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Diffstat (limited to 'src/src/elflint.c')
| -rw-r--r-- | src/src/elflint.c | 4390 |
1 files changed, 4390 insertions, 0 deletions
diff --git a/src/src/elflint.c b/src/src/elflint.c new file mode 100644 index 00000000..abca8b75 --- /dev/null +++ b/src/src/elflint.c @@ -0,0 +1,4390 @@ +/* Pedantic checking of ELF files compliance with gABI/psABI spec. + Copyright (C) 2001-2012 Red Hat, Inc. + This file is part of Red Hat elfutils. + Written by Ulrich Drepper <drepper@redhat.com>, 2001. + + Red Hat elfutils is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by the + Free Software Foundation; version 2 of the License. + + Red Hat elfutils is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License along + with Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <argp.h> +#include <assert.h> +#include <byteswap.h> +#include <endian.h> +#include <error.h> +#include <fcntl.h> +#include <gelf.h> +#include <inttypes.h> +#include <libintl.h> +#include <locale.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/stat.h> +#include <sys/param.h> + +#include <elf-knowledge.h> +#include <system.h> +#include "../libelf/libelfP.h" +#include "../libelf/common.h" +#include "../libebl/libeblP.h" +#include "../libdw/libdwP.h" +#include "../libdwfl/libdwflP.h" +#include "../libdw/memory-access.h" + + +/* Name and version of program. */ +static void print_version (FILE *stream, struct argp_state *state); +ARGP_PROGRAM_VERSION_HOOK_DEF = print_version; + +/* Bug report address. */ +ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT; + +#define ARGP_strict 300 +#define ARGP_gnuld 301 + +/* Definitions of arguments for argp functions. */ +static const struct argp_option options[] = +{ + { "strict", ARGP_strict, NULL, 0, + N_("Be extremely strict, flag level 2 features."), 0 }, + { "quiet", 'q', NULL, 0, N_("Do not print anything if successful"), 0 }, + { "debuginfo", 'd', NULL, 0, N_("Binary is a separate debuginfo file"), 0 }, + { "gnu-ld", ARGP_gnuld, NULL, 0, + N_("Binary has been created with GNU ld and is therefore known to be \ +broken in certain ways"), 0 }, + { NULL, 0, NULL, 0, NULL, 0 } +}; + +/* Short description of program. */ +static const char doc[] = N_("\ +Pedantic checking of ELF files compliance with gABI/psABI spec."); + +/* Strings for arguments in help texts. */ +static const char args_doc[] = N_("FILE..."); + +/* Prototype for option handler. */ +static error_t parse_opt (int key, char *arg, struct argp_state *state); + +/* Data structure to communicate with argp functions. */ +static struct argp argp = +{ + options, parse_opt, args_doc, doc, NULL, NULL, NULL +}; + + +/* Declarations of local functions. */ +static void process_file (int fd, Elf *elf, const char *prefix, + const char *suffix, const char *fname, size_t size, + bool only_one); +static void process_elf_file (Elf *elf, const char *prefix, const char *suffix, + const char *fname, size_t size, bool only_one); +static void check_note_section (Ebl *ebl, GElf_Ehdr *ehdr, + GElf_Shdr *shdr, int idx); + + +/* Report an error. */ +#define ERROR(str, args...) \ + do { \ + printf (str, ##args); \ + ++error_count; \ + } while (0) +static unsigned int error_count; + +/* True if we should perform very strict testing. */ +static bool be_strict; + +/* True if no message is to be printed if the run is succesful. */ +static bool be_quiet; + +/* True if binary is from strip -f, not a normal ELF file. */ +static bool is_debuginfo; + +/* True if binary is assumed to be generated with GNU ld. */ +static bool gnuld; + +/* Index of section header string table. */ +static uint32_t shstrndx; + +/* Array to count references in section groups. */ +static int *scnref; + + +int +main (int argc, char *argv[]) +{ + /* Set locale. */ + setlocale (LC_ALL, ""); + + /* Initialize the message catalog. */ + textdomain (PACKAGE_TARNAME); + + /* Parse and process arguments. */ + int remaining; + argp_parse (&argp, argc, argv, 0, &remaining, NULL); + + /* Before we start tell the ELF library which version we are using. */ + elf_version (EV_CURRENT); + + /* Now process all the files given at the command line. */ + bool only_one = remaining + 1 == argc; + do + { + /* Open the file. */ + int fd = open (argv[remaining], O_RDONLY); + if (fd == -1) + { + error (0, errno, gettext ("cannot open input file")); + continue; + } + + /* Create an `Elf' descriptor. */ + Elf *elf = elf_begin (fd, ELF_C_READ_MMAP, NULL); + if (elf == NULL) + ERROR (gettext ("cannot generate Elf descriptor: %s\n"), + elf_errmsg (-1)); + else + { + unsigned int prev_error_count = error_count; + struct stat64 st; + + if (fstat64 (fd, &st) != 0) + { + printf ("cannot stat '%s': %m\n", argv[remaining]); + close (fd); + continue; + } + + process_file (fd, elf, NULL, NULL, argv[remaining], st.st_size, + only_one); + + /* Now we can close the descriptor. */ + if (elf_end (elf) != 0) + ERROR (gettext ("error while closing Elf descriptor: %s\n"), + elf_errmsg (-1)); + + if (prev_error_count == error_count && !be_quiet) + puts (gettext ("No errors")); + } + + close (fd); + } + while (++remaining < argc); + + return error_count != 0; +} + + +/* Handle program arguments. */ +static error_t +parse_opt (int key, char *arg __attribute__ ((unused)), + struct argp_state *state __attribute__ ((unused))) +{ + switch (key) + { + case ARGP_strict: + be_strict = true; + break; + + case 'q': + be_quiet = true; + break; + + case 'd': + is_debuginfo = true; + + case ARGP_gnuld: + gnuld = true; + break; + + case ARGP_KEY_NO_ARGS: + fputs (gettext ("Missing file name.\n"), stderr); + argp_help (&argp, stderr, ARGP_HELP_SEE, program_invocation_short_name); + exit (EXIT_FAILURE); + + default: + return ARGP_ERR_UNKNOWN; + } + return 0; +} + + +/* Print the version information. */ +static void +print_version (FILE *stream, struct argp_state *state __attribute__ ((unused))) +{ + fprintf (stream, "elflint (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION); + fprintf (stream, gettext ("\ +Copyright (C) %s Red Hat, Inc.\n\ +This is free software; see the source for copying conditions. There is NO\n\ +warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\ +"), "2012"); + fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper"); +} + + +/* Process one file. */ +static void +process_file (int fd, Elf *elf, const char *prefix, const char *suffix, + const char *fname, size_t size, bool only_one) +{ + /* We can handle two types of files: ELF files and archives. */ + Elf_Kind kind = elf_kind (elf); + + switch (kind) + { + case ELF_K_ELF: + /* Yes! It's an ELF file. */ + process_elf_file (elf, prefix, suffix, fname, size, only_one); + break; + + case ELF_K_AR: + { + Elf *subelf; + Elf_Cmd cmd = ELF_C_READ_MMAP; + size_t prefix_len = prefix == NULL ? 0 : strlen (prefix); + size_t fname_len = strlen (fname) + 1; + char new_prefix[prefix_len + 1 + fname_len]; + char new_suffix[(suffix == NULL ? 0 : strlen (suffix)) + 2]; + char *cp = new_prefix; + + /* Create the full name of the file. */ + if (prefix != NULL) + { + cp = mempcpy (cp, prefix, prefix_len); + *cp++ = '('; + strcpy (stpcpy (new_suffix, suffix), ")"); + } + else + new_suffix[0] = '\0'; + memcpy (cp, fname, fname_len); + + /* It's an archive. We process each file in it. */ + while ((subelf = elf_begin (fd, cmd, elf)) != NULL) + { + kind = elf_kind (subelf); + + /* Call this function recursively. */ + if (kind == ELF_K_ELF || kind == ELF_K_AR) + { + Elf_Arhdr *arhdr = elf_getarhdr (subelf); + assert (arhdr != NULL); + + process_file (fd, subelf, new_prefix, new_suffix, + arhdr->ar_name, arhdr->ar_size, false); + } + + /* Get next archive element. */ + cmd = elf_next (subelf); + if (elf_end (subelf) != 0) + ERROR (gettext (" error while freeing sub-ELF descriptor: %s\n"), + elf_errmsg (-1)); + } + } + break; + + default: + /* We cannot do anything. */ + ERROR (gettext ("\ +Not an ELF file - it has the wrong magic bytes at the start\n")); + break; + } +} + + +static const char * +section_name (Ebl *ebl, int idx) +{ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr; + + shdr = gelf_getshdr (elf_getscn (ebl->elf, idx), &shdr_mem); + + return elf_strptr (ebl->elf, shstrndx, shdr->sh_name); +} + + +static const int valid_e_machine[] = + { + EM_M32, EM_SPARC, EM_386, EM_68K, EM_88K, EM_860, EM_MIPS, EM_S370, + EM_MIPS_RS3_LE, EM_PARISC, EM_VPP500, EM_SPARC32PLUS, EM_960, EM_PPC, + EM_PPC64, EM_S390, EM_V800, EM_FR20, EM_RH32, EM_RCE, EM_ARM, + EM_FAKE_ALPHA, EM_SH, EM_SPARCV9, EM_TRICORE, EM_ARC, EM_H8_300, + EM_H8_300H, EM_H8S, EM_H8_500, EM_IA_64, EM_MIPS_X, EM_COLDFIRE, + EM_68HC12, EM_MMA, EM_PCP, EM_NCPU, EM_NDR1, EM_STARCORE, EM_ME16, + EM_ST100, EM_TINYJ, EM_X86_64, EM_PDSP, EM_FX66, EM_ST9PLUS, EM_ST7, + EM_68HC16, EM_68HC11, EM_68HC08, EM_68HC05, EM_SVX, EM_ST19, EM_VAX, + EM_CRIS, EM_JAVELIN, EM_FIREPATH, EM_ZSP, EM_MMIX, EM_HUANY, EM_PRISM, + EM_AVR, EM_FR30, EM_D10V, EM_D30V, EM_V850, EM_M32R, EM_MN10300, + EM_MN10200, EM_PJ, EM_OPENRISC, EM_ARC_A5, EM_XTENSA, EM_ALPHA + }; +#define nvalid_e_machine \ + (sizeof (valid_e_machine) / sizeof (valid_e_machine[0])) + + +/* Numbers of sections and program headers. */ +static unsigned int shnum; +static unsigned int phnum; + + +static void +check_elf_header (Ebl *ebl, GElf_Ehdr *ehdr, size_t size) +{ + char buf[512]; + size_t cnt; + + /* Check e_ident field. */ + if (ehdr->e_ident[EI_MAG0] != ELFMAG0) + ERROR ("e_ident[%d] != '%c'\n", EI_MAG0, ELFMAG0); + if (ehdr->e_ident[EI_MAG1] != ELFMAG1) + ERROR ("e_ident[%d] != '%c'\n", EI_MAG1, ELFMAG1); + if (ehdr->e_ident[EI_MAG2] != ELFMAG2) + ERROR ("e_ident[%d] != '%c'\n", EI_MAG2, ELFMAG2); + if (ehdr->e_ident[EI_MAG3] != ELFMAG3) + ERROR ("e_ident[%d] != '%c'\n", EI_MAG3, ELFMAG3); + + if (ehdr->e_ident[EI_CLASS] != ELFCLASS32 + && ehdr->e_ident[EI_CLASS] != ELFCLASS64) + ERROR (gettext ("e_ident[%d] == %d is no known class\n"), + EI_CLASS, ehdr->e_ident[EI_CLASS]); + + if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB + && ehdr->e_ident[EI_DATA] != ELFDATA2MSB) + ERROR (gettext ("e_ident[%d] == %d is no known data encoding\n"), + EI_DATA, ehdr->e_ident[EI_DATA]); + + if (ehdr->e_ident[EI_VERSION] != EV_CURRENT) + ERROR (gettext ("unknown ELF header version number e_ident[%d] == %d\n"), + EI_VERSION, ehdr->e_ident[EI_VERSION]); + + /* We currently don't handle any OS ABIs other than Linux. */ + if (ehdr->e_ident[EI_OSABI] != ELFOSABI_NONE + && ehdr->e_ident[EI_OSABI] != ELFOSABI_LINUX) + ERROR (gettext ("unsupported OS ABI e_ident[%d] == '%s'\n"), + EI_OSABI, + ebl_osabi_name (ebl, ehdr->e_ident[EI_OSABI], buf, sizeof (buf))); + + /* No ABI versions other than zero supported either. */ + if (ehdr->e_ident[EI_ABIVERSION] != 0) + ERROR (gettext ("unsupport ABI version e_ident[%d] == %d\n"), + EI_ABIVERSION, ehdr->e_ident[EI_ABIVERSION]); + + for (cnt = EI_PAD; cnt < EI_NIDENT; ++cnt) + if (ehdr->e_ident[cnt] != 0) + ERROR (gettext ("e_ident[%zu] is not zero\n"), cnt); + + /* Check the e_type field. */ + if (ehdr->e_type != ET_REL && ehdr->e_type != ET_EXEC + && ehdr->e_type != ET_DYN && ehdr->e_type != ET_CORE) + ERROR (gettext ("unknown object file type %d\n"), ehdr->e_type); + + /* Check the e_machine field. */ + for (cnt = 0; cnt < nvalid_e_machine; ++cnt) + if (valid_e_machine[cnt] == ehdr->e_machine) + break; + if (cnt == nvalid_e_machine) + ERROR (gettext ("unknown machine type %d\n"), ehdr->e_machine); + + /* Check the e_version field. */ + if (ehdr->e_version != EV_CURRENT) + ERROR (gettext ("unknown object file version\n")); + + /* Check the e_phoff and e_phnum fields. */ + if (ehdr->e_phoff == 0) + { + if (ehdr->e_phnum != 0) + ERROR (gettext ("invalid program header offset\n")); + else if (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN) + ERROR (gettext ("\ +executables and DSOs cannot have zero program header offset\n")); + } + else if (ehdr->e_phnum == 0) + ERROR (gettext ("invalid number of program header entries\n")); + + /* Check the e_shoff field. */ + shnum = ehdr->e_shnum; + shstrndx = ehdr->e_shstrndx; + if (ehdr->e_shoff == 0) + { + if (ehdr->e_shnum != 0) + ERROR (gettext ("invalid section header table offset\n")); + else if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN + && ehdr->e_type != ET_CORE) + ERROR (gettext ("section header table must be present\n")); + } + else + { + if (ehdr->e_shnum == 0) + { + /* Get the header of the zeroth section. The sh_size field + might contain the section number. */ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (elf_getscn (ebl->elf, 0), &shdr_mem); + if (shdr != NULL) + { + /* The error will be reported later. */ + if (shdr->sh_size == 0) + ERROR (gettext ("\ +invalid number of section header table entries\n")); + else + shnum = shdr->sh_size; + } + } + + if (ehdr->e_shstrndx == SHN_XINDEX) + { + /* Get the header of the zeroth section. The sh_size field + might contain the section number. */ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (elf_getscn (ebl->elf, 0), &shdr_mem); + if (shdr != NULL && shdr->sh_link < shnum) + shstrndx = shdr->sh_link; + } + else if (shstrndx >= shnum) + ERROR (gettext ("invalid section header index\n")); + } + + phnum = ehdr->e_phnum; + if (ehdr->e_phnum == PN_XNUM) + { + /* Get the header of the zeroth section. The sh_info field + might contain the phnum count. */ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (elf_getscn (ebl->elf, 0), &shdr_mem); + if (shdr != NULL) + { + /* The error will be reported later. */ + if (shdr->sh_info < PN_XNUM) + ERROR (gettext ("\ +invalid number of program header table entries\n")); + else + phnum = shdr->sh_info; + } + } + + /* Check the e_flags field. */ + if (!ebl_machine_flag_check (ebl, ehdr->e_flags)) + ERROR (gettext ("invalid machine flags: %s\n"), + ebl_machine_flag_name (ebl, ehdr->e_flags, buf, sizeof (buf))); + + /* Check e_ehsize, e_phentsize, and e_shentsize fields. */ + if (gelf_getclass (ebl->elf) == ELFCLASS32) + { + if (ehdr->e_ehsize != 0 && ehdr->e_ehsize != sizeof (Elf32_Ehdr)) + ERROR (gettext ("invalid ELF header size: %hd\n"), ehdr->e_ehsize); + + if (ehdr->e_phentsize != 0 && ehdr->e_phentsize != sizeof (Elf32_Phdr)) + ERROR (gettext ("invalid program header size: %hd\n"), + ehdr->e_phentsize); + else if (ehdr->e_phoff + phnum * ehdr->e_phentsize > size) + ERROR (gettext ("invalid program header position or size\n")); + + if (ehdr->e_shentsize != 0 && ehdr->e_shentsize != sizeof (Elf32_Shdr)) + ERROR (gettext ("invalid section header size: %hd\n"), + ehdr->e_shentsize); + else if (ehdr->e_shoff + shnum * ehdr->e_shentsize > size) + ERROR (gettext ("invalid section header position or size\n")); + } + else if (gelf_getclass (ebl->elf) == ELFCLASS64) + { + if (ehdr->e_ehsize != 0 && ehdr->e_ehsize != sizeof (Elf64_Ehdr)) + ERROR (gettext ("invalid ELF header size: %hd\n"), ehdr->e_ehsize); + + if (ehdr->e_phentsize != 0 && ehdr->e_phentsize != sizeof (Elf64_Phdr)) + ERROR (gettext ("invalid program header size: %hd\n"), + ehdr->e_phentsize); + else if (ehdr->e_phoff + phnum * ehdr->e_phentsize > size) + ERROR (gettext ("invalid program header position or size\n")); + + if (ehdr->e_shentsize != 0 && ehdr->e_shentsize != sizeof (Elf64_Shdr)) + ERROR (gettext ("invalid section header size: %hd\n"), + ehdr->e_shentsize); + else if (ehdr->e_shoff + ehdr->e_shnum * ehdr->e_shentsize > size) + ERROR (gettext ("invalid section header position or size\n")); + } +} + + +/* Check that there is a section group section with index < IDX which + contains section IDX and that there is exactly one. */ +static void +check_scn_group (Ebl *ebl, int idx) +{ + if (scnref[idx] == 0) + { + /* No reference so far. Search following sections, maybe the + order is