From patchwork Mon Feb 22 17:04:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v2] Fix segfault in ltpy_iternext() when symtab has no linetable. X-Patchwork-Submitter: Keith Seitz via Gdb-patches X-Patchwork-Id: 49629 Message-Id: <20210222170420.229421-1-tlloyddavies@undo.io> To: gdb-patches@sourceware.org Cc: Toby Lloyd Davies Date: Mon, 22 Feb 2021 17:04:20 +0000 From: Toby Lloyd Davies via Gdb-patches List-Id: Gdb-patches mailing list SYMTAB_LINETABLE (symtab) is set to NULL in buildsym_compunit::end_symtab_with_blockvector() if the symtab has no linetable. Attempting to iterate over this linetable using the Python API caused GDB to segfault. Add test of Python API linetable methods on an empty linetable. gdb/ChangeLog: * python/py-linetable.c (ltpy_iternext): Fix segfault when there is no linetable. gdb/testsuite/ChangeLog: * gdb.python/py-linetable-empty-main-body.h: New test. * gdb.python/py-linetable-empty.S: New test. * gdb.python/py-linetable-empty.c: New test. * gdb.python/py-linetable-empty.exp: New test. --- gdb/python/py-linetable.c | 3 +- .../gdb.python/py-linetable-empty-main-body.h | 20 ++ gdb/testsuite/gdb.python/py-linetable-empty.S | 183 ++++++++++++++++++ gdb/testsuite/gdb.python/py-linetable-empty.c | 20 ++ .../gdb.python/py-linetable-empty.exp | 62 ++++++ 5 files changed, 287 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.python/py-linetable-empty-main-body.h create mode 100644 gdb/testsuite/gdb.python/py-linetable-empty.S create mode 100644 gdb/testsuite/gdb.python/py-linetable-empty.c create mode 100644 gdb/testsuite/gdb.python/py-linetable-empty.exp -- 2.25.1 diff --git a/gdb/python/py-linetable.c b/gdb/python/py-linetable.c index e989204a7f5..6daf97ae356 100644 --- a/gdb/python/py-linetable.c +++ b/gdb/python/py-linetable.c @@ -399,7 +399,8 @@ ltpy_iternext (PyObject *self) LTPY_REQUIRE_VALID (iter_obj->source, symtab); - if (iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems) + if (SYMTAB_LINETABLE (symtab) == NULL + || iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems) { PyErr_SetNone (PyExc_StopIteration); return NULL; diff --git a/gdb/testsuite/gdb.python/py-linetable-empty-main-body.h b/gdb/testsuite/gdb.python/py-linetable-empty-main-body.h new file mode 100644 index 00000000000..bac1c2a1a01 --- /dev/null +++ b/gdb/testsuite/gdb.python/py-linetable-empty-main-body.h @@ -0,0 +1,20 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2021 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 . */ + +{ + return 0; +} diff --git a/gdb/testsuite/gdb.python/py-linetable-empty.S b/gdb/testsuite/gdb.python/py-linetable-empty.S new file mode 100644 index 00000000000..4cf51d5ad39 --- /dev/null +++ b/gdb/testsuite/gdb.python/py-linetable-empty.S @@ -0,0 +1,183 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2021 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 . */ + + .file "py-linetable-empty.c" + .text +.Ltext0: + .globl main + .type main, @function +main: +.LFB0: + .file 1 "./py-linetable-empty-main-body.h" + # ./py-linetable-empty-main-body.h:18:1 + .loc 1 18 1 + .cfi_startproc + endbr64 +# BLOCK 2 seq:0 +# PRED: ENTRY (FALLTHRU) + pushq %rbp + .cfi_def_cfa_offset 16 + .cfi_offset 6, -16 + movq %rsp, %rbp + .cfi_def_cfa_register 6 + # ./py-linetable-empty-main-body.h:19:10 + .loc 1 19 10 + movl $0, %eax + # ./py-linetable-empty-main-body.h:20:1 + .loc 1 20 1 + popq %rbp + .cfi_def_cfa 7, 8 +# SUCC: EXIT [always] + ret + .cfi_endproc +.LFE0: + .size main, .