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3376 lines (2903 loc) · 90 KB
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/*
SPDX-License-Identifier: GPL-2.0-only
Copyright (C) 2019 Facebook
Derived from ctf_encoder.c, which is:
Copyright (C) Arnaldo Carvalho de Melo <acme@redhat.com>
Copyright (C) Red Hat Inc
*/
#include <linux/btf.h>
#include "dwarves.h"
#include "elf_symtab.h"
#include "btf_encoder.h"
#include "gobuffer.h"
#include <bpf/btf.h>
#include <bpf/libbpf.h>
#include <ctype.h> /* for isalpha() and isalnum() */
#include <stdlib.h> /* for qsort() and bsearch() */
#include <inttypes.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <stdint.h>
#include <search.h> /* for tsearch(), tfind() and tdestroy() */
#include <pthread.h>
#define BTF_BASE_ELF_SEC ".BTF.base"
#define BTF_IDS_SECTION ".BTF_ids"
#define BTF_ID_FUNC_PFX "__BTF_ID__func__"
#define BTF_ID_SET8_PFX "__BTF_ID__set8__"
#define BTF_SET8_KFUNCS (1 << 0)
#define BTF_KFUNC_TYPE_TAG "bpf_kfunc"
#define BTF_FASTCALL_TAG "bpf_fastcall"
#define BPF_ARENA_ATTR "address_space(1)"
/* kfunc flags, see include/linux/btf.h in the kernel source */
#define KF_FASTCALL (1 << 12)
#define KF_ARENA_RET (1 << 13)
#define KF_ARENA_ARG1 (1 << 14)
#define KF_ARENA_ARG2 (1 << 15)
struct btf_id_and_flag {
uint32_t id;
uint32_t flags;
};
/*
* This corresponds to the same macro defined in
* include/linux/kallsyms.h
*/
#define KSYM_NAME_LEN 128
/* Adapted from include/linux/btf_ids.h */
struct btf_id_set8 {
uint32_t cnt;
uint32_t flags;
struct btf_id_and_flag pairs[];
};
struct btf_encoder_func_parm {
int name_off;
uint32_t type_id;
};
struct btf_encoder_func_annot {
int value;
int16_t component_idx;
};
struct elf_function_sym {
const char *name;
uint64_t addr;
};
/* state used to do later encoding of saved functions */
struct btf_encoder_func_state {
struct elf_function *elf;
struct elf_function_sym *sym;
uint64_t addr;
uint32_t type_id_off;
uint16_t nr_parms;
uint16_t nr_annots;
uint8_t optimized_parms:1;
uint8_t unexpected_reg:1;
uint8_t inconsistent_proto:1;
uint8_t uncertain_parm_loc:1;
uint8_t reordered_parm:1;
uint8_t signature_changed:1;
uint8_t optimized_symbol:1;
uint8_t ambiguous_addr:1;
int ret_type_id;
struct btf_encoder_func_parm *parms;
struct btf_encoder_func_annot *annots;
};
struct elf_function {
char *name;
struct elf_function_sym *syms;
uint16_t sym_cnt;
uint16_t ambiguous_addr:1;
uint16_t kfunc:1;
uint32_t kfunc_flags;
};
struct elf_secinfo {
uint64_t addr;
const char *name;
uint64_t sz;
uint32_t type;
bool include;
struct gobuffer secinfo;
};
struct elf_functions {
struct list_head node; /* for elf_functions_list */
Elf *elf; /* source ELF */
struct elf_symtab *symtab;
struct elf_function *entries;
int cnt;
};
/*
* cu: cu being processed.
*/
struct btf_encoder {
struct list_head node;
struct btf *btf;
struct cu *cu;
const char *source_filename;
const char *filename;
struct elf_symtab *symtab;
uint32_t type_id_off;
bool has_index_type,
need_index_type,
raw_output,
verbose,
force,
gen_floats,
skip_encoding_decl_tag,
tag_kfuncs,
gen_distilled_base,
encode_attributes,
true_signature;
uint32_t array_index_id;
uint32_t *type_id_null_adj;
/*
* Maps DWARF core_id → actual BTF type id. Populated by
* btf_encoder__precompute_btf_ids() before encoding begins.
