Commit ee971630 authored by Feng Yang's avatar Feng Yang Committed by Andrii Nakryiko
Browse files

bpf: Allow some trace helpers for all prog types 

if it works under NMI and doesn't use any context-dependent things,
should be fine for any program type. The detailed discussion is in [1].

[1] https://lore.kernel.org/all/CAEf4Bza6gK3dsrTosk6k3oZgtHesNDSrDd8sdeQ-GiS6oJixQg@mail.gmail.com/



Suggested-by: default avatarAndrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: default avatarFeng Yang <yangfeng@kylinos.cn>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20250506061434.94277-2-yangfeng59949@163.com
parent 32c563d1

include/linux/bpf-cgroup.h

+0 −8
Original line number Diff line number Diff line
@@ -427,8 +427,6 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, 


const struct bpf_func_proto *

cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);

const struct bpf_func_proto *

cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);

#else



static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
@@ -465,12 +463,6 @@ cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	return NULL;

}



static inline const struct bpf_func_proto *

cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)

{

	return NULL;

}



static inline int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux,

					    struct bpf_map *map) { return 0; }

static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(

kernel/bpf/cgroup.c

+0 −32
Original line number Diff line number Diff line
@@ -1653,10 +1653,6 @@ cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	if (func_proto)

		return func_proto;



	func_proto = cgroup_current_func_proto(func_id, prog);

	if (func_proto)

		return func_proto;



	switch (func_id) {

	case BPF_FUNC_perf_event_output:

		return &bpf_event_output_data_proto;
@@ -2204,10 +2200,6 @@ sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	if (func_proto)

		return func_proto;



	func_proto = cgroup_current_func_proto(func_id, prog);

	if (func_proto)

		return func_proto;



	switch (func_id) {

	case BPF_FUNC_sysctl_get_name:

		return &bpf_sysctl_get_name_proto;
@@ -2351,10 +2343,6 @@ cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	if (func_proto)

		return func_proto;



	func_proto = cgroup_current_func_proto(func_id, prog);

	if (func_proto)

		return func_proto;



	switch (func_id) {

#ifdef CONFIG_NET

	case BPF_FUNC_get_netns_cookie:
@@ -2601,23 +2589,3 @@ cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return NULL;

	}

}
 


/* Common helpers for cgroup hooks with valid process context. */

const struct bpf_func_proto *

cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)

{

	switch (func_id) {

	case BPF_FUNC_get_current_uid_gid:

		return &bpf_get_current_uid_gid_proto;

	case BPF_FUNC_get_current_comm:

		return &bpf_get_current_comm_proto;

#ifdef CONFIG_CGROUP_NET_CLASSID

	case BPF_FUNC_get_cgroup_classid:

		return &bpf_get_cgroup_classid_curr_proto;

#endif

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

	default:

		return NULL;

	}

}

kernel/bpf/helpers.c

+42 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/btf_ids.h>

#include <linux/bpf_mem_alloc.h>

#include <linux/kasan.h>

#include <linux/bpf_verifier.h>



#include "../../lib/kstrtox.h"
@@ -1912,6 +1913,12 @@ const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; 
const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;

const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;

const struct bpf_func_proto bpf_task_pt_regs_proto __weak;

const struct bpf_func_proto bpf_perf_event_read_proto __weak;

const struct bpf_func_proto bpf_send_signal_proto __weak;

const struct bpf_func_proto bpf_send_signal_thread_proto __weak;

const struct bpf_func_proto bpf_get_task_stack_sleepable_proto __weak;

const struct bpf_func_proto bpf_get_task_stack_proto __weak;

const struct bpf_func_proto bpf_get_branch_snapshot_proto __weak;



const struct bpf_func_proto *

bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
@@ -1965,6 +1972,8 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_get_current_pid_tgid_proto;

	case BPF_FUNC_get_ns_current_pid_tgid:

		return &bpf_get_ns_current_pid_tgid_proto;

	case BPF_FUNC_get_current_uid_gid:

		return &bpf_get_current_uid_gid_proto;

	default:

		break;

