When ELF data for a section has been read by elf_rawdata, data_read and rawdata_base are set, but data_list_rear will not be set until the data will be converted (by elf_getdata). elf_newdata would overwrite the existing data in that case.
Add newdata test that calls elf_newdata before and after elf_rawdata and elf_getdata and checks the new size of the section. Signed-off-by: Mark Wielaard <[email protected]> --- libelf/ChangeLog | 4 + libelf/elf_newdata.c | 13 +- tests/ChangeLog | 7 + tests/Makefile.am | 5 +- tests/newdata.c | 365 +++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 390 insertions(+), 4 deletions(-) create mode 100644 tests/newdata.c diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 6699052..36a6031 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,5 +1,9 @@ 2015-01-20 Mark Wielaard <[email protected]> + * elf_newdata.c (elf_newdata): Check scn->rawdata_base. + +2015-01-20 Mark Wielaard <[email protected]> + * elf_strptr.c (elf_strptr): Call __elf[32|64]_getshdr_rdlock if necessary. diff --git a/libelf/elf_newdata.c b/libelf/elf_newdata.c index 90d1813..06baeb5 100644 --- a/libelf/elf_newdata.c +++ b/libelf/elf_newdata.c @@ -1,5 +1,5 @@ /* Create new, empty section data. - Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc. + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2015 Red Hat, Inc. This file is part of elfutils. Contributed by Ulrich Drepper <[email protected]>, 1998. @@ -64,7 +64,16 @@ elf_newdata (Elf_Scn *scn) rwlock_wrlock (scn->elf->lock); - if (scn->data_read && scn->data_list_rear == NULL) + /* data_read is set when data has been read from the ELF image or + when a new section has been created by elf_newscn. If data has + been read from the ELF image, then rawdata_base will point to raw + data. If data_read has been set by elf_newscn, then rawdata_base + will be NULL. data_list_rear will be set by elf_getdata if the + data has been converted, or by this function, elf_newdata, when + new data has been added. */ + if (scn->data_read + && scn->rawdata_base == NULL + && scn->data_list_rear == NULL) { /* This means the section was created by the user and this is the first data. */ diff --git a/tests/ChangeLog b/tests/ChangeLog index f94d9be..d41d0e1 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,5 +1,12 @@ 2015-01-20 Mark Wielaard <[email protected]> + * Makefile.am (check_PROGRAMS): Add newdata. + (TESTS): Likewise. + (newdata_LDADD): new variable. + * newdata.c: New test. + +2015-01-20 Mark Wielaard <[email protected]> + * strptr.c: New file. * run-strptr.sh: New test. * Makefile.am (check_PROGRAMS): Add strptr. diff --git a/tests/Makefile.am b/tests/Makefile.am index c3364a2..4420e8b 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -51,7 +51,7 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \ dwfl-report-elf-align varlocs backtrace backtrace-child \ backtrace-data backtrace-dwarf debuglink debugaltlink \ buildid deleted deleted-lib.so aggregate_size vdsosyms \ - getsrc_die strptr + getsrc_die strptr newdata asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \ asm-tst6 asm-tst7 asm-tst8 asm-tst9 @@ -113,7 +113,7 @@ TESTS = run-arextract.sh run-arsymtest.sh newfile test-nlist \ run-backtrace-demangle.sh run-stack-d-test.sh run-stack-i-test.sh \ run-readelf-dwz-multi.sh run-allfcts-multi.sh run-deleted.sh \ run-linkmap-cut.sh run-aggregate-size.sh vdsosyms run-readelf-A.sh \ - run-getsrc-die.sh run-strptr.sh + run-getsrc-die.sh run-strptr.sh newdata if !BIARCH export ELFUTILS_DISABLE_BIARCH = 1 @@ -426,6 +426,7 @@ aggregate_size_LDADD = $(libdw) $(libelf) vdsosyms_LDADD = $(libdw) $(libelf) getsrc_die_LDADD = $(libdw) $(libelf) strptr_LDADD = $(libelf) +newdata_LDADD = $(libelf) if GCOV check: check-am coverage diff --git a/tests/newdata.c b/tests/newdata.c new file mode 100644 index 0000000..7dfe962 --- /dev/null +++ b/tests/newdata.c @@ -0,0 +1,365 @@ +/* Test program for elf_newdata function. + Copyright (C) 2015 Red Hat, Inc. + This file is part of elfutils. + + This file 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; either version 3 of the License, or + (at your option) any later version. + + 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 this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <errno.h> +#include <fcntl.