*
* Entry value 0 means "skipped" (e.g. DW_TAG_unspecified_type);
* this is safe as a sentinel because BTF type id 0 is void and
* the first real type id is always >= 1.
*
* tag__nr_btf_ids() is the single source of truth for how many
* BTF ids each DWARF tag consumes; both precompute and encode
* use it so the mapping stays consistent.
*/
uint32_t *btf_id_map;
uint32_t btf_id_map_sz;
/*
* Final extra/skipped counts from btf_encoder__precompute_btf_ids(),
* used to compute the fallback array_index_id when "int" is absent.
*/
uint32_t btf_id_extra;
uint32_t btf_id_skipped;
struct elf_secinfo *secinfo;
size_t seccnt;
int encode_vars;
struct {
struct btf_encoder_func_state *array;
int cnt;
int cap;
} func_states;
/* This is a list of elf_functions tables, one per ELF.
* Multiple ELF modules can be processed in one pahole run,
* so we have to store elf_functions tables per ELF.
*/
struct list_head elf_functions_list;
};
/* Half open interval representing range of addresses containing kfuncs */
struct btf_kfunc_set_range {
uint64_t start;
uint64_t end;
};
static inline void elf_function__clear(struct elf_function *func)
{
free(func->name);
if (func->sym_cnt)
free(func->syms);
memset(func, 0, sizeof(*func));
}
static inline void elf_functions__delete(struct elf_functions *funcs)
{
for (int i = 0; i < funcs->cnt; i++)
elf_function__clear(&funcs->entries[i]);
free(funcs->entries);
elf_symtab__delete(funcs->symtab);
free(funcs);
}
static int elf_functions__collect(struct elf_functions *functions);
struct elf_functions *elf_functions__new(Elf *elf)
{
struct elf_functions *funcs;
int err;
funcs = calloc(1, sizeof(*funcs));
if (!funcs) {
err = -ENOMEM;
goto out_delete;
}
funcs->symtab = elf_symtab__new(NULL, elf);
if (!funcs->symtab) {
err = -1;
goto out_delete;
}
funcs->elf = elf;
err = elf_functions__collect(funcs);
if (err < 0)
goto out_delete;
return funcs;
out_delete:
elf_functions__delete(funcs);
return NULL;
}
static inline void elf_functions_list__clear(struct list_head *elf_functions_list)
{
struct elf_functions *funcs;
struct list_head *pos, *tmp;
list_for_each_safe(pos, tmp, elf_functions_list) {
funcs = list_entry(pos, struct elf_functions, node);
list_del(&funcs->node);
elf_functions__delete(funcs);
}
}
static struct elf_functions *elf_functions__find(const Elf *elf, const struct list_head *elf_functions_list)
{
struct elf_functions *funcs;
struct list_head *pos;
list_for_each(pos, elf_functions_list) {
funcs = list_entry(pos, struct elf_functions, node);
if (funcs->elf == elf)
return funcs;
}
return NULL;
}
#define PERCPU_SECTION ".data..percpu"
/*
* This depends on the GNU extension to eliminate the stray comma in the zero
* arguments case.
*
* The difference between elf_errmsg(-1) and elf_errmsg(elf_errno()) is that the
* latter clears the current error.
*/
#define elf_error(fmt, ...) \
fprintf(stderr, "%s: " fmt ": %s.\n", __func__, ##__VA_ARGS__, elf_errmsg(-1))
/*
* This depends on the GNU extension to eliminate the stray comma in the zero
* arguments case.
*
* The difference between elf_errmsg(-1) and elf_errmsg(elf_errno()) is that the
* latter clears the current error.
