Test adding and removing a symbol file at runtime.

This test exercises the commands 'add-symbol-file'
and 'remove-symbol-file'.

2013-10-29  Nicolas Blanc  <nicolas.blanc@intel.com>

gdb/testsuite
	* gdb.base/sym-file-lib.c: New file.
	* gdb.base/sym-file-loader.c: New file.
	* gdb.base/sym-file-loader.h: New file.
	* gdb.base/sym-file-main.c: New file.
	* gdb.base/sym-file.exp: New file.

Signed-off-by: Nicolas Blanc <nicolas.blanc@intel.com>
This commit is contained in:
Nicolas Blanc
2013-07-17 11:44:26 +02:00
parent e9f0e62efd
commit 681f229a9f
5 changed files with 715 additions and 0 deletions

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/* Copyright 2013 Free Software Foundation, Inc.
This program 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.
This program 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/>.
*/
extern int
bar ()
{
return 1; /* gdb break at bar */
}
extern int
foo (int a)
{
return a; /* gdb break at foo */
}

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/* Copyright 2013 Free Software Foundation, Inc.
This program 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.
This program 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/>.
*/
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include "sym-file-loader.h"
#ifdef TARGET_LP64
uint8_t
elf_st_type (uint8_t st_info)
{
return ELF64_ST_TYPE (st_info);
}
#elif defined TARGET_ILP32
uint8_t
elf_st_type (uint8_t st_info)
{
return ELF32_ST_TYPE (st_info);
}
#endif
/* Load a program segment. */
static struct segment *
load (uint8_t *addr, Elf_External_Phdr *phdr, struct segment *tail_seg)
{
struct segment *seg = NULL;
uint8_t *mapped_addr = NULL;
void *from = NULL;
void *to = NULL;
/* For the sake of simplicity all operations are permitted. */
unsigned perm = PROT_READ | PROT_WRITE | PROT_EXEC;
mapped_addr = (uint8_t *) mmap ((void *) GETADDR (phdr, p_vaddr),
GET (phdr, p_memsz), perm,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
from = (void *) (addr + GET (phdr, p_offset));
to = (void *) mapped_addr;
memcpy (to, from, GET (phdr, p_filesz));
seg = (struct segment *) malloc (sizeof (struct segment));
if (seg == 0)
return 0;
seg->mapped_addr = mapped_addr;
seg->phdr = phdr;
seg->next = 0;
if (tail_seg != 0)
tail_seg->next = seg;
return seg;
}
/* Mini shared library loader. No reallocation
is performed for the sake of simplicity. */
int
load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
struct segment **seg_out)
{
uint64_t i;
int fd;
off_t fsize;
uint8_t *addr;
Elf_External_Ehdr *ehdr;
Elf_External_Phdr *phdr;
struct segment *head_seg = NULL;
struct segment *tail_seg = NULL;
/* Map the lib in memory for reading. */
fd = open (file, O_RDONLY);
if (fd < 0)
{
perror ("fopen failed.");
return -1;
}
fsize = lseek (fd, 0, SEEK_END);
if (fsize < 0)
{
perror ("lseek failed.");
return -1;
}
addr = (uint8_t *) mmap (NULL, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
if (addr == (uint8_t *) -1)
{
perror ("mmap failed.");
return -1;
}
/* Check if the lib is an ELF file. */
ehdr = (Elf_External_Ehdr *) addr;
if (ehdr->e_ident[EI_MAG0] != ELFMAG0
|| ehdr->e_ident[EI_MAG1] != ELFMAG1
|| ehdr->e_ident[EI_MAG2] != ELFMAG2
|| ehdr->e_ident[EI_MAG3] != ELFMAG3)
{
printf ("Not an ELF file: %x\n", ehdr->e_ident[EI_MAG0]);
return -1;
}
if (ehdr->e_ident[EI_CLASS] == ELFCLASS32)
{
if (sizeof (void *) != 4)
{
printf ("Architecture mismatch.");
return -1;
}
}
else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
{
if (sizeof (void *) != 8)
{
printf ("Architecture mismatch.");
return -1;
}
}
/* Load the program segments. For the sake of simplicity
assume that no reallocation is needed. */
phdr = (Elf_External_Phdr *) (addr + GET (ehdr, e_phoff));
for (i = 0; i < GET (ehdr, e_phnum); i++, phdr++)
{
if (GET (phdr, p_type) == PT_LOAD)
{
struct segment *next_seg = load (addr, phdr, tail_seg);
if (next_seg == 0)
continue;
