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libbpf: Constify all high-level program attach APIs
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Attach APIs shouldn't need to modify bpf_program/bpf_map structs, so
change all struct bpf_program and struct bpf_map pointers to const
pointers. This is completely backwards compatible with no functional
change.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-8-andrii@kernel.org
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Andrii Nakryiko authored and Alexei Starovoitov committed Sep 17, 2021
1 parent 91b555d commit 942025c
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Showing 2 changed files with 52 additions and 52 deletions.
68 changes: 34 additions & 34 deletions tools/lib/bpf/libbpf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -220,7 +220,7 @@ struct reloc_desc {

struct bpf_sec_def;

typedef struct bpf_link *(*attach_fn_t)(struct bpf_program *prog);
typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog);

struct bpf_sec_def {
const char *sec;
Expand Down Expand Up @@ -7947,12 +7947,12 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
__VA_ARGS__ \
}

static struct bpf_link *attach_kprobe(struct bpf_program *prog);
static struct bpf_link *attach_tp(struct bpf_program *prog);
static struct bpf_link *attach_raw_tp(struct bpf_program *prog);
static struct bpf_link *attach_trace(struct bpf_program *prog);
static struct bpf_link *attach_lsm(struct bpf_program *prog);
static struct bpf_link *attach_iter(struct bpf_program *prog);
static struct bpf_link *attach_kprobe(const struct bpf_program *prog);
static struct bpf_link *attach_tp(const struct bpf_program *prog);
static struct bpf_link *attach_raw_tp(const struct bpf_program *prog);
static struct bpf_link *attach_trace(const struct bpf_program *prog);
static struct bpf_link *attach_lsm(const struct bpf_program *prog);
static struct bpf_link *attach_iter(const struct bpf_program *prog);

static const struct bpf_sec_def section_defs[] = {
BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
Expand Down Expand Up @@ -9092,7 +9092,7 @@ static void bpf_link_perf_dealloc(struct bpf_link *link)
free(perf_link);
}

struct bpf_link *bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd,
struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
const struct bpf_perf_event_opts *opts)
{
char errmsg[STRERR_BUFSIZE];
Expand Down Expand Up @@ -9167,7 +9167,7 @@ struct bpf_link *bpf_program__attach_perf_event_opts(struct bpf_program *prog, i
return libbpf_err_ptr(err);
}

struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd)
struct bpf_link *bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd)
{
return bpf_program__attach_perf_event_opts(prog, pfd, NULL);
}
Expand Down Expand Up @@ -9332,7 +9332,7 @@ static int perf_event_kprobe_open_legacy(bool retprobe, const char *name, uint64
}

struct bpf_link *
bpf_program__attach_kprobe_opts(struct bpf_program *prog,
bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
const char *func_name,
const struct bpf_kprobe_opts *opts)
{
Expand Down Expand Up @@ -9389,7 +9389,7 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
return link;
}

struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
bool retprobe,
const char *func_name)
{
Expand All @@ -9400,7 +9400,7 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
}

static struct bpf_link *attach_kprobe(struct bpf_program *prog)
static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
{
DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
unsigned long offset = 0;
Expand Down Expand Up @@ -9432,7 +9432,7 @@ static struct bpf_link *attach_kprobe(struct bpf_program *prog)
}

LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
const char *binary_path, size_t func_offset,
const struct bpf_uprobe_opts *opts)
{
Expand Down Expand Up @@ -9472,7 +9472,7 @@ bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
return link;
}

struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog,
bool retprobe, pid_t pid,
const char *binary_path,
size_t func_offset)
Expand Down Expand Up @@ -9532,7 +9532,7 @@ static int perf_event_open_tracepoint(const char *tp_category,
return pfd;
}

struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name,
const struct bpf_tracepoint_opts *opts)
Expand Down Expand Up @@ -9566,14 +9566,14 @@ struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
return link;
}

struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name)
{
return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
}

static struct bpf_link *attach_tp(struct bpf_program *prog)
static struct bpf_link *attach_tp(const struct bpf_program *prog)
{
char *sec_name, *tp_cat, *tp_name;
struct bpf_link *link;
Expand All @@ -9597,7 +9597,7 @@ static struct bpf_link *attach_tp(struct bpf_program *prog)
return link;
}

struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
const char *tp_name)
{
char errmsg[STRERR_BUFSIZE];
Expand Down Expand Up @@ -9627,15 +9627,15 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
return link;
}

static struct bpf_link *attach_raw_tp(struct bpf_program *prog)
static struct bpf_link *attach_raw_tp(const struct bpf_program *prog)
{
const char *tp_name = prog->sec_name + prog->sec_def->len;

return bpf_program__attach_raw_tracepoint(prog, tp_name);
}

/* Common logic for all BPF program types that attach to a btf_id */
static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link *link;
Expand Down Expand Up @@ -9664,28 +9664,28 @@ static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
return (struct bpf_link *)link;
}

struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog)
{
return bpf_program__attach_btf_id(prog);
}

struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog)
struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog)
{
return bpf_program__attach_btf_id(prog);
}

static struct bpf_link *attach_trace(struct bpf_program *prog)
static struct bpf_link *attach_trace(const struct bpf_program *prog)
{
return bpf_program__attach_trace(prog);
}