-main +.Letext0: + .file 2 "py-linetable-empty.c" + .section .debug_info,"",@progbits +.Ldebug_info0: + .long 0x4f # Length of Compilation Unit Info + .value 0x4 # DWARF version number + .long .Ldebug_abbrev0 # Offset Into Abbrev. Section + .byte 0x8 # Pointer Size (in bytes) + .uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit) + .long .LASF0 # DW_AT_producer: "GNU C17 9.3.0 -mtune=generic -march=x86-64 -g -fasynchronous-unwind-tables -fstack-protector-strong -fstack-clash-protection -fcf-protection" + .byte 0xc # DW_AT_language + .long .LASF1 # DW_AT_name: "py-linetable-empty.c" + .long .LASF2 # DW_AT_comp_dir: "" + .quad .Ltext0 # DW_AT_low_pc + .quad .Letext0-.Ltext0 # DW_AT_high_pc + .long .Ldebug_line0 # DW_AT_stmt_list + .uleb128 0x2 # (DIE (0x2d) DW_TAG_subprogram) + # DW_AT_external + .long .LASF3 # DW_AT_name: "main" + .byte 0x2 # DW_AT_decl_file (py-linetable-empty.c) + .byte 0x13 # DW_AT_decl_line + .byte 0x1 # DW_AT_decl_column + # DW_AT_prototyped + .long 0x4b # DW_AT_type + .quad .LFB0 # DW_AT_low_pc + .quad .LFE0-.LFB0 # DW_AT_high_pc + .uleb128 0x1 # DW_AT_frame_base + .byte 0x9c # DW_OP_call_frame_cfa + # DW_AT_GNU_all_call_sites + .uleb128 0x3 # (DIE (0x4b) DW_TAG_base_type) + .byte 0x4 # DW_AT_byte_size + .byte 0x5 # DW_AT_encoding + .ascii "int\0" # DW_AT_name + .byte 0 # end of children of DIE 0xb + .section .debug_abbrev,"",@progbits +.Ldebug_abbrev0: + .uleb128 0x1 # (abbrev code) + .uleb128 0x11 # (TAG: DW_TAG_compile_unit) + .byte 0x1 # DW_children_yes + .uleb128 0x25 # (DW_AT_producer) + .uleb128 0xe # (DW_FORM_strp) + .uleb128 0x13 # (DW_AT_language) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x3 # (DW_AT_name) + .uleb128 0xe # (DW_FORM_strp) + .uleb128 0x1b # (DW_AT_comp_dir) + .uleb128 0xe # (DW_FORM_strp) + .uleb128 0x11 # (DW_AT_low_pc) + .uleb128 0x1 # (DW_FORM_addr) + .uleb128 0x12 # (DW_AT_high_pc) + .uleb128 0x7 # (DW_FORM_data8) + .uleb128 0x10 # (DW_AT_stmt_list) + .uleb128 0x17 # (DW_FORM_sec_offset) + .byte 0 + .byte 0 + .uleb128 0x2 # (abbrev code) + .uleb128 0x2e # (TAG: DW_TAG_subprogram) + .byte 0 # DW_children_no + .uleb128 0x3f # (DW_AT_external) + .uleb128 0x19 # (DW_FORM_flag_present) + .uleb128 0x3 # (DW_AT_name) + .uleb128 0xe # (DW_FORM_strp) + .uleb128 0x3a # (DW_AT_decl_file) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x3b # (DW_AT_decl_line) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x39 # (DW_AT_decl_column) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x27 # (DW_AT_prototyped) + .uleb128 0x19 # (DW_FORM_flag_present) + .uleb128 0x49 # (DW_AT_type) + .uleb128 0x13 # (DW_FORM_ref4) + .uleb128 0x11 # (DW_AT_low_pc) + .uleb128 0x1 # (DW_FORM_addr) + .uleb128 0x12 # (DW_AT_high_pc) + .uleb128 0x7 # (DW_FORM_data8) + .uleb128 0x40 # (DW_AT_frame_base) + .uleb128 0x18 # (DW_FORM_exprloc) + .uleb128 0x2117 # (DW_AT_GNU_all_call_sites) + .uleb128 0x19 # (DW_FORM_flag_present) + .byte 0 + .byte 0 + .uleb128 0x3 # (abbrev code) + .uleb128 0x24 # (TAG: DW_TAG_base_type) + .byte 0 # DW_children_no + .uleb128 0xb # (DW_AT_byte_size) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x3e # (DW_AT_encoding) + .uleb128 0xb # (DW_FORM_data1) + .uleb128 0x3 # (DW_AT_name) + .uleb128 0x8 # (DW_FORM_string) + .byte 0 + .byte 0 + .byte 0 + .section .debug_aranges,"",@progbits + .long 0x2c # Length of Address Ranges Info + .value 0x2 # DWARF aranges version + .long .Ldebug_info0 # Offset of Compilation Unit Info + .byte 0x8 # Size of Address + .byte 0 # Size of Segment Descriptor + .value 0 # Pad to 16 byte boundary + .value 0 + .quad .Ltext0 # Address + .quad .Letext0-.Ltext0 # Length + .quad 0 + .quad 0 + .section .debug_line,"",@progbits +.Ldebug_line0: + .section .debug_str,"MS",@progbits,1 +.LASF0: + .string "GNU C17 9.3.0 -mtune=generic -march=x86-64 -g -fasynchronous-unwind-tables -fstack-protector-strong -fstack-clash-protection -fcf-protection" +.LASF2: + .string "" +.LASF3: + .string "main" +.LASF1: + .string "py-linetable-empty.c" + .ident "GCC: (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0" + .section .note.GNU-stack,"",@progbits + .section .note.gnu.property,"a" + .align 8 + .long 1f - 0f + .long 4f - 1f + .long 5 +0: + .string "GNU" +1: + .align 8 + .long 0xc0000002 + .long 3f - 2f +2: + .long 0x3 +3: + .align 8 +4: diff --git a/gdb/testsuite/gdb.python/py-linetable-empty.c b/gdb/testsuite/gdb.python/py-linetable-empty.c new file mode 100644 index 00000000000..e0fc00b51f7 --- /dev/null +++ b/gdb/testsuite/gdb.python/py-linetable-empty.c @@ -0,0 +1,20 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2021 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 . */ + +int +main (void) +#include "./py-linetable-empty-main-body.h" diff --git a/gdb/testsuite/gdb.python/py-linetable-empty.exp b/gdb/testsuite/gdb.python/py-linetable-empty.exp new file mode 100644 index 00000000000..a00e929a17a --- /dev/null +++ b/gdb/testsuite/gdb.python/py-linetable-empty.exp @@ -0,0 +1,62 @@ +# Copyright 2021 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 . + +# Test Python API linetable methods on an empty linetable. + +load_lib gdb-python.exp +standard_testfile .S + +if [info exists COMPILE] { + # make check RUNTESTFLAGS="gdb.python/py-linetable-empty.exp COMPILE=1" + standard_testfile +} elseif { ![istarget x86_64-*-* ] || ![is_lp64_target] } { + verbose "Skipping ${testfile}." + return +} + +if { [prepare_for_testing "failed to prepare" \ + ${testfile} ${srcfile}] } { + return +} + +if { ![runto_main] } { + untested "could not run to main" + return +} + +# Skip all tests if Python scripting is not enabled. +if { [skip_python_tests] } { continue } + +# Get the linetable for main's symbol table. This is empty as +# main's body was included from another file. +gdb_py_test_silent_cmd "python lt = gdb.selected_frame().function().symtab.linetable()" \ + "get linetable" 0 + +gdb_test "python print(lt.is_valid())" "True" \ + "Test linetable is valid" + +gdb_test "python print(lt.line(1))" "None" \ + "Test line() returns None" + +gdb_test "python print(lt.has_line(1))" \ + ".*RuntimeError: Linetable information not found in symbol table.*" \ + "Test has_line() throws exception" + +gdb_test "python print(lt.source_lines())" \ + ".*RuntimeError: Linetable information not found in symbol table.*" \ + "Test source_lines() throws exception" + +gdb_test "python print(list(lt))" "\\\[\\\]" \ + "Test iterating over linetable"