*/
#define elf_error(fmt, ...) \
fprintf(stderr, "%s: " fmt ": %s.\n", __func__, ##__VA_ARGS__, elf_errmsg(-1))
static int btf_var_secinfo_cmp(const void *a, const void *b)
{
const struct btf_var_secinfo *av = a;
const struct btf_var_secinfo *bv = b;
return av->offset - bv->offset;
}
#define BITS_PER_BYTE 8
#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
#define BITS_ROUNDUP_BYTES(bits) (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
static const char * const btf_kind_str[] = {
[BTF_KIND_UNKN] = "UNKNOWN",
[BTF_KIND_INT] = "INT",
[BTF_KIND_PTR] = "PTR",
[BTF_KIND_ARRAY] = "ARRAY",
[BTF_KIND_STRUCT] = "STRUCT",
[BTF_KIND_UNION] = "UNION",
[BTF_KIND_ENUM] = "ENUM",
[BTF_KIND_FWD] = "FWD",
[BTF_KIND_TYPEDEF] = "TYPEDEF",
[BTF_KIND_VOLATILE] = "VOLATILE",
[BTF_KIND_CONST] = "CONST",
[BTF_KIND_RESTRICT] = "RESTRICT",
[BTF_KIND_FUNC] = "FUNC",
[BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
[BTF_KIND_VAR] = "VAR",
[BTF_KIND_DATASEC] = "DATASEC",
[BTF_KIND_FLOAT] = "FLOAT",
[BTF_KIND_DECL_TAG] = "DECL_TAG",
[BTF_KIND_TYPE_TAG] = "TYPE_TAG",
[BTF_KIND_ENUM64] = "ENUM64",
};
static const char *btf__printable_name(const struct btf *btf, uint32_t offset)
{
if (!offset)
return "(anon)";
else
return btf__str_by_offset(btf, offset);
}
static const char * btf__int_encoding_str(uint8_t encoding)
{
if (encoding == 0)
return "(none)";
else if (encoding == BTF_INT_SIGNED)
return "SIGNED";
else if (encoding == BTF_INT_CHAR)
return "CHAR";
else if (encoding == BTF_INT_BOOL)
return "BOOL";
else
return "UNKN";
}
__attribute ((format (printf, 6, 7)))
static void btf__log_err(const struct btf *btf, int kind, const char *name,
bool output_cr, int libbpf_err, const char *fmt, ...)
{
fprintf(stderr, "[%u] %s %s", btf__type_cnt(btf),
btf_kind_str[kind], name ?: "(anon)");
if (fmt && *fmt) {
va_list ap;
fprintf(stderr, " ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
if (libbpf_err < 0)
fprintf(stderr, " (libbpf error %d)", libbpf_err);
if (output_cr)
fprintf(stderr, "\n");
}
__attribute ((format (printf, 5, 6)))
static void btf_encoder__log_type(const struct btf_encoder *encoder, const struct btf_type *t,
bool err, bool output_cr, const char *fmt, ...)
{
const struct btf *btf = encoder->btf;
uint8_t kind;
FILE *out;
if (!encoder->verbose && !err)
return;
kind = BTF_INFO_KIND(t->info);
out = err ? stderr : stdout;
fprintf(out, "[%u] %s %s",
btf__type_cnt(btf) - 1, btf_kind_str[kind],
btf__printable_name(btf, t->name_off));
if (fmt && *fmt) {
va_list ap;
fprintf(out, " ");
va_start(ap, fmt);
vfprintf(out, fmt, ap);
va_end(ap);
}
if (output_cr)
fprintf(out, "\n");
}
__attribute ((format (printf, 5, 6)))
static void btf_encoder__log_member(const struct btf_encoder *encoder, const struct btf_type *t,
const struct btf_member *member, bool err, const char *fmt, ...)