tail_seg = next_seg;
if (head_seg == 0)
head_seg = next_seg;
}
}
*ehdr_out = ehdr;
*seg_out = head_seg;
return 0;
}
/* Return the section-header table. */
Elf_External_Shdr *
find_shdrtab (Elf_External_Ehdr *ehdr)
{
return (Elf_External_Shdr *) (((uint8_t *) ehdr) + GET (ehdr, e_shoff));
}
/* Return the string table of the section headers. */
const char *
find_shstrtab (Elf_External_Ehdr *ehdr, uint64_t *size)
{
const Elf_External_Shdr *shdr;
const Elf_External_Shdr *shstr;
if (GET (ehdr, e_shnum) <= GET (ehdr, e_shstrndx))
{
printf ("The index of the string table is corrupt.");
return NULL;
}
shdr = find_shdrtab (ehdr);
shstr = &shdr[GET (ehdr, e_shstrndx)];
*size = GET (shstr, sh_size);
return ((const char *) ehdr) + GET (shstr, sh_offset);
}
/* Return the string table named SECTION. */
const char *
find_strtab (Elf_External_Ehdr *ehdr,
const char *section, uint64_t *strtab_size)
{
uint64_t shstrtab_size = 0;
const char *shstrtab;
uint64_t i;
const Elf_External_Shdr *shdr = find_shdrtab (ehdr);
/* Get the string table of the section headers. */
shstrtab = find_shstrtab (ehdr, &shstrtab_size);
if (shstrtab == NULL)
return NULL;
for (i = 0; i < GET (ehdr, e_shnum); i++)
{
uint64_t name = GET (shdr + i, sh_name);
if (GET (shdr + i, sh_type) == SHT_STRTAB && name <= shstrtab_size
&& strcmp ((const char *) &shstrtab[name], section) == 0)
{
*strtab_size = GET (shdr + i, sh_size);
return ((const char *) ehdr) + GET (shdr + i, sh_offset);
}
}
return NULL;
}
/* Return the section header named SECTION. */
Elf_External_Shdr *
find_shdr (Elf_External_Ehdr *ehdr, const char *section)
{
uint64_t shstrtab_size = 0;
const char *shstrtab;
uint64_t i;
/* Get the string table of the section headers. */
shstrtab = find_shstrtab (ehdr, &shstrtab_size);
if (shstrtab == NULL)
return NULL;
Elf_External_Shdr *shdr = find_shdrtab (ehdr);
for (i = 0; i < GET (ehdr, e_shnum); i++)
{
uint64_t name = GET (shdr + i, sh_name);
if (name <= shstrtab_size)
{
if (strcmp ((const char *) &shstrtab[name], section) == 0)
return &shdr[i];
}
}
return NULL;
}
/* Return the symbol table. */
Elf_External_Sym *
find_symtab (Elf_External_Ehdr *ehdr, uint64_t *symtab_size)
{
uint64_t i;
const Elf_External_Shdr *shdr = find_shdrtab (ehdr);
for (i = 0; i < GET (ehdr, e_shnum); i++)
{
if (GET (shdr + i, sh_type) == SHT_SYMTAB)
{
*symtab_size = GET (shdr + i, sh_size) / sizeof (Elf_External_Sym);
return (Elf_External_Sym *) (((const char *) ehdr) +
GET (shdr + i, sh_offset));
}
}
return NULL;
}
/* Translate a file offset to an address in a loaded segment. */
int
translate_offset (uint64_t file_offset, struct segment *seg, void **addr)
{
while (seg)
{
uint64_t p_from, p_to;
Elf_External_Phdr *phdr = seg->phdr;
if (phdr == NULL)
{
seg = seg->next;
continue;
}
p_from = GET (phdr, p_offset);
p_to = p_from + GET (phdr, p_filesz);
if (p_from <= file_offset && file_offset < p_to)
{
*addr = (void *) (seg->mapped_addr + (file_offset - p_from));
return 0;
}
seg = seg->next;
}
return -1;
}
/* Lookup the address of FUNC. */
int
lookup_function (const char *func,
Elf_External_Ehdr *ehdr, struct segment *seg, void **addr)
{
const char *strtab;
uint64_t strtab_size = 0;
Elf_External_Sym *symtab;
uint64_t symtab_size = 0;
uint64_t i;
/* Get the string table for the symbols. */
strtab = find_strtab (ehdr, ".strtab", &strtab_size);
if (strtab == NULL)
{
printf (".strtab not found.");
return -1;
}
/* Get the symbol table. */
symtab = find_symtab (ehdr, &symtab_size);
if (symtab == NULL)
{
printf ("symbol table not found.");
return -1;
}
for (i = 0; i < symtab_size; i++)
{
Elf_External_Sym *sym = &symtab[i];
if (elf_st_type (GET (sym, st_info)) != STT_FUNC)
continue;
if (GET (sym, st_name) < strtab_size)
{
const char *name = &strtab[GET (sym, st_name)];
if (strcmp (name, func) == 0)
{
uint64_t offset = GET (sym, st_value);
return translate_offset (offset, seg, addr);
}
}
}
return -1;
}

