libctf/ctf-impl.h

   1 /* Implementation header.
   2    Copyright (C) 2019 Free Software Foundation, Inc.
   3
   4    This file is part of libctf.
   5
   6    libctf is free software; you can redistribute it and/or modify it under
   7    the terms of the GNU General Public License as published by the Free
   8    Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    This program is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14    See the GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _CTF_IMPL_H
  21 #define _CTF_IMPL_H
  22
  23 #include "config.h"
  24 #include <errno.h>
  25 #include "ctf-decls.h"
  26 #include <ctf-api.h>
  27 #include <sys/types.h>
  28 #include <stdlib.h>
  29 #include <stdarg.h>
  30 #include <stdio.h>
  31 #include <stdint.h>
  32 #include <limits.h>
  33 #include <ctype.h>
  34 #include <elf.h>
  35 #include <bfd.h>
  36
  37 #ifdef  __cplusplus
  38 extern "C"
  39   {
  40 #endif
  41
  42 /* Compiler attributes.  */
  43
  44 #if defined (__GNUC__)
  45
  46 /* GCC.  We assume that all compilers claiming to be GCC support sufficiently
  47    many GCC attributes that the code below works.  If some non-GCC compilers
  48    masquerading as GCC in fact do not implement these attributes, version checks
  49    may be required.  */
  50
  51 /* We use the _libctf_*_ pattern to avoid clashes with any future attribute
  52    macros glibc may introduce, which have names of the pattern
  53    __attribute_blah__.  */
  54
  55 #define _libctf_printflike_(string_index,first_to_check) \
  56     __attribute__ ((__format__ (__printf__, (string_index), (first_to_check))))
  57 #define _libctf_unlikely_(x) __builtin_expect ((x), 0)
  58 #define _libctf_unused_ __attribute__ ((__unused__))
  59 #define _libctf_malloc_ __attribute__((__malloc__))
  60
  61 #endif
  62
  63 /* libctf in-memory state.  */
  64
  65 typedef struct ctf_fixed_hash ctf_hash_t; /* Private to ctf-hash.c.  */
  66 typedef struct ctf_dynhash ctf_dynhash_t; /* Private to ctf-hash.c.  */
  67
  68 typedef struct ctf_strs
  69 {
  70   const char *cts_strs;         /* Base address of string table.  */
  71   size_t cts_len;               /* Size of string table in bytes.  */
  72 } ctf_strs_t;
  73
  74 typedef struct ctf_strs_writable
  75 {
  76   char *cts_strs;               /* Base address of string table.  */
  77   size_t cts_len;               /* Size of string table in bytes.  */
  78 } ctf_strs_writable_t;
  79
  80 typedef struct ctf_dmodel
  81 {
  82   const char *ctd_name;         /* Data model name.  */
  83   int ctd_code;                 /* Data model code.  */
  84   size_t ctd_pointer;           /* Size of void * in bytes.  */
  85   size_t ctd_char;              /* Size of char in bytes.  */
  86   size_t ctd_short;             /* Size of short in bytes.  */
  87   size_t ctd_int;               /* Size of int in bytes.  */
  88   size_t ctd_long;              /* Size of long in bytes.  */
  89 } ctf_dmodel_t;
  90
  91 typedef struct ctf_lookup
  92 {
  93   const char *ctl_prefix;       /* String prefix for this lookup.  */
  94   size_t ctl_len;               /* Length of prefix string in bytes.  */
  95   ctf_hash_t *ctl_hash;         /* Pointer to hash table for lookup.  */
  96 } ctf_lookup_t;
  97
  98 typedef struct ctf_fileops
  99 {
 100   uint32_t (*ctfo_get_kind) (uint32_t);
 101   uint32_t (*ctfo_get_root) (uint32_t);
 102   uint32_t (*ctfo_get_vlen) (uint32_t);
