diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | elf/Makefile | 35 | ||||
| -rw-r--r-- | elf/check-localplt.c | 298 | ||||
| -rw-r--r-- | scripts/localplt.awk | 59 |
4 files changed, 90 insertions, 312 deletions
@@ -1,5 +1,15 @@ 2012-05-01 Roland McGrath <roland@hack.frob.com> + * scripts/localplt.awk: New file. + * elf/Makefile ($(objpfx)check-localplt): Target removed. + (check-localplt-CFLAGS): Variable removed. + ($(all-built-dso:=.jmprel)): New static pattern rule. + (generated): Add those targets. + (localplt-built-dso): New variable. + ($(objpfx)check-localplt.out): Use the script on the .jmprel files. + + * elf/check-localplt.c: File removed. + * scripts/check-execstack.awk: New file. * elf/Makefile ($(objpfx)check-execstack): Target removed. (check-execstack-CFLAGS): Variable removed. diff --git a/elf/Makefile b/elf/Makefile index c207b53..0b5359f 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -872,10 +872,6 @@ CFLAGS-tst-pie1.c += $(pie-ccflag) $(objpfx)tst-pie1: $(objpfx)tst-piemod1.so -check-localplt-CFLAGS = -O -Wall -D_GNU_SOURCE -std=gnu99 -$(objpfx)check-localplt: check-localplt.c - $(native-compile) - ifeq (yes,$(build-shared)) tests: $(objpfx)check-textrel.out $(objpfx)check-execstack.out @@ -927,6 +923,13 @@ generated += check-execstack.out $(objpfx)tst-dlmodcount: $(libdl) $(objpfx)tst-dlmodcount.out: $(test-modules) +$(all-built-dso:=.jmprel): %.jmprel: % Makefile + @rm -f $@T + LC_ALL=C $(READELF) -W -S -d -r $< > $@T + test -s $@T + mv -f $@T $@ +generated += $(all-built-dso:=.jmprel) + check-data := $(firstword $(wildcard \ $(foreach D,$(add-ons) scripts,\ $(patsubst %,$(..)$D/data/localplt-%.data,\ @@ -938,20 +941,24 @@ check-data := $(firstword $(wildcard \ tests: $(objpfx)check-localplt.out +localplt-built-dso := $(addprefix $(common-objpfx),\ + libc.so \ + math/libm.so \ + rt/librt.so \ + dlfcn/libdl.so \ + resolv/libresolv.so \ + crypt/libcrypt.so \ + ) ifeq ($(have-thread-library),yes) -thread-dso := $(filter-out %_nonshared.a, $(shared-thread-library)) +localplt-built-dso += $(filter-out %_nonshared.a, $(shared-thread-library)) endif -$(objpfx)check-localplt.out: $(objpfx)check-localplt \ - $(common-objpfx)libc.so \ - $(common-objpfx)math/libm.so $(thread-dso) \ - $(common-objpfx)rt/librt.so \ - $(common-objpfx)dlfcn/libdl.so \ - $(common-objpfx)resolv/libresolv.so \ - $(common-objpfx)crypt/libcrypt.so \ +$(objpfx)check-localplt.out: $(..)scripts/check-localplt.awk \ + $(..)scripts/localplt.awk \ + $(localplt-built-dso:=.jmprel) \ $(check-data) - $(dir $<)$(notdir $<) $(filter-out $< $(check-data),$^) | \ - $(AWK) -f $(..)scripts/check-localplt.awk $(check-data) - + LC_ALL=C $(AWK) -f $(filter-out $< $(check-data),$^) | \ + LC_ALL=C $(AWK) -f $< $(check-data) - endif $(objpfx)tst-dlopenrpathmod.so: $(libdl) diff --git a/elf/check-localplt.c b/elf/check-localplt.c deleted file mode 100644 index edab1d2..0000000 --- a/elf/check-localplt.c +++ /dev/null @@ -1,298 +0,0 @@ -/* Show local PLT use in DSOs. - Copyright (C) 2006 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contribute by Ulrich Drepper <drepper@redhat.com>. 2006. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <byteswap.h> -#include <elf.h> -#include <endian.h> -#include <fcntl.h> -#include <stdint.