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include ELFUTILS_HEADER(elf) +#include <gelf.h> + +// Random data string (16 bytes). +static char *DATA = "123456789ABCDEF"; +static size_t DATA_LEN = 16; + +static void +add_section_data (Elf *elf, char *buf, size_t len) +{ + printf ("Adding %zd bytes.\n", len); + + Elf_Scn *scn = elf_getscn (elf, 1); + if (scn == NULL) + { + printf ("couldn't get data section: %s\n", elf_errmsg (-1)); + exit (1); + } + + Elf_Data *data = elf_newdata (scn); + if (data == NULL) + { + printf ("cannot create newdata for section: %s\n", elf_errmsg (-1)); + exit (1); + } + + data->d_buf = buf; + data->d_type = ELF_T_BYTE; + data->d_size = len; + data->d_align = 1; + data->d_version = EV_CURRENT; + + // Let the library compute the internal structure information. + if (elf_update (elf, ELF_C_NULL) < 0) + { + printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1)); + exit (1); + } + +} + +static Elf * +create_elf (int fd, int class) +{ + Elf *elf = elf_begin (fd, ELF_C_WRITE, NULL); + if (elf == NULL) + { + printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1)); + exit (1); + } + + // Create an ELF header. + if (gelf_newehdr (elf, class) == 0) + { + printf ("cannot create ELF header: %s\n", elf_errmsg (-1)); + exit (1); + } + + GElf_Ehdr ehdr_mem; + GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); + if (ehdr == NULL) + { + printf ("cannot get ELF header: %s\n", elf_errmsg (-1)); + exit (1); + } + + // Initialize header. + ehdr->e_ident[EI_DATA] = ELFCLASS32 ? ELFDATA2LSB : ELFDATA2MSB; + ehdr->e_ident[EI_OSABI] = ELFOSABI_GNU; + ehdr->e_type = ET_NONE; + ehdr->e_machine = class == ELFCLASS32 ? EM_PPC : EM_X86_64; + ehdr->e_version = EV_CURRENT; + + // Update the ELF header. + if (gelf_update_ehdr (elf, ehdr) == 0) + { + printf ("cannot update ELF header: %s\n", elf_errmsg (-1)); + exit (1); + } + + // Create a section. + Elf_Scn *scn = elf_newscn (elf); + if (scn == NULL) + { + printf ("cannot create new section: %s\n", elf_errmsg (-1)); + exit (1); + } + + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr == NULL) + { + printf ("cannot get header for data section: %s\n", elf_errmsg (-1)); + exit (1); + } + + shdr->sh_type = SHT_PROGBITS; + shdr->sh_flags = 0; + shdr->sh_addr = 0; + shdr->sh_link = SHN_UNDEF; + shdr->sh_info = SHN_UNDEF; + shdr->sh_addralign = 1; + shdr->sh_entsize = 1; + shdr->sh_name = 0; + + // Finish section, update the header. + if (gelf_update_shdr (scn, shdr) == 0) + { + printf ("cannot update header for DATA section: %s\n", elf_errmsg (-1)); + exit (1); + } + + // Add some data to the section. + add_section_data (elf, DATA, DATA_LEN); + + // Write everything to disk. + if (elf_update (elf, ELF_C_WRITE) < 0) + { + printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1)); + exit (1); + } + + return elf; +} + +static Elf * +read_elf (int fd) +{ + printf ("Reading ELF file\n"); + Elf *elf = elf_begin (fd, ELF_C_RDWR, NULL); + if (elf == NULL) + { + printf ("cannot create ELF descriptor read-again: %s\n", elf_errmsg (-1)); + exit (1); + } + + return elf; +} + +static void +check_section_size (Elf *elf, size_t size) +{ + Elf_Scn *scn = elf_getscn (elf, 1); + if (scn == NULL) + { + printf ("couldn't get data section: %s\n", elf_errmsg (-1)); + exit (1); + } + + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr == NULL) + { + printf ("cannot get header for DATA section: %s\n", elf_errmsg (-1)); + exit (1); + } + + if (shdr->sh_size == size) + printf ("OK %zd bytes.