 103   ssize_t (*ctfo_get_ctt_size) (const ctf_file_t *, const ctf_type_t *,
 104                                 ssize_t *, ssize_t *);
 105   ssize_t (*ctfo_get_vbytes) (unsigned short, ssize_t, size_t);
 106 } ctf_fileops_t;
 107
 108 typedef struct ctf_list
 109 {
 110   struct ctf_list *l_prev;      /* Previous pointer or tail pointer.  */
 111   struct ctf_list *l_next;      /* Next pointer or head pointer.  */
 112 } ctf_list_t;
 113
 114 typedef enum
 115   {
 116    CTF_PREC_BASE,
 117    CTF_PREC_POINTER,
 118    CTF_PREC_ARRAY,
 119    CTF_PREC_FUNCTION,
 120    CTF_PREC_MAX
 121   } ctf_decl_prec_t;
 122
 123 typedef struct ctf_decl_node
 124 {
 125   ctf_list_t cd_list;           /* Linked list pointers.  */
 126   ctf_id_t cd_type;             /* Type identifier.  */
 127   uint32_t cd_kind;             /* Type kind.  */
 128   uint32_t cd_n;                /* Type dimension if array.  */
 129 } ctf_decl_node_t;
 130
 131 typedef struct ctf_decl
 132 {
 133   ctf_list_t cd_nodes[CTF_PREC_MAX]; /* Declaration node stacks.  */
 134   int cd_order[CTF_PREC_MAX];        /* Storage order of decls.  */
 135   ctf_decl_prec_t cd_qualp;          /* Qualifier precision.  */
 136   ctf_decl_prec_t cd_ordp;           /* Ordered precision.  */
 137   char *cd_buf;                      /* Buffer for output.  */
 138   int cd_err;                        /* Saved error value.  */
 139   int cd_enomem;                     /* Nonzero if OOM during printing.  */
 140 } ctf_decl_t;
 141
 142 typedef struct ctf_dmdef
 143 {
 144   ctf_list_t dmd_list;          /* List forward/back pointers.  */
 145   char *dmd_name;               /* Name of this member.  */
 146   ctf_id_t dmd_type;            /* Type of this member (for sou).  */
 147   unsigned long dmd_offset;     /* Offset of this member in bits (for sou).  */
 148   int dmd_value;                /* Value of this member (for enum).  */
 149 } ctf_dmdef_t;
 150
 151 typedef struct ctf_dtdef
 152 {
 153   ctf_list_t dtd_list;          /* List forward/back pointers.  */
 154   char *dtd_name;               /* Name associated with definition (if any).  */
 155   ctf_id_t dtd_type;            /* Type identifier for this definition.  */
 156   ctf_type_t dtd_data;          /* Type node: name left unpopulated.  */
 157   union
 158   {
 159     ctf_list_t dtu_members;     /* struct, union, or enum */
 160     ctf_arinfo_t dtu_arr;       /* array */
 161     ctf_encoding_t dtu_enc;     /* integer or float */
 162     ctf_id_t *dtu_argv;         /* function */
 163     ctf_slice_t dtu_slice;      /* slice */
 164   } dtd_u;
 165 } ctf_dtdef_t;
 166
 167 typedef struct ctf_dvdef
 168 {
 169   ctf_list_t dvd_list;          /* List forward/back pointers.  */
 170   char *dvd_name;               /* Name associated with variable.  */
 171   ctf_id_t dvd_type;            /* Type of variable.  */
 172   unsigned long dvd_snapshots;  /* Snapshot count when inserted.  */
 173 } ctf_dvdef_t;
 174
 175 typedef struct ctf_bundle
 176 {
 177   ctf_file_t *ctb_file;         /* CTF container handle.  */
 178   ctf_id_t ctb_type;            /* CTF type identifier.  */
 179   ctf_dtdef_t *ctb_dtd;         /* CTF dynamic type definition (if any).  */
 180 } ctf_bundle_t;
 181
 182 /* Atoms associate strings with a list of the CTF items that reference that
 183    string, so that ctf_update() can instantiate all the strings using the
 184    ctf_str_atoms and then reassociate them with the real string later.
