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bpf: Refactor the core bpf_task_storage_get logic into a new function

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This patch creates a new function __bpf_task_storage_get() and
moves the core logic of the existing bpf_task_storage_get()
into this new function.   This new function will be shared
by another new helper proto in the latter patch.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20221025184524.3526117-4-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Martin KaFai Lau 2022-10-25 11:45:18 -07:00 committed by Alexei Starovoitov
parent 0593dd34e5
commit 6d65500c34
1 changed files with 28 additions and 20 deletions
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48
kernel/bpf/bpf_task_storage.c
View File

@ -227,37 +227,45 @@ out:
return err;
}
/* Called by bpf_task_storage_get*() helpers */
static void *__bpf_task_storage_get(struct bpf_map *map,
struct task_struct *task, void *value,
u64 flags, gfp_t gfp_flags)
{
struct bpf_local_storage_data *sdata;
sdata = task_storage_lookup(task, map, true);
if (sdata)
return sdata->data;
/* only allocate new storage, when the task is refcounted */
if (refcount_read(&task->usage) &&
(flags & BPF_LOCAL_STORAGE_GET_F_CREATE)) {
sdata = bpf_local_storage_update(
task, (struct bpf_local_storage_map *)map, value,
BPF_NOEXIST, gfp_flags);
return IS_ERR(sdata) ? NULL : sdata->data;
}
return NULL;
}
/* *gfp_flags* is a hidden argument provided by the verifier */
BPF_CALL_5(bpf_task_storage_get_recur, struct bpf_map *, map, struct task_struct *,
task, void *, value, u64, flags, gfp_t, gfp_flags)
{
struct bpf_local_storage_data *sdata;
void *data;
WARN_ON_ONCE(!bpf_rcu_lock_held());
if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
return (unsigned long)NULL;
if (!task)
if (flags & ~BPF_LOCAL_STORAGE_GET_F_CREATE || !task)
return (unsigned long)NULL;
if (!bpf_task_storage_trylock())
return (unsigned long)NULL;
sdata = task_storage_lookup(task, map, true);
if (sdata)
goto unlock;
/* only allocate new storage, when the task is refcounted */
if (refcount_read(&task->usage) &&
(flags & BPF_LOCAL_STORAGE_GET_F_CREATE))
sdata = bpf_local_storage_update(
task, (struct bpf_local_storage_map *)map, value,
BPF_NOEXIST, gfp_flags);
unlock:
data = __bpf_task_storage_get(map, task, value, flags,
gfp_flags);
bpf_task_storage_unlock();
return IS_ERR_OR_NULL(sdata) ? (unsigned long)NULL :
(unsigned long)sdata->data;
return (unsigned long)data;
}
BPF_CALL_2(bpf_task_storage_delete_recur, struct bpf_map *, map, struct task_struct *,