Commit d9d93f3b authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'bpf: Support ksym detection in light skeleton.' 



Alexei Starovoitov says:

====================

From: Alexei Starovoitov <ast@kernel.org>

v1->v2: update denylist on s390

Patch 1: Cleanup internal libbpf names.
Patch 2: Teach the verifier that rdonly_mem != NULL.
Patch 3: Fix gen_loader to support ksym detection.
Patch 4: Selftest and update denylist.
====================

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents 9a321fd3 3b2ec214

kernel/bpf/verifier.c

+9 −5
Original line number Diff line number Diff line
@@ -486,8 +486,17 @@ static bool type_is_sk_pointer(enum bpf_reg_type type) 
		type == PTR_TO_XDP_SOCK;

}









static bool type_may_be_null(u32 type)









{









	return type & PTR_MAYBE_NULL;









}

















static bool reg_type_not_null(enum bpf_reg_type type)









{









	if (type_may_be_null(type))









		return false;

















	type = base_type(type);









	return type == PTR_TO_SOCKET ||









		type == PTR_TO_TCP_SOCK ||









		type == PTR_TO_MAP_VALUE ||








@@ -531,11 +540,6 @@ static bool type_is_rdonly_mem(u32 type)







	return type & MEM_RDONLY;









}

















static bool type_may_be_null(u32 type)









{









	return type & PTR_MAYBE_NULL;









}

















static bool is_acquire_function(enum bpf_func_id func_id,









				const struct bpf_map *map)









{
































tools/lib/bpf/bpf_gen_internal.h



+3
−1






























Original line number
Diff line number
Diff line







@@ -11,6 +11,7 @@ struct ksym_relo_desc {







	int insn_idx;









	bool is_weak;









	bool is_typeless;









	bool is_ld64;









};



















struct ksym_desc {








@@ -24,6 +25,7 @@ struct ksym_desc {







		bool typeless;









	};









	int insn;









	bool is_ld64;









};



















struct bpf_gen {








@@ -65,7 +67,7 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u







void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx);









void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum bpf_attach_type type);









void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,









			    bool is_typeless, int kind, int insn_idx);









			    bool is_typeless, bool is_ld64, int kind, int insn_idx);









void bpf_gen__record_relo_core(struct bpf_gen *gen, const struct bpf_core_relo *core_relo);









void bpf_gen__populate_outer_map(struct bpf_gen *gen, int outer_map_idx, int key, int inner_map_idx);










































tools/lib/bpf/gen_loader.c



+19
−19






























Original line number
Diff line number
Diff line







@@ -560,7 +560,7 @@ static void emit_find_attach_target(struct bpf_gen *gen)







}



















void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,









			    bool is_typeless, int kind, int insn_idx)









			    bool is_typeless, bool is_ld64, int kind, int insn_idx)









{









	struct ksym_relo_desc *relo;


















@@ -574,6 +574,7 @@ void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,







	relo->name = name;









	relo->is_weak = is_weak;









	relo->is_typeless = is_typeless;









	relo->is_ld64 = is_ld64;









	relo->kind = kind;









	relo->insn_idx = insn_idx;









	gen->relo_cnt++;








@@ -586,9 +587,11 @@ static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_des







	int i;



















	for (i = 0; i < gen->nr_ksyms; i++) {









		if (!strcmp(gen->ksyms[i].name, relo->name)) {









			gen->ksyms[i].ref++;









			return &gen->ksyms[i];









		kdesc = &gen->ksyms[i];









		if (kdesc->kind == relo->kind && kdesc->is_ld64 == relo->is_ld64 &&









		    !strcmp(kdesc->name, relo->name)) {









			kdesc->ref++;









			return kdesc;









		}









	}









	kdesc = libbpf_reallocarray(gen->ksyms, gen->nr_ksyms + 1, sizeof(*kdesc));








@@ -603,6 +606,7 @@ static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_des







	kdesc->ref = 1;









	kdesc->off = 0;









	kdesc->insn = 0;









	kdesc->is_ld64 = relo->is_ld64;









	return kdesc;









}


















@@ -864,23 +868,17 @@ static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn







{









	int insn;



















	pr_debug("gen: emit_relo (%d): %s at %d\n", relo->kind, relo->name, relo->insn_idx);









	pr_debug("gen: emit_relo (%d): %s at %d %s\n",









		 relo->kind, relo->name, relo->insn_idx, relo->is_ld64 ? "ld64" : "call");









	insn = insns + sizeof(struct bpf_insn) * relo->insn_idx;









	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn));









	switch (relo->kind) {









	case BTF_KIND_VAR:









	if (relo->is_ld64) {









		if (relo->is_typeless)









			emit_relo_ksym_typeless(gen, relo, insn);









		else









			emit_relo_ksym_btf(gen, relo, insn);









		break;









	case BTF_KIND_FUNC:









	} else {









		emit_relo_kfunc_btf(gen, relo, insn);









		break;









	default:









		pr_warn("Unknown relocation kind '%d'\n", relo->kind);









		gen->error = -EDOM;









		return;









	}









}


















@@ -903,18 +901,20 @@ static void cleanup_core_relo(struct bpf_gen *gen)

















static void cleanup_relos(struct bpf_gen *gen, int insns)