 185
 186    Strings can be interned into ctf_str_atom without having refs associated
 187    with them, for values that are returned to callers, etc.  Items are only
 188    removed from this table on ctf_close(), but on every ctf_update(), all the
 189    csa_refs in all entries are purged.  */
 190
 191 typedef struct ctf_str_atom
 192 {
 193   const char *csa_str;          /* Backpointer to string (hash key).  */
 194   ctf_list_t csa_refs;          /* This string's refs.  */
 195   unsigned long csa_snapshot_id; /* Snapshot ID at time of creation.  */
 196 } ctf_str_atom_t;
 197
 198 /* The refs of a single string in the atoms table.  */
 199
 200 typedef struct ctf_str_atom_ref
 201 {
 202   ctf_list_t caf_list;          /* List forward/back pointers.  */
 203   uint32_t *caf_ref;            /* A single ref to this string.  */
 204 } ctf_str_atom_ref_t;
 205
 206 /* The ctf_file is the structure used to represent a CTF container to library
 207    clients, who see it only as an opaque pointer.  Modifications can therefore
 208    be made freely to this structure without regard to client versioning.  The
 209    ctf_file_t typedef appears in <ctf-api.h> and declares a forward tag.
 210
 211    NOTE: ctf_update() requires that everything inside of ctf_file either be an
 212    immediate value, a pointer to dynamically allocated data *outside* of the
 213    ctf_file itself, or a pointer to statically allocated data.  If you add a
 214    pointer to ctf_file that points to something within the ctf_file itself,
 215    you must make corresponding changes to ctf_update().  */
 216
 217 struct ctf_file
 218 {
 219   const ctf_fileops_t *ctf_fileops; /* Version-specific file operations.  */
 220   ctf_sect_t ctf_data;              /* CTF data from object file.  */
 221   ctf_sect_t ctf_symtab;            /* Symbol table from object file.  */
 222   ctf_sect_t ctf_strtab;            /* String table from object file.  */
 223   void *ctf_data_mmapped;           /* CTF data we mmapped, to free later.  */
 224   size_t ctf_data_mmapped_len;      /* Length of CTF data we mmapped.  */
 225   ctf_hash_t *ctf_structs;          /* Hash table of struct types.  */
 226   ctf_hash_t *ctf_unions;           /* Hash table of union types.  */
 227   ctf_hash_t *ctf_enums;            /* Hash table of enum types.  */
 228   ctf_hash_t *ctf_names;            /* Hash table of remaining type names.  */
 229   ctf_lookup_t ctf_lookups[5];      /* Pointers to hashes for name lookup.  */
 230   ctf_strs_t ctf_str[2];            /* Array of string table base and bounds.  */
 231   ctf_dynhash_t *ctf_str_atoms;   /* Hash table of ctf_str_atoms_t.  */
 232   uint64_t ctf_str_num_refs;      /* Number of refs to cts_str_atoms.  */
 233   const unsigned char *ctf_base;  /* Base of CTF header + uncompressed buffer.  */
 234   const unsigned char *ctf_buf;   /* Uncompressed CTF data buffer.  */
 235   size_t ctf_size;                /* Size of CTF header + uncompressed data.  */
 236   uint32_t *ctf_sxlate;           /* Translation table for symtab entries.  */
 237   unsigned long ctf_nsyms;        /* Number of entries in symtab xlate table.  */
 238   uint32_t *ctf_txlate;           /* Translation table for type IDs.  */
