54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
#include <linux/btf.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
|
||
|
|
#include "trace_btf.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Find a function proto type by name, and return the btf_type with its btf
|
||
|
|
* in *@btf_p. Return NULL if not found.
|
||
|
|
* Note that caller has to call btf_put(*@btf_p) after using the btf_type.
|
||
|
|
*/
|
||
|
|
const struct btf_type *btf_find_func_proto(const char *func_name, struct btf **btf_p)
|
||
|
|
{
|
||
|
|
const struct btf_type *t;
|
||
|
|
s32 id;
|
||
|
|
|
||
|
|
id = bpf_find_btf_id(func_name, BTF_KIND_FUNC, btf_p);
|
||
|
|
if (id < 0)
|
||
|
|
return NULL;
|
||
|
|
|
||
|
|
/* Get BTF_KIND_FUNC type */
|
||
|
|
t = btf_type_by_id(*btf_p, id);
|
||
|
|
if (!t || !btf_type_is_func(t))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
/* The type of BTF_KIND_FUNC is BTF_KIND_FUNC_PROTO */
|
||
|
|
t = btf_type_by_id(*btf_p, t->type);
|
||
|
|
if (!t || !btf_type_is_func_proto(t))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
return t;
|
||
|
|
err:
|
||
|
|
btf_put(*btf_p);
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Get function parameter with the number of parameters.
|
||
|
|
* This can return NULL if the function has no parameters.
|
||
|
|
* It can return -EINVAL if the @func_proto is not a function proto type.
|
||
|
|
*/
|
||
|
|
const struct btf_param *btf_get_func_param(const struct btf_type *func_proto, s32 *nr)
|
||
|
|
{
|
||
|
|
if (!btf_type_is_func_proto(func_proto))
|
||
|
|
return ERR_PTR(-EINVAL);
|
||
|
|
|
||
|
|
*nr = btf_type_vlen(func_proto);
|
||
|
|
if (*nr > 0)
|
||
|
|
return (const struct btf_param *)(func_proto + 1);
|
||
|
|
else
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|