iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpf: Define no-ops for externally called bpf dynptr functions

Browse Source 
Some bpf dynptr functions will be called from places where
if CONFIG_BPF_SYSCALL is not set, then the dynptr function is
undefined. For example, when skb type dynptrs are added in the
next commit, dynptr functions are called from net/core/filter.c

This patch defines no-op implementations of these dynptr functions
so that they do not break compilation by being an undefined reference.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20230301154953.641654-5-joannelkoong@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Joanne Koong 2023-03-01 07:49:47 -08:00 committed by Alexei Starovoitov
parent 1d18feb2c9
commit 8357b366cb
1 changed files with 45 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
include/linux/bpf.h
View File

@ -1124,6 +1124,33 @@ static __always_inline __nocfi unsigned int bpf_dispatcher_nop_func(
return bpf_func(ctx, insnsi);
}
/* the implementation of the opaque uapi struct bpf_dynptr */
struct bpf_dynptr_kern {
void *data;
/* Size represents the number of usable bytes of dynptr data.
* If for example the offset is at 4 for a local dynptr whose data is
* of type u64, the number of usable bytes is 4.
*
* The upper 8 bits are reserved. It is as follows:
* Bits 0 - 23 = size
* Bits 24 - 30 = dynptr type
* Bit 31 = whether dynptr is read-only
*/
u32 size;
u32 offset;
} __aligned(8);
enum bpf_dynptr_type {
BPF_DYNPTR_TYPE_INVALID,
/* Points to memory that is local to the bpf program */
BPF_DYNPTR_TYPE_LOCAL,
/* Underlying data is a ringbuf record */
BPF_DYNPTR_TYPE_RINGBUF,
};
int bpf_dynptr_check_size(u32 size);
u32 bpf_dynptr_get_size(const struct bpf_dynptr_kern *ptr);
#ifdef CONFIG_BPF_JIT
int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr);
int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr);
@ -2266,6 +2293,11 @@ static inline bool has_current_bpf_ctx(void)
}
void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog);
void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
enum bpf_dynptr_type type, u32 offset, u32 size);
void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr);
void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr);
#else /* !CONFIG_BPF_SYSCALL */
static inline struct bpf_prog *bpf_prog_get(u32 ufd)
{
@ -2495,6 +2527,19 @@ static inline void bpf_prog_inc_misses_counter(struct bpf_prog *prog)
static inline void bpf_cgrp_storage_free(struct cgroup *cgroup)
{
}
static inline void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
enum bpf_dynptr_type type, u32 offset, u32 size)
{
}
static inline void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
{
}
static inline void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr)
{
}
#endif /* CONFIG_BPF_SYSCALL */
void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
@ -2913,36 +2958,6 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
u32 num_args, struct bpf_bprintf_data *data);
void bpf_bprintf_cleanup(struct bpf_bprintf_data *data);
/* the implementation of the opaque uapi struct bpf_dynptr */
struct bpf_dynptr_kern {
void *data;
/* Size represents the number of usable bytes of dynptr data.
* If for example the offset is at 4 for a local dynptr whose data is
* of type u64, the number of usable bytes is 4.
*
* The upper 8 bits are reserved. It is as follows:
* Bits 0 - 23 = size
* Bits 24 - 30 = dynptr type
* Bit 31 = whether dynptr is read-only
*/
u32 size;
u32 offset;
} __aligned(8);
enum bpf_dynptr_type {
BPF_DYNPTR_TYPE_INVALID,
/* Points to memory that is local to the bpf program */
BPF_DYNPTR_TYPE_LOCAL,
/* Underlying data is a kernel-produced ringbuf record */
BPF_DYNPTR_TYPE_RINGBUF,
};
void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
enum bpf_dynptr_type type, u32 offset, u32 size);
void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr);
int bpf_dynptr_check_size(u32 size);
u32 bpf_dynptr_get_size(const struct bpf_dynptr_kern *ptr);
#ifdef CONFIG_BPF_LSM
void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype);
void bpf_cgroup_atype_put(int cgroup_atype);