The following testcases make GDB crash whenever an invalid sysroot is
provided, when GDB is unable to find a valid path to the symbol file:
gdb.base/catch-syscall.exp
gdb.base/execl-update-breakpoints.exp
gdb.base/foll-exec-mode.exp
gdb.base/foll-exec.exp
gdb.base/foll-vfork.exp
gdb.base/pie-execl.exp
gdb.multi/bkpt-multi-exec.exp
gdb.python/py-finish-breakpoint.exp
gdb.threads/execl.exp
gdb.threads/non-ldr-exc-1.exp
gdb.threads/non-ldr-exc-2.exp
gdb.threads/non-ldr-exc-3.exp
gdb.threads/non-ldr-exc-4.exp
gdb.threads/thread-execl.exp
The immediate cause of the segv is that follow_exec is passing a NULL
argument (the result of exec_file_find) to strlen.
However, the problem is deeper than that: follow_exec simply isn't
prepared for the case where sysroot translation fails to locate the
new executable. Actually all callers of exec_file_find have bugs due
to confusion between host and target pathnames. This commit attempts
to fix all that.
In terms of the testcases that were formerly segv'ing, GDB now prints
a warning but continues execution of the new program, so that the
tests now mostly FAIL instead. You could argue the FAILs are due to a
legitimate problem with the test environment setting up the sysroot
translation incorrectly.
A new representative test is added which exercises the ne wwarning
code path even with native testing.
Tested on x86_64 Fedora 23, native and gdbserver.
gdb/ChangeLog:
2016-10-25 Sandra Loosemore <sandra@codesourcery.com>
Luis Machado <lgustavo@codesourcery.com>
Pedro Alves <palves@redhat.com>
PR gdb/20569
* exceptions.c (exception_print_same): Moved here from exec.c.
* exceptions.h (exception_print_same): Declare.
* exec.h: Include "symfile-add-flags.h".
(try_open_exec_file): New declaration.
* exec.c (exception_print_same): Moved to exceptions.c.
(try_open_exec_file): New function.
(exec_file_locate_attach): Rename exec_file and full_exec_path
variables to avoid confusion between target and host pathnames.
Move pathname processing logic to exec_file_find. Do not return
early if pathname lookup fails; Call try_open_exec_file.
* infrun.c (follow_exec): Split and rename execd_pathname variable
to avoid confusion between target and host pathnames. Warn if
pathname lookup fails. Pass target pathname to
target_follow_exec, not hostpathname. Call try_open_exec_file.
* main.c (symbol_file_add_main_adapter): New function.
(captured_main_1): Use it.
* solib-svr4.c (open_symbol_file_object): Adjust to pass
symfile_add_flags to symbol_file_add_main.
* solib.c (exec_file_find): Incorporate fallback logic for relative
pathnames formerly in exec_file_locate_attach.
* symfile.c (symbol_file_add_main, symbol_file_add_main_1):
Replace 'from_tty' parameter with a symfile_add_file.
(symbol_file_command): Adjust to pass symfile_add_flags to
symbol_file_add_main.
* symfile.h (symbol_file_add_main): Replace 'from_tty' parameter
with a symfile_add_file.
gdb/testsuite/ChangeLog:
2016-10-25 Luis Machado <lgustavo@codesourcery.com>
* gdb.base/exec-invalid-sysroot.exp: New file.
+2016-10-25 Sandra Loosemore <sandra@codesourcery.com>
+ Luis Machado <lgustavo@codesourcery.com>
+ Pedro Alves <palves@redhat.com>
+
+ PR gdb/20569
+ * exceptions.c (exception_print_same): Moved here from exec.c.
+ * exceptions.h (exception_print_same): Declare.
+ * exec.h: Include "symfile-add-flags.h".
+ (try_open_exec_file): New declaration.
+ * exec.c (exception_print_same): Moved to exceptions.c.
+ (try_open_exec_file): New function.
+ (exec_file_locate_attach): Rename exec_file and full_exec_path
+ variables to avoid confusion between target and host pathnames.
+ Move pathname processing logic to exec_file_find. Do not return
+ early if pathname lookup fails; Call try_open_exec_file.
+ * infrun.c (follow_exec): Split and rename execd_pathname variable
+ to avoid confusion between target and host pathnames. Warn if
+ pathname lookup fails. Pass target pathname to
+ target_follow_exec, not hostpathname. Call try_open_exec_file.
+ * main.c (symbol_file_add_main_adapter): New function.
+ (captured_main_1): Use it.
+ * solib-svr4.c (open_symbol_file_object): Adjust to pass
+ symfile_add_flags to symbol_file_add_main.
+ * solib.c (exec_file_find): Incorporate fallback logic for relative
+ pathnames formerly in exec_file_locate_attach.
+ * symfile.c (symbol_file_add_main, symbol_file_add_main_1):
+ Replace 'from_tty' parameter with a symfile_add_file.
+ (symbol_file_command): Adjust to pass symfile_add_flags to
+ symbol_file_add_main.
+ * symfile.h (symbol_file_add_main): Replace 'from_tty' parameter
+ with a symfile_add_file.
+
2016-10-26 Pedro Alves <palves@redhat.com>
* coffread.c (coff_symfile_read): Use symfile_add_flags.
return 0;
return val;
}
+
+/* See exceptions.h. */
+
+int
+exception_print_same (struct gdb_exception e1, struct gdb_exception e2)
+{
+ const char *msg1 = e1.message;
+ const char *msg2 = e2.message;
+
+ if (msg1 == NULL)
+ msg1 = "";
+ if (msg2 == NULL)
+ msg2 = "";
+
+ return (e1.reason == e2.reason
+ && e1.error == e2.error
+ && strcmp (msg1, msg2) == 0);
+}
typedef int (catch_errors_ftype) (void *);
extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);
+/* Compare two exception objects for print equality. */
+extern int exception_print_same (struct gdb_exception e1,
+ struct gdb_exception e2);
#endif
printf_unfiltered (_("No executable file now.\n"));
}
-/* Returns non-zero if exceptions E1 and E2 are equal. Returns zero
- otherwise. */
-
-static int
-exception_print_same (struct gdb_exception e1, struct gdb_exception e2)
-{
- const char *msg1 = e1.message;
- const char *msg2 = e2.message;
-
- if (msg1 == NULL)
- msg1 = "";
- if (msg2 == NULL)
- msg2 = "";
-
- return (e1.reason == e2.reason
- && e1.error == e2.error
- && strcmp (msg1, msg2) == 0);
-}
-
-/* See gdbcore.h. */
+/* See exec.h. */
void
-exec_file_locate_attach (int pid, int defer_bp_reset, int from_tty)
+try_open_exec_file (const char *exec_file_host, struct inferior *inf,
+ symfile_add_flags add_flags)
{
- char *exec_file, *full_exec_path = NULL;
struct cleanup *old_chain;
struct gdb_exception prev_err = exception_none;
- /* Do nothing if we already have an executable filename. */
- exec_file = (char *) get_exec_file (0);
- if (exec_file != NULL)
- return;
-
- /* Try to determine a filename from the process itself. */
- exec_file = target_pid_to_exec_file (pid);
- if (exec_file == NULL)
- {
- warning (_("No executable has been specified and target does not "
- "support\n"
- "determining executable automatically. "
- "Try using the \"file\" command."));
- return;
- }
-
- /* If gdb_sysroot is not empty and the discovered filename
- is absolute then prefix the filename with gdb_sysroot. */
- if (*gdb_sysroot != '\0' && IS_ABSOLUTE_PATH (exec_file))
- {
- full_exec_path = exec_file_find (exec_file, NULL);
- if (full_exec_path == NULL)
- return;
- }
- else
- {
- /* It's possible we don't have a full path, but rather just a
- filename. Some targets, such as HP-UX, don't provide the
- full path, sigh.
-
- Attempt to qualify the filename against the source path.
- (If that fails, we'll just fall back on the original
- filename. Not much more we can do...) */
- if (!source_full_path_of (exec_file, &full_exec_path))
- full_exec_path = xstrdup (exec_file);
- }
-
- old_chain = make_cleanup (xfree, full_exec_path);
- make_cleanup (free_current_contents, &prev_err.message);
+ old_chain = make_cleanup (free_current_contents, &prev_err.message);
/* exec_file_attach and symbol_file_add_main may throw an error if the file
cannot be opened either locally or remotely.