{









	struct ksym_desc *kdesc;









	int i, insn;



















	for (i = 0; i < gen->nr_ksyms; i++) {









		kdesc = &gen->ksyms[i];









		/* only close fds for typed ksyms and kfuncs */









		if (gen->ksyms[i].kind == BTF_KIND_VAR && !gen->ksyms[i].typeless) {









		if (kdesc->is_ld64 && !kdesc->typeless) {









			/* close fd recorded in insn[insn_idx + 1].imm */









			insn = gen->ksyms[i].insn;









			insn = kdesc->insn;









			insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm);









			emit_sys_close_blob(gen, insn);









		} else if (gen->ksyms[i].kind == BTF_KIND_FUNC) {









			emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off));









			if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ)









		} else if (!kdesc->is_ld64) {









			emit_sys_close_blob(gen, blob_fd_array_off(gen, kdesc->off));









			if (kdesc->off < MAX_FD_ARRAY_SZ)









				gen->nr_fd_array--;









		}









	}
































tools/lib/bpf/libbpf.c



+14
−11






























Original line number
Diff line number
Diff line







@@ -315,8 +315,8 @@ enum reloc_type {







	RELO_LD64,









	RELO_CALL,









	RELO_DATA,









	RELO_EXTERN_VAR,









	RELO_EXTERN_FUNC,









	RELO_EXTERN_LD64,









	RELO_EXTERN_CALL,









	RELO_SUBPROG_ADDR,









	RELO_CORE,









};








@@ -4009,9 +4009,9 @@ static int bpf_program__record_reloc(struct bpf_program *prog,







		pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n",









			 prog->name, i, ext->name, ext->sym_idx, insn_idx);









		if (insn->code == (BPF_JMP | BPF_CALL))









			reloc_desc->type = RELO_EXTERN_FUNC;









			reloc_desc->type = RELO_EXTERN_CALL;









		else









			reloc_desc->type = RELO_EXTERN_VAR;









			reloc_desc->type = RELO_EXTERN_LD64;









		reloc_desc->insn_idx = insn_idx;









		reloc_desc->sym_off = i; /* sym_off stores extern index */









		return 0;








@@ -5855,7 +5855,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)







						   relo->map_idx, map);









			}









			break;









		case RELO_EXTERN_VAR:









		case RELO_EXTERN_LD64:









			ext = &obj->externs[relo->sym_off];









			if (ext->type == EXT_KCFG) {









				if (obj->gen_loader) {








@@ -5877,7 +5877,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)







				}









			}









			break;









		case RELO_EXTERN_FUNC:









		case RELO_EXTERN_CALL:









			ext = &obj->externs[relo->sym_off];









			insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;









			if (ext->is_set) {








@@ -6115,7 +6115,7 @@ bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog,







			continue;



















		relo = find_prog_insn_relo(prog, insn_idx);









		if (relo && relo->type == RELO_EXTERN_FUNC)









		if (relo && relo->type == RELO_EXTERN_CALL)









			/* kfunc relocations will be handled later









			 * in bpf_object__relocate_data()









			 */








@@ -7070,18 +7070,21 @@ static int bpf_program_record_relos(struct bpf_program *prog)







	for (i = 0; i < prog->nr_reloc; i++) {









		struct reloc_desc *relo = &prog->reloc_desc[i];









		struct extern_desc *ext = &obj->externs[relo->sym_off];









		int kind;



















		switch (relo->type) {









		case RELO_EXTERN_VAR:









		case RELO_EXTERN_LD64:









			if (ext->type != EXT_KSYM)









				continue;









			kind = btf_is_var(btf__type_by_id(obj->btf, ext->btf_id)) ?









				BTF_KIND_VAR : BTF_KIND_FUNC;









			bpf_gen__record_extern(obj->gen_loader, ext->name,









					       ext->is_weak, !ext->ksym.type_id,









					       BTF_KIND_VAR, relo->insn_idx);









					       true, kind, relo->insn_idx);









			break;









		case RELO_EXTERN_FUNC:









		case RELO_EXTERN_CALL:









			bpf_gen__record_extern(obj->gen_loader, ext->name,









					       ext->is_weak, false, BTF_KIND_FUNC,









					       ext->is_weak, false, false, BTF_KIND_FUNC,









					       relo->insn_idx);









			break;









		case RELO_CORE: {
































tools/testing/selftests/bpf/DENYLIST.s390x



+1
−0






























Original line number
Diff line number
Diff line







@@ -11,6 +11,7 @@ get_stack_raw_tp                         # user_stack corrupted user stack







iters/testmod_seq*                       # s390x doesn't support kfuncs in modules yet









kprobe_multi_bench_attach                # bpf_program__attach_kprobe_multi_opts unexpected error: -95









kprobe_multi_test                        # relies on fentry









ksyms_btf/weak_ksyms*                    # test_ksyms_weak__open_and_load unexpected error: -22                        (kfunc)









ksyms_module                             # test_ksyms_module__open_and_load unexpected error: -9                       (?)









ksyms_module_libbpf                      # JIT does not support calling kernel function                                (kfunc)









ksyms_module_lskel                       # test_ksyms_module_lskel__open_and_load unexpected error: -9                 (?)