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - - -#ifdef BITS - -# define AB(name) _AB (name, BITS) -# define _AB(name, bits) __AB (name, bits) -# define __AB(name, bits) name##bits -# define E(name) _E (name, BITS) -# define _E(name, bits) __E (name, bits) -# define __E(name, bits) Elf##bits##_##name -# define EE(name) _EE (name, BITS) -# define _EE(name, bits) __EE (name, bits) -# define __EE(name, bits) ELF##bits##_##name -# define SWAP(val) \ - ({ __typeof (val) __res; \ - if (((ehdr.e_ident[EI_DATA] == ELFDATA2MSB \ - && BYTE_ORDER == LITTLE_ENDIAN) \ - || (ehdr.e_ident[EI_DATA] == ELFDATA2LSB \ - && BYTE_ORDER == BIG_ENDIAN)) \ - && sizeof (val) != 1) \ - { \ - if (sizeof (val) == 2) \ - __res = bswap_16 (val); \ - else if (sizeof (val) == 4) \ - __res = bswap_32 (val); \ - else \ - __res = bswap_64 (val); \ - } \ - else \ - __res = (val); \ - __res; }) - - -static int -AB(handle_file) (const char *fname, int fd) -{ - E(Ehdr) ehdr; - - if (pread (fd, &ehdr, sizeof (ehdr), 0) != sizeof (ehdr)) - { - read_error: - printf ("%s: read error: %m\n", fname); - return 1; - } - - const size_t phnum = SWAP (ehdr.e_phnum); - const size_t phentsize = SWAP (ehdr.e_phentsize); - - /* Read the program header. */ - E(Phdr) *phdr = alloca (phentsize * phnum); - if (pread (fd, phdr, phentsize * phnum, SWAP (ehdr.e_phoff)) - != phentsize * phnum) - goto read_error; - - /* Search for the PT_DYNAMIC entry. */ - size_t cnt; - E(Phdr) *dynphdr = NULL; - for (cnt = 0; cnt < phnum; ++cnt) - if (SWAP (phdr[cnt].p_type) == PT_DYNAMIC) - { - dynphdr = &phdr[cnt]; - break; - } - - if (dynphdr == NULL) - { - printf ("%s: no DYNAMIC segment found\n", fname); - return 1; - } - - /* Read the dynamic segment. */ - size_t pmemsz = SWAP(dynphdr->p_memsz); - E(Dyn) *dyn = alloca (pmemsz); - if (pread64 (fd, dyn, pmemsz, SWAP(dynphdr->p_offset)) != pmemsz) - goto read_error; - - /* Search for an DT_PLTREL, DT_JMPREL, DT_PLTRELSZ, DT_STRTAB, - DT_STRSZ, and DT_SYMTAB entries. */ - size_t pltrel_idx = SIZE_MAX; - size_t jmprel_idx = SIZE_MAX; - size_t pltrelsz_idx = SIZE_MAX; - size_t strtab_idx = SIZE_MAX; - size_t strsz_idx = SIZE_MAX; - size_t symtab_idx = SIZE_MAX; - for (cnt = 0; (cnt + 1) * sizeof (E(Dyn)) - 1 < pmemsz; ++cnt) - { - unsigned int tag = SWAP (dyn[cnt].d_tag); - - if (tag == DT_NULL) - /* We reached the end. */ - break; - - if (tag == DT_PLTREL) - pltrel_idx = cnt; - else if (tag == DT_JMPREL) - jmprel_idx = cnt; - else if (tag == DT_PLTRELSZ) - pltrelsz_idx = cnt; - else if (tag == DT_STRTAB) - strtab_idx = cnt; - else if (tag == DT_STRSZ) - strsz_idx = cnt; - else if (tag == DT_SYMTAB) - symtab_idx = cnt; - } - - if (pltrel_idx == SIZE_MAX || jmprel_idx == SIZE_MAX - || pltrelsz_idx == SIZE_MAX || strtab_idx == SIZE_MAX - || strsz_idx == SIZE_MAX || symtab_idx == SIZE_MAX) - { - puts ("not all PLT information found"); - return 1; - } - - E(Xword) relsz = SWAP (dyn[pltrelsz_idx].d_un.d_val); - - void *relmem = NULL; - char *strtab = NULL; - E(Xword) symtab_offset = 0; - - /* Find the offset of DT_JMPREL and load the data. */ - for (cnt = 0; cnt < phnum; ++cnt) - if (SWAP (phdr[cnt].p_type) == PT_LOAD) - { - E(Addr) vaddr = SWAP (phdr[cnt].p_vaddr); - E(Xword) memsz = SWAP (phdr[cnt].p_memsz); - - if (vaddr <= SWAP (dyn[jmprel_idx].d_un.d_val) - && vaddr + memsz >= SWAP (dyn[jmprel_idx].d_un.d_val) + relsz) - { - relmem = alloca (SWAP (dyn[pltrelsz_idx].d_un.d_val)); - if (pread64 (fd, relmem, relsz, - SWAP (phdr[cnt].p_offset) - + SWAP (dyn[jmprel_idx].d_un.d_val) - vaddr) - != relsz) - { - puts ("cannot read JMPREL"); - return 1; - } - } - - if (vaddr <= SWAP (dyn[symtab_idx].d_un.d_val) - && vaddr + memsz > SWAP (dyn[symtab_idx].d_un.d_val)) - symtab_offset = (SWAP (phdr[cnt].p_offset) - + SWAP (dyn[symtab_idx].d_un.d_val) - vaddr); - - if (vaddr <= SWAP (dyn[strtab_idx].d_un.d_val) - && vaddr + memsz >= (SWAP (dyn[strtab_idx].d_un.d_val) - + SWAP(dyn[strsz_idx].d_un.d_val))) - { - strtab = alloca (SWAP(dyn[strsz_idx].d_un.d_val)); - if (pread64 (fd, strtab, SWAP(dyn[strsz_idx].d_un.d_val), - SWAP (phdr[cnt].p_offset) - + SWAP (dyn[strtab_idx].d_un.d_val) - vaddr) - != SWAP(dyn[strsz_idx].d_un.d_val)) - { - puts ("cannot read STRTAB"); - return 1; - } - } - } - - if (relmem == NULL || strtab == NULL || symtab_offset == 0) - { - puts ("couldn't load PLT data"); - return 1; - } - - if (SWAP (dyn[pltrel_idx].d_un.d_val) == DT_RELA) - for (E(Rela) *rela = relmem; (char *) rela - (char *) relmem < relsz; - ++rela) - { - E(Sym) sym; - - if (pread64 (fd, &sym, sizeof (sym), - symtab_offset - + EE(R_SYM) (SWAP (rela->r_info)) * sizeof (sym)) - != sizeof (sym)) - { - puts ("cannot read symbol"); - return 1; - } - - if (sym.st_value != 0) - /* This symbol is locally defined. */ - printf ("%s: %s\n", basename (fname), strtab + SWAP (sym.st_name)); - } - else - for (E(Rel) *rel = relmem; (char *) rel - (char *) relmem < relsz; ++rel) - { - E(Sym) sym; - - if (pread64 (fd, &sym, sizeof (sym), - symtab_offset - + EE(R_SYM) (SWAP (rel->r_info)) * sizeof (sym)) - != sizeof (sym)) - { - puts ("cannot read symbol"); - return 1; - } - - if (sym.st_value != 0) - /* This symbol is locally defined. */ - printf ("%s: %s\n", basename (fname), strtab + SWAP (sym.st_name)); - } - - return 0; -} - -# undef BITS -#else - -# define BITS 32 -# include "check-localplt.c" - -# define BITS 64 -# include "check-localplt.c" - - -static int -handle_file (const char *fname) -{ - int fd = open (fname, O_RDONLY); - if (fd == -1) - { - printf ("cannot open %s: %m\n", fname); - return 1; - } - - /* Read was is supposed to be the ELF header. Read the initial - bytes to determine whether this is a 32 or 64 bit file. */ - char ident[EI_NIDENT]; - if (read (fd, ident, EI_NIDENT) != EI_NIDENT) - { - printf ("%s: read error: %m\n", fname); - close (fd); - return 1; - } - - if (memcmp (&ident[EI_MAG0], ELFMAG, SELFMAG) != 0) - { - printf ("%s: not an ELF file\n", fname); - close (fd); - return 1; - } - - int result; - if (ident[EI_CLASS] == ELFCLASS64) - result = handle_file64 (fname, fd); - else - result = handle_file32 (fname, fd); - - close (fd); - - return result; -} - - -int -main (int argc, char *argv[]) -{ - int cnt; - int result = 0; - - for (cnt = 1; cnt < argc; ++cnt) - result |= handle_file (argv[cnt]); - - return result; -} -#endif diff --git a/scripts/localplt.awk b/scripts/localplt.awk new file mode 100644 index 0000000..2265b02 --- /dev/null +++ b/scripts/localplt.awk @@ -0,0 +1,59 @@ +# This awk script expects to get command-line files that are each +# the output of 'readelf -WSdr' on a single shared object, and named +# .../NAME.jmprel where NAME is the unadorned file name of the shared object. +# It writes "NAME: SYMBOL" for each PLT entry in NAME that refers to a +# symbol defined in the same object. + +BEGIN { result = 0 } + +FILENAME != lastfile { + if (lastfile && jmprel_offset == 0) { + print FILENAME ": *** failed to find expected output (readelf -WSdr)"; + result = 2; + } + lastfile = FILENAME; + jmprel_offset = 0; + delete section_offset_by_address; +} + +/^Section Headers:/ { in_shdrs = 1; next } +in_shdrs && !/^ +\[/ { in_shdrs = 0 } + +in_shdrs && /^ +\[/ { sub(/\[ +/, "[") } +in_shdrs { + address = strtonum("0x" $4); + offset = strtonum("0x" $5); + section_offset_by_address[address] = offset; +} + +in_shdrs { next } + +$1 == "Offset" && $2 == "Info" { in_relocs = 1; next } +NF == 0 { in_relocs = 0 } + +in_relocs && relocs_offset == jmprel_offset && NF >= 5 { + symval = strtonum("0x" $4); + if (symval != 0) + print whatfile, $5 +} + +in_relocs { next } + +$1 == "Relocation" && $2 == "section" && $5 == "offset" { + relocs_offset = strtonum($6); + whatfile = gensub(/^.*\/([^/]+)\.jmprel$/, "\\1:", 1, FILENAME); + next +} + +$2 == "(JMPREL)" { + jmprel_addr = strtonum($3); + if (jmprel_addr in section_offset_by_address) { + jmprel_offset = section_offset_by_address[jmprel_addr]; + } else { + print FILENAME ": *** DT_JMPREL does not match any section's address"; + result = 2; + } + next +} + +END { exit(result) } |