errors/exceptions in the following code. */
TRY
{
- exec_file_attach (full_exec_path, from_tty);
+ /* We must do this step even if exec_file_host is NULL, so that
+ exec_file_attach will clear state. */
+ exec_file_attach (exec_file_host, add_flags & SYMFILE_VERBOSE);
}
CATCH (err, RETURN_MASK_ERROR)
{
}
END_CATCH
- TRY
+ if (exec_file_host != NULL)
{
- if (defer_bp_reset)
- current_inferior ()->symfile_flags |= SYMFILE_DEFER_BP_RESET;
- symbol_file_add_main (full_exec_path, from_tty);
+ TRY
+ {
+ symbol_file_add_main (exec_file_host, add_flags);
+ }
+ CATCH (err, RETURN_MASK_ERROR)
+ {
+ if (!exception_print_same (prev_err, err))
+ warning ("%s", err.message);
+ }
+ END_CATCH
}
- CATCH (err, RETURN_MASK_ERROR)
+
+ do_cleanups (old_chain);
+}
+
+/* See gdbcore.h. */
+
+void
+exec_file_locate_attach (int pid, int defer_bp_reset, int from_tty)
+{
+ char *exec_file_target, *exec_file_host;
+ struct cleanup *old_chain;
+ symfile_add_flags add_flags = 0;
+
+ /* Do nothing if we already have an executable filename. */
+ if (get_exec_file (0) != NULL)
+ return;
+
+ /* Try to determine a filename from the process itself. */
+ exec_file_target = target_pid_to_exec_file (pid);
+ if (exec_file_target == NULL)
{
- if (!exception_print_same (prev_err, err))
- warning ("%s", err.message);
+ warning (_("No executable has been specified and target does not "
+ "support\n"
+ "determining executable automatically. "
+ "Try using the \"file\" command."));
+ return;
}
- END_CATCH
- current_inferior ()->symfile_flags &= ~SYMFILE_DEFER_BP_RESET;
+ exec_file_host = exec_file_find (exec_file_target, NULL);
+ old_chain = make_cleanup (xfree, exec_file_host);
+
+ if (defer_bp_reset)
+ add_flags |= SYMFILE_DEFER_BP_RESET;
+
+ if (from_tty)
+ add_flags |= SYMFILE_VERBOSE;
+
+ /* Attempt to open the exec file. */
+ try_open_exec_file (exec_file_host, current_inferior (), add_flags);
do_cleanups (old_chain);
}
#include "target.h"
#include "progspace.h"
#include "memrange.h"
+#include "symfile-add-flags.h"
struct target_section;
struct target_ops;
extern void exec_close (void);
+/* Helper function that attempts to open the symbol file at EXEC_FILE_HOST.
+ If successful, it proceeds to add the symbol file as the main symbol file.
+
+ ADD_FLAGS is passed on to the function adding the symbol file. */
+extern void try_open_exec_file (const char *exec_file_host,
+ struct inferior *inf,
+ symfile_add_flags add_flags);
#endif
int i, copies = 1;
char *exec = NULL;
char **argv;
+ symfile_add_flags add_flags = 0;
struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
+ if (from_tty)
+ add_flags |= SYMFILE_VERBOSE;
+
if (args)
{
argv = gdb_buildargv (args);
switch_to_thread (null_ptid);
exec_file_attach (exec, from_tty);
- symbol_file_add_main (exec, from_tty);
+ symbol_file_add_main (exec, add_flags);
}
}
fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
}
-/* EXECD_PATHNAME is assumed to be non-NULL. */
+/* EXEC_FILE_TARGET is assumed to be non-NULL. */
static void
-follow_exec (ptid_t ptid, char *execd_pathname)
+follow_exec (ptid_t ptid, char *exec_file_target)
{
struct thread_info *th, *tmp;
struct inferior *inf = current_inferior ();
int pid = ptid_get_pid (ptid);
ptid_t process_ptid;
+ char *exec_file_host;
+ struct cleanup *old_chain;
/* This is an exec event that we actually wish to pay attention to.
Refresh our symbol table to the newly exec'd program, remove any
process_ptid = pid_to_ptid (pid);
printf_unfiltered (_("%s is executing new program: %s\n"),
target_pid_to_str (process_ptid),
- execd_pathname);
+ exec_file_target);
/* We've followed the inferior through an exec. Therefore, the
inferior has essentially been killed & reborn. */
breakpoint_init_inferior (inf_execd);
- if (*gdb_sysroot != '\0')
- {
- char *name = exec_file_find (execd_pathname, NULL);
+ exec_file_host = exec_file_find (exec_file_target, NULL);
+ old_chain = make_cleanup (xfree, exec_file_host);
- execd_pathname = (char *) alloca (strlen (name) + 1);
- strcpy (execd_pathname, name);
- xfree (name);
- }
+ /* If we were unable to map the executable target pathname onto a host
+ pathname, tell the user that. Otherwise GDB's subsequent behavior
+ is confusing. Maybe it would even be better to stop at this point
+ so that the user can specify a file manually before continuing. */
+ if (exec_file_host == NULL)
+ warning (_("Could not load symbols for executable %s.\n"
+ "Do you need \"set sysroot\"?"),
+ exec_file_target);
/* Reset the shared library package. This ensures that we get a
shlib event when the child reaches "_start", at which point the
inf = add_inferior_with_spaces ();
inf->pid = pid;
- target_follow_exec (inf, execd_pathname);
+ target_follow_exec (inf, exec_file_target);
set_current_inferior (inf);
set_current_program_space (inf->pspace);
gdb_assert (current_program_space == inf->pspace);
- /* That a.out is now the one to use. */
- exec_file_attach (execd_pathname, 0);
+ /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
+ because the proper displacement for a PIE (Position Independent
+ Executable) main symbol file will only be computed by
+ solib_create_inferior_hook below. breakpoint_re_set would fail
+ to insert the breakpoints with the zero displacement. */
+ try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
- /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
- (Position Independent Executable) main symbol file will get applied by
- solib_create_inferior_hook below. breakpoint_re_set would fail to insert
- the breakpoints with the zero displacement. */
-
- symbol_file_add (execd_pathname,
- (inf->symfile_flags
- | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
- NULL, 0);
-
- if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
- set_initial_language ();
+ do_cleanups (old_chain);
/* If the target can specify a description, read it. Must do this
after flipping to the new executable (because the target supplied
return 1;
}
+/* Adapter for symbol_file_add_main that translates 'from_tty' to a
+ symfile_add_flags. */
+
+static void
+symbol_file_add_main_adapter (const char *arg, int from_tty)
+{
+ symfile_add_flags add_flags = 0;
+
+ if (from_tty)
+ add_flags |= SYMFILE_VERBOSE;
+
+ symbol_file_add_main (arg, add_flags);
+}
+
/* Type of this option. */
enum cmdarg_kind
{
catch_command_errors returns non-zero on success! */
if (catch_command_errors_const (exec_file_attach, execarg,
!batch_flag))
- catch_command_errors_const (symbol_file_add_main, symarg,
+ catch_command_errors_const (symbol_file_add_main_adapter, symarg,
!batch_flag);
}
else
catch_command_errors_const (exec_file_attach, execarg,
!batch_flag);
if (symarg != NULL)
- catch_command_errors_const (symbol_file_add_main, symarg,
+ catch_command_errors_const (symbol_file_add_main_adapter, symarg,
!batch_flag);
}
gdb_byte *l_name_buf = (gdb_byte *) xmalloc (l_name_size);
struct cleanup *cleanups = make_cleanup (xfree, l_name_buf);
struct svr4_info *info = get_svr4_info ();
+ symfile_add_flags add_flags = 0;
+
+ if (from_tty)
+ add_flags |= SYMFILE_VERBOSE;
if (symfile_objfile)
if (!query (_("Attempt to reload symbols from process? ")))
}
/* Have a pathname: read the symbol file. */
- symbol_file_add_main (filename, from_tty);
+ symbol_file_add_main (filename, add_flags);
do_cleanups (cleanups);
return 1;
/* Return the full pathname of the main executable, or NULL if not
found. The returned pathname is malloc'ed and must be freed by
the caller. If FD is non-NULL, *FD is set to either -1 or an open
- file handle for the main executable.
-
- The search algorithm used is described in solib_find_1's comment
- above. */
+ file handle for the main executable. */
char *
exec_file_find (char *in_pathname, int *fd)
{
- char *result = solib_find_1 (in_pathname, fd, 0);
+ char *result;
+ const char *fskind = effective_target_file_system_kind ();
+
+ if (in_pathname == NULL)
+ return NULL;
- if (result == NULL)
+ if (*gdb_sysroot != '\0' && IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname))
{
- const char *fskind = effective_target_file_system_kind ();
+ result = solib_find_1 (in_pathname, fd, 0);
- if (fskind == file_system_kind_dos_based)
+ if (result == NULL && fskind == file_system_kind_dos_based)
{
char *new_pathname;
result = solib_find_1 (new_pathname, fd, 0);
}
}
+ else
+ {
+ /* It's possible we don't have a full path, but rather just a
+ filename. Some targets, such as HP-UX, don't provide the
+ full path, sigh.