{
const struct btf *btf = encoder->btf;
FILE *out;
if (!encoder->verbose && !err)
return;
out = err ? stderr : stdout;
if (btf_kflag(t))
fprintf(out, "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
btf__printable_name(btf, member->name_off),
member->type,
BTF_MEMBER_BITFIELD_SIZE(member->offset),
BTF_MEMBER_BIT_OFFSET(member->offset));
else
fprintf(out, "\t%s type_id=%u bits_offset=%u",
btf__printable_name(btf, member->name_off),
member->type,
member->offset);
if (fmt && *fmt) {
va_list ap;
fprintf(out, " ");
va_start(ap, fmt);
vfprintf(out, fmt, ap);
va_end(ap);
}
fprintf(out, "\n");
}
__attribute ((format (printf, 6, 7)))
static void btf_encoder__log_func_param(struct btf_encoder *encoder, const char *name, uint32_t type,
bool err, bool is_last_param, const char *fmt, ...)
{
FILE *out;
if (!encoder->verbose && !err)
return;
out = err ? stderr : stdout;
if (is_last_param && !type)
fprintf(out, "vararg)\n");
else
fprintf(out, "%u %s%s", type, name, is_last_param ? ")\n" : ", ");
if (fmt && *fmt) {
va_list ap;
fprintf(out, " ");
va_start(ap, fmt);
vfprintf(out, fmt, ap);
va_end(ap);
}
}
static int32_t btf_encoder__add_float(struct btf_encoder *encoder, const struct base_type *bt, const char *name)
{
int32_t id = btf__add_float(encoder->btf, name, BITS_ROUNDUP_BYTES(bt->bit_size));
if (id < 0) {
btf__log_err(encoder->btf, BTF_KIND_FLOAT, name, true, id,
"Error emitting BTF type");
} else {
const struct btf_type *t;
10BC8
t = btf__type_by_id(encoder->btf, id);
btf_encoder__log_type(encoder, t, false, true, "size=%u nr_bits=%u", t->size, bt->bit_size);
}
return id;
}
static int32_t btf_encoder__add_base_type(struct btf_encoder *encoder, const struct base_type *bt, const char *name)
{
const struct btf_type *t;
uint8_t encoding = 0;
uint16_t byte_sz;
int32_t id;
if (bt->is_signed) {
encoding = BTF_INT_SIGNED;
} else if (bt->is_bool) {
encoding = BTF_INT_BOOL;
} else if (bt->float_type && encoder->gen_floats) {
/*
* Encode floats as BTF_KIND_FLOAT if allowed, otherwise (in
* compatibility mode) encode them as BTF_KIND_INT - that's not
* fully correct, but that's what it used to be.
*/
if (bt->float_type == BT_FP_SINGLE ||
bt->float_type == BT_FP_DOUBLE ||
bt->float_type == BT_FP_LDBL)
return btf_encoder__add_float(encoder, bt, name);
fprintf(stderr, "Complex, interval and imaginary float types are not supported\n");
return -1;
}
/* dwarf5 may emit DW_ATE_[un]signed_{num} base types where
* {num} is not power of 2 and may exceed 128. Such attributes
* are mostly used to record operation for an actual parameter
* or variable.
* For example,
* DW_AT_location (indexed (0x3c) loclist = 0x00008fb0:
* [0xffffffff82808812, 0xffffffff82808817):
* DW_OP_breg0 RAX+0,
* DW_OP_convert (0x000e97d5) "DW_ATE_unsigned_64",
* DW_OP_convert (0x000e97df) "DW_ATE_unsigned_8",
* DW_OP_stack_value,
* DW_OP_piece 0x1,
* DW_OP_breg0 RAX+0,
* DW_OP_convert (0x000e97d5) "DW_ATE_unsigned_64",
* DW_OP_convert (0x000e97da) "DW_ATE_unsigned_32",
* DW_OP_lit8,
* DW_OP_shr,
* DW_OP_convert (0x000e97da) "DW_ATE_unsigned_32",
* DW_OP_convert (0x000e97e4) "DW_ATE_unsigned_24",
* DW_OP_stack_value, DW_OP_piece 0x3
* DW_AT_name ("ebx")
* DW_AT_decl_file ("/linux/arch/x86/events/intel/core.c")
*
* In the above example, at some point, one unsigned_32 value
* is right shifted by 8 and the result is converted to unsigned_32
* and then unsigned_24.