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/* Copyright 2013 Free Software Foundation, Inc.
This program 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.
This program 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/>.
*/
#ifndef __SYM_FILE_LOADER__
#define __SYM_FILE_LOADER__
#include <inttypes.h>
#include <ansidecl.h>
#include <elf/common.h>
#include <elf/external.h>
#ifdef TARGET_LP64
typedef Elf64_External_Phdr Elf_External_Phdr;
typedef Elf64_External_Ehdr Elf_External_Ehdr;
typedef Elf64_External_Shdr Elf_External_Shdr;
typedef Elf64_External_Sym Elf_External_Sym;
typedef uint64_t Elf_Addr;
#elif defined TARGET_ILP32
typedef Elf32_External_Phdr Elf_External_Phdr;
typedef Elf32_External_Ehdr Elf_External_Ehdr;
typedef Elf32_External_Shdr Elf_External_Shdr;
typedef Elf32_External_Sym Elf_External_Sym;
typedef uint32_t Elf_Addr;
#endif
#define GET(hdr, field) (\
sizeof ((hdr)->field) == 1 ? (uint64_t) (hdr)->field[0] : \
sizeof ((hdr)->field) == 2 ? (uint64_t) *(uint16_t *) (hdr)->field : \
sizeof ((hdr)->field) == 4 ? (uint64_t) *(uint32_t *) (hdr)->field : \
sizeof ((hdr)->field) == 8 ? *(uint64_t *) (hdr)->field : \
*(uint64_t *) NULL)
#define GETADDR(hdr, field) (\
sizeof ((hdr)->field) == sizeof (Elf_Addr) ? *(Elf_Addr *) (hdr)->field : \
*(Elf_Addr *) NULL)
struct segment
{
uint8_t *mapped_addr;
Elf_External_Phdr *phdr;
struct segment *next;
};
/* Mini shared library loader. No reallocation is performed
for the sake of simplicity. */
int
load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
struct segment **seg_out);
/* Return the section-header table. */
Elf_External_Shdr *find_shdrtab (Elf_External_Ehdr *ehdr);
/* Return the string table of the section headers. */
const char *find_shstrtab (Elf_External_Ehdr *ehdr, uint64_t *size);
/* Return the string table named SECTION. */
const char *find_strtab (Elf_External_Ehdr *ehdr,
const char *section, uint64_t *strtab_size);
/* Return the section header named SECTION. */
Elf_External_Shdr *find_shdr (Elf_External_Ehdr *ehdr, const char *section);
/* Return the symbol table. */
Elf_External_Sym *find_symtab (Elf_External_Ehdr *ehdr,
uint64_t *symtab_size);
/* Translate a file offset to an address in a loaded segment. */
int translate_offset (uint64_t file_offset, struct segment *seg, void **addr);
/* Lookup the address of FUNC. */
int
lookup_function (const char *func, Elf_External_Ehdr* ehdr,
struct segment *seg, void **addr);
#endif

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/* Copyright 2013 Free Software Foundation, Inc.
This program 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.
This program 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/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include "sym-file-loader.h"
void
gdb_add_symbol_file (void *addr, const char *file)
{
return;
}
void
gdb_remove_symbol_file (void *addr)
{
return;
}
/* Load a shared library without relying on the standard
loader to test GDB's commands for adding and removing
symbol files at runtime. */
int
main (int argc, const char *argv[])
{
const char *file = SHLIB_NAME;
Elf_External_Ehdr *ehdr = NULL;
struct segment *head_seg = NULL;
Elf_External_Shdr *text;
char *text_addr = NULL;
int (*pbar) () = NULL;
int (*pfoo) (int) = NULL;
if (load_shlib (file, &ehdr, &head_seg) != 0)
return -1;
/* Get the text section. */
text = find_shdr (ehdr, ".text");
if (text == NULL)
return -1;
/* Notify GDB to add the symbol file. */
if (translate_offset (GET (text, sh_offset), head_seg, (void **) &text_addr)
!= 0)
return -1;
gdb_add_symbol_file (text_addr, file);
/* Call bar from SHLIB_NAME. */
if (lookup_function ("bar", ehdr, head_seg, (void *) &pbar) != 0)
return -1;
(*pbar) ();
/* Call foo from SHLIB_NAME. */
if (lookup_function ("foo", ehdr, head_seg, (void *) &pfoo) != 0)
return -1;
(*pfoo) (2);
/* Notify GDB to remove the symbol file. */
gdb_remove_symbol_file (text_addr);
return 0;
}