+
+ Attempt to qualify the filename against the source path.
+ (If that fails, we'll just fall back on the original
+ filename. Not much more we can do...) */
+
+ if (!source_full_path_of (in_pathname, &result))
+ result = xstrdup (in_pathname);
+ if (fd != NULL)
+ *fd = -1;
+ }
return result;
}
static void load_command (char *, int);
-static void symbol_file_add_main_1 (const char *args, int from_tty,
+static void symbol_file_add_main_1 (const char *args, symfile_add_flags add_flags,
objfile_flags flags);
static void add_symbol_file_command (char *, int);
command itself. */
void
-symbol_file_add_main (const char *args, int from_tty)
+symbol_file_add_main (const char *args, symfile_add_flags add_flags)
{
- symbol_file_add_main_1 (args, from_tty, 0);
+ symbol_file_add_main_1 (args, add_flags, 0);
}
static void
-symbol_file_add_main_1 (const char *args, int from_tty, objfile_flags flags)
+symbol_file_add_main_1 (const char *args, symfile_add_flags add_flags,
+ objfile_flags flags)
{
- symfile_add_flags add_flags = (current_inferior ()->symfile_flags
- | SYMFILE_MAINLINE);
-
- if (from_tty)
- add_flags |= SYMFILE_VERBOSE;
+ add_flags |= current_inferior ()->symfile_flags | SYMFILE_MAINLINE;
symbol_file_add (args, add_flags, NULL, flags);
{
char **argv = gdb_buildargv (args);
objfile_flags flags = OBJF_USERLOADED;
+ symfile_add_flags add_flags = 0;
struct cleanup *cleanups;
char *name = NULL;
+ if (from_tty)
+ add_flags |= SYMFILE_VERBOSE;
+
cleanups = make_cleanup_freeargv (argv);
while (*argv != NULL)
{
error (_("unknown option `%s'"), *argv);
else
{
- symbol_file_add_main_1 (*argv, from_tty, flags);
+ symbol_file_add_main_1 (*argv, add_flags, flags);
name = *argv;
}
extern CORE_ADDR symbol_overlayed_address (CORE_ADDR, struct obj_section *);
/* Load symbols from a file. */
-extern void symbol_file_add_main (const char *args, int from_tty);
+extern void symbol_file_add_main (const char *args,
+ symfile_add_flags add_flags);
/* Clear GDB symbol tables. */
extern void symbol_file_clear (int from_tty);
+2016-10-25 Luis Machado <lgustavo@codesourcery.com>
+
+ * gdb.base/exec-invalid-sysroot.exp: New file.
+
2016-10-24 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.base/morestack.exp: Try to build it using -fuse-ld=gold first.
--- /dev/null
+# Copyright 1997-2016 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/>.
+
+# This test exercises PR20569. GDB would crash when attempting to follow
+# an exec call when it could not resolve the path to the symbol file.
+# This was the case when an invalid sysroot is provided.
+
+standard_testfile foll-exec.c
+
+global binfile
+set binfile [standard_output_file "foll-exec"]
+set testfile2 "execd-prog"
+set srcfile2 ${testfile2}.c
+set binfile2 [standard_output_file ${testfile2}]
+
+set compile_options debug
+
+# build the first test case
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable $compile_options] != "" } {
+ untested "could not compile test program ${binfile2}"
+ return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable $compile_options] != "" } {
+ untested "could not compile test program ${binfile}"
+ return -1
+}
+
+proc do_exec_sysroot_test {} {
+ global binfile srcfile srcfile2 testfile testfile2
+ global gdb_prompt
+
+ gdb_test_no_output "set sysroot /a/path/that/does/not/exist"
+
+ # Start the program running, and stop at main.
+ #
+ if ![runto_main] then {
+ fail "Couldn't run ${testfile}"
+ return
+ }
+
+ # Verify that the system supports "catch exec".
+ gdb_test "catch exec" "Catchpoint \[0-9\]* \\(exec\\)" "insert exec catchpoint"
+ set test "continue to exec catchpoint"
+ gdb_test_multiple "continue" $test {
+ -re ".*Your system does not support this type\r\nof catchpoint.*$gdb_prompt $" {
+ unsupported $test
+ return
+ }
+ -re ".*Could not load symbols for executable.*$gdb_prompt $" {
+ pass $test
+ }
+ }
+}
+
+# Start with a fresh gdb
+clean_restart $binfile
+do_exec_sysroot_test
projects / binutils-gdb.git / commitdiff