*
* BTF does not need such DW_OP_* information so let us sanitize
* these non-regular int types to avoid libbpf/kernel complaints.
*/
byte_sz = BITS_ROUNDUP_BYTES(bt->bit_size);
if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16) {
name = "__SANITIZED_FAKE_INT__";
byte_sz = 4;
}
id = btf__add_int(encoder->btf, name, byte_sz, encoding);
if (id < 0) {
btf__log_err(encoder->btf, BTF_KIND_INT, name, true, id, "Error emitting BTF type");
} else {
t = btf__type_by_id(encoder->btf, id);
btf_encoder__log_type(encoder, t, false, true, "size=%u nr_bits=%u encoding=%s%s",
t->size, bt->bit_size, btf__int_encoding_str(encoding),
id < 0 ? " Error in emitting BTF" : "" );
}
return id;
}
static int32_t btf_encoder__add_ref_type(struct btf_encoder *encoder, uint16_t kind, uint32_t type,
const char *name, bool kind_flag)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
int32_t id;
switch (kind) {
case BTF_KIND_PTR:
id = btf__add_ptr(btf, type);
break;
case BTF_KIND_VOLATILE:
id = btf__add_volatile(btf, type);
break;
case BTF_KIND_CONST:
id = btf__add_const(btf, type);
break;
case BTF_KIND_RESTRICT:
id = btf__add_restrict(btf, type);
break;
case BTF_KIND_TYPEDEF:
id = btf__add_typedef(btf, name, type);
break;
case BTF_KIND_TYPE_TAG:
id = btf__add_type_tag(btf, name, type);
break;
case BTF_KIND_FWD:
id = btf__add_fwd(btf, name, kind_flag);
break;
case BTF_KIND_FUNC:
id = btf__add_func(btf, name, BTF_FUNC_STATIC, type);
break;
default:
btf__log_err(btf, kind, name, true, 0, "Unexpected kind for reference");
return -1;
}
if (id > 0) {
t = btf__type_by_id(btf, id);
if (kind == BTF_KIND_FWD)
btf_encoder__log_type(encoder, t, false, true, "%s", kind_flag ? "union" : "struct");
else
btf_encoder__log_type(encoder, t, false, true, "type_id=%u", t->type);
} else {
btf__log_err(btf, kind, name, true, id, "Error emitting BTF type");
}
return id;
}
static int32_t btf_encoder__add_array(struct btf_encoder *encoder, uint32_t type, uint32_t index_type, uint32_t nelems)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
const struct btf_array *array;
int32_t id;
id = btf__add_array(btf, index_type, type, nelems);
if (id > 0) {
t = btf__type_by_id(btf, id);
array = btf_array(t);
btf_encoder__log_type(encoder, t, false, true, "type_id=%u index_type_id=%u nr_elems=%u",
array->type, array->index_type, array->nelems);
} else {
btf__log_err(btf, BTF_KIND_ARRAY, NULL, true, id,
"type_id=%u index_type_id=%u nr_elems=%u Error emitting BTF type",
type, index_type, nelems);
}
return id;
}
static int btf_encoder__add_field(struct btf_encoder *encoder, const char *name, uint32_t type, uint32_t bitfield_size, uint32_t offset)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
const struct btf_member *m;
int err;
err = btf__add_field(btf, name, type, offset, bitfield_size);
t = btf__type_by_id(btf, btf__type_cnt(btf) - 1);
if (err) {
fprintf(stderr, "[%u] %s %s's field '%s' offset=%u bit_size=%u type=%u Error emitting field\n",
btf__type_cnt(btf) - 1, btf_kind_str[btf_kind(t)],
btf__printable_name(btf, t->name_off),
name, offset, bitfield_size, type);
} else {
m = &btf_members(t)[btf_vlen(t) - 1];
btf_encoder__log_member(encoder, t, m, false, NULL);
}
return err;
}