wrong. */ + size_t cnt; + + for (cnt = idx + 1; cnt < shnum; ++cnt) + { + Elf_Scn *scn = elf_getscn (ebl->elf, cnt); + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr == NULL) + /* We cannot get the section header so we cannot check it. + The error to get the section header will be shown + somewhere else. */ + continue; + + if (shdr->sh_type != SHT_GROUP) + continue; + + Elf_Data *data = elf_getdata (scn, NULL); + if (data == NULL || data->d_size < sizeof (Elf32_Word)) + /* Cannot check the section. */ + continue; + + Elf32_Word *grpdata = (Elf32_Word *) data->d_buf; + for (size_t inner = 1; inner < data->d_size / sizeof (Elf32_Word); + ++inner) + if (grpdata[inner] == (Elf32_Word) idx) + goto out; + } + + out: + if (cnt == shnum) + ERROR (gettext ("\ +section [%2d] '%s': section with SHF_GROUP flag set not part of a section group\n"), + idx, section_name (ebl, idx)); + else + ERROR (gettext ("\ +section [%2d] '%s': section group [%2zu] '%s' does not precede group member\n"), + idx, section_name (ebl, idx), + cnt, section_name (ebl, cnt)); + } +} + + +static void +check_symtab (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + bool no_xndx_warned = false; + int no_pt_tls = 0; + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + GElf_Shdr strshdr_mem; + GElf_Shdr *strshdr = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), + &strshdr_mem); + if (strshdr == NULL) + return; + + if (strshdr->sh_type != SHT_STRTAB) + { + ERROR (gettext ("section [%2d] '%s': referenced as string table for section [%2d] '%s' but type is not SHT_STRTAB\n"), + shdr->sh_link, section_name (ebl, shdr->sh_link), + idx, section_name (ebl, idx)); + strshdr = NULL; + } + + /* Search for an extended section index table section. */ + Elf_Data *xndxdata = NULL; + Elf32_Word xndxscnidx = 0; + bool found_xndx = false; + for (size_t cnt = 1; cnt < shnum; ++cnt) + if (cnt != (size_t) idx) + { + Elf_Scn *xndxscn = elf_getscn (ebl->elf, cnt); + GElf_Shdr xndxshdr_mem; + GElf_Shdr *xndxshdr = gelf_getshdr (xndxscn, &xndxshdr_mem); + if (xndxshdr == NULL) + continue; + + if (xndxshdr->sh_type == SHT_SYMTAB_SHNDX + && xndxshdr->sh_link == (GElf_Word) idx) + { + if (found_xndx) + ERROR (gettext ("\ +section [%2d] '%s': symbol table cannot have more than one extended index section\n"), + idx, section_name (ebl, idx)); + + xndxdata = elf_getdata (xndxscn, NULL); + xndxscnidx = elf_ndxscn (xndxscn); + found_xndx = true; + } + } + + if (shdr->sh_entsize != gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT)) + ERROR (gettext ("\ +section [%2u] '%s': entry size is does not match ElfXX_Sym\n"), + idx, section_name (ebl, idx)); + + /* Test the zeroth entry. */ + GElf_Sym sym_mem; + Elf32_Word xndx; + GElf_Sym *sym = gelf_getsymshndx (data, xndxdata, 0, &sym_mem, &xndx); + if (sym == NULL) + ERROR (gettext ("section [%2d] '%s': cannot get symbol %d: %s\n"), + idx, section_name (ebl, idx), 0, elf_errmsg (-1)); + else + { + if (sym->st_name != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_name"); + if (sym->st_value != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_value"); + if (sym->st_size != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_size"); + if (sym->st_info != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_info"); + if (sym->st_other != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_other"); + if (sym->st_shndx != 0) + ERROR (gettext ("section [%2d] '%s': '%s' in zeroth entry not zero\n"), + idx, section_name (ebl, idx), "st_shndx"); + if (xndxdata != NULL && xndx != 0) + ERROR (gettext ("\ +section [%2d] '%s': XINDEX for zeroth entry not zero\n"), + xndxscnidx, section_name (ebl, xndxscnidx)); + } + + for (size_t cnt = 1; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt) + { + sym = gelf_getsymshndx (data, xndxdata, cnt, &sym_mem, &xndx); + if (sym == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get symbol %zu: %s\n"), + idx, section_name (ebl, idx), cnt, elf_errmsg (-1)); + continue; + } + + const char *name = NULL; + if (strshdr == NULL) + name = ""; + else if (sym->st_name >= strshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: invalid name value\n"), + idx, section_name (ebl, idx), cnt); + else + { + name = elf_strptr (ebl->elf, shdr->sh_link, sym->st_name); + assert (name != NULL); + } + + if (sym->st_shndx == SHN_XINDEX) + { + if (xndxdata == NULL) + { + if (!no_xndx_warned) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: too large section index but no extended section index section\n"), + idx, section_name (ebl, idx), cnt); + no_xndx_warned = true; + } + else if (xndx < SHN_LORESERVE) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: XINDEX used for index which would fit in st_shndx (%" PRIu32 ")\n"), + xndxscnidx, section_name (ebl, xndxscnidx), cnt, + xndx); + } + else if ((sym->st_shndx >= SHN_LORESERVE + // && sym->st_shndx <= SHN_HIRESERVE always true + && sym->st_shndx != SHN_ABS + && sym->st_shndx != SHN_COMMON) + || (sym->st_shndx >= shnum + && (sym->st_shndx < SHN_LORESERVE + /* || sym->st_shndx > SHN_HIRESERVE always false */))) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: invalid section index\n"), + idx, section_name (ebl, idx), cnt); + else + xndx = sym->st_shndx; + + if (GELF_ST_TYPE (sym->st_info) >= STT_NUM + && !ebl_symbol_type_name (ebl, GELF_ST_TYPE (sym->st_info), NULL, 0)) + ERROR (gettext ("section [%2d] '%s': symbol %zu: unknown type\n"), + idx, section_name (ebl, idx), cnt); + + if (GELF_ST_BIND (sym->st_info) >= STB_NUM + && !ebl_symbol_binding_name (ebl, GELF_ST_BIND (sym->st_info), NULL, + 0)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: unknown symbol binding\n"), + idx, section_name (ebl, idx), cnt); + if (GELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE + && GELF_ST_TYPE (sym->st_info) != STT_OBJECT) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: unique symbol not of object type\n"), + idx, section_name (ebl, idx), cnt); + + if (xndx == SHN_COMMON) + { + /* Common symbols can only appear in relocatable files. */ + if (ehdr->e_type != ET_REL) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: COMMON only allowed in relocatable files\n"), + idx, section_name (ebl, idx), cnt); + if (cnt < shdr->sh_info) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: local COMMON symbols are nonsense\n"), + idx, section_name (ebl, idx), cnt); + if (GELF_R_TYPE (sym->st_info) == STT_FUNC) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: function in COMMON section is nonsense\n"), + idx, section_name (ebl, idx), cnt); + } + else if (xndx > 0 && xndx < shnum) + { + GElf_Shdr destshdr_mem; + GElf_Shdr *destshdr; + + destshdr = gelf_getshdr (elf_getscn (ebl->elf, xndx), &destshdr_mem); + if (destshdr != NULL) + { + GElf_Addr sh_addr = (ehdr->e_type == ET_REL ? 0 + : destshdr->sh_addr); + if (GELF_ST_TYPE (sym->st_info) != STT_TLS) + { + if (! ebl_check_special_symbol (ebl, ehdr, sym, name, + destshdr)) + { + if (sym->st_value - sh_addr > destshdr->sh_size) + { + /* GNU ld has severe bugs. When it decides to remove + empty sections it leaves symbols referencing them + behind. These are symbols in .symtab. */ + if (!gnuld + || strcmp (section_name (ebl, idx), ".symtab") + || (strcmp (name, "__preinit_array_start") != 0 + && strcmp (name, "__preinit_array_end") != 0 + && strcmp (name, "__init_array_start") != 0 + && strcmp (name, "__init_array_end") != 0 + && strcmp (name, "__fini_array_start") != 0 + && strcmp (name, "__fini_array_end") != 0)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: st_value out of bounds\n"), + idx, section_name (ebl, idx), cnt); + } + else if ((sym->st_value - sh_addr + + sym->st_size) > destshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu does not fit completely in referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + } + } + else + { + if ((destshdr->sh_flags & SHF_TLS) == 0) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: referenced section [%2d] '%s' does not have SHF_TLS flag set\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + + if (ehdr->e_type == ET_REL) + { + /* For object files the symbol value must fall + into the section. */ + if (sym->st_value > destshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: st_value out of bounds of referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + else if (sym->st_value + sym->st_size + > destshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu does not fit completely in referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + } + else + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = NULL; + unsigned int pcnt; + + for (pcnt = 0; pcnt < phnum; ++pcnt) + { + phdr = gelf_getphdr (ebl->elf, pcnt, &phdr_mem); + if (phdr != NULL && phdr->p_type == PT_TLS) + break; + } + + if (pcnt == phnum) + { + if (no_pt_tls++ == 0) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: TLS symbol but no TLS program header entry\n"), + idx, section_name (ebl, idx), cnt); + } + else + { + if (sym->st_value + < destshdr->sh_offset - phdr->p_offset) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: st_value short of referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + else if (sym->st_value + > (destshdr->sh_offset - phdr->p_offset + + destshdr->sh_size)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: st_value out of bounds of referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + else if (sym->st_value + sym->st_size + > (destshdr->sh_offset - phdr->p_offset + + destshdr->sh_size)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu does not fit completely in referenced section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + (int) xndx, section_name (ebl, xndx)); + } + } + } + } + } + + if (GELF_ST_BIND (sym->st_info) == STB_LOCAL) + { + if (cnt >= shdr->sh_info) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: local symbol outside range described in sh_info\n"), + idx, section_name (ebl, idx), cnt); + } + else + { + if (cnt < shdr->sh_info) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: non-local symbol outside range described in sh_info\n"), + idx, section_name (ebl, idx), cnt); + } + + if (GELF_ST_TYPE (sym->st_info) == STT_SECTION + && GELF_ST_BIND (sym->st_info) != STB_LOCAL) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: non-local section symbol\n"), + idx, section_name (ebl, idx), cnt); + + if (name != NULL) + { + if (strcmp (name, "_GLOBAL_OFFSET_TABLE_") == 0) + { + /* Check that address and size match the global offset table. */ + + GElf_Shdr destshdr_mem; + GElf_Shdr *destshdr = gelf_getshdr (elf_getscn (ebl->elf, xndx), + &destshdr_mem); + + if (destshdr == NULL && xndx == SHN_ABS) + { + /* In a DSO, we have to find the GOT section by name. */ + Elf_Scn *gotscn = NULL; + Elf_Scn *gscn = NULL; + while ((gscn = elf_nextscn (ebl->elf, gscn)) != NULL) + { + destshdr = gelf_getshdr (gscn, &destshdr_mem); + assert (destshdr != NULL); + const char *sname = elf_strptr (ebl->elf, + ehdr->e_shstrndx, + destshdr->sh_name); + if (sname != NULL) + { + if (strcmp (sname, ".got.plt") == 0) + break; + if (strcmp (sname, ".got") == 0) + /* Do not stop looking. + There might be a .got.plt section. */ + gotscn = gscn; + } + + destshdr = NULL; + } + + if (destshdr == NULL && gotscn != NULL) + destshdr = gelf_getshdr (gotscn, &destshdr_mem); + } + + const char *sname = ((destshdr == NULL || xndx == SHN_UNDEF) + ? NULL + : elf_strptr (ebl->elf, ehdr->e_shstrndx, + destshdr->sh_name)); + if (sname == NULL) + { + if (xndx != SHN_UNDEF || ehdr->e_type != ET_REL) + ERROR (gettext ("\ +section [%2d] '%s': _GLOBAL_OFFSET_TABLE_ symbol refers to \ +bad section [%2d]\n"), + idx, section_name (ebl, idx), xndx); + } + else if (strcmp (sname, ".got.plt") != 0 + && strcmp (sname, ".got") != 0) + ERROR (gettext ("\ +section [%2d] '%s': _GLOBAL_OFFSET_TABLE_ symbol refers to \ +section [%2d] '%s'\n"), + idx, section_name (ebl, idx), xndx, sname); + + if (destshdr != NULL) + { + /* Found it. */ + if (!ebl_check_special_symbol (ebl, ehdr, sym, name, + destshdr)) + { + if (ehdr->e_type != ET_REL + && sym->st_value != destshdr->sh_addr) + /* This test is more strict than the psABIs which + usually allow the symbol to be in the middle of + the .got section, allowing negative offsets. */ + ERROR (gettext ("\ +section [%2d] '%s': _GLOBAL_OFFSET_TABLE_ symbol value %#" PRIx64 " does not match %s section address %#" PRIx64 "\n"), + idx, section_name (ebl, idx), + (uint64_t) sym->st_value, + sname, (uint64_t) destshdr->sh_addr); + + if (!gnuld && sym->st_size != destshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': _GLOBAL_OFFSET_TABLE_ symbol size %" PRIu64 " does not match %s section size %" PRIu64 "\n"), + idx, section_name (ebl, idx), + (uint64_t) sym->st_size, + sname, (uint64_t) destshdr->sh_size); + } + } + else + ERROR (gettext ("\ +section [%2d] '%s': _GLOBAL_OFFSET_TABLE_ symbol present, but no .got section\n"), + idx, section_name (ebl, idx)); + } + else if (strcmp (name, "_DYNAMIC") == 0) + /* Check that address and size match the dynamic section. + We locate the dynamic section via the program header + entry. */ + for (unsigned int pcnt = 0; pcnt < phnum; ++pcnt) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = gelf_getphdr (ebl->elf, pcnt, &phdr_mem); + + if (phdr != NULL && phdr->p_type == PT_DYNAMIC) + { + if (sym->st_value != phdr->p_vaddr) + ERROR (gettext ("\ +section [%2d] '%s': _DYNAMIC_ symbol value %#" PRIx64 " does not match dynamic segment address %#" PRIx64 "\n"), + idx, section_name (ebl, idx), + (uint64_t) sym->st_value, + (uint64_t) phdr->p_vaddr); + + if (!gnuld && sym->st_size != phdr->p_memsz) + ERROR (gettext ("\ +section [%2d] '%s': _DYNAMIC symbol size %" PRIu64 " does not match dynamic segment size %" PRIu64 "\n"), + idx, section_name (ebl, idx), + (uint64_t) sym->st_size, + (uint64_t) phdr->p_memsz); + + break; + } + } + } + + if (GELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT + && shdr->sh_type == SHT_DYNSYM) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: symbol in dynamic symbol table with non-default visibility\n"), + idx, section_name (ebl, idx), cnt); + if (! ebl_check_st_other_bits (ebl, sym->st_other)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %zu: unknown bit set in st_other\n"), + idx, section_name (ebl, idx), cnt); + + } +} + + +static bool +is_rel_dyn (Ebl *ebl, const GElf_Ehdr *ehdr, int idx, const GElf_Shdr *shdr, + bool is_rela) +{ + /* If this is no executable or DSO it cannot be a .rel.dyn section. */ + if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + return false; + + /* Check the section name. Unfortunately necessary. */ + if (strcmp (section_name (ebl, idx), is_rela ? ".rela.dyn" : ".rel.dyn")) + return false; + + /* When a .rel.dyn section is used a DT_RELCOUNT dynamic section + entry can be present as well. */ + Elf_Scn *scn = NULL; + while ((scn = elf_nextscn (ebl->elf, scn)) != NULL) + { + GElf_Shdr rcshdr_mem; + const GElf_Shdr *rcshdr = gelf_getshdr (scn, &rcshdr_mem); + assert (rcshdr != NULL); + + if (rcshdr->sh_type == SHT_DYNAMIC) + { + /* Found the dynamic section. Look through it. */ + Elf_Data *d = elf_getdata (scn, NULL); + size_t cnt; + + for (cnt = 1; cnt < rcshdr->sh_size / rcshdr->sh_entsize; ++cnt) + { + GElf_Dyn dyn_mem; + GElf_Dyn *dyn = gelf_getdyn (d, cnt, &dyn_mem); + assert (dyn != NULL); + + if (dyn->d_tag == DT_RELCOUNT) + { + /* Found it. Does the type match. */ + if (is_rela) + ERROR (gettext ("\ +section [%2d] '%s': DT_RELCOUNT used for this RELA section\n"), + idx, section_name (ebl, idx)); + else + { + /* Does the number specified number of relative + relocations exceed the total number of + relocations? */ + if (dyn->d_un.d_val > shdr->sh_size / shdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s': DT_RELCOUNT value %d too high for this section\n"), + idx, section_name (ebl, idx), + (int) dyn->d_un.d_val); + + /* Make sure the specified number of relocations are + relative. */ + Elf_Data *reldata = elf_getdata (elf_getscn (ebl->elf, + idx), NULL); + if (reldata != NULL) + for (size_t inner = 0; + inner < shdr->sh_size / shdr->sh_entsize; + ++inner) + { + GElf_Rel rel_mem; + GElf_Rel *rel = gelf_getrel (reldata, inner, + &rel_mem); + if (rel == NULL) + /* The problem will be reported elsewhere. */ + break; + + if (ebl_relative_reloc_p (ebl, + GELF_R_TYPE (rel->r_info))) + { + if (inner >= dyn->d_un.d_val) + ERROR (gettext ("\ +section [%2d] '%s': relative relocations after index %d as specified by DT_RELCOUNT\n"), + idx, section_name (ebl, idx), + (int) dyn->d_un.d_val); + } + else if (inner < dyn->d_un.d_val) + ERROR (gettext ("\ +section [%2d] '%s': non-relative relocation at index %zu; DT_RELCOUNT specified %d relative relocations\n"), + idx, section_name (ebl, idx), + inner, (int) dyn->d_un.d_val); + } + } + } + + if (dyn->d_tag == DT_RELACOUNT) + { + /* Found it. Does the type match. */ + if (!is_rela) + ERROR (gettext ("\ +section [%2d] '%s': DT_RELACOUNT used for this REL section\n"), + idx, section_name (ebl, idx)); + else + { + /* Does the number specified number of relative + relocations exceed the total number of + relocations? */ + if (dyn->d_un.d_val > shdr->sh_size / shdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s': DT_RELCOUNT value %d too high for this section\n"), + idx, section_name (ebl, idx), + (int) dyn->d_un.d_val); + + /* Make sure the specified number of relocations are + relative. */ + Elf_Data *reldata = elf_getdata (elf_getscn (ebl->elf, + idx), NULL); + if (reldata != NULL) + for (size_t inner = 0; + inner < shdr->sh_size / shdr->sh_entsize; + ++inner) + { + GElf_Rela rela_mem; + GElf_Rela *rela = gelf_getrela (reldata, inner, + &rela_mem); + if (rela == NULL) + /* The problem will be reported elsewhere. */ + break; + + if (ebl_relative_reloc_p (ebl, + GELF_R_TYPE (rela->r_info))) + { + if (inner >= dyn->d_un.d_val) + ERROR (gettext ("\ +section [%2d] '%s': relative relocations after index %d as specified by DT_RELCOUNT\n"), + idx, section_name (ebl, idx), + (int) dyn->d_un.d_val); + } + else if (inner < dyn->d_un.d_val) + ERROR (gettext ("\ +section [%2d] '%s': non-relative relocation at index %zu; DT_RELCOUNT specified %d relative relocations\n"), + idx, section_name (ebl, idx), + inner, (int) dyn->d_un.d_val); + } + } + } + } + + break; + } + } + + return true; +} + + +struct loaded_segment +{ + GElf_Addr from; + GElf_Addr to; + bool read_only; + struct loaded_segment *next; +}; + + +/* Check whether binary has text relocation flag set. */ +static bool textrel; + +/* Keep track of whether text relocation flag is needed. */ +static bool needed_textrel; + + +static bool +check_reloc_shdr (Ebl *ebl, const GElf_Ehdr *ehdr, const GElf_Shdr *shdr, + int idx, int reltype, GElf_Shdr **destshdrp, + GElf_Shdr *destshdr_memp, struct loaded_segment **loadedp) +{ + bool reldyn = false; + + /* Check whether the link to the section we relocate is reasonable. */ + if (shdr->sh_info >= shnum) + ERROR (gettext ("section [%2d] '%s': invalid destination section index\n"), + idx, section_name (ebl, idx)); + else if (shdr->sh_info != 0) + { + *destshdrp = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_info), + destshdr_memp); + if (*destshdrp != NULL) + { + if((*destshdrp)->sh_type != SHT_PROGBITS + && (*destshdrp)->sh_type != SHT_NOBITS) + { + reldyn = is_rel_dyn (ebl, ehdr, idx, shdr, true); + if (!reldyn) + ERROR (gettext ("\ +section [%2d] '%s': invalid destination section type\n"), + idx, section_name (ebl, idx)); + else + { + /* There is no standard, but we require that .rel{,a}.dyn + sections have a sh_info value of zero. */ + if (shdr->sh_info != 0) + ERROR (gettext ("\ +section [%2d] '%s': sh_info should be zero\n"), + idx, section_name (ebl, idx)); + } + } + + if (((*destshdrp)->sh_flags & (SHF_MERGE | SHF_STRINGS)) != 0) + ERROR (gettext ("\ +section [%2d] '%s': no relocations for merge-able sections possible\n"), + idx, section_name (ebl, idx)); + } + } + + if (shdr->sh_entsize != gelf_fsize (ebl->elf, reltype, 1, EV_CURRENT)) + ERROR (gettext (reltype == ELF_T_RELA ? "\ +section [%2d] '%s': section entry size does not match ElfXX_Rela\n" : "\ +section [%2d] '%s': section entry size does not match ElfXX_Rel\n"), + idx, section_name (ebl, idx)); + + /* In preparation of checking whether relocations are text + relocations or not we need to determine whether the file is + flagged to have text relocation and we need to determine a) what + the loaded segments are and b) which are read-only. This will + also allow us to determine whether the same reloc section is + modifying loaded and not loaded segments. */ + for (unsigned int i = 0; i < phnum; ++i) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = gelf_getphdr (ebl->elf, i, &phdr_mem); + if (phdr == NULL) + continue; + + if (phdr->p_type == PT_LOAD) + { + struct loaded_segment *newp = xmalloc (sizeof (*newp)); + newp->from = phdr->p_vaddr; + newp->to = phdr->p_vaddr + phdr->p_memsz; + newp->read_only = (phdr->p_flags & PF_W) == 0; + newp->next = *loadedp; + *loadedp = newp; + } + else if (phdr->p_type == PT_DYNAMIC) + { + Elf_Scn *dynscn = gelf_offscn (ebl->elf, phdr->p_offset); + GElf_Shdr dynshdr_mem; + GElf_Shdr *dynshdr = gelf_getshdr (dynscn, &dynshdr_mem); + Elf_Data *dyndata = elf_getdata (dynscn, NULL); + if (dynshdr != NULL && dynshdr->sh_type == SHT_DYNAMIC + && dyndata != NULL) + for (size_t j = 0; j < dynshdr->sh_size / dynshdr->sh_entsize; ++j) + { + GElf_Dyn dyn_mem; + GElf_Dyn *dyn = gelf_getdyn (dyndata, j, &dyn_mem); + if (dyn != NULL + && (dyn->d_tag == DT_TEXTREL + || (dyn->d_tag == DT_FLAGS + && (dyn->d_un.d_val & DF_TEXTREL) != 0))) + { + textrel = true; + break; + } + } + } + } + + /* A quick test which can be easily done here (although it is a bit + out of place): the text relocation flag makes only sense if there + is a segment which is not writable. */ + if (textrel) + { + struct loaded_segment *seg = *loadedp; + while (seg != NULL && !seg->read_only) + seg = seg->next; + if (seg == NULL) + ERROR (gettext ("\ +text relocation flag set but there is no read-only segment\n")); + } + + return reldyn; +} + + +enum load_state + { + state_undecided, + state_loaded, + state_unloaded, + state_error + }; + + +static void +check_one_reloc (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *relshdr, int idx, + size_t cnt, const GElf_Shdr *symshdr, Elf_Data *symdata, + GElf_Addr r_offset, GElf_Xword r_info, + const GElf_Shdr *destshdr, bool reldyn, + struct loaded_segment *loaded, enum load_state *statep) +{ + bool known_broken = gnuld; + + if (!ebl_reloc_type_check (ebl, GELF_R_TYPE (r_info))) + ERROR (gettext ("section [%2d] '%s': relocation %zu: invalid type\n"), + idx, section_name (ebl, idx), cnt); + else if (((ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + /* The executable/DSO can contain relocation sections with + all the relocations the linker has applied. Those sections + are marked non-loaded, though. */ + || (relshdr->sh_flags & SHF_ALLOC) != 0) + && !ebl_reloc_valid_use (ebl, GELF_R_TYPE (r_info))) + ERROR (gettext ("\ +section [%2d] '%s': relocation %zu: relocation type invalid for the file type\n"), + idx, section_name (ebl, idx), cnt); + + if (symshdr != NULL + && ((GELF_R_SYM (r_info) + 1) + * gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT) + > symshdr->sh_size)) + ERROR (gettext ("\ +section [%2d] '%s': relocation %zu: invalid symbol index\n"), + idx, section_name (ebl, idx), cnt); + + /* No more tests if this is a no-op relocation. */ + if (ebl_none_reloc_p (ebl, GELF_R_TYPE (r_info))) + return; + + if (ebl_gotpc_reloc_check (ebl, GELF_R_TYPE (r_info))) + { + const char *name; + char buf[64]; + GElf_Sym sym_mem; + GElf_Sym *sym = gelf_getsym (symdata, GELF_R_SYM (r_info), &sym_mem); + if (sym != NULL + /* Get the name for the symbol. */ + && (name = elf_strptr (ebl->elf, symshdr->sh_link, sym->st_name)) + && strcmp (name, "_GLOBAL_OFFSET_TABLE_") !=0 ) + ERROR (gettext ("\ +section [%2d] '%s': relocation %zu: only symbol '_GLOBAL_OFFSET_TABLE_' can be used with %s\n"), + idx, section_name (ebl, idx), cnt, + ebl_reloc_type_name (ebl, GELF_R_SYM (r_info), + buf, sizeof (buf))); + } + + if (reldyn) + { + // XXX TODO Check .rel.dyn section addresses. + } + else if (!known_broken) + { + if (destshdr != NULL + && GELF_R_TYPE (r_info) != 0 + && (r_offset - (ehdr->e_type == ET_REL ? 0 + : destshdr->sh_addr)) >= destshdr->sh_size) + ERROR (gettext ("\ +section [%2d] '%s': relocation %zu: offset out of bounds\n"), + idx, section_name (ebl, idx), cnt); + } + + GElf_Sym sym_mem; + GElf_Sym *sym = gelf_getsym (symdata, GELF_R_SYM (r_info), &sym_mem); + + if (ebl_copy_reloc_p (ebl, GELF_R_TYPE (r_info)) + /* Make sure the referenced symbol is an object or unspecified. */ + && sym != NULL + && GELF_ST_TYPE (sym->st_info) != STT_NOTYPE + && GELF_ST_TYPE (sym->st_info) != STT_OBJECT) + { + char buf[64]; + ERROR (gettext ("section [%2d] '%s': relocation %zu: copy relocation against symbol of type %s\n"), + idx, section_name (ebl, idx), cnt, + ebl_symbol_type_name (ebl, GELF_ST_TYPE (sym->st_info), + buf, sizeof (buf))); + } + + if ((ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + || (relshdr->sh_flags & SHF_ALLOC) != 0) + { + bool in_loaded_seg = false; + while (loaded != NULL) + { + if (r_offset < loaded->to + && r_offset + (sym == NULL ? 0 : sym->st_size) >= loaded->from) + { + /* The symbol is in this segment. */ + if (loaded->read_only) + { + if (textrel) + needed_textrel = true; + else + ERROR (gettext ("section [%2d] '%s': relocation %zu: read-only section modified but text relocation flag not set\n"), + idx, section_name (ebl, idx), cnt); + } + + in_loaded_seg = true; + } + + loaded = loaded->next; + } + + if (*statep == state_undecided) + *statep = in_loaded_seg ? state_loaded : state_unloaded; + else if ((*statep == state_unloaded && in_loaded_seg) + || (*statep == state_loaded && !in_loaded_seg)) + { + ERROR (gettext ("\ +section [%2d] '%s': relocations are against loaded and unloaded data\n"), + idx, section_name (ebl, idx)); + *statep = state_error; + } + } +} + + +static void +check_rela (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + /* Check the fields of the section header. */ + GElf_Shdr destshdr_mem; + GElf_Shdr *destshdr = NULL; + struct loaded_segment *loaded = NULL; + bool reldyn = check_reloc_shdr (ebl, ehdr, shdr, idx, ELF_T_RELA, &destshdr, + &destshdr_mem, &loaded); + + Elf_Scn *symscn = elf_getscn (ebl->elf, shdr->sh_link); + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (symscn, &symshdr_mem); + Elf_Data *symdata = elf_getdata (symscn, NULL); + enum load_state state = state_undecided; + + for (size_t cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt) + { + GElf_Rela rela_mem; + GElf_Rela *rela = gelf_getrela (data, cnt, &rela_mem); + if (rela == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': cannot get relocation %zu: %s\n"), + idx, section_name (ebl, idx), cnt, elf_errmsg (-1)); + continue; + } + + check_one_reloc (ebl, ehdr, shdr, idx, cnt, symshdr, symdata, + rela->r_offset, rela->r_info, destshdr, reldyn, loaded, + &state); + } + + while (loaded != NULL) + { + struct loaded_segment *old = loaded; + loaded = loaded->next; + free (old); + } +} + + +static void +check_rel (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + /* Check the fields of the section header. */ + GElf_Shdr destshdr_mem; + GElf_Shdr *destshdr = NULL; + struct loaded_segment *loaded = NULL; + bool reldyn = check_reloc_shdr (ebl, ehdr, shdr, idx, ELF_T_REL, &destshdr, + &destshdr_mem, &loaded); + + Elf_Scn *symscn = elf_getscn (ebl->elf, shdr->sh_link); + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (symscn, &symshdr_mem); + Elf_Data *symdata = elf_getdata (symscn, NULL); + enum load_state state = state_undecided; + + for (size_t cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt) + { + GElf_Rel rel_mem; + GElf_Rel *rel = gelf_getrel (data, cnt, &rel_mem); + if (rel == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': cannot get relocation %zu: %s\n"), + idx, section_name (ebl, idx), cnt, elf_errmsg (-1)); + continue; + } + + check_one_reloc (ebl, ehdr, shdr, idx, cnt, symshdr, symdata, + rel->r_offset, rel->r_info, destshdr, reldyn, loaded, + &state); + } + + while (loaded != NULL) + { + struct loaded_segment *old = loaded; + loaded = loaded->next; + free (old); + } +} + + +/* Number of dynamic sections. */ +static int ndynamic; + + +static void +check_dynamic (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + Elf_Data *data; + GElf_Shdr strshdr_mem; + GElf_Shdr *strshdr; + size_t cnt; + static const bool dependencies[DT_NUM][DT_NUM] = + { + [DT_NEEDED] = { [DT_STRTAB] = true }, + [DT_PLTRELSZ] = { [DT_JMPREL] = true }, + [DT_HASH] = { [DT_SYMTAB] = true }, + [DT_STRTAB] = { [DT_STRSZ] = true }, + [DT_SYMTAB] = { [DT_STRTAB] = true, [DT_SYMENT] = true }, + [DT_RELA] = { [DT_RELASZ] = true, [DT_RELAENT] = true }, + [DT_RELASZ] = { [DT_RELA] = true }, + [DT_RELAENT] = { [DT_RELA] = true }, + [DT_STRSZ] = { [DT_STRTAB] = true }, + [DT_SYMENT] = { [DT_SYMTAB] = true }, + [DT_SONAME] = { [DT_STRTAB] = true }, + [DT_RPATH] = { [DT_STRTAB] = true }, + [DT_REL] = { [DT_RELSZ] = true, [DT_RELENT] = true }, + [DT_RELSZ] = { [DT_REL] = true }, + [DT_RELENT] = { [DT_REL] = true }, + [DT_JMPREL] = { [DT_PLTRELSZ] = true, [DT_PLTREL] = true }, + [DT_RUNPATH] = { [DT_STRTAB] = true }, + [DT_PLTREL] = { [DT_JMPREL] = true }, + }; + bool has_dt[DT_NUM]; + bool has_val_dt[DT_VALNUM]; + bool has_addr_dt[DT_ADDRNUM]; + static const bool level2[DT_NUM] = + { + [DT_RPATH] = true, + [DT_SYMBOLIC] = true, + [DT_TEXTREL] = true, + [DT_BIND_NOW] = true + }; + static const bool mandatory[DT_NUM] = + { + [DT_NULL] = true, + [DT_STRTAB] = true, + [DT_SYMTAB] = true, + [DT_STRSZ] = true, + [DT_SYMENT] = true + }; + + memset (has_dt, '\0', sizeof (has_dt)); + memset (has_val_dt, '\0', sizeof (has_val_dt)); + memset (has_addr_dt, '\0', sizeof (has_addr_dt)); + + if (++ndynamic == 2) + ERROR (gettext ("more than one dynamic section present\n")); + + data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + strshdr = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), &strshdr_mem); + if (strshdr != NULL && strshdr->sh_type != SHT_STRTAB) + ERROR (gettext ("\ +section [%2d] '%s': referenced as string table for section [%2d] '%s' but type is not SHT_STRTAB\n"), + shdr->sh_link, section_name (ebl, shdr->sh_link), + idx, section_name (ebl, idx)); + + if (shdr->sh_entsize != gelf_fsize (ebl->elf, ELF_T_DYN, 1, EV_CURRENT)) + ERROR (gettext ("\ +section [%2d] '%s': section entry size does not match ElfXX_Dyn\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_info != 0) + ERROR (gettext ("section [%2d] '%s': sh_info not zero\n"), + idx, section_name (ebl, idx)); + + bool non_null_warned = false; + for (cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt) + { + GElf_Dyn dyn_mem; + GElf_Dyn *dyn = gelf_getdyn (data, cnt, &dyn_mem); + if (dyn == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': cannot get dynamic section entry %zu: %s\n"), + idx, section_name (ebl, idx), cnt, elf_errmsg (-1)); + continue; + } + + if (has_dt[DT_NULL] && dyn->d_tag != DT_NULL && ! non_null_warned) + { + ERROR (gettext ("\ +section [%2d] '%s': non-DT_NULL entries follow DT_NULL entry\n"), + idx, section_name (ebl, idx)); + non_null_warned = true; + } + + if (!ebl_dynamic_tag_check (ebl, dyn->d_tag)) + ERROR (gettext ("section [%2d] '%s': entry %zu: unknown tag\n"), + idx, section_name (ebl, idx), cnt); + + if (dyn->d_tag >= 0 && dyn->d_tag < DT_NUM) + { + if (has_dt[dyn->d_tag] + && dyn->d_tag != DT_NEEDED + && dyn->d_tag != DT_NULL + && dyn->d_tag != DT_POSFLAG_1) + { + char buf[50]; + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: more than one entry with tag %s\n"), + idx, section_name (ebl, idx), cnt, + ebl_dynamic_tag_name (ebl, dyn->d_tag, + buf, sizeof (buf))); + } + + if (be_strict && level2[dyn->d_tag]) + { + char buf[50]; + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: level 2 tag %s used\n"), + idx, section_name (ebl, idx), cnt, + ebl_dynamic_tag_name (ebl, dyn->d_tag, + buf, sizeof (buf))); + } + + has_dt[dyn->d_tag] = true; + } + else if (dyn->d_tag <= DT_VALRNGHI + && DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM) + has_val_dt[DT_VALTAGIDX (dyn->d_tag)] = true; + else if (dyn->d_tag <= DT_ADDRRNGHI + && DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM) + has_addr_dt[DT_ADDRTAGIDX (dyn->d_tag)] = true; + + if (dyn->d_tag == DT_PLTREL && dyn->d_un.d_val != DT_REL + && dyn->d_un.d_val != DT_RELA) + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: DT_PLTREL value must be DT_REL or DT_RELA\n"), + idx, section_name (ebl, idx), cnt); + + /* Check that addresses for entries are in loaded segments. */ + switch (dyn->d_tag) + { + size_t n; + case DT_STRTAB: + /* We require the referenced section is the same as the one + specified in sh_link. */ + if (strshdr->sh_addr != dyn->d_un.d_val) + { + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: pointer does not match address of section [%2d] '%s' referenced by sh_link\n"), + idx, section_name (ebl, idx), cnt, + shdr->sh_link, section_name (ebl, shdr->sh_link)); + break; + } + goto check_addr; + + default: + if (dyn->d_tag < DT_ADDRRNGLO || dyn->d_tag > DT_ADDRRNGHI) + /* Value is no pointer. */ + break; + /* FALLTHROUGH */ + + case DT_AUXILIARY: + case DT_FILTER: + case DT_FINI: + case DT_FINI_ARRAY: + case DT_HASH: + case DT_INIT: + case DT_INIT_ARRAY: + case DT_JMPREL: + case DT_PLTGOT: + case DT_REL: + case DT_RELA: + case DT_SYMBOLIC: + case DT_SYMTAB: + case DT_VERDEF: + case DT_VERNEED: + case DT_VERSYM: + check_addr: + for (n = 0; n < phnum; ++n) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = gelf_getphdr (ebl->elf, n, &phdr_mem); + if (phdr != NULL && phdr->p_type == PT_LOAD + && phdr->p_vaddr <= dyn->d_un.d_ptr + && phdr->p_vaddr + phdr->p_memsz > dyn->d_un.d_ptr) + break; + } + if (unlikely (n >= phnum)) + { + char buf[50]; + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: %s value must point into loaded segment\n"), + idx, section_name (ebl, idx), cnt, + ebl_dynamic_tag_name (ebl, dyn->d_tag, buf, + sizeof (buf))); + } + break; + + case DT_NEEDED: + case DT_RPATH: + case DT_RUNPATH: + case DT_SONAME: + if (dyn->d_un.d_ptr >= strshdr->sh_size) + { + char buf[50]; + ERROR (gettext ("\ +section [%2d] '%s': entry %zu: %s value must be valid offset in section [%2d] '%s'\n"), + idx, section_name (ebl, idx), cnt, + ebl_dynamic_tag_name (ebl, dyn->d_tag, buf, + sizeof (buf)), + shdr->sh_link, section_name (ebl, shdr->sh_link)); + } + break; + } + } + + for (cnt = 1; cnt < DT_NUM; ++cnt) + if (has_dt[cnt]) + { + for (int inner = 0; inner < DT_NUM; ++inner) + if (dependencies[cnt][inner] && ! has_dt[inner]) + { + char buf1[50]; + char buf2[50]; + + ERROR (gettext ("\ +section [%2d] '%s': contains %s entry but not %s\n"), + idx, section_name (ebl, idx), + ebl_dynamic_tag_name (ebl, cnt, buf1, sizeof (buf1)), + ebl_dynamic_tag_name (ebl, inner, buf2, sizeof (buf2))); + } + } + else + { + if (mandatory[cnt]) + { + char buf[50]; + ERROR (gettext ("\ +section [%2d] '%s': mandatory tag %s not present\n"), + idx, section_name (ebl, idx), + ebl_dynamic_tag_name (ebl, cnt, buf, sizeof (buf))); + } + } + + /* Make sure we have an hash table. */ + if (!has_dt[DT_HASH] && !has_addr_dt[DT_ADDRTAGIDX (DT_GNU_HASH)]) + ERROR (gettext ("\ +section [%2d] '%s': no hash section present\n"), + idx, section_name (ebl, idx)); + + /* The GNU-style hash table also needs a symbol table. */ + if (!has_dt[DT_HASH] && has_addr_dt[DT_ADDRTAGIDX (DT_GNU_HASH)] + && !has_dt[DT_SYMTAB]) + ERROR (gettext ("\ +section [%2d] '%s': contains %s entry but not %s\n"), + idx, section_name (ebl, idx), + "DT_GNU_HASH", "DT_SYMTAB"); + + /* Check the rel/rela tags. At least one group must be available. */ + if ((has_dt[DT_RELA] || has_dt[DT_RELASZ] || has_dt[DT_RELAENT]) + && (!has_dt[DT_RELA] || !has_dt[DT_RELASZ] || !has_dt[DT_RELAENT])) + ERROR (gettext ("\ +section [%2d] '%s': not all of %s, %s, and %s are present\n"), + idx, section_name (ebl, idx), + "DT_RELA", "DT_RELASZ", "DT_RELAENT"); + + if ((has_dt[DT_REL] || has_dt[DT_RELSZ] || has_dt[DT_RELENT]) + && (!has_dt[DT_REL] || !has_dt[DT_RELSZ] || !has_dt[DT_RELENT])) + ERROR (gettext ("\ +section [%2d] '%s': not all of %s, %s, and %s are present\n"), + idx, section_name (ebl, idx), + "DT_REL", "DT_RELSZ", "DT_RELENT"); + + /* Check that all prelink sections are present if any of them is. */ + if (has_val_dt[DT_VALTAGIDX (DT_GNU_PRELINKED)] + || has_val_dt[DT_VALTAGIDX (DT_CHECKSUM)]) + { + if (!has_val_dt[DT_VALTAGIDX (DT_GNU_PRELINKED)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in DSO marked during prelinking\n"), + idx, section_name (ebl, idx), "DT_GNU_PRELINKED"); + if (!has_val_dt[DT_VALTAGIDX (DT_CHECKSUM)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in DSO marked during prelinking\n"), + idx, section_name (ebl, idx), "DT_CHECKSUM"); + + /* Only DSOs can be marked like this. */ + if (ehdr->e_type != ET_DYN) + ERROR (gettext ("\ +section [%2d] '%s': non-DSO file marked as dependency during prelink\n"), + idx, section_name (ebl, idx)); + } + + if (has_val_dt[DT_VALTAGIDX (DT_GNU_CONFLICTSZ)] + || has_val_dt[DT_VALTAGIDX (DT_GNU_LIBLISTSZ)] + || has_addr_dt[DT_ADDRTAGIDX (DT_GNU_CONFLICT)] + || has_addr_dt[DT_ADDRTAGIDX (DT_GNU_LIBLIST)]) + { + if (!has_val_dt[DT_VALTAGIDX (DT_GNU_CONFLICTSZ)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in prelinked executable\n"), + idx, section_name (ebl, idx), "DT_GNU_CONFLICTSZ"); + if (!has_val_dt[DT_VALTAGIDX (DT_GNU_LIBLISTSZ)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in prelinked executable\n"), + idx, section_name (ebl, idx), "DT_GNU_LIBLISTSZ"); + if (!has_addr_dt[DT_ADDRTAGIDX (DT_GNU_CONFLICT)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in prelinked executable\n"), + idx, section_name (ebl, idx), "DT_GNU_CONFLICT"); + if (!has_addr_dt[DT_ADDRTAGIDX (DT_GNU_LIBLIST)]) + ERROR (gettext ("\ +section [%2d] '%s': %s tag missing in prelinked executable\n"), + idx, section_name (ebl, idx), "DT_GNU_LIBLIST"); + } +} + + +static void +check_symtab_shndx (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + if (ehdr->e_type != ET_REL) + { + ERROR (gettext ("\ +section [%2d] '%s': only relocatable files can have extended section index\n"), + idx, section_name (ebl, idx)); + return; + } + + Elf_Scn *symscn = elf_getscn (ebl->elf, shdr->sh_link); + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (symscn, &symshdr_mem); + if (symshdr != NULL && symshdr->sh_type != SHT_SYMTAB) + ERROR (gettext ("\ +section [%2d] '%s': extended section index section not for symbol table\n"), + idx, section_name (ebl, idx)); + Elf_Data *symdata = elf_getdata (symscn, NULL); + if (symdata == NULL) + ERROR (gettext ("cannot get data for symbol section\n")); + + if (shdr->sh_entsize != sizeof (Elf32_Word)) + ERROR (gettext ("\ +section [%2d] '%s': entry size does not match Elf32_Word\n"), + idx, section_name (ebl, idx)); + + if (symshdr != NULL + && (shdr->sh_size / shdr->sh_entsize + < symshdr->sh_size / symshdr->sh_entsize)) + ERROR (gettext ("\ +section [%2d] '%s': extended index table too small for symbol table\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_info != 0) + ERROR (gettext ("section [%2d] '%s': sh_info not zero\n"), + idx, section_name (ebl, idx)); + + for (size_t cnt = idx + 1; cnt < shnum; ++cnt) + { + GElf_Shdr rshdr_mem; + GElf_Shdr *rshdr = gelf_getshdr (elf_getscn (ebl->elf, cnt), &rshdr_mem); + if (rshdr != NULL && rshdr->sh_type == SHT_SYMTAB_SHNDX + && rshdr->sh_link == shdr->sh_link) + { + ERROR (gettext ("\ +section [%2d] '%s': extended section index in section [%2zu] '%s' refers to same symbol table\n"), + idx, section_name (ebl, idx), + cnt, section_name (ebl, cnt)); + break; + } + } + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + + if (*((Elf32_Word *) data->d_buf) != 0) + ERROR (gettext ("symbol 0 should have zero extended section index\n")); + + for (size_t cnt = 1; cnt < data->d_size / sizeof (Elf32_Word); ++cnt) + { + Elf32_Word xndx = ((Elf32_Word *) data->d_buf)[cnt]; + + if (xndx != 0) + { + GElf_Sym sym_data; + GElf_Sym *sym = gelf_getsym (symdata, cnt, &sym_data); + if (sym == NULL) + { + ERROR (gettext ("cannot get data for symbol %zu\n"), cnt); + continue; + } + + if (sym->st_shndx != SHN_XINDEX) + ERROR (gettext ("\ +extended section index is %" PRIu32 " but symbol index is not XINDEX\n"), + (uint32_t) xndx); + } + } +} + + +static void +check_sysv_hash (Ebl *ebl, GElf_Shdr *shdr, Elf_Data *data, int idx, + GElf_Shdr *symshdr) +{ + Elf32_Word nbucket = ((Elf32_Word *) data->d_buf)[0]; + Elf32_Word nchain = ((Elf32_Word *) data->d_buf)[1]; + + if (shdr->sh_size < (2 + nbucket + nchain) * shdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s': hash table section is too small (is %ld, expected %ld)\n"), + idx, section_name (ebl, idx), (long int) shdr->sh_size, + (long int) ((2 + nbucket + nchain) * shdr->sh_entsize)); + + size_t maxidx = nchain; + + if (symshdr != NULL) + { + size_t symsize = symshdr->sh_size / symshdr->sh_entsize; + + if (nchain > symshdr->sh_size / symshdr->sh_entsize) + ERROR (gettext ("section [%2d] '%s': chain array too large\n"), + idx, section_name (ebl, idx)); + + maxidx = symsize; + } + + size_t cnt; + for (cnt = 2; cnt < 2 + nbucket; ++cnt) + if (((Elf32_Word *) data->d_buf)[cnt] >= maxidx) + ERROR (gettext ("\ +section [%2d] '%s': hash bucket reference %zu out of bounds\n"), + idx, section_name (ebl, idx), cnt - 2); + + for (; cnt < 2 + nbucket + nchain; ++cnt) + if (((Elf32_Word *) data->d_buf)[cnt] >= maxidx) + ERROR (gettext ("\ +section [%2d] '%s': hash chain reference %zu out of bounds\n"), + idx, section_name (ebl, idx), cnt - 2 - nbucket); +} + + +static void +check_sysv_hash64 (Ebl *ebl, GElf_Shdr *shdr, Elf_Data *data, int idx, + GElf_Shdr *symshdr) +{ + Elf64_Xword nbucket = ((Elf64_Xword *) data->d_buf)[0]; + Elf64_Xword nchain = ((Elf64_Xword *) data->d_buf)[1]; + + if (shdr->sh_size < (2 + nbucket + nchain) * shdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s': hash table section is too small (is %ld, expected %ld)\n"), + idx, section_name (ebl, idx), (long int) shdr->sh_size, + (long int) ((2 + nbucket + nchain) * shdr->sh_entsize)); + + size_t maxidx = nchain; + + if (symshdr != NULL) + { + size_t symsize = symshdr->sh_size / symshdr->sh_entsize; + + if (nchain > symshdr->sh_size / symshdr->sh_entsize) + ERROR (gettext ("section [%2d] '%s': chain array too large\n"), + idx, section_name (ebl, idx)); + + maxidx = symsize; + } + + size_t cnt; + for (cnt = 2; cnt < 2 + nbucket; ++cnt) + if (((Elf64_Xword *) data->d_buf)[cnt] >= maxidx) + ERROR (gettext ("\ +section [%2d] '%s': hash bucket reference %zu out of bounds\n"), + idx, section_name (ebl, idx), cnt - 2); + + for (; cnt < 2 + nbucket + nchain; ++cnt) + if (((Elf64_Xword *) data->d_buf)[cnt] >= maxidx) + ERROR (gettext ("\ +section [%2d] '%s': hash chain reference %" PRIu64 " out of bounds\n"), + idx, section_name (ebl, idx), (uint64_t) (cnt - 2 - nbucket)); +} + + +static void +check_gnu_hash (Ebl *ebl, GElf_Shdr *shdr, Elf_Data *data, int idx, + GElf_Shdr *symshdr) +{ + Elf32_Word nbuckets = ((Elf32_Word *) data->d_buf)[0]; + Elf32_Word symbias = ((Elf32_Word *) data->d_buf)[1]; + Elf32_Word bitmask_words = ((Elf32_Word *) data->d_buf)[2]; + + if (!powerof2 (bitmask_words)) + ERROR (gettext ("\ +section [%2d] '%s': bitmask size not power of 2: %u\n"), + idx, section_name (ebl, idx), bitmask_words); + + size_t bitmask_idxmask = bitmask_words - 1; + if (gelf_getclass (ebl->elf) == ELFCLASS64) + bitmask_words *= 2; + Elf32_Word shift = ((Elf32_Word *) data->d_buf)[3]; + + if (shdr->sh_size < (4 + bitmask_words + nbuckets) * sizeof (Elf32_Word)) + { + ERROR (gettext ("\ +section [%2d] '%s': hash table section is too small (is %ld, expected at least%ld)\n"), + idx, section_name (ebl, idx), (long int) shdr->sh_size, + (long int) ((4 + bitmask_words + nbuckets) * sizeof (Elf32_Word))); + return; + } + + if (shift > 31) + ERROR (gettext ("\ +section [%2d] '%s': 2nd hash function shift too big: %u\n"), + idx, section_name (ebl, idx), shift); + + size_t maxidx = shdr->sh_size / sizeof (Elf32_Word) - (4 + bitmask_words + + nbuckets); + + if (symshdr != NULL) + maxidx = MIN (maxidx, symshdr->sh_size / symshdr->sh_entsize); + + /* We need the symbol section data. */ + Elf_Data *symdata = elf_getdata (elf_getscn (ebl->elf, shdr->sh_link), NULL); + + union + { + Elf32_Word *p32; + Elf64_Xword *p64; + } bitmask = { .p32 = &((Elf32_Word *) data->d_buf)[4] }, + collected = { .p32 = xcalloc (bitmask_words, sizeof (Elf32_Word)) }; + + size_t classbits = gelf_getclass (ebl->elf) == ELFCLASS32 ? 32 : 64; + + size_t cnt; + for (cnt = 4 + bitmask_words; cnt < 4 + bitmask_words + nbuckets; ++cnt) + { + Elf32_Word symidx = ((Elf32_Word *) data->d_buf)[cnt]; + + if (symidx == 0) + continue; + + if (symidx < symbias) + { + ERROR (gettext ("\ +section [%2d] '%s': hash chain for bucket %zu lower than symbol index bias\n"), + idx, section_name (ebl, idx), cnt - (4 + bitmask_words)); + continue; + } + + while (symidx - symbias < maxidx) + { + Elf32_Word chainhash = ((Elf32_Word *) data->d_buf)[4 + + bitmask_words + + nbuckets + + symidx + - symbias]; + + if (symdata != NULL) + { + /* Check that the referenced symbol is not undefined. */ + GElf_Sym sym_mem; + GElf_Sym *sym = gelf_getsym (symdata, symidx, &sym_mem); + if (sym != NULL && sym->st_shndx == SHN_UNDEF + && GELF_ST_TYPE (sym->st_info) != STT_FUNC) + ERROR (gettext ("\ +section [%2d] '%s': symbol %u referenced in chain for bucket %zu is undefined\n"), + idx, section_name (ebl, idx), symidx, + cnt - (4 + bitmask_words)); + + const char *symname = elf_strptr (ebl->elf, symshdr->sh_link, + sym->st_name); + if (symname != NULL) + { + Elf32_Word hval = elf_gnu_hash (symname); + if ((hval & ~1u) != (chainhash & ~1u)) + ERROR (gettext ("\ +section [%2d] '%s': hash value for symbol %u in chain for bucket %zu wrong\n"), + idx, section_name (ebl, idx), symidx, + cnt - (4 + bitmask_words)); + + /* Set the bits in the bitmask. */ + size_t maskidx = (hval / classbits) & bitmask_idxmask; + if (classbits == 32) + { + collected.p32[maskidx] + |= UINT32_C (1) << (hval & (classbits - 1)); + collected.p32[maskidx] + |= UINT32_C (1) << ((hval >> shift) & (classbits - 1)); + } + else + { + collected.p64[maskidx] + |= UINT64_C (1) << (hval & (classbits - 1)); + collected.p64[maskidx] + |= UINT64_C (1) << ((hval >> shift) & (classbits - 1)); + } + } + } + + if ((chainhash & 1) != 0) + break; + + ++symidx; + } + + if (symidx - symbias >= maxidx) + ERROR (gettext ("\ +section [%2d] '%s': hash chain for bucket %zu out of bounds\n"), + idx, section_name (ebl, idx), cnt - (4 + bitmask_words)); + else if (symshdr != NULL + && symidx > symshdr->sh_size / symshdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s': symbol reference in chain for bucket %zu out of bounds\n"), + idx, section_name (ebl, idx), cnt - (4 + bitmask_words)); + } + + if (memcmp (collected.p32, bitmask.p32, bitmask_words * sizeof (Elf32_Word))) + ERROR (gettext ("\ +section [%2d] '%s': bitmask does not match names in the hash table\n"), + idx, section_name (ebl, idx)); + + free (collected.p32); +} + + +static void +check_hash (int tag, Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + if (ehdr->e_type == ET_REL) + { + ERROR (gettext ("\ +section [%2d] '%s': relocatable files cannot have hash tables\n"), + idx, section_name (ebl, idx)); + return; + } + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), + &symshdr_mem); + if (symshdr != NULL && symshdr->sh_type != SHT_DYNSYM) + ERROR (gettext ("\ +section [%2d] '%s': hash table not for dynamic symbol table\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_entsize != (tag == SHT_GNU_HASH + ? (gelf_getclass (ebl->elf) == ELFCLASS32 + ? sizeof (Elf32_Word) : 0) + : (size_t) ebl_sysvhash_entrysize (ebl))) + ERROR (gettext ("\ +section [%2d] '%s': hash table entry size incorrect\n"), + idx, section_name (ebl, idx)); + + if ((shdr->sh_flags & SHF_ALLOC) == 0) + ERROR (gettext ("section [%2d] '%s': not marked to be allocated\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_size < (tag == SHT_GNU_HASH ? 