static struct bpf_link *attach_lsm(struct bpf_program *prog)
static struct bpf_link *attach_lsm(const struct bpf_program *prog)
{
return bpf_program__attach_lsm(prog);
}

static struct bpf_link *
bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id,
const char *target_name)
{
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
Expand Down Expand Up @@ -9721,24 +9721,24 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
}

struct bpf_link *
bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd)
{
return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
}

struct bpf_link *
bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd)
{
return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
}

struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex)
{
/* target_fd/target_ifindex use the same field in LINK_CREATE */
return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
}

struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd,
const char *attach_func_name)
{
Expand Down Expand Up @@ -9771,7 +9771,7 @@ struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
}

struct bpf_link *
bpf_program__attach_iter(struct bpf_program *prog,
bpf_program__attach_iter(const struct bpf_program *prog,
const struct bpf_iter_attach_opts *opts)
{
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
Expand Down Expand Up @@ -9810,12 +9810,12 @@ bpf_program__attach_iter(struct bpf_program *prog,
return link;
}

static struct bpf_link *attach_iter(struct bpf_program *prog)
static struct bpf_link *attach_iter(const struct bpf_program *prog)
{
return bpf_program__attach_iter(prog, NULL);
}

struct bpf_link *bpf_program__attach(struct bpf_program *prog)
struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
{
if (!prog->sec_def || !prog->sec_def->attach_fn)
return libbpf_err_ptr(-ESRCH);
Expand All @@ -9833,7 +9833,7 @@ static int bpf_link__detach_struct_ops(struct bpf_link *link)
return 0;
}

struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map)
struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
{
struct bpf_struct_ops *st_ops;
struct bpf_link *link;
Expand Down Expand Up @@ -10918,7 +10918,7 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
if (!prog->sec_def || !prog->sec_def->attach_fn)
continue;

*link = prog->sec_def->attach_fn(prog);
*link = bpf_program__attach(prog);
err = libbpf_get_error(*link);
if (err) {
pr_warn("failed to auto-attach program '%s': %d\n",
Expand Down
36 changes: 18 additions & 18 deletions tools/lib/bpf/libbpf.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -246,7 +246,7 @@ LIBBPF_API int bpf_link__detach(struct bpf_link *link);
LIBBPF_API int bpf_link__destroy(struct bpf_link *link);

LIBBPF_API struct bpf_link *
bpf_program__attach(struct bpf_program *prog);
bpf_program__attach(const struct bpf_program *prog);

struct bpf_perf_event_opts {
/* size of this struct, for forward/backward compatiblity */
Expand All @@ -257,10 +257,10 @@ struct bpf_perf_event_opts {
#define bpf_perf_event_opts__last_field bpf_cookie

LIBBPF_API struct bpf_link *
bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);

LIBBPF_API struct bpf_link *
bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd,
bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
const struct bpf_perf_event_opts *opts);

struct bpf_kprobe_opts {
Expand All @@ -277,10 +277,10 @@ struct bpf_kprobe_opts {
#define bpf_kprobe_opts__last_field retprobe

LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
const char *func_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe_opts(struct bpf_program *prog,
bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
const char *func_name,
const struct bpf_kprobe_opts *opts);

Expand All @@ -300,11 +300,11 @@ struct bpf_uprobe_opts {
#define bpf_uprobe_opts__last_field retprobe

LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
pid_t pid, const char *binary_path,
size_t func_offset);
LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
const char *binary_path, size_t func_offset,
const struct bpf_uprobe_opts *opts);

Expand All @@ -317,35 +317,35 @@ struct bpf_tracepoint_opts {
#define bpf_tracepoint_opts__last_field bpf_cookie

LIBBPF_API struct bpf_link *
bpf_program__attach_tracepoint(struct bpf_program *prog,
bpf_program__attach_tracepoint(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name,
const struct bpf_tracepoint_opts *opts);

LIBBPF_API struct bpf_link *
bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
const char *tp_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_trace(struct bpf_program *prog);
bpf_program__attach_trace(const struct bpf_program *prog);
LIBBPF_API struct bpf_link *
bpf_program__attach_lsm(struct bpf_program *prog);
bpf_program__attach_lsm(const struct bpf_program *prog);
LIBBPF_API struct bpf_link *
bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd);
bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_netns(struct bpf_program *prog, int netns_fd);
bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_xdp(struct bpf_program *prog, int ifindex);
bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
LIBBPF_API struct bpf_link *
bpf_program__attach_freplace(struct bpf_program *prog,
bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd, const char *attach_func_name);

struct bpf_map;

LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map);
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);

struct bpf_iter_attach_opts {
size_t sz; /* size of this struct for forward/backward compatibility */
Expand All @@ -355,7 +355,7 @@ struct bpf_iter_attach_opts {
#define bpf_iter_attach_opts__last_field link_info_len

LIBBPF_API struct bpf_link *
bpf_program__attach_iter(struct bpf_program *prog,
bpf_program__attach_iter(const struct bpf_program *prog,
const struct bpf_iter_attach_opts *opts);

struct bpf_insn;
Expand Down

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