\n", size); + else + { + printf ("BAD size, expected %zd, got %" PRIu64 "\n", + size, shdr->sh_size); + exit (-1); + } +} + +static void +check_elf (int class) +{ + static const char *fname; + fname = class == ELFCLASS32 ? "newdata.elf32" : "newdata.elf64"; + + printf ("check_elf: %s\n", fname); + + int fd = open (fname, O_RDWR|O_CREAT|O_TRUNC, 00666); + if (fd == -1) + { + printf ("cannot create `%s': %s\n", fname, strerror (errno)); + exit (1); + } + + Elf *elf = create_elf (fd, class); + check_section_size (elf, DATA_LEN); + + // Add some more data (won't be written to disk). + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 2 * DATA_LEN); + + if (elf_end (elf) != 0) + { + printf ("failure in elf_end: %s\n", elf_errmsg (-1)); + exit (1); + } + + close (fd); + + // Read the ELF from disk now. And add new data directly. + fd = open (fname, O_RDONLY); + if (fd == -1) + { + printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno)); + exit (1); + } + + elf = read_elf (fd); + check_section_size (elf, DATA_LEN); + + // Add some more data. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 2 * DATA_LEN); + + // And some more. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 3 * DATA_LEN); + + if (elf_end (elf) != 0) + { + printf ("failure in elf_end: %s\n", elf_errmsg (-1)); + exit (1); + } + + close (fd); + + // Read the ELF from disk now. And add new data after raw reading. + fd = open (fname, O_RDONLY); + if (fd == -1) + { + printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno)); + exit (1); + } + + elf = read_elf (fd); + check_section_size (elf, DATA_LEN); + + // Get raw data before adding new data. + Elf_Scn *scn = elf_getscn (elf, 1); + if (scn == NULL) + { + printf ("couldn't get data section: %s\n", elf_errmsg (-1)); + exit (1); + } + + printf ("elf_rawdata\n"); + Elf_Data *data = elf_rawdata (scn, NULL); + if (data == NULL) + { + printf ("couldn't get raw data from section: %s\n", elf_errmsg (-1)); + exit (1); + } + + if (data->d_size != DATA_LEN) + { + printf ("Unexpected Elf_Data: %zd", data->d_size); + exit (1); + } + + // Now add more data. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 2 * DATA_LEN); + + // And some more. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 3 * DATA_LEN); + + if (elf_end (elf) != 0) + { + printf ("failure in elf_end: %s\n", elf_errmsg (-1)); + exit (1); + } + + close (fd); + + // Read the ELF from disk now. And add new data after data reading. + fd = open (fname, O_RDONLY); + if (fd == -1) + { + printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno)); + exit (1); + } + + elf = read_elf (fd); + check_section_size (elf, DATA_LEN); + + // Get raw data before adding new data. + scn = elf_getscn (elf, 1); + if (scn == NULL) + { + printf ("couldn't get data section: %s\n", elf_errmsg (-1)); + exit (1); + } + + printf ("elf_getdata\n"); + data = elf_getdata (scn, NULL); + if (data == NULL) + { + printf ("couldn't get raw data from section: %s\n", elf_errmsg (-1)); + exit (1); + } + + if (data->d_size != DATA_LEN) + { + printf ("Unexpected Elf_Data: %zd", data->d_size); + exit (1); + } + + // Now add more data. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 2 * DATA_LEN); + + // And some more. + add_section_data (elf, DATA, DATA_LEN); + check_section_size (elf, 3 * DATA_LEN); + + if (elf_end (elf) != 0) + { + printf ("failure in elf_end: %s\n", elf_errmsg (-1)); + exit (1); + } + + close (fd); + + unlink (fname); +} + +int +main (int argc __attribute__ ((unused)), char *argv[] __attribute__ ((unused))) +{ + // Initialize libelf. + elf_version (EV_CURRENT); + + check_elf (ELFCLASS32); + check_elf (ELFCLASS64); + + return 0; +} -- 1.8.3.1