4 : 2) * (shdr->sh_entsize ?: 4)) + { + ERROR (gettext ("\ +section [%2d] '%s': hash table has not even room for initial administrative entries\n"), + idx, section_name (ebl, idx)); + return; + } + + switch (tag) + { + case SHT_HASH: + if (ebl_sysvhash_entrysize (ebl) == sizeof (Elf64_Xword)) + check_sysv_hash64 (ebl, shdr, data, idx, symshdr); + else + check_sysv_hash (ebl, shdr, data, idx, symshdr); + break; + + case SHT_GNU_HASH: + check_gnu_hash (ebl, shdr, data, idx, symshdr); + break; + + default: + assert (! "should not happen"); + } +} + + +/* Compare content of both hash tables, it must be identical. */ +static void +compare_hash_gnu_hash (Ebl *ebl, GElf_Ehdr *ehdr, size_t hash_idx, + size_t gnu_hash_idx) +{ + Elf_Scn *hash_scn = elf_getscn (ebl->elf, hash_idx); + Elf_Data *hash_data = elf_getdata (hash_scn, NULL); + GElf_Shdr hash_shdr_mem; + GElf_Shdr *hash_shdr = gelf_getshdr (hash_scn, &hash_shdr_mem); + Elf_Scn *gnu_hash_scn = elf_getscn (ebl->elf, gnu_hash_idx); + Elf_Data *gnu_hash_data = elf_getdata (gnu_hash_scn, NULL); + GElf_Shdr gnu_hash_shdr_mem; + GElf_Shdr *gnu_hash_shdr = gelf_getshdr (gnu_hash_scn, &gnu_hash_shdr_mem); + + if (hash_shdr == NULL || gnu_hash_shdr == NULL + || hash_data == NULL || gnu_hash_data == NULL) + /* None of these pointers should be NULL since we used the + sections already. We are careful nonetheless. */ + return; + + /* The link must point to the same symbol table. */ + if (hash_shdr->sh_link != gnu_hash_shdr->sh_link) + { + ERROR (gettext ("\ +sh_link in hash sections [%2zu] '%s' and [%2zu] '%s' not identical\n"), + hash_idx, elf_strptr (ebl->elf, shstrndx, hash_shdr->sh_name), + gnu_hash_idx, + elf_strptr (ebl->elf, shstrndx, gnu_hash_shdr->sh_name)); + return; + } + + Elf_Scn *sym_scn = elf_getscn (ebl->elf, hash_shdr->sh_link); + Elf_Data *sym_data = elf_getdata (sym_scn, NULL); + GElf_Shdr sym_shdr_mem; + GElf_Shdr *sym_shdr = gelf_getshdr (sym_scn, &sym_shdr_mem); + + if (sym_data == NULL || sym_shdr == NULL) + return; + + int nentries = sym_shdr->sh_size / sym_shdr->sh_entsize; + char *used = alloca (nentries); + memset (used, '\0', nentries); + + /* First go over the GNU_HASH table and mark the entries as used. */ + const Elf32_Word *gnu_hasharr = (Elf32_Word *) gnu_hash_data->d_buf; + Elf32_Word gnu_nbucket = gnu_hasharr[0]; + const int bitmap_factor = ehdr->e_ident[EI_CLASS] == ELFCLASS32 ? 1 : 2; + const Elf32_Word *gnu_bucket = (gnu_hasharr + + (4 + gnu_hasharr[2] * bitmap_factor)); + const Elf32_Word *gnu_chain = gnu_bucket + gnu_hasharr[0] - gnu_hasharr[1]; + + for (Elf32_Word cnt = 0; cnt < gnu_nbucket; ++cnt) + { + Elf32_Word symidx = gnu_bucket[cnt]; + if (symidx != STN_UNDEF) + do + used[symidx] |= 1; + while ((gnu_chain[symidx++] & 1u) == 0); + } + + /* Now go over the old hash table and check that we cover the same + entries. */ + if (hash_shdr->sh_entsize == sizeof (Elf32_Word)) + { + const Elf32_Word *hasharr = (Elf32_Word *) hash_data->d_buf; + Elf32_Word nbucket = hasharr[0]; + const Elf32_Word *bucket = &hasharr[2]; + const Elf32_Word *chain = &hasharr[2 + nbucket]; + + for (Elf32_Word cnt = 0; cnt < nbucket; ++cnt) + { + Elf32_Word symidx = bucket[cnt]; + while (symidx != STN_UNDEF) + { + used[symidx] |= 2; + symidx = chain[symidx]; + } + } + } + else + { + const Elf64_Xword *hasharr = (Elf64_Xword *) hash_data->d_buf; + Elf64_Xword nbucket = hasharr[0]; + const Elf64_Xword *bucket = &hasharr[2]; + const Elf64_Xword *chain = &hasharr[2 + nbucket]; + + for (Elf64_Xword cnt = 0; cnt < nbucket; ++cnt) + { + Elf64_Xword symidx = bucket[cnt]; + while (symidx != STN_UNDEF) + { + used[symidx] |= 2; + symidx = chain[symidx]; + } + } + } + + /* Now see which entries are not set in one or both hash tables + (unless the symbol is undefined in which case it can be omitted + in the new table format). */ + if ((used[0] & 1) != 0) + ERROR (gettext ("section [%2zu] '%s': reference to symbol index 0\n"), + gnu_hash_idx, + elf_strptr (ebl->elf, shstrndx, gnu_hash_shdr->sh_name)); + if ((used[0] & 2) != 0) + ERROR (gettext ("section [%2zu] '%s': reference to symbol index 0\n"), + hash_idx, elf_strptr (ebl->elf, shstrndx, hash_shdr->sh_name)); + + for (int cnt = 1; cnt < nentries; ++cnt) + if (used[cnt] != 0 && used[cnt] != 3) + { + if (used[cnt] == 1) + ERROR (gettext ("\ +symbol %d referenced in new hash table in [%2zu] '%s' but not in old hash table in [%2zu] '%s'\n"), + cnt, gnu_hash_idx, + elf_strptr (ebl->elf, shstrndx, gnu_hash_shdr->sh_name), + hash_idx, + elf_strptr (ebl->elf, shstrndx, hash_shdr->sh_name)); + else + { + GElf_Sym sym_mem; + GElf_Sym *sym = gelf_getsym (sym_data, cnt, &sym_mem); + + if (sym != NULL && sym->st_shndx != STN_UNDEF) + ERROR (gettext ("\ +symbol %d referenced in old hash table in [%2zu] '%s' but not in new hash table in [%2zu] '%s'\n"), + cnt, hash_idx, + elf_strptr (ebl->elf, shstrndx, hash_shdr->sh_name), + gnu_hash_idx, + elf_strptr (ebl->elf, shstrndx, gnu_hash_shdr->sh_name)); + } + } +} + + +static void +check_null (Ebl *ebl, GElf_Shdr *shdr, int idx) +{ +#define TEST(name, extra) \ + if (extra && shdr->sh_##name != 0) \ + ERROR (gettext ("section [%2d] '%s': nonzero sh_%s for NULL section\n"), \ + idx, section_name (ebl, idx), #name) + + TEST (name, 1); + TEST (flags, 1); + TEST (addr, 1); + TEST (offset, 1); + TEST (size, idx != 0); + TEST (link, idx != 0); + TEST (info, 1); + TEST (addralign, 1); + TEST (entsize, 1); +} + + +static void +check_group (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + if (ehdr->e_type != ET_REL) + { + ERROR (gettext ("\ +section [%2d] '%s': section groups only allowed in relocatable object files\n"), + idx, section_name (ebl, idx)); + return; + } + + /* Check that sh_link is an index of a symbol table. */ + Elf_Scn *symscn = elf_getscn (ebl->elf, shdr->sh_link); + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (symscn, &symshdr_mem); + if (symshdr == NULL) + ERROR (gettext ("section [%2d] '%s': cannot get symbol table: %s\n"), + idx, section_name (ebl, idx), elf_errmsg (-1)); + else + { + if (symshdr->sh_type != SHT_SYMTAB) + ERROR (gettext ("\ +section [%2d] '%s': section reference in sh_link is no symbol table\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_info >= symshdr->sh_size / gelf_fsize (ebl->elf, ELF_T_SYM, + 1, EV_CURRENT)) + ERROR (gettext ("\ +section [%2d] '%s': invalid symbol index in sh_info\n"), + idx, section_name (ebl, idx)); + + if (shdr->sh_flags != 0) + ERROR (gettext ("section [%2d] '%s': sh_flags not zero\n"), + idx, section_name (ebl, idx)); + + GElf_Sym sym_data; + GElf_Sym *sym = gelf_getsym (elf_getdata (symscn, NULL), shdr->sh_info, + &sym_data); + if (sym == NULL) + ERROR (gettext ("\ +section [%2d] '%s': cannot get symbol for signature\n"), + idx, section_name (ebl, idx)); + else if (strcmp (elf_strptr (ebl->elf, symshdr->sh_link, sym->st_name), + "") == 0) + ERROR (gettext ("\ +section [%2d] '%s': signature symbol cannot be empty string\n"), + idx, section_name (ebl, idx)); + + if (be_strict + && shdr->sh_entsize != elf32_fsize (ELF_T_WORD, 1, EV_CURRENT)) + ERROR (gettext ("section [%2d] '%s': sh_flags not set correctly\n"), + idx, section_name (ebl, idx)); + } + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + ERROR (gettext ("section [%2d] '%s': cannot get data: %s\n"), + idx, section_name (ebl, idx), elf_errmsg (-1)); + else + { + size_t elsize = elf32_fsize (ELF_T_WORD, 1, EV_CURRENT); + size_t cnt; + Elf32_Word val; + + if (data->d_size % elsize != 0) + ERROR (gettext ("\ +section [%2d] '%s': section size not multiple of sizeof(Elf32_Word)\n"), + idx, section_name (ebl, idx)); + + if (data->d_size < elsize) + ERROR (gettext ("\ +section [%2d] '%s': section group without flags word\n"), + idx, section_name (ebl, idx)); + else if (be_strict) + { + if (data->d_size < 2 * elsize) + ERROR (gettext ("\ +section [%2d] '%s': section group without member\n"), + idx, section_name (ebl, idx)); + else if (data->d_size < 3 * elsize) + ERROR (gettext ("\ +section [%2d] '%s': section group with only one member\n"), + idx, section_name (ebl, idx)); + } + +#if ALLOW_UNALIGNED + val = *((Elf32_Word *) data->d_buf); +#else + memcpy (&val, data->d_buf, elsize); +#endif + if ((val & ~GRP_COMDAT) != 0) + ERROR (gettext ("section [%2d] '%s': unknown section group flags\n"), + idx, section_name (ebl, idx)); + + for (cnt = elsize; cnt < data->d_size; cnt += elsize) + { +#if ALLOW_UNALIGNED + val = *((Elf32_Word *) ((char *) data->d_buf + cnt)); +#else + memcpy (&val, (char *) data->d_buf + cnt, elsize); +#endif + + if (val > shnum) + ERROR (gettext ("\ +section [%2d] '%s': section index %Zu out of range\n"), + idx, section_name (ebl, idx), cnt / elsize); + else + { + GElf_Shdr refshdr_mem; + GElf_Shdr *refshdr = gelf_getshdr (elf_getscn (ebl->elf, val), + &refshdr_mem); + if (refshdr == NULL) + ERROR (gettext ("\ +section [%2d] '%s': cannot get section header for element %zu: %s\n"), + idx, section_name (ebl, idx), cnt / elsize, + elf_errmsg (-1)); + else + { + if (refshdr->sh_type == SHT_GROUP) + ERROR (gettext ("\ +section [%2d] '%s': section group contains another group [%2d] '%s'\n"), + idx, section_name (ebl, idx), + val, section_name (ebl, val)); + + if ((refshdr->sh_flags & SHF_GROUP) == 0) + ERROR (gettext ("\ +section [%2d] '%s': element %Zu references section [%2d] '%s' without SHF_GROUP flag set\n"), + idx, section_name (ebl, idx), cnt / elsize, + val, section_name (ebl, val)); + } + + if (++scnref[val] == 2) + ERROR (gettext ("\ +section [%2d] '%s' is contained in more than one section group\n"), + val, section_name (ebl, val)); + } + } + } +} + + +static const char * +section_flags_string (GElf_Word flags, char *buf, size_t len) +{ + if (flags == 0) + return "none"; + + static const struct + { + GElf_Word flag; + const char *name; + } known_flags[] = + { +#define NEWFLAG(name) { SHF_##name, #name } + NEWFLAG (WRITE), + NEWFLAG (ALLOC), + NEWFLAG (EXECINSTR), + NEWFLAG (MERGE), + NEWFLAG (STRINGS), + NEWFLAG (INFO_LINK), + NEWFLAG (LINK_ORDER), + NEWFLAG (OS_NONCONFORMING), + NEWFLAG (GROUP), + NEWFLAG (TLS) + }; +#undef NEWFLAG + const size_t nknown_flags = sizeof (known_flags) / sizeof (known_flags[0]); + + char *cp = buf; + + for (size_t cnt = 0; cnt < nknown_flags; ++cnt) + if (flags & known_flags[cnt].flag) + { + if (cp != buf && len > 1) + { + *cp++ = '|'; + --len; + } + + size_t ncopy = MIN (len - 1, strlen (known_flags[cnt].name)); + cp = mempcpy (cp, known_flags[cnt].name, ncopy); + len -= ncopy; + + flags ^= known_flags[cnt].flag; + } + + if (flags != 0 || cp == buf) + snprintf (cp, len - 1, "%" PRIx64, (uint64_t) flags); + + *cp = '\0'; + + return buf; +} + + +static int +has_copy_reloc (Ebl *ebl, unsigned int symscnndx, unsigned int symndx) +{ + /* First find the relocation section for the symbol table. */ + Elf_Scn *scn = NULL; + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = NULL; + while ((scn = elf_nextscn (ebl->elf, scn)) != NULL) + { + shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr != NULL + && (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA) + && shdr->sh_link == symscnndx) + /* Found the section. */ + break; + } + + if (scn == NULL) + return 0; + + Elf_Data *data = elf_getdata (scn, NULL); + if (data == NULL) + return 0; + + if (shdr->sh_type == SHT_REL) + for (int i = 0; (size_t) i < shdr->sh_size / shdr->sh_entsize; ++i) + { + GElf_Rel rel_mem; + GElf_Rel *rel = gelf_getrel (data, i, &rel_mem); + if (rel == NULL) + continue; + + if (GELF_R_SYM (rel->r_info) == symndx + && ebl_copy_reloc_p (ebl, GELF_R_TYPE (rel->r_info))) + return 1; + } + else + for (int i = 0; (size_t) i < shdr->sh_size / shdr->sh_entsize; ++i) + { + GElf_Rela rela_mem; + GElf_Rela *rela = gelf_getrela (data, i, &rela_mem); + if (rela == NULL) + continue; + + if (GELF_R_SYM (rela->r_info) == symndx + && ebl_copy_reloc_p (ebl, GELF_R_TYPE (rela->r_info))) + return 1; + } + + return 0; +} + + +static int +in_nobits_scn (Ebl *ebl, unsigned int shndx) +{ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (elf_getscn (ebl->elf, shndx), &shdr_mem); + return shdr != NULL && shdr->sh_type == SHT_NOBITS; +} + + +static struct version_namelist +{ + const char *objname; + const char *name; + GElf_Versym ndx; + enum { ver_def, ver_need } type; + struct version_namelist *next; +} *version_namelist; + + +static int +add_version (const char *objname, const char *name, GElf_Versym ndx, int type) +{ + /* Check that there are no duplications. */ + struct version_namelist *nlp = version_namelist; + while (nlp != NULL) + { + if (((nlp->objname == NULL && objname == NULL) + || (nlp->objname != NULL && objname != NULL + && strcmp (nlp->objname, objname) == 0)) + && strcmp (nlp->name, name) == 0) + return nlp->type == ver_def ? 