	}
@@ -2022,7 +2031,21 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_get_current_cgroup_id_proto;

	case BPF_FUNC_get_current_ancestor_cgroup_id:

		return &bpf_get_current_ancestor_cgroup_id_proto;

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

#endif

#ifdef CONFIG_CGROUP_NET_CLASSID

	case BPF_FUNC_get_cgroup_classid:

		return &bpf_get_cgroup_classid_curr_proto;

#endif

	case BPF_FUNC_task_storage_get:

		if (bpf_prog_check_recur(prog))

			return &bpf_task_storage_get_recur_proto;

		return &bpf_task_storage_get_proto;

	case BPF_FUNC_task_storage_delete:

		if (bpf_prog_check_recur(prog))

			return &bpf_task_storage_delete_recur_proto;

		return &bpf_task_storage_delete_proto;

	default:

		break;

	}
@@ -2037,6 +2060,8 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_get_current_task_proto;

	case BPF_FUNC_get_current_task_btf:

		return &bpf_get_current_task_btf_proto;

	case BPF_FUNC_get_current_comm:

		return &bpf_get_current_comm_proto;

	case BPF_FUNC_probe_read_user:

		return &bpf_probe_read_user_proto;

	case BPF_FUNC_probe_read_kernel:
@@ -2047,6 +2072,10 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	case BPF_FUNC_probe_read_kernel_str:

		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?

		       NULL : &bpf_probe_read_kernel_str_proto;

	case BPF_FUNC_copy_from_user:

		return &bpf_copy_from_user_proto;

	case BPF_FUNC_copy_from_user_task:

		return &bpf_copy_from_user_task_proto;

	case BPF_FUNC_snprintf_btf:

		return &bpf_snprintf_btf_proto;

	case BPF_FUNC_snprintf:
@@ -2057,6 +2086,19 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return bpf_get_trace_vprintk_proto();

	case BPF_FUNC_perf_event_read_value:

		return bpf_get_perf_event_read_value_proto();

	case BPF_FUNC_perf_event_read:

		return &bpf_perf_event_read_proto;

	case BPF_FUNC_send_signal:

		return &bpf_send_signal_proto;

	case BPF_FUNC_send_signal_thread:

		return &bpf_send_signal_thread_proto;

	case BPF_FUNC_get_task_stack:

		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto

				       : &bpf_get_task_stack_proto;

	case BPF_FUNC_get_branch_snapshot:

		return &bpf_get_branch_snapshot_proto;

	case BPF_FUNC_find_vma:

		return &bpf_find_vma_proto;

	default:

		return NULL;

	}

kernel/trace/bpf_trace.c

+4 −37
Original line number Diff line number Diff line
@@ -572,7 +572,7 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 
	return value;

}



static const struct bpf_func_proto bpf_perf_event_read_proto = {

const struct bpf_func_proto bpf_perf_event_read_proto = {

	.func		= bpf_perf_event_read,

	.gpl_only	= true,

	.ret_type	= RET_INTEGER,
@@ -882,7 +882,7 @@ BPF_CALL_1(bpf_send_signal, u32, sig) 
	return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);

}



static const struct bpf_func_proto bpf_send_signal_proto = {

const struct bpf_func_proto bpf_send_signal_proto = {

	.func		= bpf_send_signal,

	.gpl_only	= false,

	.ret_type	= RET_INTEGER,
@@ -894,7 +894,7 @@ BPF_CALL_1(bpf_send_signal_thread, u32, sig) 
	return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);

}



static const struct bpf_func_proto bpf_send_signal_thread_proto = {

const struct bpf_func_proto bpf_send_signal_thread_proto = {

	.func		= bpf_send_signal_thread,

	.gpl_only	= false,

	.ret_type	= RET_INTEGER,
@@ -1185,7 +1185,7 @@ BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 
	return entry_cnt * br_entry_size;

