binutils-gdb/gdb/gdbarch-selftests.c
Yao Qi b77b02a5ca Add unit test to gdbarch methods register_to_value and value_to_register
This patch adds one unit test for gdbarch methods register_to_value and
value_to_register.  The test pass different combinations of {regnu, type}
to gdbarch_register_to_value and gdbarch_value_to_register.  In order
to do the test, add a new function create_new_frame to create a fake
frame.  It can be improved after we converted frame_info to class.

In order to isolate regcache (from target_ops operations on writing
registers, like target_store_registers), the sub-class of regcache in the
test override raw_write.  Also, in order to get the right regcache from
get_thread_arch_aspace_regcache, the sub-class of regcache inserts itself
to current_regcache.

Suppose I incorrectly modified the size of buffer as below,

@@ -1228,7 +1228,7 @@ ia64_register_to_value (struct frame_info *frame, int regnum,
                        int *optimizedp, int *unavailablep)
 {
   struct gdbarch *gdbarch = get_frame_arch (frame);
-  gdb_byte in[MAX_REGISTER_SIZE];
+  gdb_byte in[1];

   /* Convert to TYPE.  */
   if (!get_frame_register_bytes (frame, regnum, 0,

build GDB with "-fsanitize=address" and run unittest.exp, asan can detect
such error

==2302==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff98193870 at pc 0xbd55ea bp 0x7fff981935a0 sp 0x7fff98193598
WRITE of size 16 at 0x7fff98193870 thread T0
    #0 0xbd55e9 in frame_register_unwind(frame_info*, int, int*, int*, lval_type*, unsigned long*, int*, unsigned char*) /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1119
    #1 0xbd58c8 in frame_register(frame_info*, int, int*, int*, lval_type*, unsigned long*, int*, unsigned char*) /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1147
    #2 0xbd6e25 in get_frame_register_bytes(frame_info*, int, unsigned long, int, unsigned char*, int*, int*) /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1427
    #3 0x70080a in ia64_register_to_value /home/yao/SourceCode/gnu/gdb/git/gdb/ia64-tdep.c:1236
    #4 0xbf570e in gdbarch_register_to_value(gdbarch*, frame_info*, int, type*, unsigned char*, int*, int*) /home/yao/SourceCode/gnu/gdb/git/gdb/gdbarch.c:2619
    #5 0xc05975 in register_to_value_test /home/yao/SourceCode/gnu/gdb/git/gdb/gdbarch-selftests.c:131

Or, even if GDB is not built with asan, GDB just crashes.

*** stack smashing detected ***: ./gdb terminated
Aborted (core dumped)

gdb:

2017-05-24  Yao Qi  <yao.qi@linaro.org>

	* Makefile.in (SFILES): Add gdbarch-selftests.c.
	(COMMON_OBS): Add gdbarch-selftests.o.
	* frame.c [GDB_SELF_TESTS] (create_new_frame): New function.
	* frame.h [GDB_SELF_TESTS] (create_new_frame): Declare.
	* gdbarch-selftests.c: New file.
	* regcache.h (regcache) <~regcache>: Mark it virtual if
	GDB_SELF_TEST.
	<raw_write>: Likewise.
2017-05-24 22:15:23 +01:00

157 lines
4.4 KiB
C

/* Self tests for gdbarch for GDB, the GNU debugger.
Copyright (C) 2017 Free Software Foundation, Inc.
This file is part of GDB.
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 "defs.h"
#if GDB_SELF_TEST
#include "selftest.h"
#include "selftest-arch.h"
#include "inferior.h"
namespace selftests {
/* A read-write regcache which doesn't write the target. */
class regcache_test : public regcache
{
public:
explicit regcache_test (struct gdbarch *gdbarch)
: regcache (gdbarch, NULL, false)
{
set_ptid (inferior_ptid);
current_regcache.push_front (this);
}
void raw_write (int regnum, const gdb_byte *buf) override
{
raw_set_cached_value (regnum, buf);
}
};
/* Test gdbarch methods register_to_value and value_to_register. */
static void
register_to_value_test (struct gdbarch *gdbarch)
{
const struct builtin_type *builtin = builtin_type (gdbarch);
struct type *types[] =
{
builtin->builtin_void,
builtin->builtin_char,
builtin->builtin_short,
builtin->builtin_int,
builtin->builtin_long,
builtin->builtin_signed_char,
builtin->builtin_unsigned_short,
builtin->builtin_unsigned_int,
builtin->builtin_unsigned_long,
builtin->builtin_float,
builtin->builtin_double,
builtin->builtin_long_double,
builtin->builtin_complex,
builtin->builtin_double_complex,
builtin->builtin_string,
builtin->builtin_bool,
builtin->builtin_long_long,
builtin->builtin_unsigned_long_long,
builtin->builtin_int8,
builtin->builtin_uint8,
builtin->builtin_int16,
builtin->builtin_uint16,
builtin->builtin_int32,
builtin->builtin_uint32,
builtin->builtin_int64,
builtin->builtin_uint64,
builtin->builtin_int128,
builtin->builtin_uint128,
builtin->builtin_char16,
builtin->builtin_char32,
};
current_inferior()->gdbarch = gdbarch;
struct regcache *regcache = new regcache_test (gdbarch);
struct frame_info *frame = create_test_frame (regcache);
const int num_regs = (gdbarch_num_regs (gdbarch)
+ gdbarch_num_pseudo_regs (gdbarch));
SELF_CHECK (regcache == get_current_regcache ());
/* Test gdbarch methods register_to_value and value_to_register with
different combinations of register numbers and types. */
for (const auto &type : types)
{
for (auto regnum = 0; regnum < num_regs; regnum++)
{
if (gdbarch_convert_register_p (gdbarch, regnum, type))
{
std::vector<gdb_byte> expected (TYPE_LENGTH (type), 0);
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
DOUBLEST d = 1.25;
/* Generate valid float format. */
floatformat_from_doublest (floatformat_from_type (type),
&d, expected.data ());
}
else
{
for (auto j = 0; j < expected.size (); j++)
expected[j] = (regnum + j) % 16;
}
gdbarch_value_to_register (gdbarch, frame, regnum, type,
expected.data ());
/* Allocate two bytes more for overflow check. */
std::vector<gdb_byte> buf (TYPE_LENGTH (type) + 2, 0);
int optim, unavail, ok;
/* Set the fingerprint in the last two bytes. */
buf [TYPE_LENGTH (type)]= 'w';
buf [TYPE_LENGTH (type) + 1]= 'l';
ok = gdbarch_register_to_value (gdbarch, frame, regnum, type,
buf.data (), &optim, &unavail);
SELF_CHECK (ok);
SELF_CHECK (!optim);
SELF_CHECK (!unavail);
SELF_CHECK (buf[TYPE_LENGTH (type)] == 'w');
SELF_CHECK (buf[TYPE_LENGTH (type) + 1] == 'l');
for (auto k = 0; k < TYPE_LENGTH(type); k++)
SELF_CHECK (buf[k] == expected[k]);
}
}
}
}
} // namespace selftests
#endif /* GDB_SELF_TEST */
void
_initialize_gdbarch_selftests (void)
{
#if GDB_SELF_TEST
register_self_test_foreach_arch (selftests::register_to_value_test);
#endif
}