static int32_t btf_encoder__add_struct(struct btf_encoder *encoder, uint8_t kind, const char *name, uint32_t size)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
int32_t id;
switch (kind) {
case BTF_KIND_STRUCT:
id = btf__add_struct(btf, name, size);
break;
case BTF_KIND_UNION:
id = btf__add_union(btf, name, size);
break;
default:
btf__log_err(btf, kind, name, true, 0, "Unexpected kind of struct");
return -1;
}
if (id < 0) {
btf__log_err(btf, kind, name, true, id, "Error emitting BTF type");
} else {
t = btf__type_by_id(btf, id);
btf_encoder__log_type(encoder, t, false, true, "size=%u", t->size);
}
return id;
}
static int32_t btf_encoder__add_enum(struct btf_encoder *encoder, const char *name, struct type *etype,
struct conf_load *conf_load)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
int32_t id, size;
bool is_enum32;
size = BITS_ROUNDUP_BYTES(etype->size);
is_enum32 = size <= 4 || conf_load->skip_encoding_btf_enum64;
if (is_enum32)
id = btf__add_enum(btf, name, size);
else if (btf__add_enum64)
id = btf__add_enum64(btf, name, size, etype->is_signed_enum);
else {
fprintf(stderr, "btf__add_enum64 is not available, is libbpf < 1.0?\n");
return -ENOTSUP;
}
if (id > 0) {
t = btf__type_by_id(btf, id);
btf_encoder__log_type(encoder, t, false, true, "size=%u", t->size);
} else {
btf__log_err(btf, is_enum32 ? BTF_KIND_ENUM : BTF_KIND_ENUM64, name, true, id,
"size=%u Error emitting BTF type", size);
}
return id;
}
static int btf_encoder__add_enum_val(struct btf_encoder *encoder, const char *name, int64_t value,
struct type *etype, struct conf_load *conf_load)
{
const char *fmt_str;
int err;
/* If enum64 is not allowed, generate enum32 with unsigned int value. In enum64-supported
* libbpf library, btf__add_enum_value() will set the kflag (sign bit) in common_type
* if the value is negative.
*/
if (conf_load->skip_encoding_btf_enum64)
err = btf__add_enum_value(encoder->btf, name, (uint32_t)value);
else if (etype->size <= 32)
err = btf__add_enum_value(encoder->btf, name, value);
else if (btf__add_enum64_value)
err = btf__add_enum64_value(encoder->btf, name, value);
else {
fprintf(stderr, "btf__add_enum64_value is not available, is libbpf < 1.0?\n");
return -ENOTSUP;
}
if (!err) {
if (encoder->verbose) {
if (conf_load->skip_encoding_btf_enum64) {
printf("\t%s val=%u\n", name, (uint32_t)value);
} else {
fmt_str = etype->is_signed_enum ? "\t%s val=%lld\n" : "\t%s val=%llu\n";
printf(fmt_str, name, (unsigned long long)value);
}
}
} else {
if (conf_load->skip_encoding_btf_enum64) {
fprintf(stderr, "\t%s val=%u Error emitting BTF enum value\n", name, (uint32_t)value);
} else {
fmt_str = etype->is_signed_enum ? "\t%s val=%lld Error emitting BTF enum value\n"
: "\t%s val=%llu Error emitting BTF enum value\n";
fprintf(stderr, fmt_str, name, (unsigned long long)value);
}
}
return err;
}
static int32_t btf_encoder__add_func_param(struct btf_encoder *encoder, const char *name, uint32_t type, bool is_last_param)
{
int err = btf__add_func_param(encoder->btf, name, type);
if (!err) {
btf_encoder__log_func_param(encoder, name, type, false, is_last_param, NULL);
return 0;
} else {
btf_encoder__log_func_param(encoder, name, type, true, is_last_param, "Error adding func param");