1 : -1; + nlp = nlp->next; + } + + nlp = xmalloc (sizeof (*nlp)); + nlp->objname = objname; + nlp->name = name; + nlp->ndx = ndx; + nlp->type = type; + nlp->next = version_namelist; + version_namelist = nlp; + + return 0; +} + + +static void +check_versym (Ebl *ebl, int idx) +{ + Elf_Scn *scn = elf_getscn (ebl->elf, idx); + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr == NULL) + /* The error has already been reported. */ + return; + + Elf_Data *data = elf_getdata (scn, NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + Elf_Scn *symscn = elf_getscn (ebl->elf, shdr->sh_link); + GElf_Shdr symshdr_mem; + GElf_Shdr *symshdr = gelf_getshdr (symscn, &symshdr_mem); + if (symshdr == NULL) + /* The error has already been reported. */ + return; + + if (symshdr->sh_type != SHT_DYNSYM) + { + ERROR (gettext ("\ +section [%2d] '%s' refers in sh_link to section [%2d] '%s' which is no dynamic symbol table\n"), + idx, section_name (ebl, idx), + shdr->sh_link, section_name (ebl, shdr->sh_link)); + return; + } + + /* The number of elements in the version symbol table must be the + same as the number of symbols. */ + if (shdr->sh_size / shdr->sh_entsize + != symshdr->sh_size / symshdr->sh_entsize) + ERROR (gettext ("\ +section [%2d] '%s' has different number of entries than symbol table [%2d] '%s'\n"), + idx, section_name (ebl, idx), + shdr->sh_link, section_name (ebl, shdr->sh_link)); + + Elf_Data *symdata = elf_getdata (symscn, NULL); + if (symdata == NULL) + /* The error has already been reported. */ + return; + + for (int cnt = 1; (size_t) cnt < shdr->sh_size / shdr->sh_entsize; ++cnt) + { + GElf_Versym versym_mem; + GElf_Versym *versym = gelf_getversym (data, cnt, &versym_mem); + if (versym == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: cannot read version data\n"), + idx, section_name (ebl, idx), cnt); + break; + } + + GElf_Sym sym_mem; + GElf_Sym *sym = gelf_getsym (symdata, cnt, &sym_mem); + if (sym == NULL) + /* Already reported elsewhere. */ + continue; + + if (*versym == VER_NDX_GLOBAL) + { + /* Global symbol. Make sure it is not defined as local. */ + if (GELF_ST_BIND (sym->st_info) == STB_LOCAL) + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: local symbol with global scope\n"), + idx, section_name (ebl, idx), cnt); + } + else if (*versym != VER_NDX_LOCAL) + { + /* Versioned symbol. Make sure it is not defined as local. */ + if (!gnuld && GELF_ST_BIND (sym->st_info) == STB_LOCAL) + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: local symbol with version\n"), + idx, section_name (ebl, idx), cnt); + + /* Look through the list of defined versions and locate the + index we need for this symbol. */ + struct version_namelist *runp = version_namelist; + while (runp != NULL) + if (runp->ndx == (*versym & (GElf_Versym) 0x7fff)) + break; + else + runp = runp->next; + + if (runp == NULL) + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: invalid version index %d\n"), + idx, section_name (ebl, idx), cnt, (int) *versym); + else if (sym->st_shndx == SHN_UNDEF + && runp->type == ver_def) + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: version index %d is for defined version\n"), + idx, section_name (ebl, idx), cnt, (int) *versym); + else if (sym->st_shndx != SHN_UNDEF + && runp->type == ver_need) + { + /* Unless this symbol has a copy relocation associated + this must not happen. */ + if (!has_copy_reloc (ebl, shdr->sh_link, cnt) + && !in_nobits_scn (ebl, sym->st_shndx)) + ERROR (gettext ("\ +section [%2d] '%s': symbol %d: version index %d is for requested version\n"), + idx, section_name (ebl, idx), cnt, (int) *versym); + } + } + } +} + + +static int +unknown_dependency_p (Elf *elf, const char *fname) +{ + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = NULL; + + unsigned int i; + for (i = 0; i < phnum; ++i) + if ((phdr = gelf_getphdr (elf, i, &phdr_mem)) != NULL + && phdr->p_type == PT_DYNAMIC) + break; + + if (i == phnum) + return 1; + assert (phdr != NULL); + Elf_Scn *scn = gelf_offscn (elf, phdr->p_offset); + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + Elf_Data *data = elf_getdata (scn, NULL); + if (shdr != NULL && shdr->sh_type == SHT_DYNAMIC && data != NULL) + for (size_t j = 0; j < shdr->sh_size / shdr->sh_entsize; ++j) + { + GElf_Dyn dyn_mem; + GElf_Dyn *dyn = gelf_getdyn (data, j, &dyn_mem); + if (dyn != NULL && dyn->d_tag == DT_NEEDED) + { + const char *str = elf_strptr (elf, shdr->sh_link, dyn->d_un.d_val); + if (str != NULL && strcmp (str, fname) == 0) + /* Found it. */ + return 0; + } + } + + return 1; +} + + +static unsigned int nverneed; + +static void +check_verneed (Ebl *ebl, GElf_Shdr *shdr, int idx) +{ + if (++nverneed == 2) + ERROR (gettext ("more than one version reference section present\n")); + + GElf_Shdr strshdr_mem; + GElf_Shdr *strshdr = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), + &strshdr_mem); + if (strshdr == NULL) + return; + if (strshdr->sh_type != SHT_STRTAB) + ERROR (gettext ("\ +section [%2d] '%s': sh_link does not link to string table\n"), + idx, section_name (ebl, idx)); + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + unsigned int offset = 0; + for (int cnt = shdr->sh_info; --cnt >= 0; ) + { + /* Get the data at the next offset. */ + GElf_Verneed needmem; + GElf_Verneed *need = gelf_getverneed (data, offset, &needmem); + if (need == NULL) + break; + + unsigned int auxoffset = offset + need->vn_aux; + + if (need->vn_version != EV_CURRENT) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong version %d\n"), + idx, section_name (ebl, idx), cnt, (int) need->vn_version); + + if (need->vn_cnt > 0 && need->vn_aux < gelf_fsize (ebl->elf, ELF_T_VNEED, + 1, EV_CURRENT)) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong offset of auxiliary data\n"), + idx, section_name (ebl, idx), cnt); + + const char *libname = elf_strptr (ebl->elf, shdr->sh_link, + need->vn_file); + if (libname == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': entry %d has invalid file reference\n"), + idx, section_name (ebl, idx), cnt); + goto next_need; + } + + /* Check that there is a DT_NEEDED entry for the referenced library. */ + if (unknown_dependency_p (ebl->elf, libname)) + ERROR (gettext ("\ +section [%2d] '%s': entry %d references unknown dependency\n"), + idx, section_name (ebl, idx), cnt); + + for (int cnt2 = need->vn_cnt; --cnt2 >= 0; ) + { + GElf_Vernaux auxmem; + GElf_Vernaux *aux = gelf_getvernaux (data, auxoffset, &auxmem); + if (aux == NULL) + break; + + if ((aux->vna_flags & ~VER_FLG_WEAK) != 0) + ERROR (gettext ("\ +section [%2d] '%s': auxiliary entry %d of entry %d has unknown flag\n"), + idx, section_name (ebl, idx), need->vn_cnt - cnt2, cnt); + + const char *verstr = elf_strptr (ebl->elf, shdr->sh_link, + aux->vna_name); + if (verstr == NULL) + ERROR (gettext ("\ +section [%2d] '%s': auxiliary entry %d of entry %d has invalid name reference\n"), + idx, section_name (ebl, idx), need->vn_cnt - cnt2, cnt); + else + { + GElf_Word hashval = elf_hash (verstr); + if (hashval != aux->vna_hash) + ERROR (gettext ("\ +section [%2d] '%s': auxiliary entry %d of entry %d has wrong hash value: %#x, expected %#x\n"), + idx, section_name (ebl, idx), need->vn_cnt - cnt2, + cnt, (int) hashval, (int) aux->vna_hash); + + int res = add_version (libname, verstr, aux->vna_other, + ver_need); + if (unlikely (res !=0)) + { + assert (res > 0); + ERROR (gettext ("\ +section [%2d] '%s': auxiliary entry %d of entry %d has duplicate version name '%s'\n"), + idx, section_name (ebl, idx), need->vn_cnt - cnt2, + cnt, verstr); + } + } + + if ((aux->vna_next != 0 || cnt2 > 0) + && aux->vna_next < gelf_fsize (ebl->elf, ELF_T_VNAUX, 1, + EV_CURRENT)) + { + ERROR (gettext ("\ +section [%2d] '%s': auxiliary entry %d of entry %d has wrong next field\n"), + idx, section_name (ebl, idx), need->vn_cnt - cnt2, cnt); + break; + } + + auxoffset += MAX (aux->vna_next, + gelf_fsize (ebl->elf, ELF_T_VNAUX, 1, EV_CURRENT)); + } + + /* Find the next offset. */ + next_need: + offset += need->vn_next; + + if ((need->vn_next != 0 || cnt > 0) + && offset < auxoffset) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has invalid offset to next entry\n"), + idx, section_name (ebl, idx), cnt); + } +} + + +static unsigned int nverdef; + +static void +check_verdef (Ebl *ebl, GElf_Shdr *shdr, int idx) +{ + if (++nverdef == 2) + ERROR (gettext ("more than one version definition section present\n")); + + GElf_Shdr strshdr_mem; + GElf_Shdr *strshdr = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), + &strshdr_mem); + if (strshdr == NULL) + return; + if (strshdr->sh_type != SHT_STRTAB) + ERROR (gettext ("\ +section [%2d] '%s': sh_link does not link to string table\n"), + idx, section_name (ebl, idx)); + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + no_data: + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + /* Iterate over all version definition entries. We check that there + is a BASE entry and that each index is unique. To do the later + we collection the information in a list which is later + examined. */ + struct namelist + { + const char *name; + struct namelist *next; + } *namelist = NULL; + struct namelist *refnamelist = NULL; + + bool has_base = false; + unsigned int offset = 0; + for (int cnt = shdr->sh_info; --cnt >= 0; ) + { + /* Get the data at the next offset. */ + GElf_Verdef defmem; + GElf_Verdef *def = gelf_getverdef (data, offset, &defmem); + if (def == NULL) + goto no_data; + + if ((def->vd_flags & VER_FLG_BASE) != 0) + { + if (has_base) + ERROR (gettext ("\ +section [%2d] '%s': more than one BASE definition\n"), + idx, section_name (ebl, idx)); + if (def->vd_ndx != VER_NDX_GLOBAL) + ERROR (gettext ("\ +section [%2d] '%s': BASE definition must have index VER_NDX_GLOBAL\n"), + idx, section_name (ebl, idx)); + has_base = true; + } + if ((def->vd_flags & ~(VER_FLG_BASE|VER_FLG_WEAK)) != 0) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has unknown flag\n"), + idx, section_name (ebl, idx), cnt); + + if (def->vd_version != EV_CURRENT) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong version %d\n"), + idx, section_name (ebl, idx), cnt, (int) def->vd_version); + + if (def->vd_cnt > 0 && def->vd_aux < gelf_fsize (ebl->elf, ELF_T_VDEF, + 1, EV_CURRENT)) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong offset of auxiliary data\n"), + idx, section_name (ebl, idx), cnt); + + unsigned int auxoffset = offset + def->vd_aux; + GElf_Verdaux auxmem; + GElf_Verdaux *aux = gelf_getverdaux (data, auxoffset, &auxmem); + if (aux == NULL) + goto no_data; + + const char *name = elf_strptr (ebl->elf, shdr->sh_link, aux->vda_name); + if (name == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': entry %d has invalid name reference\n"), + idx, section_name (ebl, idx), cnt); + goto next_def; + } + GElf_Word hashval = elf_hash (name); + if (def->vd_hash != hashval) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong hash value: %#x, expected %#x\n"), + idx, section_name (ebl, idx), cnt, (int) hashval, + (int) def->vd_hash); + + int res = add_version (NULL, name, def->vd_ndx, ver_def); + if (unlikely (res !=0)) + { + assert (res > 0); + ERROR (gettext ("\ +section [%2d] '%s': entry %d has duplicate version name '%s'\n"), + idx, section_name (ebl, idx), cnt, name); + } + + struct namelist *newname = alloca (sizeof (*newname)); + newname->name = name; + newname->next = namelist; + namelist = newname; + + auxoffset += aux->vda_next; + for (int cnt2 = 1; cnt2 < def->vd_cnt; ++cnt2) + { + aux = gelf_getverdaux (data, auxoffset, &auxmem); + if (aux == NULL) + goto no_data; + + name = elf_strptr (ebl->elf, shdr->sh_link, aux->vda_name); + if (name == NULL) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has invalid name reference in auxiliary data\n"), + idx, section_name (ebl, idx), cnt); + else + { + newname = alloca (sizeof (*newname)); + newname->name = name; + newname->next = refnamelist; + refnamelist = newname; + } + + if ((aux->vda_next != 0 || cnt2 + 1 < def->vd_cnt) + && aux->vda_next < gelf_fsize (ebl->elf, ELF_T_VDAUX, 1, + EV_CURRENT)) + { + ERROR (gettext ("\ +section [%2d] '%s': entry %d has wrong next field in auxiliary data\n"), + idx, section_name (ebl, idx), cnt); + break; + } + + auxoffset += MAX (aux->vda_next, + gelf_fsize (ebl->elf, ELF_T_VDAUX, 1, EV_CURRENT)); + } + + /* Find the next offset. */ + next_def: + offset += def->vd_next; + + if ((def->vd_next != 0 || cnt > 0) + && offset < auxoffset) + ERROR (gettext ("\ +section [%2d] '%s': entry %d has invalid offset to next entry\n"), + idx, section_name (ebl, idx), cnt); + } + + if (!has_base) + ERROR (gettext ("section [%2d] '%s': no BASE definition\n"), + idx, section_name (ebl, idx)); + + /* Check whether the referenced names are available. */ + while (namelist != NULL) + { + struct version_namelist *runp = version_namelist; + while (runp != NULL) + { + if (runp->type == ver_def + && strcmp (runp->name, namelist->name) == 0) + break; + runp = runp->next; + } + + if (runp == NULL) + ERROR (gettext ("\ +section [%2d] '%s': unknown parent version '%s'\n"), + idx, section_name (ebl, idx), namelist->name); + + namelist = namelist->next; + } +} + +static void +check_attributes (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + if (shdr->sh_size == 0) + { + ERROR (gettext ("section [%2d] '%s': empty object attributes section\n"), + idx, section_name (ebl, idx)); + return; + } + + Elf_Data *data = elf_rawdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL || data->d_size == 0) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + inline size_t pos (const unsigned char *p) + { + return p - (const unsigned char *) data->d_buf; + } + + const unsigned char *p = data->d_buf; + if (*p++ != 'A') + { + ERROR (gettext ("section [%2d] '%s': unrecognized attribute format\n"), + idx, section_name (ebl, idx)); + return; + } + + inline size_t left (void) + { + return (const unsigned char *) data->d_buf + data->d_size - p; + } + + while (left () >= 4) + { + uint32_t len; + memcpy (&len, p, sizeof len); + + if (len == 0) + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: zero length field in attribute section\n"), + idx, section_name (ebl, idx), pos (p)); + + if (MY_ELFDATA != ehdr->e_ident[EI_DATA]) + CONVERT (len); + + if (len > left ()) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: invalid length in attribute section\n"), + idx, section_name (ebl, idx), pos (p)); + break; + } + + const unsigned char *name = p + sizeof len; + p += len; + + unsigned const char *q = memchr (name, '\0', len); + if (q == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: unterminated vendor name string\n"), + idx, section_name (ebl, idx), pos (p)); + continue; + } + ++q; + + if (q - name == sizeof "gnu" && !memcmp (name, "gnu", sizeof "gnu")) + while (q < p) + { + unsigned const char *chunk = q; + + unsigned int subsection_tag; + get_uleb128 (subsection_tag, q); + + if (q >= p) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: endless ULEB128 in attribute subsection tag\n"), + idx, section_name (ebl, idx), pos (chunk)); + break; + } + + uint32_t subsection_len; + if (p - q < (ptrdiff_t) sizeof subsection_len) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: truncated attribute section\n"), + idx, section_name (ebl, idx), pos (q)); + break; + } + + memcpy (&subsection_len, q, sizeof subsection_len); + if (subsection_len == 0) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: zero length field in attribute subsection\n"), + idx, section_name (ebl, idx), pos (q)); + + q += sizeof subsection_len; + continue; + } + + if (MY_ELFDATA != ehdr->e_ident[EI_DATA]) + CONVERT (subsection_len); + + if (p - chunk < (ptrdiff_t) subsection_len) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: invalid length in attribute subsection\n"), + idx, section_name (ebl, idx), pos (q)); + break; + } + + const unsigned char *subsection_end = chunk + subsection_len; + chunk = q; + q = subsection_end; + + if (subsection_tag != 1) /* Tag_File */ + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: attribute subsection has unexpected tag %u\n"), + idx, section_name (ebl, idx), pos (chunk), subsection_tag); + else + { + chunk += sizeof subsection_len; + while (chunk < q) + { + unsigned int tag; + get_uleb128 (tag, chunk); + + uint64_t value = 0; + const unsigned char *r = chunk; + if (tag == 32 || (tag & 1) == 0) + { + get_uleb128 (value, r); + if (r > q) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: endless ULEB128 in attribute tag\n"), + idx, section_name (ebl, idx), pos (chunk)); + break; + } + } + if (tag == 32 || (tag & 1) != 0) + { + r = memchr (r, '\0', q - r); + if (r == NULL) + { + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: unterminated string in attribute\n"), + idx, section_name (ebl, idx), pos (chunk)); + break; + } + ++r; + } + + const char *tag_name = NULL; + const char *value_name = NULL; + if (!ebl_check_object_attribute (ebl, (const char *) name, + tag, value, + &tag_name, &value_name)) + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: unrecognized attribute tag %u\n"), + idx, section_name (ebl, idx), pos (chunk), tag); + else if ((tag & 1) == 0 && value_name == NULL) + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: unrecognized %s attribute value %" PRIu64 "\n"), + idx, section_name (ebl, idx), pos (chunk), + tag_name, value); + + chunk = r; + } + } + } + else + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: vendor '%s' unknown\n"), + idx, section_name (ebl, idx), pos (p), name); + } + + if (left () != 0) + ERROR (gettext ("\ +section [%2d] '%s': offset %zu: extra bytes after last attribute section\n"), + idx, section_name (ebl, idx), pos (p)); +} + +static bool has_loadable_segment; +static bool has_interp_segment; + +static const struct +{ + const char *name; + size_t namelen; + GElf_Word type; + enum { unused, exact, atleast, exact_or_gnuld } attrflag; + GElf_Word attr; + GElf_Word attr2; +} special_sections[] = + { + /* See figure 4-14 in the gABI. */ + { ".bss", 5, SHT_NOBITS, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".comment", 8, SHT_PROGBITS, atleast, 0, SHF_MERGE | SHF_STRINGS }, + { ".data", 6, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".data1", 7, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".debug_str", 11, SHT_PROGBITS, exact_or_gnuld, SHF_MERGE | SHF_STRINGS, 0 }, + { ".debug", 6, SHT_PROGBITS, exact, 0, 0 }, + { ".dynamic", 9, SHT_DYNAMIC, atleast, SHF_ALLOC, SHF_WRITE }, + { ".dynstr", 8, SHT_STRTAB, exact, SHF_ALLOC, 0 }, + { ".dynsym", 8, SHT_DYNSYM, exact, SHF_ALLOC, 0 }, + { ".fini", 6, SHT_PROGBITS, exact, SHF_ALLOC | SHF_EXECINSTR, 0 }, + { ".fini_array", 12, SHT_FINI_ARRAY, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".got", 5, SHT_PROGBITS, unused, 0, 0 }, // XXX more info? + { ".hash", 6, SHT_HASH, exact, SHF_ALLOC, 0 }, + { ".init", 6, SHT_PROGBITS, exact, SHF_ALLOC | SHF_EXECINSTR, 0 }, + { ".init_array", 12, SHT_INIT_ARRAY, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".interp", 8, SHT_PROGBITS, atleast, 0, SHF_ALLOC }, // XXX more tests? + { ".line", 6, SHT_PROGBITS, exact, 0, 0 }, + { ".note", 6, SHT_NOTE, atleast, 0, SHF_ALLOC }, + { ".plt", 5, SHT_PROGBITS, unused, 0, 0 }, // XXX more tests + { ".preinit_array", 15, SHT_PREINIT_ARRAY, exact, SHF_ALLOC | SHF_WRITE, 0 }, + { ".rela", 5, SHT_RELA, atleast, 0, SHF_ALLOC }, // XXX more tests + { ".rel", 4, SHT_REL, atleast, 0, SHF_ALLOC }, // XXX more tests + { ".rodata", 8, SHT_PROGBITS, atleast, SHF_ALLOC, SHF_MERGE | SHF_STRINGS }, + { ".rodata1", 9, SHT_PROGBITS, atleast, SHF_ALLOC, SHF_MERGE | SHF_STRINGS }, + { ".shstrtab", 10, SHT_STRTAB, exact, 0, 0 }, + { ".strtab", 8, SHT_STRTAB, atleast, 0, SHF_ALLOC }, // XXX more tests + { ".symtab", 8, SHT_SYMTAB, atleast, 0, SHF_ALLOC }, // XXX more tests + { ".symtab_shndx", 14, SHT_SYMTAB_SHNDX, atleast, 0, SHF_ALLOC }, // XXX more tests + { ".tbss", 6, SHT_NOBITS, exact, SHF_ALLOC | SHF_WRITE | SHF_TLS, 0 }, + { ".tdata", 7, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE | SHF_TLS, 0 }, + { ".tdata1", 8, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE | SHF_TLS, 0 }, + { ".text", 6, SHT_PROGBITS, exact, SHF_ALLOC | SHF_EXECINSTR, 0 }, + + /* The following are GNU extensions. */ + { ".gnu.version", 13, SHT_GNU_versym, exact, SHF_ALLOC, 0 }, + { ".gnu.version_d", 15, SHT_GNU_verdef, exact, SHF_ALLOC, 0 }, + { ".gnu.version_r", 15, SHT_GNU_verneed, exact, SHF_ALLOC, 0 }, + { ".gnu.attributes", 16, SHT_GNU_ATTRIBUTES, exact, 0, 0 }, + }; +#define nspecial_sections \ + (sizeof (special_sections) / sizeof (special_sections[0])) + +#define IS_KNOWN_SPECIAL(idx, string, prefix) \ + (special_sections[idx].namelen == sizeof string - (prefix ? 1 : 0) \ + && !memcmp (special_sections[idx].name, string, \ + sizeof string - (prefix ? 1 : 0))) + + +/* Indeces of some sections we need later. */ +static size_t eh_frame_hdr_scnndx; +static size_t eh_frame_scnndx; +static size_t gcc_except_table_scnndx; + + +static void +check_sections (Ebl *ebl, GElf_Ehdr *ehdr) +{ + if (ehdr->e_shoff == 0) + /* No section header. */ + return; + + /* Allocate array to count references in section groups. */ + scnref = (int *) xcalloc (shnum, sizeof (int)); + + /* Check the zeroth section first. It must not have any contents + and the section header must contain nonzero value at most in the + sh_size and sh_link fields. */ + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (elf_getscn (ebl->elf, 0), &shdr_mem); + if (shdr == NULL) + ERROR (gettext ("cannot get section header of zeroth section\n")); + else + { + if (shdr->sh_name != 0) + ERROR (gettext ("zeroth section has nonzero name\n")); + if (shdr->sh_type != 0) + ERROR (gettext ("zeroth section has nonzero type\n")); + if (shdr->sh_flags != 0) + ERROR (gettext ("zeroth section has nonzero flags\n")); + if (shdr->sh_addr != 0) + ERROR (gettext ("zeroth section has nonzero address\n")); + if (shdr->sh_offset != 0) + ERROR (gettext ("zeroth section has nonzero offset\n")); + if (shdr->sh_addralign != 0) + ERROR (gettext ("zeroth section has nonzero align value\n")); + if (shdr->sh_entsize != 0) + ERROR (gettext ("zeroth section has nonzero entry size value\n")); + + if (shdr->sh_size != 0 && ehdr->e_shnum != 0) + ERROR (gettext ("\ +zeroth section has nonzero size value while ELF header has nonzero shnum value\n")); + + if (shdr->sh_link != 0 && ehdr->e_shstrndx != SHN_XINDEX) + ERROR (gettext ("\ +zeroth section has nonzero link value while ELF header does not signal overflow in shstrndx\n")); + + if (shdr->sh_info != 0 && ehdr->e_phnum != PN_XNUM) + ERROR (gettext ("\ +zeroth section has nonzero link value while ELF header does not signal overflow in phnum\n")); + } + + int *segment_flags = xcalloc (phnum, sizeof segment_flags[0]); + + bool dot_interp_section = false; + + size_t hash_idx = 0; + size_t gnu_hash_idx = 0; + + size_t versym_scnndx = 0; + for (size_t cnt = 1; cnt < shnum; ++cnt) + { + shdr = gelf_getshdr (elf_getscn (ebl->elf, cnt), &shdr_mem); + if (shdr == NULL) + { + ERROR (gettext ("\ +cannot get section header for section [%2zu] '%s': %s\n"), + cnt, section_name (ebl, cnt), elf_errmsg (-1)); + continue; + } + + const char *scnname = elf_strptr (ebl->elf, shstrndx, shdr->sh_name); + + if (scnname == NULL) + ERROR (gettext ("section [%2zu]: invalid name\n"), cnt); + else + { + /* Check whether it is one of the special sections defined in + the gABI. */ + size_t s; + for (s = 0; s < nspecial_sections; ++s) + if (strncmp (scnname, special_sections[s].name, + special_sections[s].namelen) == 0) + { + char stbuf1[100]; + char stbuf2[100]; + char stbuf3[100]; + + GElf_Word good_type = special_sections[s].type; + if (IS_KNOWN_SPECIAL (s, ".plt", false) + && ebl_bss_plt_p (ebl, ehdr)) + good_type = SHT_NOBITS; + + /* In a debuginfo file, any normal section can be SHT_NOBITS. + This is only invalid for DWARF sections and .shstrtab. */ + if (shdr->sh_type != good_type + && (shdr->sh_type != SHT_NOBITS + || !is_debuginfo + || IS_KNOWN_SPECIAL (s, ".debug_str", false) + || IS_KNOWN_SPECIAL (s, ".debug", true) + || IS_KNOWN_SPECIAL (s, ".shstrtab", false))) + ERROR (gettext ("\ +section [%2d] '%s' has wrong type: expected %s, is %s\n"), + (int) cnt, scnname, + ebl_section_type_name (ebl, special_sections[s].type, + stbuf1, sizeof (stbuf1)), + ebl_section_type_name (ebl, shdr->sh_type, + stbuf2, sizeof (stbuf2))); + + if (special_sections[s].attrflag == exact + || special_sections[s].attrflag == exact_or_gnuld) + { + /* Except for the link order and group bit all the + other bits should match exactly. */ + if ((shdr->sh_flags & ~(SHF_LINK_ORDER | SHF_GROUP)) + != special_sections[s].attr + && (special_sections[s].attrflag == exact || !gnuld)) + ERROR (gettext ("\ +section [%2zu] '%s' has wrong flags: expected %s, is %s\n"), + cnt, scnname, + section_flags_string (special_sections[s].attr, + stbuf1, sizeof (stbuf1)), + section_flags_string (shdr->sh_flags + & ~SHF_LINK_ORDER, + stbuf2, sizeof (stbuf2))); + } + else if (special_sections[s].attrflag == atleast) + { + if ((shdr->sh_flags & special_sections[s].attr) + != special_sections[s].attr + || ((shdr->sh_flags & ~(SHF_LINK_ORDER | SHF_GROUP + | special_sections[s].attr + | special_sections[s].attr2)) + != 0)) + ERROR (gettext ("\ +section [%2zu] '%s' has wrong flags: expected %s and possibly %s, is %s\n"), + cnt, scnname, + section_flags_string (special_sections[s].attr, + stbuf1, sizeof (stbuf1)), + section_flags_string (special_sections[s].attr2, + stbuf2, sizeof (stbuf2)), + section_flags_string (shdr->sh_flags + & ~(SHF_LINK_ORDER + | SHF_GROUP), + stbuf3, sizeof (stbuf3))); + } + + if (strcmp (scnname, ".interp") == 0) + { + dot_interp_section = true; + + if (ehdr->e_type == ET_REL) + ERROR (gettext ("\ +section [%2zu] '%s' present in object file\n"), + cnt, scnname); + + if ((shdr->sh_flags & SHF_ALLOC) != 0 + && !has_loadable_segment) + ERROR (gettext ("\ +section [%2zu] '%s' has SHF_ALLOC flag set but there is no loadable segment\n"), + cnt, scnname); + else if ((shdr->sh_flags & SHF_ALLOC) == 0 + && has_loadable_segment) + ERROR (gettext ("\ +section [%2zu] '%s' has SHF_ALLOC flag not set but there are loadable segments\n"), + cnt, scnname); + } + else + { + if (strcmp (scnname, ".symtab_shndx") == 0 + && ehdr->e_type != ET_REL) + ERROR (gettext ("\ +section [%2zu] '%s' is extension section index table in non-object file\n"), + cnt, scnname); + + /* These sections must have the SHF_ALLOC flag set iff + a loadable segment is available. + + .relxxx + .strtab + .symtab + .symtab_shndx + + Check that if there is a reference from the + loaded section these sections also have the + ALLOC flag set. */ +#if 0 + // XXX TODO + if ((shdr->sh_flags & SHF_ALLOC) != 0 + && !has_loadable_segment) + ERROR (gettext ("\ +section [%2zu] '%s' has SHF_ALLOC flag set but there is no loadable segment\n"), + cnt, scnname); + else if ((shdr->sh_flags & SHF_ALLOC) == 0 + && has_loadable_segment) + ERROR (gettext ("\ +section [%2zu] '%s' has SHF_ALLOC flag not set but there are loadable segments\n"), + cnt, scnname); +#endif + } + + break; + } + + /* Remember a few special sections for later. */ + if (strcmp (scnname, ".eh_frame_hdr") == 0) + eh_frame_hdr_scnndx = cnt; + else if (strcmp (scnname, ".eh_frame") == 0) + eh_frame_scnndx = cnt; + else if (strcmp (scnname, ".gcc_except_table") == 0) + gcc_except_table_scnndx = cnt; + } + + if (shdr->sh_entsize != 0 && shdr->sh_size % shdr->sh_entsize) + ERROR (gettext ("\ +section [%2zu] '%s': size not multiple of entry size\n"), + cnt, section_name (ebl, cnt)); + + if (elf_strptr (ebl->elf, shstrndx, shdr->sh_name) == NULL) + ERROR (gettext ("cannot get section header\n")); + + if (shdr->sh_type >= SHT_NUM + && shdr->sh_type != SHT_GNU_ATTRIBUTES + && shdr->sh_type != SHT_GNU_LIBLIST + && shdr->sh_type != SHT_CHECKSUM + && shdr->sh_type != SHT_GNU_verdef + && shdr->sh_type != SHT_GNU_verneed + && shdr->sh_type != SHT_GNU_versym + && ebl_section_type_name (ebl, shdr->sh_type, NULL, 0) == NULL) + ERROR (gettext ("section [%2zu] '%s' has unsupported type %d\n"), + cnt, section_name (ebl, cnt), + (int) shdr->sh_type); + +#define ALL_SH_FLAGS (SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR | SHF_MERGE \ + | SHF_STRINGS | SHF_INFO_LINK | SHF_LINK_ORDER \ + | SHF_OS_NONCONFORMING | SHF_GROUP | SHF_TLS) + if (shdr->sh_flags & ~(GElf_Xword) ALL_SH_FLAGS) + { + GElf_Xword sh_flags = shdr->sh_flags & ~(GElf_Xword) ALL_SH_FLAGS; + if (sh_flags & SHF_MASKPROC) + { + if (!ebl_machine_section_flag_check (ebl, + sh_flags & SHF_MASKPROC)) + ERROR (gettext ("section [%2zu] '%s'" + " contains invalid processor-specific flag(s)" + " %#" PRIx64 "\n"), + cnt, section_name (ebl, cnt), sh_flags & SHF_MASKPROC); + sh_flags &= ~(GElf_Xword) SHF_MASKPROC; + } + if (sh_flags != 0) + ERROR (gettext ("section [%2zu] '%s' contains unknown flag(s)" + " %#" PRIx64 "\n"), + cnt, section_name (ebl, cnt), sh_flags); + } + if (shdr->sh_flags & SHF_TLS) + { + // XXX Correct? + if (shdr->sh_addr != 0 && !gnuld) + ERROR (gettext ("\ +section [%2zu] '%s': thread-local data sections address not zero\n"), + cnt, section_name (ebl, cnt)); + + // XXX TODO more tests!? + } + + if (shdr->sh_link >= shnum) + ERROR (gettext ("\ +section [%2zu] '%s': invalid section reference in link value\n"), + cnt, section_name (ebl, cnt)); + + if (SH_INFO_LINK_P (shdr) && shdr->sh_info >= shnum) + ERROR (gettext ("\ +section [%2zu] '%s': invalid section reference in info value\n"), + cnt, section_name (ebl, cnt)); + + if ((shdr->sh_flags & SHF_MERGE) == 0 + && (shdr->sh_flags & SHF_STRINGS) != 0 + && be_strict) + ERROR (gettext ("\ +section [%2zu] '%s': strings flag set without merge flag\n"), + cnt, section_name (ebl, cnt)); + + if ((shdr->sh_flags & SHF_MERGE) != 0 && shdr->sh_entsize == 0) + ERROR (gettext ("\ +section [%2zu] '%s': merge flag set but entry size is zero\n"), + cnt, section_name (ebl, cnt)); + + if (shdr->sh_flags & SHF_GROUP) + check_scn_group (ebl, cnt); + + if (shdr->sh_flags & SHF_EXECINSTR) + { + switch (shdr->sh_type) + { + case SHT_PROGBITS: + break; + + case SHT_NOBITS: + if (is_debuginfo) + break; + default: + ERROR (gettext ("\ +section [%2zu] '%s' has unexpected type %d for an executable section\n"), + cnt, section_name (ebl, cnt), shdr->sh_type); + break; + } + + if ((shdr->sh_flags & SHF_WRITE) + && !ebl_check_special_section (ebl, cnt, shdr, + section_name (ebl, cnt))) + ERROR (gettext ("\ +section [%2zu] '%s' is both executable and writable\n"), + cnt, section_name (ebl, cnt)); + } + + if (ehdr->e_type != ET_REL && (shdr->sh_flags & SHF_ALLOC) != 0) + { + /* Make sure the section is contained in a loaded segment + and that the initialization part matches NOBITS sections. */ + unsigned int pcnt; + GElf_Phdr phdr_mem; + GElf_Phdr *phdr; + + for (pcnt = 0; pcnt < phnum; ++pcnt) + if ((phdr = gelf_getphdr (ebl->elf, pcnt, &phdr_mem)) != NULL + && ((phdr->p_type == PT_LOAD + && (shdr->sh_flags & SHF_TLS) == 0) + || (phdr->p_type == PT_TLS + && (shdr->sh_flags & SHF_TLS) != 0)) + && phdr->p_offset <= shdr->sh_offset + && (phdr->p_offset + phdr->p_filesz > shdr->sh_offset + || (phdr->p_offset + phdr->p_memsz > shdr->sh_offset + && shdr->sh_type == SHT_NOBITS))) + { + /* Found the segment. */ + if (phdr->p_offset + phdr->p_memsz + < shdr->sh_offset + shdr->sh_size) + ERROR (gettext ("\ +section [%2zu] '%s' not fully contained in segment of program header entry %d\n"), + cnt, section_name (ebl, cnt), pcnt); + + if (shdr->sh_type == SHT_NOBITS) + { + if (shdr->sh_offset < phdr->p_offset + phdr->p_filesz + && !is_debuginfo) + ERROR (gettext ("\ +section [%2zu] '%s' has type NOBITS but is read from the file in segment of program header entry %d\n"), + cnt, section_name (ebl, cnt), pcnt); + } + else + { + const GElf_Off end = phdr->p_offset + phdr->p_filesz; + if (shdr->sh_offset > end || + (shdr->sh_offset == end && shdr->sh_size != 0)) + ERROR (gettext ("\ +section [%2zu] '%s' has not type NOBITS but is not read from the file in segment of program header entry %d\n"), + cnt, section_name (ebl, cnt), pcnt); + } + + if (shdr->sh_type != SHT_NOBITS) + { + if ((shdr->sh_flags & SHF_EXECINSTR) != 0) + { + segment_flags[pcnt] |= PF_X; + if ((phdr->p_flags & PF_X) == 0) + ERROR (gettext ("\ +section [%2zu] '%s' is executable in nonexecutable segment %d\n"), + cnt, section_name (ebl, cnt), pcnt); + } + + if ((shdr->sh_flags & SHF_WRITE) != 0) + { + segment_flags[pcnt] |= PF_W; + if (0 /* XXX vdso images have this */ + && (phdr->p_flags & PF_W) == 0) + ERROR (gettext ("\ +section [%2zu] '%s' is writable in unwritable segment %d\n"), + cnt, section_name (ebl, cnt), pcnt); + } + } + + break; + } + + if (pcnt == phnum) + ERROR (gettext ("\ +section [%2zu] '%s': alloc flag set but section not in any loaded segment\n"), + cnt, section_name (ebl, cnt)); + } + + if (cnt == shstrndx && shdr->sh_type != SHT_STRTAB) + ERROR (gettext ("\ +section [%2zu] '%s': ELF header says this is the section header string table but type is not SHT_TYPE\n"), + cnt, section_name (ebl, cnt)); + + switch (shdr->sh_type) + { + case SHT_DYNSYM: + if (ehdr->e_type == ET_REL) + ERROR (gettext ("\ +section [%2zu] '%s': relocatable files cannot have dynamic