 239   uint32_t *ctf_ptrtab;           /* Translation table for pointer-to lookups.  */
 240   struct ctf_varent *ctf_vars;    /* Sorted variable->type mapping.  */
 241   unsigned long ctf_nvars;        /* Number of variables in ctf_vars.  */
 242   unsigned long ctf_typemax;      /* Maximum valid type ID number.  */
 243   const ctf_dmodel_t *ctf_dmodel; /* Data model pointer (see above).  */
 244   struct ctf_file *ctf_parent;    /* Parent CTF container (if any).  */
 245   const char *ctf_parlabel;       /* Label in parent container (if any).  */
 246   const char *ctf_parname;        /* Basename of parent (if any).  */
 247   char *ctf_dynparname;           /* Dynamically allocated name of parent.  */
 248   uint32_t ctf_parmax;            /* Highest type ID of a parent type.  */
 249   uint32_t ctf_refcnt;            /* Reference count (for parent links).  */
 250   uint32_t ctf_flags;             /* Libctf flags (see below).  */
 251   int ctf_errno;                  /* Error code for most recent error.  */
 252   int ctf_version;                /* CTF data version.  */
 253   ctf_dynhash_t *ctf_dthash;      /* Hash of dynamic type definitions.  */
 254   ctf_dynhash_t *ctf_dtbyname;    /* DTDs, indexed by name.  */
 255   ctf_list_t ctf_dtdefs;          /* List of dynamic type definitions.  */
 256   ctf_dynhash_t *ctf_dvhash;      /* Hash of dynamic variable mappings.  */
 257   ctf_list_t ctf_dvdefs;          /* List of dynamic variable definitions.  */
 258   unsigned long ctf_dtnextid;     /* Next dynamic type id to assign.  */
 259   unsigned long ctf_dtoldid;      /* Oldest id that has been committed.  */
 260   unsigned long ctf_snapshots;    /* ctf_snapshot() plus ctf_update() count.  */
 261   unsigned long ctf_snapshot_lu;  /* ctf_snapshot() call count at last update.  */
 262   ctf_archive_t *ctf_archive;     /* Archive this ctf_file_t came from.  */
 263   char *ctf_tmp_typeslice;        /* Storage for slicing up type names.  */
 264   size_t ctf_tmp_typeslicelen;    /* Size of the typeslice.  */
 265   void *ctf_specific;             /* Data for ctf_get/setspecific().  */
 266 };
 267
 268 /* An abstraction over both a ctf_file_t and a ctf_archive_t.  */
 269
 270 struct ctf_archive_internal
 271 {
 272   int ctfi_is_archive;
 273   ctf_file_t *ctfi_file;
 274   struct ctf_archive *ctfi_archive;
 275   ctf_sect_t ctfi_symsect;
 276   ctf_sect_t ctfi_strsect;
 277   void *ctfi_data;
 278   bfd *ctfi_abfd;                   /* Optional source of section data.  */
 279   void (*ctfi_bfd_close) (struct ctf_archive_internal *);
 280 };
 281
 282 /* Return x rounded up to an alignment boundary.
 283    eg, P2ROUNDUP(0x1234, 0x100) == 0x1300 (0x13*align)
 284    eg, P2ROUNDUP(0x5600, 0x100) == 0x5600 (0x56*align)  */
 285 #define P2ROUNDUP(x, align)             (-(-(x) & -(align)))
 286
 287 /* * If an offs is not aligned already then round it up and align it. */
 288 #define LCTF_ALIGN_OFFS(offs, align) ((offs + (align - 1)) & ~(align - 1))
 289
 290 #define LCTF_TYPE_ISPARENT(fp, id) ((id) <= fp->ctf_parmax)
 291 #define LCTF_TYPE_ISCHILD(fp, id) ((id) > fp->ctf_parmax)
 292 #define LCTF_TYPE_TO_INDEX(fp, id) ((id) & (fp->ctf_parmax))