return -1;
}
}
static int32_t btf_encoder__tag_type(struct btf_encoder *encoder, uint32_t tag_type)
{
if (tag_type == 0)
return 0;
/* Map is authoritative when it covers this id: entry 0 means
* skipped (DW_TAG_unspecified_type, dwz-pruned) → void. */
if (encoder->btf_id_map && tag_type < encoder->btf_id_map_sz)
return encoder->btf_id_map[tag_type];
/* Fallback for map-absent CUs (nr == 0) or out-of-range ids;
* adjust for NULL holes left by dwz alt PU pruning */
uint32_t adj = encoder->type_id_null_adj ? encoder->type_id_null_adj[tag_type] : 0;
return encoder->type_id_off + tag_type - adj;
}
static int btf__tag_bpf_arena_ptr(struct btf *btf, int ptr_id)
{
const struct btf_type *ptr;
int tagged_type_id;
ptr = btf__type_by_id(btf, ptr_id);
if (!btf_is_ptr(ptr))
return -EINVAL;
tagged_type_id = btf__add_type_attr(btf, BPF_ARENA_ATTR, ptr->type);
if (tagged_type_id < 0)
return tagged_type_id;
return btf__add_ptr(btf, tagged_type_id);
}
static int btf__tag_bpf_arena_arg(struct btf *btf, struct btf_encoder_func_state *state, int idx)
{
int id;
if (state->nr_parms <= idx)
return -EINVAL;
id = btf__tag_bpf_arena_ptr(btf, state->parms[idx].type_id);
if (id < 0) {
btf__log_err(btf, BTF_KIND_TYPE_TAG, BPF_ARENA_ATTR, true, id,
"Error adding BPF_ARENA_ATTR for an argument of kfunc '%s'", state->elf->name);
return id;
}
state->parms[idx].type_id = id;
return id;
}
/* Modifies state->ret_type_id and state->parms[i].type_id for flagged kfuncs */
static int btf__add_bpf_arena_type_tags(struct btf *btf, struct btf_encoder_func_state *state)
{
uint32_t flags = state->elf->kfunc_flags;
int ret_type_id;
int err;
if (!btf__add_type_attr) {
fprintf(stderr, "btf__add_type_attr is not available, is libbpf < 1.6?\n");
return -ENOTSUP;
}
if (KF_ARENA_RET & flags) {
ret_type_id = btf__tag_bpf_arena_ptr(btf, state->ret_type_id);
if (ret_type_id < 0) {
btf__log_err(btf, BTF_KIND_TYPE_TAG, BPF_ARENA_ATTR, true, ret_type_id,
"Error adding BPF_ARENA_ATTR for return type of kfunc '%s'", state->elf->name);
return ret_type_id;
}
state->ret_type_id = ret_type_id;
}
if (KF_ARENA_ARG1 & flags) {
err = btf__tag_bpf_arena_arg(btf, state, 0);
if (err < 0)
return err;
}
if (KF_ARENA_ARG2 & flags) {
err = btf__tag_bpf_arena_arg(btf, state, 1);
if (err < 0)
return err;
}
return 0;
}
static inline bool is_kfunc_state(struct btf_encoder_func_state *state)
{
return state && state->elf && state->elf->kfunc;
}
static int32_t btf_encoder__emit_func_proto(struct btf_encoder *encoder,
uint32_t type_id,
uint16_t nr_params)
{
const struct btf_type *t;
uint32_t ret;
ret = btf__add_func_proto(encoder->btf, type_id);
if (ret > 0) {
t = btf__type_by_id(encoder->btf, ret);
btf_encoder__log_type(encoder, t, false, false,
"return=%u args=(%s", t->type, !nr_params ? "void)\n" : "");
} else {
btf__log_err(encoder->btf, BTF_KIND_FUNC_PROTO, NULL, true, ret,
"return=%u vlen=%u Error emitting BTF type",
type_id, nr_params);
}
return ret;
}
static int32_t btf_encoder__add_func_proto_for_ftype(struct btf_encoder *encoder,
struct ftype *ftype)
{
uint16_t nr_params, param_idx;
struct parameter *param;
int32_t id, type_id;
const char *name;
assert(ftype != NULL);
/* add btf_type for func_proto */
