Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-08 15:04:45 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

bpf: Add new bpf_task_storage_delete proto with no deadlock detection

Browse Source 
The bpf_lsm and bpf_iter do not recur that will cause a deadlock.
The situation is similar to the bpf_pid_task_storage_delete_elem()
which is called from the syscall map_delete_elem.  It does not need
deadlock detection.  Otherwise, it will cause unnecessary failure
when calling the bpf_task_storage_delete() helper.

This patch adds bpf_task_storage_delete proto that does not do deadlock
detection.  It will be used by bpf_lsm and bpf_iter program.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20221025184524.3526117-8-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Martin KaFai Lau 2022-10-25 11:45:22 -07:00 committed by Alexei Starovoitov
parent fda64ae0bb
commit 8a7dac37f2
3 changed files with 32 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/bpf.h
View File

@ -2522,6 +2522,7 @@ extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto;
extern const struct bpf_func_proto bpf_task_storage_get_recur_proto;
extern const struct bpf_func_proto bpf_task_storage_get_proto;
extern const struct bpf_func_proto bpf_task_storage_delete_recur_proto;
extern const struct bpf_func_proto bpf_task_storage_delete_proto;
extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
extern const struct bpf_func_proto bpf_sk_setsockopt_proto;

28
kernel/bpf/bpf_task_storage.c
View File

@ -311,6 +311,25 @@ BPF_CALL_2(bpf_task_storage_delete_recur, struct bpf_map *, map, struct task_str
return ret;
}
BPF_CALL_2(bpf_task_storage_delete, struct bpf_map *, map, struct task_struct *,
task)
{
int ret;
WARN_ON_ONCE(!bpf_rcu_lock_held());
if (!task)
return -EINVAL;
bpf_task_storage_lock();
/* This helper must only be called from places where the lifetime of the task
* is guaranteed. Either by being refcounted or by being protected
* by an RCU read-side critical section.
*/
ret = task_storage_delete(task, map, true);
bpf_task_storage_unlock();
return ret;
}
static int notsupp_get_next_key(struct bpf_map *map, void *key, void *next_key)
{
return -ENOTSUPP;
@ -382,3 +401,12 @@ const struct bpf_func_proto bpf_task_storage_delete_recur_proto = {
.arg2_type = ARG_PTR_TO_BTF_ID,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};
const struct bpf_func_proto bpf_task_storage_delete_proto = {
.func = bpf_task_storage_delete,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_BTF_ID,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};

4
kernel/trace/bpf_trace.c
View File

@ -1493,7 +1493,9 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_task_storage_get_recur_proto;
return &bpf_task_storage_get_proto;
case BPF_FUNC_task_storage_delete:
return &bpf_task_storage_delete_recur_proto;
if (bpf_prog_check_recur(prog))
return &bpf_task_storage_delete_recur_proto;
return &bpf_task_storage_delete_proto;
case BPF_FUNC_for_each_map_elem:
return &bpf_for_each_map_elem_proto;
case BPF_FUNC_snprintf: