[patch v9 2/5] Test adding and removing a symbol file at runtime.

Nicolas Blanc
2013-06-18T14:47:52Z

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

2013-04-04 Nicolas Blanc <nicolas.blanc@intel.com>

gdb/testsuite
* gdb.base/sym-file-lib.c: 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>
---
gdb/testsuite/gdb.base/sym-file-lib.c | 19 ++
gdb/testsuite/gdb.base/sym-file-main.c | 365 ++++++++++++++++++++++++++++++++
gdb/testsuite/gdb.base/sym-file.exp | 143 +++++++++++++
3 files changed, 527 insertions(+), 0 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/sym-file-lib.c
create mode 100644 gdb/testsuite/gdb.base/sym-file-main.c
create mode 100644 gdb/testsuite/gdb.base/sym-file.exp

diff --git a/gdb/testsuite/gdb.base/sym-file-lib.c b/gdb/testsuite/gdb.base/sym-file-lib.c
new file mode 100644
index 0000000..f9faf8a
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file-lib.c
@@ -0,0 +1,19 @@
+/* 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 */
+
diff --git a/gdb/testsuite/gdb.base/sym-file-main.c b/gdb/testsuite/gdb.base/sym-file-main.c
new file mode 100644
index 0000000..f692ec5
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file-main.c
@@ -0,0 +1,365 @@
+/* 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 <fcntl.h>
+#include </usr/include/elf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#ifdef TARGET_LP64
+typedef Elf64_Phdr Elf_Phdr;
+typedef Elf64_Ehdr Elf_Ehdr;
+typedef Elf64_Shdr Elf_Shdr;
+typedef Elf64_Sym Elf_Sym;
+typedef Elf64_Word Elf_Word;
+
+unsigned char inline elf_st_type (unsigned char st_info)
+{
+ return ELF64_ST_TYPE (st_info);
+}
+#elif defined TARGET_ILP32
+typedef Elf32_Phdr Elf_Phdr;
+typedef Elf32_Ehdr Elf_Ehdr;
+typedef Elf32_Shdr Elf_Shdr;
+typedef Elf32_Sym Elf_Sym;
+typedef Elf32_Word Elf_Word;
+
+unsigned char inline elf_st_type (unsigned char st_info)
+{
+ return ELF32_ST_TYPE (st_info);
+}
+#endif
+
+void gdb_add_symbol_file (void* addr, const char* file)
+{
+ return;
+}
+
+void gdb_remove_symbol_file (void* addr)
+{
+ return;
+}
+
+struct segment
+{
+ char* mapped_addr;
+ Elf_Phdr* phdr;
+ struct segment* next;
+};
+
+/* Load a program segment. */
+
+struct segment* load (char * addr, Elf_Phdr* phdr, struct segment* tail_seg)
+{
+ /* For the sake of simplicity all operations are permitted. */
+ unsigned perm = PROT_READ | PROT_WRITE | PROT_EXEC;
+
+ char* mapped_addr = (char*) mmap ((void*) phdr->p_vaddr,
+ phdr->p_memsz, perm,
+ MAP_ANONYMOUS | MAP_PRIVATE,
+ -1, 0);
+
+ void * from = (void*) (addr + phdr->p_offset);
+ void * to = (void*) mapped_addr;
+
+ memcpy (to, from, phdr->p_filesz);
+
+ struct segment* 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;
+}
+
+/* Load a shared library without calling the standard loader. */
+
+int load_shlib (const char *file, Elf_Ehdr **ehdr_out, struct segment **seg_out)
+{
+ unsigned i = 0;
+
+ /* Map the lib in memory for reading. */
+ int fd = open (file, O_RDONLY);
+ if (fd < 0)
+ {
+ perror ("fopen failed.");
+ return -1;
+ }
+
+ off_t fsize = lseek (fd, 0, SEEK_END);
+
+ if (fsize < 0)
+ {
+ perror ("lseek failed.");
+ return -1;
+ }
+
+ char* addr = (char*) mmap (NULL, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (addr == (char*) -1)
+ {
+ perror ("mmap failed.");
+ return -1;
+ }
+
+ /* Check if the lib is an ELF file. */
+ Elf_Ehdr* ehdr = (Elf_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 (int*) != 4)
+ {
+ printf ("Architecture mismatch.");
+ return -1;
+ }
+ }
+ else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
+ {
+ if (sizeof (int*) != 8)
+ {
+ printf ("Architecture mismatch.");
+ return -1;
+ }
+ }
+
+ /* Load the program segments. For the sake of simplicity
+ assume that no reallocation is needed. */
+ Elf_Phdr* phdr = (Elf_Phdr*) (addr + ehdr->e_phoff);
+ struct segment* head_seg = 0;
+ struct segment* tail_seg = 0;
+ for (i=0; i < ehdr->e_phnum; i++, phdr++)
+ {
+ if (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_Shdr* find_shdrtab (Elf_Ehdr *ehdr)
+{
+ return (Elf_Shdr*) (((char*) ehdr) + ehdr->e_shoff);
+}
+
+/* Return the string table of the section headers. */
+
+const char* find_shstrtab (Elf_Ehdr *ehdr, unsigned *size)
+{
+ const Elf_Shdr *shdr = find_shdrtab (ehdr);
+
+ if (ehdr->e_shnum <= ehdr->e_shstrndx)
+ {
+ printf ("The index of the string table is corrupt.");
+ return NULL;
+ }
+ const Elf_Shdr* shstr = &shdr[ehdr->e_shstrndx];
+ *size = shstr->sh_size;
+ return ((const char*) ehdr) + shstr->sh_offset;
+}
+
+/* Return the string table named SECTION. */
+
+const char* find_strtab (Elf_Ehdr *ehdr,
+ const char* shstrtab, unsigned shstrtab_size,
+ const char* section, unsigned *strtab_size)
+{
+ const Elf_Shdr* shdr = find_shdrtab (ehdr);
+ unsigned i = 0;
+ for (i=0; i < ehdr->e_shnum; i++)
+ {
+ Elf_Word name = shdr[i].sh_name;
+ if (shdr[i].sh_type == SHT_STRTAB && name <= shstrtab_size
+ && strcmp ((const char*) &shstrtab[name], section) == 0)
+ {
+ *strtab_size = shdr[i].sh_size;
+ return ((const char*) ehdr) + shdr[i].sh_offset;
+ }
+
+ }
+ return NULL;
+}
+
+/* Return the section header named SECTION. */
+
+Elf_Shdr* find_shdr (Elf_Ehdr* ehdr, const char *section,
+ const char *shstrtab, unsigned shstrtab_size)
+{
+ Elf_Shdr *shdr = find_shdrtab (ehdr);
+ unsigned i = 0;
+ for (i=0; i < ehdr->e_shnum; i++)
+ {
+ Elf_Word name = 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_Sym* find_symtab (Elf_Ehdr* ehdr, unsigned *symtab_size)
+{
+ unsigned i = 0;
+ const Elf_Shdr *shdr = find_shdrtab (ehdr);
+ for (i=0; i < ehdr->e_shnum; i++)
+ {
+ if (shdr[i].sh_type == SHT_SYMTAB)
+ {
+ *symtab_size = shdr[i].sh_size / sizeof (Elf_Sym);
+ return (Elf_Sym*) (((const char*) ehdr) + shdr[i].sh_offset);
+ }
+ }
+ return NULL;
+}
+
+/* Lookup the offset of FUNC. */
+
+int lookup_function (const char *func,
+ Elf_Sym *symtab, unsigned symtab_size,
+ const char *strtab, unsigned strtab_size,
+ unsigned *offset)
+{
+ unsigned i = 0;
+ for (i=0; i < symtab_size; i++)
+ {
+ Elf_Sym* sym = &symtab[i];
+
+ if (elf_st_type (sym->st_info) != STT_FUNC)
+ continue;
+
+ if (sym->st_name < strtab_size)
+ {
+ const char* name = &strtab[sym->st_name];
+ if (strcmp (name, func) == 0)
+ {
+ *offset = (unsigned) sym->st_value;
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+/* 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_Ehdr *ehdr = 0;
+ struct segment *head_seg = 0;
+
+ if (load_shlib (file, &ehdr, &head_seg) != 0)
+ return -1;
+
+ /* Get the string table for the section headers. */
+ unsigned shstrtab_size = 0;
+ const char* shstrtab = find_shstrtab (ehdr, &shstrtab_size);
+
+ if (shstrtab == NULL)
+ return -1;
+
+ /* Get the text section. */
+ Elf_Shdr* text = find_shdr (ehdr, ".text", shstrtab, shstrtab_size);
+ if (text == NULL)
+ return -1;
+
+ char* base_addr = head_seg->mapped_addr + text->sh_offset;
+
+ /* Notify GDB to add the symbol file. */
+ gdb_add_symbol_file (base_addr, file);
+
+ /* Get the string table for the symbols. */
+ unsigned strtab_size = 0;
+ const char* strtab = find_strtab (ehdr, shstrtab, shstrtab_size,
+ ".strtab", &strtab_size);
+ if (strtab == NULL)
+ {
+ printf (".strtab not found.");
+ return -1;
+ }
+
+ /* Get the symbol table. */
+ unsigned symtab_size = 0;
+ Elf_Sym* symtab = find_symtab (ehdr, &symtab_size);
+ if (symtab == NULL)
+ {
+ printf ("symtab not found.");
+ return -1;
+ }
+
+ /* Call bar from SHLIB_NAME. */
+ unsigned bar_offset = 0;
+ if (lookup_function ("bar",
+ symtab, symtab_size,
+ strtab, strtab_size,
+ &bar_offset) != 0)
+ return -1;
+
+ int (*pbar) () = (int (*) ()) (head_seg->mapped_addr + bar_offset);
+
+ int value1 = (*pbar) ();
+
+ /* Call foo from SHLIB_NAME. */
+ unsigned foo_offset = 0;
+ if (lookup_function ("foo",
+ symtab, symtab_size,
+ strtab, strtab_size,
+ &foo_offset) != 0)
+ return -1;
+
+ int (*pfoo) (int) = (int (*) (int)) (head_seg->mapped_addr + foo_offset);
+
+ int value2 = (*pfoo) (2);
+
+ /* Notify GDB to remove the symbol file. */
+ gdb_remove_symbol_file (base_addr);
+
+ return 0;
+}
+
diff --git a/gdb/testsuite/gdb.base/sym-file.exp b/gdb/testsuite/gdb.base/sym-file.exp
new file mode 100644
index 0000000..873e488
--- /dev/null
+++ b/gdb/testsuite/gdb.base/sym-file.exp
@@ -0,0 +1,143 @@
+# 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 $libsrc.
+# 3) Load $shlib_name using 'add-symbol-file'.
+# 4) Continue to bar in $libsrc.
+# 5) Set a breakpoint at foo in $librc.
+# 6) Continue to foo in $libsrc.
+# 7) Set a breakpoint at gdb_remove_symbol_file.
+# 8) Continue to gdb_remove_symbol_file in $srcfile.
+# 9) Remove $shlib_name using 'remove-symbol-file'.
+# 10) Check that the breakpoints at foo and bar are pending.
+# 11) Check that the execution can continue without error.
+
+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 testfile sym-file.exp
+set mainfile sym-file-main
+set libfile sym-file-lib
+set srcfile ${mainfile}.c
+set libsrc "${srcdir}/${subdir}/${libfile}.c"
+set libname "${libfile}.so"
+set shlib_name "${objdir}/${subdir}/${libname}"
+set libobj "${objdir}/${subdir}/${libname}"
+set exec_opts [list debug "additional_flags=-D$target_size\
+ -DSHLIB_NAME\\=\"$shlib_name\""]
+
+if [get_compiler_info] {
+ return -1
+}
+
+if { [gdb_compile_shlib $libsrc $libobj {debug}] != "" } {
+ untested ${testfile}
+ return
+}
+
+if { [prepare_for_testing ${testfile} ${mainfile} ${srcfile} $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 $libsrc.
+set result [gdb_breakpoint bar allow-pending]
+if { !$result } then {
+ return
+}
+
+# 3) Add $shlib_name using 'add-symbol-file'.
+set result [gdb_test "add-symbol-file ${shlib_name} addr" \
+ "Reading symbols from .*${shlib_name}\\.\\.\\.done\\." \
+ "add-symbol-file ${shlib_name} addr" \
+ "add symbol table from file \".*${shlib_name}\"\
+ at.*\\(y or n\\) " \
+ "y"]
+if { $result != 0 } then {
+ return
+}
+
+# 4) Continue to bar in $libsrc to ensure that the breakpoint
+# was bound correctly after adding $shilb_name.
+set lnum_bar [gdb_get_line_number "break at bar" ${libfile}.c]
+gdb_continue_to_breakpoint bar ".*$libfile\\.c:$lnum_bar.*"
+
+# 5) Set a breakpoint at foo in $libsrc.
+set result [gdb_breakpoint foo]
+if { !$result } then {
+ return
+}
+
+# 6) Continue to foo in $libsrc to ensure that the breakpoint
+# was bound correctly.
+set lnum_foo [gdb_get_line_number "break at foo" ${libfile}.c]
+gdb_continue_to_breakpoint foo ".*$libfile\\.c:$lnum_foo.*"
+
+# 7) 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
+}
+
+# 8) Continue to gdb_remove_symbol_file in $srcfile.
+gdb_continue_to_breakpoint gdb_remove_symbol_file
+
+# 9) Remove $shlib_name using 'remove-symbol-file'.
+set result [gdb_test "remove-symbol-file -a addr" \
+ ""\
+ "remove-symbol-file -a addr" \
+ "Remove symbol table from file \".*${shlib_name}\"\\?\
+.*\\(y or n\\) " \
+ "y"]
+if { $result != 0 } then {
+ return
+}
+
+# 10) 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."
+
+# 11) Check that the execution can continue without error.
+gdb_continue_to_end
+
--
1.7.6.5