 293 #define LCTF_INDEX_TO_TYPE(fp, id, child) (child ? ((id) | (fp->ctf_parmax+1)) : \
 294                                            (id))
 295
 296 #define LCTF_INDEX_TO_TYPEPTR(fp, i) \
 297   ((ctf_type_t *)((uintptr_t)(fp)->ctf_buf + (fp)->ctf_txlate[(i)]))
 298
 299 #define LCTF_INFO_KIND(fp, info)        ((fp)->ctf_fileops->ctfo_get_kind(info))
 300 #define LCTF_INFO_ISROOT(fp, info)      ((fp)->ctf_fileops->ctfo_get_root(info))
 301 #define LCTF_INFO_VLEN(fp, info)        ((fp)->ctf_fileops->ctfo_get_vlen(info))
 302 #define LCTF_VBYTES(fp, kind, size, vlen) \
 303   ((fp)->ctf_fileops->ctfo_get_vbytes(kind, size, vlen))
 304
 305 static inline ssize_t ctf_get_ctt_size (const ctf_file_t *fp,
 306                                         const ctf_type_t *tp,
 307                                         ssize_t *sizep,
 308                                         ssize_t *incrementp)
 309 {
 310   return (fp->ctf_fileops->ctfo_get_ctt_size (fp, tp, sizep, incrementp));
 311 }
 312
 313 #define LCTF_CHILD      0x0001  /* CTF container is a child */
 314 #define LCTF_RDWR       0x0002  /* CTF container is writable */
 315 #define LCTF_DIRTY      0x0004  /* CTF container has been modified */
 316
 317 extern const ctf_type_t *ctf_lookup_by_id (ctf_file_t **, ctf_id_t);
 318
 319 typedef unsigned int (*ctf_hash_fun) (const void *ptr);
 320 extern unsigned int ctf_hash_integer (const void *ptr);
 321 extern unsigned int ctf_hash_string (const void *ptr);
 322
 323 typedef int (*ctf_hash_eq_fun) (const void *, const void *);
 324 extern int ctf_hash_eq_integer (const void *, const void *);
 325 extern int ctf_hash_eq_string (const void *, const void *);
 326
 327 typedef void (*ctf_hash_free_fun) (void *);
 328
 329 typedef void (*ctf_hash_iter_f) (void *key, void *value, void *arg);
 330 typedef int (*ctf_hash_iter_remove_f) (void *key, void *value, void *arg);
 331
 332 extern ctf_hash_t *ctf_hash_create (unsigned long, ctf_hash_fun, ctf_hash_eq_fun);
 333 extern int ctf_hash_insert_type (ctf_hash_t *, ctf_file_t *, uint32_t, uint32_t);
 334 extern int ctf_hash_define_type (ctf_hash_t *, ctf_file_t *, uint32_t, uint32_t);
 335 extern ctf_id_t ctf_hash_lookup_type (ctf_hash_t *, ctf_file_t *, const char *);
 336 extern uint32_t ctf_hash_size (const ctf_hash_t *);
 337 extern void ctf_hash_destroy (ctf_hash_t *);
 338
 339 extern ctf_dynhash_t *ctf_dynhash_create (ctf_hash_fun, ctf_hash_eq_fun,
 340                                           ctf_hash_free_fun, ctf_hash_free_fun);
 341 extern int ctf_dynhash_insert (ctf_dynhash_t *, void *, void *);
 342 extern void ctf_dynhash_remove (ctf_dynhash_t *, const void *);
 343 extern void *ctf_dynhash_lookup (ctf_dynhash_t *, const void *);
 344 extern void ctf_dynhash_destroy (ctf_dynhash_t *);
 345 extern void ctf_dynhash_iter (ctf_dynhash_t *, ctf_hash_iter_f, void *);
 346 extern void ctf_dynhash_iter_remove (ctf_dynhash_t *, ctf_hash_iter_remove_f,
 347                                      void *);
 348
 349 #define ctf_list_prev(elem)     ((void *)(((ctf_list_t *)(elem))->l_prev))
 350 #define ctf_list_next(elem)     ((void *)(((ctf_list_t *)(elem))->l_next))
 351
 352 extern void ctf_list_append (ctf_list_t *, void *);