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# Copyright 2013 Free Software Foundation, Inc.
# This program 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.
#
# This program 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/>. */
# Test adding and removing a symbol file dynamically:
# 1) Run to gdb_add_symbol_file in $srcfile.
# 2) Set a pending breakpoint at bar in $srcfile3.
# 3) Load $shlib_name using 'add-symbol-file'.
# 4) 'info files' must display ${lib_basename}.
# 5) Continue to bar in $srcfile3.
# 6) Set a breakpoint at foo in $srcfile3.
# 7) Continue to foo in $srcfile3.
# 8) Set a breakpoint at gdb_remove_symbol_file.
# 9) Continue to gdb_remove_symbol_file in $srcfile.
# 10) Remove $shlib_name using 'remove-symbol-file'.
# 11) 'info files' must not display ${lib_basename}, anymore.
# 12) Check that the breakpoints at foo and bar are pending.
# 13) Check that the execution can continue without error.
if {![is_elf_target]} {
return 0
}
if [skip_shlib_tests] {
return 0
}
if [is_remote target] {
return 0
}
set target_size TARGET_UNKNOWN
if {[is_lp64_target]} {
set target_size TARGET_LP64
} elseif {[is_ilp32_target]} {
set target_size TARGET_ILP32
} else {
return 0
}
set main_basename sym-file-main
set loader_basename sym-file-loader
set lib_basename sym-file-lib
standard_testfile $main_basename.c $loader_basename.c $lib_basename.c
set libsrc "${srcdir}/${subdir}/${srcfile3}"
set shlib_name [standard_output_file ${lib_basename}.so]
set exec_opts [list debug "additional_flags= -I$srcdir/../../include/ -D$target_size\
-DSHLIB_NAME\\=\"$shlib_name\""]
if [get_compiler_info] {
return -1
}
if {[gdb_compile_shlib $libsrc $shlib_name {debug}] != ""} {
untested ${testfile}
return
}
if {[prepare_for_testing $testfile $binfile "$srcfile $srcfile2" $exec_opts]} {
return
}
# 1) Run to GDB_ADD_SYMBOl_FILE in $srcfile for adding
# $shlib_name.
set result [runto gdb_add_symbol_file]
if {!$result} then {
return
}
# 2) Set a pending breakpoint at bar in $srcfile3.
set result [gdb_breakpoint bar allow-pending]
if {!$result} then {
return
}
# 3) Add $shlib_name using 'add-symbol-file'.
set result [gdb_test "add-symbol-file ${shlib_name} addr" \
"Reading symbols from .*${lib_basename}\\.so\\.\\.\\.done\\." \
"add-symbol-file .*${lib_basename}\\.so addr" \
"add symbol table from file \".*${lib_basename}\\.so\"\
at.*\\(y or n\\) " \
"y"]
if {$result != 0} then {
return
}
# 4) 'info files' must display $srcfile3.
gdb_test "info files" \
"^(?=(.*${lib_basename})).*" \
"info files must display ${lib_basename}"
# 5) Continue to bar in $srcfile3 to ensure that the breakpoint
# was bound correctly after adding $shilb_name.
set lnum_bar [gdb_get_line_number "break at bar" $srcfile3]
gdb_continue_to_breakpoint bar ".*${lib_basename}\\.c:$lnum_bar.*"
# 6) Set a breakpoint at foo in $srcfile3.
set result [gdb_breakpoint foo]
if {!$result} then {
return
}
# 7) Continue to foo in $srcfile3 to ensure that the breakpoint
# was bound correctly.
set lnum_foo [gdb_get_line_number "break at foo" $srcfile3]
gdb_continue_to_breakpoint foo ".*${lib_basename}\\.c:$lnum_foo.*"
# 8) Set a breakpoint at gdb_remove_symbol_file in $srcfile for
# removing $shlib_name.
set result [gdb_breakpoint gdb_remove_symbol_file]
if {!$result} then {
return
}
# 9) Continue to gdb_remove_symbol_file in $srcfile.
gdb_continue_to_breakpoint gdb_remove_symbol_file
# 10) Remove $shlib_name using 'remove-symbol-file'.
set result [gdb_test "remove-symbol-file -a addr" \
""\
"remove-symbol-file -a addr" \
"Remove symbol table from file \".*${lib_basename}\\.so\"\\?\
.*\\(y or n\\) " \
"y"]
if {$result != 0} then {
return
}
# 11) 'info files' must not display ${lib_basename}, anymore.
gdb_test "info files" \
"^(?!(.*${lib_basename})).*" \
"info files must not display ${lib_basename}"
# 12) Check that the breakpoints at foo and bar are pending after removing
# $shlib_name.
gdb_test "info breakpoints 2" \
".*PENDING.*" \
"check if Breakpoint 2 is pending."
gdb_test "info breakpoints 3" \
".*PENDING.*" \
"check if Breakpoint 3 is pending."
# 13) Check that the execution can continue without error.
gdb_continue_to_end