symbol tables\n"), + cnt, section_name (ebl, cnt)); + /* FALLTHROUGH */ + case SHT_SYMTAB: + check_symtab (ebl, ehdr, shdr, cnt); + break; + + case SHT_RELA: + check_rela (ebl, ehdr, shdr, cnt); + break; + + case SHT_REL: + check_rel (ebl, ehdr, shdr, cnt); + break; + + case SHT_DYNAMIC: + check_dynamic (ebl, ehdr, shdr, cnt); + break; + + case SHT_SYMTAB_SHNDX: + check_symtab_shndx (ebl, ehdr, shdr, cnt); + break; + + case SHT_HASH: + check_hash (shdr->sh_type, ebl, ehdr, shdr, cnt); + hash_idx = cnt; + break; + + case SHT_GNU_HASH: + check_hash (shdr->sh_type, ebl, ehdr, shdr, cnt); + gnu_hash_idx = cnt; + break; + + case SHT_NULL: + check_null (ebl, shdr, cnt); + break; + + case SHT_GROUP: + check_group (ebl, ehdr, shdr, cnt); + break; + + case SHT_NOTE: + check_note_section (ebl, ehdr, shdr, cnt); + break; + + case SHT_GNU_versym: + /* We cannot process this section now since we have no guarantee + that the verneed and verdef sections have already been read. + Just remember the section index. */ + if (versym_scnndx != 0) + ERROR (gettext ("more than one version symbol table present\n")); + versym_scnndx = cnt; + break; + + case SHT_GNU_verneed: + check_verneed (ebl, shdr, cnt); + break; + + case SHT_GNU_verdef: + check_verdef (ebl, shdr, cnt); + break; + + case SHT_GNU_ATTRIBUTES: + check_attributes (ebl, ehdr, shdr, cnt); + break; + + default: + /* Nothing. */ + break; + } + } + + if (has_interp_segment && !dot_interp_section) + ERROR (gettext ("INTERP program header entry but no .interp section\n")); + + if (!is_debuginfo) + for (unsigned int pcnt = 0; pcnt < phnum; ++pcnt) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = gelf_getphdr (ebl->elf, pcnt, &phdr_mem); + if (phdr != NULL && (phdr->p_type == PT_LOAD || phdr->p_type == PT_TLS)) + { + if ((phdr->p_flags & PF_X) != 0 + && (segment_flags[pcnt] & PF_X) == 0) + ERROR (gettext ("\ +loadable segment [%u] is executable but contains no executable sections\n"), + pcnt); + + if ((phdr->p_flags & PF_W) != 0 + && (segment_flags[pcnt] & PF_W) == 0) + ERROR (gettext ("\ +loadable segment [%u] is writable but contains no writable sections\n"), + pcnt); + } + } + + free (segment_flags); + + if (version_namelist != NULL) + { + if (versym_scnndx == 0) + ERROR (gettext ("\ +no .gnu.versym section present but .gnu.versym_d or .gnu.versym_r section exist\n")); + else + check_versym (ebl, versym_scnndx); + + /* Check for duplicate index numbers. */ + do + { + struct version_namelist *runp = version_namelist->next; + while (runp != NULL) + { + if (version_namelist->ndx == runp->ndx) + { + ERROR (gettext ("duplicate version index %d\n"), + (int) version_namelist->ndx); + break; + } + runp = runp->next; + } + + struct version_namelist *old = version_namelist; + version_namelist = version_namelist->next; + free (old); + } + while (version_namelist != NULL); + } + else if (versym_scnndx != 0) + ERROR (gettext ("\ +.gnu.versym section present without .gnu.versym_d or .gnu.versym_r\n")); + + if (hash_idx != 0 && gnu_hash_idx != 0) + compare_hash_gnu_hash (ebl, ehdr, hash_idx, gnu_hash_idx); + + free (scnref); +} + + +static GElf_Off +check_note_data (Ebl *ebl, const GElf_Ehdr *ehdr, + Elf_Data *data, int shndx, int phndx, GElf_Off start) +{ + size_t offset = 0; + size_t last_offset = 0; + GElf_Nhdr nhdr; + size_t name_offset; + size_t desc_offset; + while (offset < data->d_size + && (offset = gelf_getnote (data, offset, + &nhdr, &name_offset, &desc_offset)) > 0) + { + last_offset = offset; + + /* Make sure it is one of the note types we know about. */ + if (ehdr->e_type == ET_CORE) + switch (nhdr.n_type) + { + case NT_PRSTATUS: + case NT_FPREGSET: + case NT_PRPSINFO: + case NT_TASKSTRUCT: /* NT_PRXREG on Solaris. */ + case NT_PLATFORM: + case NT_AUXV: + case NT_GWINDOWS: + case NT_ASRS: + case NT_PSTATUS: + case NT_PSINFO: + case NT_PRCRED: + case NT_UTSNAME: + case NT_LWPSTATUS: + case NT_LWPSINFO: + case NT_PRFPXREG: + /* Known type. */ + break; + + default: + if (shndx == 0) + ERROR (gettext ("\ +phdr[%d]: unknown core file note type %" PRIu32 " at offset %" PRIu64 "\n"), + phndx, (uint32_t) nhdr.n_type, start + offset); + else + ERROR (gettext ("\ +section [%2d] '%s': unknown core file note type %" PRIu32 + " at offset %Zu\n"), + shndx, section_name (ebl, shndx), + (uint32_t) nhdr.n_type, offset); + } + else + switch (nhdr.n_type) + { + case NT_GNU_ABI_TAG: + case NT_GNU_HWCAP: + case NT_GNU_BUILD_ID: + case NT_GNU_GOLD_VERSION: + break; + + case 0: + /* Linux vDSOs use a type 0 note for the kernel version word. */ + if (nhdr.n_namesz == sizeof "Linux" + && !memcmp (data->d_buf + name_offset, "Linux", sizeof "Linux")) + break; + + default: + if (shndx == 0) + ERROR (gettext ("\ +phdr[%d]: unknown object file note type %" PRIu32 " at offset %Zu\n"), + phndx, (uint32_t) nhdr.n_type, offset); + else + ERROR (gettext ("\ +section [%2d] '%s': unknown object file note type %" PRIu32 + " at offset %Zu\n"), + shndx, section_name (ebl, shndx), + (uint32_t) nhdr.n_type, offset); + } + } + + return last_offset; +} + + +static void +check_note (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Phdr *phdr, int cnt) +{ + if (ehdr->e_type != ET_CORE && ehdr->e_type != ET_REL + && ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + ERROR (gettext ("\ +phdr[%d]: no note entries defined for the type of file\n"), + cnt); + + if (is_debuginfo) + /* The p_offset values in a separate debug file are bogus. */ + return; + + if (phdr->p_filesz == 0) + return; + + GElf_Off notes_size = 0; + Elf_Data *data = elf_getdata_rawchunk (ebl->elf, + phdr->p_offset, phdr->p_filesz, + ELF_T_NHDR); + if (data != NULL) + notes_size = check_note_data (ebl, ehdr, data, 0, cnt, phdr->p_offset); + + if (notes_size == 0) + ERROR (gettext ("phdr[%d]: cannot get content of note section: %s\n"), + cnt, elf_errmsg (-1)); + else if (notes_size != phdr->p_filesz) + ERROR (gettext ("phdr[%d]: extra %" PRIu64 " bytes after last note\n"), + cnt, phdr->p_filesz - notes_size); +} + + +static void +check_note_section (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx) +{ + if (shdr->sh_size == 0) + return; + + Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL); + if (data == NULL) + { + ERROR (gettext ("section [%2d] '%s': cannot get section data\n"), + idx, section_name (ebl, idx)); + return; + } + + if (ehdr->e_type != ET_CORE && ehdr->e_type != ET_REL + && ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + ERROR (gettext ("\ +section [%2d] '%s': no note entries defined for the type of file\n"), + idx, section_name (ebl, idx)); + + GElf_Off notes_size = check_note_data (ebl, ehdr, data, idx, 0, 0); + + if (notes_size == 0) + ERROR (gettext ("section [%2d] '%s': cannot get content of note section\n"), + idx, section_name (ebl, idx)); + else if (notes_size != shdr->sh_size) + ERROR (gettext ("section [%2d] '%s': extra %" PRIu64 + " bytes after last note\n"), + idx, section_name (ebl, idx), shdr->sh_size - notes_size); +} + + +/* Index of the PT_GNU_EH_FRAME program eader entry. */ +static int pt_gnu_eh_frame_pndx; + + +static void +check_program_header (Ebl *ebl, GElf_Ehdr *ehdr) +{ + if (ehdr->e_phoff == 0) + return; + + if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN + && ehdr->e_type != ET_CORE) + ERROR (gettext ("\ +only executables, shared objects, and core files can have program headers\n")); + + int num_pt_interp = 0; + int num_pt_tls = 0; + int num_pt_relro = 0; + + for (unsigned int cnt = 0; cnt < phnum; ++cnt) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr; + + phdr = gelf_getphdr (ebl->elf, cnt, &phdr_mem); + if (phdr == NULL) + { + ERROR (gettext ("cannot get program header entry %d: %s\n"), + cnt, elf_errmsg (-1)); + continue; + } + + if (phdr->p_type >= PT_NUM && phdr->p_type != PT_GNU_EH_FRAME + && phdr->p_type != PT_GNU_STACK && phdr->p_type != PT_GNU_RELRO + /* Check for a known machine-specific type. */ + && ebl_segment_type_name (ebl, phdr->p_type, NULL, 0) == NULL) + ERROR (gettext ("\ +program header entry %d: unknown program header entry type %#" PRIx64 "\n"), + cnt, (uint64_t) phdr->p_type); + + if (phdr->p_type == PT_LOAD) + has_loadable_segment = true; + else if (phdr->p_type == PT_INTERP) + { + if (++num_pt_interp != 1) + { + if (num_pt_interp == 2) + ERROR (gettext ("\ +more than one INTERP entry in program header\n")); + } + has_interp_segment = true; + } + else if (phdr->p_type == PT_TLS) + { + if (++num_pt_tls == 2) + ERROR (gettext ("more than one TLS entry in program header\n")); + } + else if (phdr->p_type == PT_NOTE) + check_note (ebl, ehdr, phdr, cnt); + else if (phdr->p_type == PT_DYNAMIC) + { + if (ehdr->e_type == ET_EXEC && ! has_interp_segment) + ERROR (gettext ("\ +static executable cannot have dynamic sections\n")); + else + { + /* Check that the .dynamic section, if it exists, has + the same address. */ + Elf_Scn *scn = NULL; + while ((scn = elf_nextscn (ebl->elf, scn)) != NULL) + { + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr != NULL && shdr->sh_type == SHT_DYNAMIC) + { + if (phdr->p_offset != shdr->sh_offset) + ERROR (gettext ("\ +dynamic section reference in program header has wrong offset\n")); + if (phdr->p_memsz != shdr->sh_size) + ERROR (gettext ("\ +dynamic section size mismatch in program and section header\n")); + break; + } + } + } + } + else if (phdr->p_type == PT_GNU_RELRO) + { + if (++num_pt_relro == 2) + ERROR (gettext ("\ +more than one GNU_RELRO entry in program header\n")); + else + { + /* Check that the region is in a writable segment. */ + unsigned int inner; + for (inner = 0; inner < phnum; ++inner) + { + GElf_Phdr phdr2_mem; + GElf_Phdr *phdr2; + + phdr2 = gelf_getphdr (ebl->elf, inner, &phdr2_mem); + if (phdr2 == NULL) + continue; + + if (phdr2->p_type == PT_LOAD + && phdr->p_vaddr >= phdr2->p_vaddr + && (phdr->p_vaddr + phdr->p_memsz + <= phdr2->p_vaddr + phdr2->p_memsz)) + { + if ((phdr2->p_flags & PF_W) == 0) + ERROR (gettext ("\ +loadable segment GNU_RELRO applies to is not writable\n")); + if ((phdr2->p_flags & ~PF_W) != (phdr->p_flags & ~PF_W)) + ERROR (gettext ("\ +loadable segment [%u] flags do not match GNU_RELRO [%u] flags\n"), + cnt, inner); + break; + } + } + + if (inner >= phnum) + ERROR (gettext ("\ +%s segment not contained in a loaded segment\n"), "GNU_RELRO"); + } + } + else if (phdr->p_type == PT_PHDR) + { + /* Check that the region is in a writable segment. */ + unsigned int inner; + for (inner = 0; inner < phnum; ++inner) + { + GElf_Phdr phdr2_mem; + GElf_Phdr *phdr2; + + phdr2 = gelf_getphdr (ebl->elf, inner, &phdr2_mem); + if (phdr2 != NULL + && phdr2->p_type == PT_LOAD + && phdr->p_vaddr >= phdr2->p_vaddr + && (phdr->p_vaddr + phdr->p_memsz + <= phdr2->p_vaddr + phdr2->p_memsz)) + break; + } + + if (inner >= phnum) + ERROR (gettext ("\ +%s segment not contained in a loaded segment\n"), "PHDR"); + + /* Check that offset in segment corresponds to offset in ELF + header. */ + if (phdr->p_offset != ehdr->e_phoff) + ERROR (gettext ("\ +program header offset in ELF header and PHDR entry do not match")); + } + else if (phdr->p_type == PT_GNU_EH_FRAME) + { + /* If there is an .eh_frame_hdr section it must be + referenced by this program header entry. */ + Elf_Scn *scn = NULL; + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = NULL; + bool any = false; + while ((scn = elf_nextscn (ebl->elf, scn)) != NULL) + { + any = true; + shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr != NULL + && shdr->sh_type == (is_debuginfo + ? SHT_NOBITS : SHT_PROGBITS) + && ! strcmp (".eh_frame_hdr", + elf_strptr (ebl->elf, shstrndx, shdr->sh_name))) + { + if (! is_debuginfo) + { + if (phdr->p_offset != shdr->sh_offset) + ERROR (gettext ("\ +call frame search table reference in program header has wrong offset\n")); + if (phdr->p_memsz != shdr->sh_size) + ERROR (gettext ("\ +call frame search table size mismatch in program and section header\n")); + } + break; + } + } + + if (scn == NULL) + { + /* If there is no section header table we don't + complain. But if there is one there should be an + entry for .eh_frame_hdr. */ + if (any) + ERROR (gettext ("\ +PT_GNU_EH_FRAME present but no .eh_frame_hdr section\n")); + } + else + { + /* The section must be allocated and not be writable and + executable. */ + if ((phdr->p_flags & PF_R) == 0) + ERROR (gettext ("\ +call frame search table must be allocated\n")); + else if (shdr != NULL && (shdr->sh_flags & SHF_ALLOC) == 0) + ERROR (gettext ("\ +section [%2zu] '%s' must be allocated\n"), elf_ndxscn (scn), ".eh_frame_hdr"); + + if ((phdr->p_flags & PF_W) != 0) + ERROR (gettext ("\ +call frame search table must not be writable\n")); + else if (shdr != NULL && (shdr->sh_flags & SHF_WRITE) != 0) + ERROR (gettext ("\ +section [%2zu] '%s' must not be writable\n"), + elf_ndxscn (scn), ".eh_frame_hdr"); + + if ((phdr->p_flags & PF_X) != 0) + ERROR (gettext ("\ +call frame search table must not be executable\n")); + else if (shdr != NULL && (shdr->sh_flags & SHF_EXECINSTR) != 0) + ERROR (gettext ("\ +section [%2zu] '%s' must not be executable\n"), + elf_ndxscn (scn), ".eh_frame_hdr"); + } + + /* Remember which entry this is. */ + pt_gnu_eh_frame_pndx = cnt; + } + + if (phdr->p_filesz > phdr->p_memsz + && (phdr->p_memsz != 0 || phdr->p_type != PT_NOTE)) + ERROR (gettext ("\ +program header entry %d: file size greater than memory size\n"), + cnt); + + if (phdr->p_align > 1) + { + if (!powerof2 (phdr->p_align)) + ERROR (gettext ("\ +program header entry %d: alignment not a power of 2\n"), cnt); + else if ((phdr->p_vaddr - phdr->p_offset) % phdr->p_align != 0) + ERROR (gettext ("\ +program header entry %d: file offset and virtual address not module of alignment\n"), cnt); + } + } +} + + +static void +check_exception_data (Ebl *ebl __attribute__ ((unused)), + GElf_Ehdr *ehdr __attribute__ ((unused))) +{ + if ((ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN) + && pt_gnu_eh_frame_pndx == 0 && eh_frame_hdr_scnndx != 0) + ERROR (gettext ("executable/DSO with .eh_frame_hdr section does not have " + "a PT_GNU_EH_FRAME program header entry")); +} + + +/* Process one file. */ +static void +process_elf_file (Elf *elf, const char *prefix, const char *suffix, + const char *fname, size_t size, bool only_one) +{ + /* Reset variables. */ + ndynamic = 0; + nverneed = 0; + nverdef = 0; + textrel = false; + needed_textrel = false; + has_loadable_segment = false; + has_interp_segment = false; + + GElf_Ehdr ehdr_mem; + GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); + Ebl *ebl; + + /* Print the file name. */ + if (!only_one) + { + if (prefix != NULL) + printf ("\n%s(%s)%s:\n", prefix, fname, suffix); + else + printf ("\n%s:\n", fname); + } + + if (ehdr == NULL) + { + ERROR (gettext ("cannot read ELF header: %s\n"), elf_errmsg (-1)); + return; + } + + ebl = ebl_openbackend (elf); + /* If there is no appropriate backend library we cannot test + architecture and OS specific features. Any encountered extension + is an error. */ + + /* Go straight by the gABI, check all the parts in turn. */ + check_elf_header (ebl, ehdr, size); + + /* Check the program header. */ + check_program_header (ebl, ehdr); + + /* Next the section headers. It is OK if there are no section + headers at all. */ + check_sections (ebl, ehdr); + + /* Check the exception handling data, if it exists. */ + if (pt_gnu_eh_frame_pndx != 0 || eh_frame_hdr_scnndx != 0 + || eh_frame_scnndx != 0 || gcc_except_table_scnndx != 0) + check_exception_data (ebl, ehdr); + + /* Report if no relocation section needed the text relocation flag. */ + if (textrel && !needed_textrel) + ERROR (gettext ("text relocation flag set but not needed\n")); + + /* Free the resources. */ + ebl_closebackend (ebl); +} + + +#include "debugpred.h" |