 353 extern void ctf_list_prepend (ctf_list_t *, void *);
 354 extern void ctf_list_delete (ctf_list_t *, void *);
 355
 356 extern int ctf_dtd_insert (ctf_file_t *, ctf_dtdef_t *);
 357 extern void ctf_dtd_delete (ctf_file_t *, ctf_dtdef_t *);
 358 extern ctf_dtdef_t *ctf_dtd_lookup (const ctf_file_t *, ctf_id_t);
 359 extern ctf_dtdef_t *ctf_dynamic_type (const ctf_file_t *, ctf_id_t);
 360
 361 extern int ctf_dvd_insert (ctf_file_t *, ctf_dvdef_t *);
 362 extern void ctf_dvd_delete (ctf_file_t *, ctf_dvdef_t *);
 363 extern ctf_dvdef_t *ctf_dvd_lookup (const ctf_file_t *, const char *);
 364
 365 extern void ctf_decl_init (ctf_decl_t *);
 366 extern void ctf_decl_fini (ctf_decl_t *);
 367 extern void ctf_decl_push (ctf_decl_t *, ctf_file_t *, ctf_id_t);
 368
 369 _libctf_printflike_ (2, 3)
 370 extern void ctf_decl_sprintf (ctf_decl_t *, const char *, ...);
 371 extern char *ctf_decl_buf (ctf_decl_t *cd);
 372
 373 extern const char *ctf_strraw (ctf_file_t *, uint32_t);
 374 extern const char *ctf_strptr (ctf_file_t *, uint32_t);
 375 extern int ctf_str_create_atoms (ctf_file_t *);
 376 extern void ctf_str_free_atoms (ctf_file_t *);
 377 extern const char *ctf_str_add (ctf_file_t *, const char *);
 378 extern const char *ctf_str_add_ref (ctf_file_t *, const char *, uint32_t *);
 379 extern void ctf_str_rollback (ctf_file_t *, ctf_snapshot_id_t);
 380 extern void ctf_str_purge_refs (ctf_file_t *);
 381 extern ctf_strs_writable_t ctf_str_write_strtab (ctf_file_t *);
 382
 383 extern struct ctf_archive *ctf_arc_open_internal (const char *, int *);
 384 extern struct ctf_archive *ctf_arc_bufopen (const void *, size_t, int *);
 385 extern void ctf_arc_close_internal (struct ctf_archive *);
 386 extern void *ctf_set_open_errno (int *, int);
 387 extern unsigned long ctf_set_errno (ctf_file_t *, int);
 388
 389 _libctf_malloc_
 390 extern void *ctf_mmap (size_t length, size_t offset, int fd);
 391 extern void ctf_munmap (void *, size_t);
 392 extern ssize_t ctf_pread (int fd, void *buf, ssize_t count, off_t offset);
 393
 394 _libctf_malloc_
 395 extern void *ctf_alloc (size_t);
 396 extern void ctf_free (void *);
 397 extern void *ctf_realloc (ctf_file_t *, void *, size_t);
 398
 399 _libctf_malloc_
 400 extern char *ctf_strdup (const char *);
 401 extern char *ctf_str_append (char *, const char *);
 402 extern const char *ctf_strerror (int);
 403
 404 extern ctf_id_t ctf_type_resolve_unsliced (ctf_file_t *, ctf_id_t);
 405 extern int ctf_type_kind_unsliced (ctf_file_t *, ctf_id_t);
 406
 407 _libctf_printflike_ (1, 2)
 408 extern void ctf_dprintf (const char *, ...);
 409 extern void libctf_init_debug (void);
 410
 411 extern Elf64_Sym *ctf_sym_to_elf64 (const Elf32_Sym *src, Elf64_Sym *dst);
 412 extern const char *ctf_lookup_symbol_name (ctf_file_t *fp, unsigned long symidx);
 413
 414 /* Variables, all underscore-prepended. */
 415
 416 extern const char _CTF_SECTION[];       /* name of CTF ELF section */
 417 extern const char _CTF_NULLSTR[];       /* empty string */
 418
 419 extern int _libctf_version;     /* library client version */
 420 extern int _libctf_debug;       /* debugging messages enabled */
 421
 422 #ifdef  __cplusplus
 423 }
 424 #endif
 425
 426 #endif /* _CTF_IMPL_H */