diff options
| author | Hou Tao <houtao1@huawei.com> | 2025-01-08 09:07:16 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-01-08 18:06:36 -0800 |
| commit | 25dc65f75b08281a42823673d1751c82618ce7a3 (patch) | |
| tree | fd597769329365f90106d706bf427ed922e71f90 | |
| parent | 53f2ba0b1cc087a597b43e63d35f355e9348bd61 (diff) | |
bpf: Remove migrate_{disable|enable} from bpf_cgrp_storage_lock helpers
Three callers of bpf_cgrp_storage_lock() are ->map_lookup_elem,
->map_update_elem, ->map_delete_elem from bpf syscall. BPF syscall for
these three operations of cgrp storage has already disabled migration.
Two call sites of bpf_cgrp_storage_trylock() are bpf_cgrp_storage_get(),
and bpf_cgrp_storage_delete() helpers. The running contexts of these
helpers have already disabled migration.
Therefore, it is safe to remove migrate_disable() for these callers.
However, bpf_cgrp_storage_free() also invokes bpf_cgrp_storage_lock()
and its running context doesn't disable migration. Therefore, also add
the missed migrate_{disabled|enable} in bpf_cgrp_storage_free().
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250108010728.207536-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/bpf_cgrp_storage.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c index 20f05de92e9c..d5dc65bb1755 100644 --- a/kernel/bpf/bpf_cgrp_storage.c +++ b/kernel/bpf/bpf_cgrp_storage.c @@ -15,22 +15,20 @@ static DEFINE_PER_CPU(int, bpf_cgrp_storage_busy); static void bpf_cgrp_storage_lock(void) { - migrate_disable(); + cant_migrate(); this_cpu_inc(bpf_cgrp_storage_busy); } static void bpf_cgrp_storage_unlock(void) { this_cpu_dec(bpf_cgrp_storage_busy); - migrate_enable(); } static bool bpf_cgrp_storage_trylock(void) { - migrate_disable(); + cant_migrate(); if (unlikely(this_cpu_inc_return(bpf_cgrp_storage_busy) != 1)) { this_cpu_dec(bpf_cgrp_storage_busy); - migrate_enable(); return false; } return true; @@ -47,17 +45,18 @@ void bpf_cgrp_storage_free(struct cgroup *cgroup) { struct bpf_local_storage *local_storage; + migrate_disable(); rcu_read_lock(); local_storage = rcu_dereference(cgroup->bpf_cgrp_storage); - if (!local_storage) { - rcu_read_unlock(); - return; - } + if (!local_storage) + goto out; bpf_cgrp_storage_lock(); bpf_local_storage_destroy(local_storage); bpf_cgrp_storage_unlock(); +out: rcu_read_unlock(); + migrate_enable(); } static struct bpf_local_storage_data * |