_lock);
if (!bpf_global_percpu_ma_set) {