mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-10-31 16:48:26 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs

Browse source 
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF
aware variants). This brings them up to part w.r.t. BPF cookie usage
with classic tracepoint and fentry/fexit programs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-4-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2024-03-19 16:38:50 -07:00 committed by Alexei Starovoitov
parent d4dfc5700e
commit 68ca5d4eeb
5 changed files with 28 additions and 6 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
include/linux/bpf.h
View file

@ -1610,6 +1610,7 @@ struct bpf_tracing_link {
struct bpf_raw_tp_link {
struct bpf_link link;
struct bpf_raw_event_map *btp;
u64 cookie;
};
struct bpf_link_primer {

6
include/uapi/linux/bpf.h
View file

@ -1662,8 +1662,10 @@ union bpf_attr {
} query;
struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
__u64 name;
__u32 prog_fd;
__u64 name;
__u32 prog_fd;
__u32 :32;
__aligned_u64 cookie;
} raw_tracepoint;
struct { /* anonymous struct for BPF_BTF_LOAD */

13
kernel/bpf/syscall.c
View file

@ -3774,7 +3774,7 @@ static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *pro
#endif /* CONFIG_PERF_EVENTS */
static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
const char __user *user_tp_name)
const char __user *user_tp_name, u64 cookie)
{
struct bpf_link_primer link_primer;
struct bpf_raw_tp_link *link;
@ -3821,6 +3821,7 @@ static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
&bpf_raw_tp_link_lops, prog);
link->btp = btp;
link->cookie = cookie;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
@ -3841,11 +3842,13 @@ static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
return err;
}
#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
struct bpf_prog *prog;
void __user *tp_name;
__u64 cookie;
int fd;
if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
@ -3855,7 +3858,9 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
if (IS_ERR(prog))
return PTR_ERR(prog);
fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name));
tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
cookie = attr->raw_tracepoint.cookie;
fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
if (fd < 0)
bpf_prog_put(prog);
return fd;
@ -5193,7 +5198,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
goto out;
}
if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
ret = bpf_raw_tp_link_attach(prog, NULL);
ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
else if (prog->expected_attach_type == BPF_TRACE_ITER)
ret = bpf_iter_link_attach(attr, uattr, prog);
else if (prog->expected_attach_type == BPF_LSM_CGROUP)

13
kernel/trace/bpf_trace.c
View file

@ -2004,6 +2004,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_get_stackid_proto_raw_tp;
case BPF_FUNC_get_stack:
return &bpf_get_stack_proto_raw_tp;
case BPF_FUNC_get_attach_cookie:
return &bpf_get_attach_cookie_proto_tracing;
default:
return bpf_tracing_func_proto(func_id, prog);
}
@ -2066,6 +2068,9 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_get_func_arg_cnt:
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
case BPF_FUNC_get_attach_cookie:
if (prog->type == BPF_PROG_TYPE_TRACING &&
prog->expected_attach_type == BPF_TRACE_RAW_TP)
return &bpf_get_attach_cookie_proto_tracing;
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
default:
fn = raw_tp_prog_func_proto(func_id, prog);
@ -2369,15 +2374,23 @@ static __always_inline
void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
{
struct bpf_prog *prog = link->link.prog;
struct bpf_run_ctx *old_run_ctx;
struct bpf_trace_run_ctx run_ctx;
cant_sleep();
if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
bpf_prog_inc_misses_counter(prog);
goto out;
}
run_ctx.bpf_cookie = link->cookie;
old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
rcu_read_lock();
(void) bpf_prog_run(prog, args);
rcu_read_unlock();
bpf_reset_run_ctx(old_run_ctx);
out:
this_cpu_dec(*(prog->active));
}

1
tools/include/uapi/linux/bpf.h
View file

@ -1664,6 +1664,7 @@ union bpf_attr {
struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
__u64 name;
__u32 prog_fd;
__aligned_u64 cookie;
} raw_tracepoint;
struct { /* anonymous struct for BPF_BTF_LOAD */