nr_params = ftype->nr_parms + (ftype->unspec_parms ? 1 : 0);
type_id = btf_encoder__tag_type(encoder, ftype->tag.type);
id = btf_encoder__emit_func_proto(encoder, type_id, nr_params);
if (id < 0)
return id;
/* add parameters */
param_idx = 0;
ftype__for_each_parameter(ftype, param) {
name = parameter__name(param);
type_id = btf_encoder__tag_type(encoder, param->tag.type);
++param_idx;
if (btf_encoder__add_func_param(encoder, name, type_id, param_idx == nr_params))
return -1;
}
if (ftype->unspec_parms) {
++param_idx;
if (btf_encoder__add_func_param(encoder, NULL, 0, param_idx == nr_params))
return -1;
}
return id;
}
static int32_t btf_encoder__add_func_proto_for_state(struct btf_encoder *encoder,
struct btf_encoder_func_state *state)
{
const struct btf *btf = encoder->btf;
struct btf_encoder_func_parm *p;
uint16_t nr_params, param_idx;
char tmp_name[KSYM_NAME_LEN];
int32_t id, type_id;
const char *name;
bool is_last;
type_id = state->ret_type_id;
nr_params = state->nr_parms;
id = btf_encoder__emit_func_proto(encoder, type_id, nr_params);
if (id < 0)
return id;
/* add parameters */
for (param_idx = 0; param_idx < nr_params; param_idx++) {
p = &state->parms[param_idx];
name = btf__name_by_offset(btf, p->name_off);
is_last = param_idx == (nr_params - 1);
/* adding BTF data may result in a move of the
* name string memory, so make a temporary copy.
*/
strncpy(tmp_name, name, sizeof(tmp_name) - 1);
if (btf_encoder__add_func_param(encoder, tmp_name, p->type_id, is_last))
return -1;
}
return id;
}
static int32_t btf_encoder__add_var(struct btf_encoder *encoder, uint32_t type, const char *name, uint32_t linkage)
{
struct btf *btf = encoder->btf;
const struct btf_type *t;
int32_t id;
id = btf__add_var(btf, name, linkage, type);
if (id > 0) {
t = btf__type_by_id(btf, id);
btf_encoder__log_type(encoder, t, false, true, "type=%u linkage=%u", t->type, btf_var(t)->linkage);
} else {
btf__log_err(btf, BTF_KIND_VAR, name, true, id,
"type=%u linkage=%u Error emitting BTF type",
type, linkage);
}
return id;
}
static int32_t btf_encoder__add_var_secinfo(struct btf_encoder *encoder, size_t shndx,
uint32_t type, uint32_t offset, uint32_t size)
{
struct btf_var_secinfo si = {
.type = type,
.offset = offset,
.size = size,
};
return gobuffer__add(&encoder->secinfo[shndx].secinfo, &si, sizeof(si));
}
static int32_t btf_encoder__add_datasec(struct btf_encoder *encoder, size_t shndx)
{
struct gobuffer *var_secinfo_buf = &encoder->secinfo[shndx].secinfo;
const char *section_name = encoder->secinfo[shndx].name;
struct btf *btf = encoder->btf;
size_t sz = gobuffer__size(var_secinfo_buf);
uint16_t nr_var_secinfo = sz / sizeof(struct btf_var_secinfo);
struct btf_var_secinfo *last_vsi, *vsi;
const struct btf_type *t;
uint32_t datasec_sz;
int32_t err, id, i;
qsort(var_secinfo_buf->entries, nr_var_secinfo,
sizeof(struct btf_var_secinfo), btf_var_secinfo_cmp);
last_vsi = (struct btf_var_secinfo *)var_secinfo_buf->entries + nr_var_secinfo - 1;
datasec_sz = last_vsi->offset + last_vsi->size;
id = btf__add_datasec(btf, section_name, datasec_sz);
if (id < 0) {
btf__log_err(btf, BTF_KIND_DATASEC, section_name, true, id,
"size=%u vlen=%u Error emitting BTF type",
datasec_sz, nr_var_secinfo);