[PATCHv2,2/2] gdb: allow core file containing special characters on the command line
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Commit Message
After the commit:
commit 03ad29c86c232484f9090582bbe6f221bc87c323
Date: Wed Jun 19 11:14:08 2024 +0100
gdb: 'target ...' commands now expect quoted/escaped filenames
it was no longer possible to pass GDB the name of a core file
containing any special characters (white space or quote characters) on
the command line. For example:
$ gdb -c /tmp/core\ file.core
Junk after filename "/tmp/core": file.core
(gdb)
The problem is that the above commit changed the 'target core' command
to expect quoted filenames, so before the above commit a user could
write:
(gdb) target core /tmp/core file.core
[New LWP 2345783]
Core was generated by `./mkcore'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000000000401111 in ?? ()
(gdb)
But after the above commit the user must write:
(gdb) target core /tmp/core\ file.core
or
(gdb) target core "/tmp/core file.core"
This is part of a move to make GDB's filename argument handling
consistent.
Anyway, the problem with the '-c' command line flag is that it
forwards the filename unmodified through to the 'core-file' command,
which in turn forwards to the 'target core' command.
So when the user, at a shell writes:
$ gdb -c "core file.core"
this arrives in GDB as the unquoted string 'core file.core' (without
the single quotes). GDB then forwards this to the 'core-file'
command as if the user had written this at a GDB prompt:
(gdb) core-file core file.core
Which then fails to parse due to the unquoted white space between
'core' and 'file.core'.
The solution I propose is to escape any special characters in the core
file name passed from the command line before calling 'core-file'
command from main.c.
I've updated the corefile.exp test to include a test for passing a
core file containing a white space character. While I was at it I've
modernised the part of corefile.exp that I was touching.
---
gdb/main.c | 17 ++--
gdb/testsuite/gdb.base/corefile.exp | 116 +++++++++++++---------------
gdbsupport/common-utils.cc | 21 +++++
gdbsupport/common-utils.h | 5 ++
4 files changed, 88 insertions(+), 71 deletions(-)
@@ -1235,7 +1235,8 @@ captured_main_1 (struct captured_main_args *context)
if (corearg != NULL)
{
- ret = catch_command_errors (core_file_command, corearg,
+ ret = catch_command_errors (core_file_command,
+ make_quoted_string (corearg).c_str (),
!batch_flag);
}
else if (pidarg != NULL)
@@ -1253,16 +1254,18 @@ captured_main_1 (struct captured_main_args *context)
ret = catch_command_errors (attach_command, pid_or_core_arg,
!batch_flag);
if (ret == 0)
- ret = catch_command_errors (core_file_command,
- pid_or_core_arg,
- !batch_flag);
+ ret = catch_command_errors
+ (core_file_command,
+ make_quoted_string (pid_or_core_arg).c_str (),
+ !batch_flag);
}
else
{
/* Can't be a pid, better be a corefile. */
- ret = catch_command_errors (core_file_command,
- pid_or_core_arg,
- !batch_flag);
+ ret = catch_command_errors
+ (core_file_command,
+ make_quoted_string (pid_or_core_arg).c_str (),
+ !batch_flag);
}
}
@@ -34,81 +34,69 @@ if {$corefile == ""} {
return 0
}
-# Test that we can simply startup with a "-core=$corefile" command line arg
-# and recognize that the core file is a valid, usable core file.
-# To do this, we must shutdown the currently running gdb and restart
-# with the -core args. We can't use gdb_start because it looks for
-# the first gdb prompt, and the message we are looking for occurs
-# before the first prompt.
+# Start GDB with COREFILE passed as a command line argument. COREOPT
+# is prefixed before COREFILE and is the command line flag to specify
+# the corefile, i.e. one of '--core=', '-core=', '-c '.
#
-# Another problem is that on some systems (solaris for example), there
-# is apparently a limit on the length of a fully specified path to
-# the corefile executable, at about 80 chars. For this case, consider
-# it a pass, but note that the program name is bad.
-
-gdb_exit
-if {$verbose>1} {
- send_user "Spawning $GDB $INTERNAL_GDBFLAGS $GDBFLAGS -core=$corefile\n"
-}
-
-set oldtimeout $timeout
-set timeout [expr "$timeout + 60"]
-verbose "Timeout is now $timeout seconds" 2
-eval "spawn $GDB $INTERNAL_GDBFLAGS $GDBFLAGS -core=$corefile"
-expect {
- -re "Couldn't find .* registers in core file.*$gdb_prompt $" {
- fail "args: -core=[file tail $corefile] (couldn't find regs)"
- }
- -re "Core was generated by .*corefile.*\r\n\#0 .*\(\).*\r\n$gdb_prompt $" {
- pass "args: -core=[file tail $corefile]"
- }
- -re "Core was generated by .*\r\n\#0 .*\(\).*\r\n$gdb_prompt $" {
- pass "args: -core=[file tail $corefile] (with bad program name)"
- }
- -re ".*registers from core file: File in wrong format.* $" {
- fail "args: -core=[file tail $corefile] (could not read registers from core file)"
- }
- -re ".*$gdb_prompt $" { fail "args: -core=[file tail $corefile]" }
- timeout { fail "(timeout) starting with -core" }
-}
-
-
+# If BINFILE is not the empty string then it is also added as a
+# command line argument and is the executable to load.
