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| author | Alexei Starovoitov <[email protected]> | 2023-12-13 20:49:11 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <[email protected]> | 2023-12-13 21:02:40 -0800 |
| commit | c838fe1282df540ebf6e24e386ac34acb3ef3115 (patch) | |
| tree | 0b6e496130744349f7e15d3c015e7196e9bb7217 | |
| parent | 2a0c6b41eec90c2a138ea8b574836744783c67ff (diff) | |
| parent | dc68540913ac523b46ebda3843cec179362c7a72 (diff) | |
Merge branch 'bpf-use-gfp_kernel-in-bpf_event_entry_gen'
Hou Tao says:
====================
The simple patch set aims to replace GFP_ATOMIC by GFP_KERNEL in
bpf_event_entry_gen(). These two patches in the patch set were
preparatory patches in "Fix the release of inner map" patchset [1] and
are not needed for v2, so re-post it to bpf-next tree.
Patch #1 reduces the scope of rcu_read_lock when updating fd map and
patch #2 replaces GFP_ATOMIC by GFP_KERNEL. Please see individual
patches for more details.
Change Log:
v3:
* patch #1: fallback to patch #1 in v1. Update comments in
bpf_fd_htab_map_update_elem() to explain the reason for
rcu_read_lock() (Alexei)
v2: https://lore.kernel.org/bpf/[email protected]/
* patch #1: add rcu_read_lock/unlock() for bpf_fd_array_map_update_elem
as well to make it consistent with
bpf_fd_htab_map_update_elem and update commit message
accordingly (Alexei)
* patch #1/#2: collects ack tags from Yonghong
v1: https://lore.kernel.org/bpf/[email protected]/
[1]: https://lore.kernel.org/bpf/[email protected]/
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
| -rw-r--r-- | kernel/bpf/arraymap.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/hashtab.c | 6 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 4 |
3 files changed, 7 insertions, 5 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 8d365bda9a8b..b5ec24b3563e 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -1195,7 +1195,7 @@ static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, { struct bpf_event_entry *ee; - ee = kzalloc(sizeof(*ee), GFP_ATOMIC); + ee = kzalloc(sizeof(*ee), GFP_KERNEL); if (ee) { ee->event = perf_file->private_data; ee->perf_file = perf_file; diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 5b9146fa825f..ec3bdcc6a3cf 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -2523,7 +2523,13 @@ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, if (IS_ERR(ptr)) return PTR_ERR(ptr); + /* The htab bucket lock is always held during update operations in fd + * htab map, and the following rcu_read_lock() is only used to avoid + * the WARN_ON_ONCE in htab_map_update_elem(). + */ + rcu_read_lock(); ret = htab_map_update_elem(map, key, &ptr, map_flags); + rcu_read_unlock(); if (ret) map->ops->map_fd_put_ptr(map, ptr, false); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d63c1ed42412..3fcf7741146a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -184,15 +184,11 @@ static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, err = bpf_percpu_cgroup_storage_update(map, key, value, flags); } else if (IS_FD_ARRAY(map)) { - rcu_read_lock(); err = bpf_fd_array_map_update_elem(map, map_file, key, value, flags); - rcu_read_unlock(); } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { - rcu_read_lock(); err = bpf_fd_htab_map_update_elem(map, map_file, key, value, flags); - rcu_read_unlock(); } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { /* rcu_read_lock() is not needed */ err = bpf_fd_reuseport_array_update_elem(map, key, value, |