}



static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {

const struct bpf_func_proto bpf_get_branch_snapshot_proto = {

	.func		= bpf_get_branch_snapshot,

	.gpl_only	= true,

	.ret_type	= RET_INTEGER,
@@ -1430,14 +1430,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	const struct bpf_func_proto *func_proto;



	switch (func_id) {

	case BPF_FUNC_get_current_uid_gid:

		return &bpf_get_current_uid_gid_proto;

	case BPF_FUNC_get_current_comm:

		return &bpf_get_current_comm_proto;

	case BPF_FUNC_get_smp_processor_id:

		return &bpf_get_smp_processor_id_proto;

	case BPF_FUNC_perf_event_read:

		return &bpf_perf_event_read_proto;

#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE

	case BPF_FUNC_probe_read:

		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
@@ -1446,35 +1440,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?

		       NULL : &bpf_probe_read_compat_str_proto;

#endif

#ifdef CONFIG_CGROUPS

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

#endif

	case BPF_FUNC_send_signal:

		return &bpf_send_signal_proto;

	case BPF_FUNC_send_signal_thread:

		return &bpf_send_signal_thread_proto;

	case BPF_FUNC_get_task_stack:

		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto

				       : &bpf_get_task_stack_proto;

	case BPF_FUNC_copy_from_user:

		return &bpf_copy_from_user_proto;

	case BPF_FUNC_copy_from_user_task:

		return &bpf_copy_from_user_task_proto;

	case BPF_FUNC_task_storage_get:

		if (bpf_prog_check_recur(prog))

			return &bpf_task_storage_get_recur_proto;

		return &bpf_task_storage_get_proto;

	case BPF_FUNC_task_storage_delete:

		if (bpf_prog_check_recur(prog))

			return &bpf_task_storage_delete_recur_proto;

		return &bpf_task_storage_delete_proto;

	case BPF_FUNC_get_func_ip:

		return &bpf_get_func_ip_proto_tracing;

	case BPF_FUNC_get_branch_snapshot:

		return &bpf_get_branch_snapshot_proto;

	case BPF_FUNC_find_vma:

		return &bpf_find_vma_proto;

	default:

		break;

	}

net/core/filter.c

+0 −14
Original line number Diff line number Diff line
@@ -8022,10 +8022,6 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	if (func_proto)

		return func_proto;



	func_proto = cgroup_current_func_proto(func_id, prog);

	if (func_proto)

		return func_proto;



	switch (func_id) {

	case BPF_FUNC_get_socket_cookie:

		return &bpf_get_socket_cookie_sock_proto;
@@ -8051,10 +8047,6 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	if (func_proto)

		return func_proto;



	func_proto = cgroup_current_func_proto(func_id, prog);

	if (func_proto)

		return func_proto;



	switch (func_id) {

	case BPF_FUNC_bind:

		switch (prog->expected_attach_type) {
@@ -8488,18 +8480,12 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_msg_pop_data_proto;

	case BPF_FUNC_perf_event_output:

		return &bpf_event_output_data_proto;

	case BPF_FUNC_get_current_uid_gid:

		return &bpf_get_current_uid_gid_proto;

	case BPF_FUNC_sk_storage_get:

		return &bpf_sk_storage_get_proto;

	case BPF_FUNC_sk_storage_delete:

		return &bpf_sk_storage_delete_proto;

	case BPF_FUNC_get_netns_cookie:

		return &bpf_get_netns_cookie_sk_msg_proto;

#ifdef CONFIG_CGROUP_NET_CLASSID

	case BPF_FUNC_get_cgroup_classid:

		return &bpf_get_cgroup_classid_curr_proto;

#endif

	default:

		return bpf_sk_base_func_proto(func_id, prog);

	}