#
-# Test that startup with both an executable file and -core argument.
-# See previous comments above, they are still applicable.
-#
-
-close
+# TESTNAME is used for naming the tests.
+proc start_gdb_with_corefile { testname coreopt corefile {binfile ""} } {
+ gdb_exit
-if {$verbose>1} {
- send_user "Spawning $GDB $INTERNAL_GDBFLAGS $GDBFLAGS $binfile -core=$corefile\n"
-}
+ global GDBFLAGS
+ save_vars { GDBFLAGS } {
+ append GDBFLAGS " $binfile $coreopt$corefile"
+ set res [gdb_spawn]
+ if { $res != 0 } {
+ fail "$testname (start GDB)"
+ return
+ }
-eval "spawn $GDB $INTERNAL_GDBFLAGS $GDBFLAGS $binfile -core=$corefile"
-expect {
- -re "Core was generated by .*corefile.*\r\n\#0 .*\(\).*\r\n$gdb_prompt $" {
- pass "args: execfile -core=[file tail $corefile]"
- }
- -re "Core was generated by .*\r\n\#0 .*\(\).*\r\n$gdb_prompt $" {
- pass "args: execfile -core=[file tail $corefile] (with bad program name)"
- }
- -re ".*registers from core file: File in wrong format.* $" {
- fail "args: execfile -core=[file tail $corefile] (could not read registers from core file)"
+ gdb_test_multiple "" $testname {
+ -re -wrap "Couldn't find .* registers in core file.*" {
+ fail "$gdb_test_name (couldn't find regs)"
+ }
+ -re -wrap "Core was generated by `[string_to_regexp $corefile]'\\.\r\n.*\#0 \[^\r\n\]+\(\).*" {
+ pass $gdb_test_name
+ }
+ -re -wrap "Core was generated by .*\r\n\#0 .*\(\).*" {
+ # This case is hit when the executable name is
+ # truncated in the output.
+ pass "$gdb_test_name (with bad program name)"
+ }
+ -re -wrap ".*registers from core file: File in wrong format.*" {
+ fail "$gdb_test_name (could not read registers from core file)"
+ }
+ -re -wrap "" {
+ fail "$gdb_test_name (core not loaded)"
+ }
+ }
}
- -re ".*$gdb_prompt $" { fail "args: execfile -core=[file tail $corefile]" }
- timeout { fail "(timeout) starting with -core" }
}
-set timeout $oldtimeout
-verbose "Timeout is now $timeout seconds" 2
-close
+# Create a copy of the corefile, but with a space in the filename.
+set alt_corefile [standard_output_file "core\\ file.core"]
+remote_exec host "cp $corefile $alt_corefile"
+
+# Test that we can start GDB with a corefile command line argument and
+# recognize that the core file is a valid, usable core file. We test
+# using '--core=...', '-core=...', and '-c ...' style arguments. We
+# also test with, and without an executable.
+foreach_with_prefix coreopt {--core= -core= "-c "} {
+ start_gdb_with_corefile "just core file" $coreopt $corefile
+ start_gdb_with_corefile "core file and executable" $coreopt $corefile $binfile
+ start_gdb_with_corefile "core file with white space in name" \
+ $coreopt $alt_corefile
+ start_gdb_with_corefile "core file with white space in name and executable" \
+ $coreopt $alt_corefile $binfile
+}
# Now restart normally.
-gdb_start
-gdb_reinitialize_dir $srcdir/$subdir
-gdb_load ${binfile}
+clean_restart $binfile
# Test basic corefile recognition via core-file command.
@@ -222,6 +222,27 @@ extract_string_maybe_quoted (const char **arg)
return result;
}
+/* See gdbsupport/common-utils.h. */
+
+std::string
+make_quoted_string (const char *str)
+{
+ gdb_assert (str != nullptr);
+
+ std::string result;
+
+ for (; *str != '\0'; ++str)
+ {
+ const char ch = *str;
+
+ if (strchr ("\"' \t\n", ch) != nullptr)
+ result.push_back ('\\');
+ result.push_back (ch);
+ }
+
+ return result;
+}
+
/* The bit offset of the highest byte in a ULONGEST, for overflow
checking. */
@@ -84,6 +84,11 @@ char *savestring (const char *ptr, size_t len);
std::string extract_string_maybe_quoted (const char **arg);
+/* Return a copy of STR, but with any white space, single quote, or
+ double quote characters escaped with a backslash. */
+
+std::string make_quoted_string (const char *str);
+
/* The strerror() function can return NULL for errno values that are
out of range. Provide a "safe" version that always returns a
printable string. This version is also thread-safe. */