From b77b02a5ca5a021ee8b5e5453e8843447d1132b2 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 24 May 2017 22:15:23 +0100 Subject: [PATCH] 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 * 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. : Likewise. --- gdb/ChangeLog | 11 ++++ gdb/Makefile.in | 2 + gdb/frame.c | 17 ++++++ gdb/frame.h | 8 +++ gdb/gdbarch-selftests.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++++ gdb/regcache.h | 11 ++++ 6 files changed, 205 insertions(+) create mode 100644 gdb/gdbarch-selftests.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index fc09819..8454c09 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,16 @@ 2017-05-24 Yao Qi + * 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. + : Likewise. + +2017-05-24 Yao Qi + * regcache.c (current_regcache): Change it to regcache::current_regcache. (regcache_observer_target_changed): Update. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 452f146..8be73ba 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -1106,6 +1106,7 @@ SFILES = \ gdb_obstack.c \ gdb_usleep.c \ gdbarch.c \ + gdbarch-selftests.c \ gdbtypes.c \ gnu-v2-abi.c \ gnu-v3-abi.c \ @@ -1719,6 +1720,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \ gdb_usleep.o \ gdb_vecs.o \ gdbarch.o \ + gdbarch-selftests.o \ gdbtypes.o \ gnu-v2-abi.o \ gnu-v3-abi.o \ diff --git a/gdb/frame.c b/gdb/frame.c index d4fc456..efe5a20 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1704,6 +1704,23 @@ select_frame (struct frame_info *fi) } } +#if GDB_SELF_TEST +struct frame_info * +create_test_frame (struct regcache *regcache) +{ + struct frame_info *this_frame = XCNEW (struct frame_info); + + sentinel_frame = create_sentinel_frame (NULL, regcache); + sentinel_frame->prev = this_frame; + sentinel_frame->prev_p = 1;; + this_frame->prev_arch.p = 1; + this_frame->prev_arch.arch = get_regcache_arch (regcache); + this_frame->next = sentinel_frame; + + return this_frame; +} +#endif + /* Create an arbitrary (i.e. address specified by user) or innermost frame. Always returns a non-NULL value. */ diff --git a/gdb/frame.h b/gdb/frame.h index 1d0644f..56cbd44 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -833,6 +833,14 @@ extern struct frame_info *deprecated_safe_get_selected_frame (void); extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc); +#if GDB_SELF_TEST + +/* Create a frame for unit test. Its next frame is sentinel frame, + created from REGCACHE. */ + +extern struct frame_info *create_test_frame (struct regcache *regcache); +#endif + /* Return true if the frame unwinder for frame FI is UNWINDER; false otherwise. */ diff --git a/gdb/gdbarch-selftests.c b/gdb/gdbarch-selftests.c new file mode 100644 index 0000000..096ba97 --- /dev/null +++ b/gdb/gdbarch-selftests.c @@ -0,0 +1,156 @@ +/* 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 . */ + +#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 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 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 +} diff --git a/gdb/regcache.h b/gdb/regcache.h index fdc47ba..11126e6 100644 --- a/gdb/regcache.h +++ b/gdb/regcache.h @@ -250,6 +250,11 @@ public: regcache (const regcache &) = delete; void operator= (const regcache &) = delete; + /* class regcache is only extended in unit test, so only mark it + virtual when selftest is enabled. */ +#if GDB_SELF_TEST + virtual +#endif ~regcache () { xfree (m_registers); @@ -269,6 +274,12 @@ public: void cooked_write (int regnum, const gdb_byte *buf); enum register_status raw_read (int regnum, gdb_byte *buf); + + /* class regcache is only extended in unit test, so only mark it + virtual when selftest is enabled. */ +#if GDB_SELF_TEST + virtual +#endif void raw_write (int regnum, const gdb_byte *buf); enum register_status raw_read_signed (int regnum, LONGEST *val); -- 2.7.4