From patchwork Fri Jun 8 12:39:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Tesarik X-Patchwork-Id: 27713 Received: (qmail 30797 invoked by alias); 8 Jun 2018 12:40:36 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 30374 invoked by uid 89); 8 Jun 2018 12:40:35 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_PASS autolearn=ham version=3.3.2 spammy=locate, H*Ad:D*ca X-HELO: mx2.suse.de Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 08 Jun 2018 12:40:33 +0000 Received: from relay2.suse.de (charybdis-ext-too.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D6818AEA7; Fri, 8 Jun 2018 12:40:29 +0000 (UTC) From: Petr Tesarik To: gdb-patches@sourceware.org Cc: Simon Marchi , John Baldwin , Petr Tesarik , Jeff Mahoney Subject: [PATCH 1/4] Add an optional offset option to the "symbol-file" command Date: Fri, 8 Jun 2018 14:39:57 +0200 Message-Id: <20180608124000.10668-2-ptesarik@suse.cz> In-Reply-To: <20180608124000.10668-1-ptesarik@suse.cz> References: <20180608124000.10668-1-ptesarik@suse.cz> X-IsSubscribed: yes From: Petr Tesarik If the main file is relocated at runtime, all symbols are offset by a fixed amount. Let the user specify this offset when loading a symbol file. gdb/ChangeLog: 2018-06-08 Petr Tesarik * symfile.c (symbol_file_command, symbol_file_add_main_1) (_initialize_symfile): Add option "-o" to symbol-file to add an offset to each section of the symbol file. gdb/doc/ChangeLog: 2018-06-08 Petr Tesarik * gdb.texinfo (Files): Document "symbol-file -o offset". gdb/testsuite/ChangeLog: 2018-06-08 Petr Tesarik * gdb.base/relocate.exp: Add test for "symbol-file -o ". --- gdb/ChangeLog | 6 ++++++ gdb/doc/ChangeLog | 4 ++++ gdb/doc/gdb.texinfo | 7 ++++++- gdb/symfile.c | 24 ++++++++++++++++++------ gdb/testsuite/ChangeLog | 4 ++++ gdb/testsuite/gdb.base/relocate.exp | 24 ++++++++++++++++++++++++ 6 files changed, 62 insertions(+), 7 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f0b6b95f7e..27c6ed0a7c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2018-06-08 Petr Tesarik + + * symfile.c (symbol_file_command, symbol_file_add_main_1) + (_initialize_symfile): Add option "-o" to symbol-file to add an + offset to each section of the symbol file. + 2018-06-07 Pedro Alves * target.h (target_ops) : Now a method. All references diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 6191e84cc0..319d06a25f 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,7 @@ +2018-06-08 Petr Tesarik + + * gdb.texinfo (Files): Document "symbol-file -o offset". + 2018-06-05 Tom Tromey PR cli/12326: diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 4968b374af..9d1c29612b 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -18822,11 +18822,16 @@ if necessary to locate your program. Omitting @var{filename} means to discard information on the executable file. @kindex symbol-file -@item symbol-file @r{[} @var{filename} @r{]} +@item symbol-file @r{[} -o @var{offset} @r{]} @r{[} @var{filename} @r{]} Read symbol table information from file @var{filename}. @code{PATH} is searched when necessary. Use the @code{file} command to get both symbol table and program to run from the same file. +If an optional @var{offset} is specified, it is added to the start +address of each section in the symbol file. This is useful if the +program is relocated at runtime, such as the Linux kernel with kASLR +enabled. + @code{symbol-file} with no argument clears out @value{GDBN} information on your program's symbol table. diff --git a/gdb/symfile.c b/gdb/symfile.c index f8177ea8b1..09344f83d2 100644 --- a/gdb/symfile.c +++ b/gdb/symfile.c @@ -87,7 +87,7 @@ int readnever_symbol_files; /* Never read full symbols. */ /* Functions this file defines. */ static void symbol_file_add_main_1 (const char *args, symfile_add_flags add_flags, - objfile_flags flags); + objfile_flags flags, CORE_ADDR reloff); static const struct sym_fns *find_sym_fns (bfd *); @@ -1225,16 +1225,18 @@ symbol_file_add (const char *name, symfile_add_flags add_flags, void symbol_file_add_main (const char *args, symfile_add_flags add_flags) { - symbol_file_add_main_1 (args, add_flags, 0); + symbol_file_add_main_1 (args, add_flags, 0, 0); } static void symbol_file_add_main_1 (const char *args, symfile_add_flags add_flags, - objfile_flags flags) + objfile_flags flags, CORE_ADDR reloff) { add_flags |= current_inferior ()->symfile_flags | SYMFILE_MAINLINE; - symbol_file_add (args, add_flags, NULL, flags); + struct objfile *objfile = symbol_file_add (args, add_flags, NULL, flags); + if (reloff != 0) + objfile_rebase (objfile, reloff); /* Getting new symbols may change our opinion about what is frameless. */ @@ -1551,6 +1553,7 @@ symbol_file_command (const char *args, int from_tty) symfile_add_flags add_flags = 0; char *name = NULL; bool stop_processing_options = false; + CORE_ADDR offset = 0; int idx; char *arg; @@ -1571,6 +1574,14 @@ symbol_file_command (const char *args, int from_tty) flags |= OBJF_READNOW; else if (strcmp (arg, "-readnever") == 0) flags |= OBJF_READNEVER; + else if (strcmp (arg, "-o") == 0) + { + arg = built_argv[++idx]; + if (arg == NULL) + error (_("Missing argument to -o")); + + offset = parse_and_eval_address (arg); + } else if (strcmp (arg, "--") == 0) stop_processing_options = true; else @@ -1582,7 +1593,7 @@ symbol_file_command (const char *args, int from_tty) validate_readnow_readnever (flags); - symbol_file_add_main_1 (name, add_flags, flags); + symbol_file_add_main_1 (name, add_flags, flags, offset); } } @@ -3774,7 +3785,8 @@ symbolic debug information." c = add_cmd ("symbol-file", class_files, symbol_file_command, _("\ Load symbol table from executable file FILE.\n\ -Usage: symbol-file [-readnow | -readnever] FILE\n\ +Usage: symbol-file [-readnow | -readnever] [-o ] FILE\n\ +OFF is an optional offset which is added to each section address.\n\ The `file' command can also load symbol tables, as well as setting the file\n\ to execute.\n" READNOW_READNEVER_HELP), &cmdlist); set_cmd_completer (c, filename_completer); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index eea782f05e..a9e0ec09ff 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2018-06-08 Petr Tesarik + + * gdb.base/relocate.exp: Add test for "symbol-file -o ". + 2018-06-05 Tom Tromey * gdb.base/default.exp: Update expected "show version" output. diff --git a/gdb/testsuite/gdb.base/relocate.exp b/gdb/testsuite/gdb.base/relocate.exp index 89f2fffcd9..77f6a88159 100644 --- a/gdb/testsuite/gdb.base/relocate.exp +++ b/gdb/testsuite/gdb.base/relocate.exp @@ -196,6 +196,30 @@ if { "${function_foo_addr}" == "${new_function_foo_addr}" } { pass "function foo has a different address" } +# Load the object using symbol-file with an offset and check that +# all addresses are moved by that offset. + +set offset 0x10000 +clean_restart +gdb_test "symbol-file -o $offset $binfile" \ + "Reading symbols from ${binfile}\.\.\.done\." \ + "symbol-file with offset" + +# Make sure the address of a static variable is moved by offset. +set new_static_foo_addr [get_var_address static_foo] +gdb_assert {${new_static_foo_addr} == ${static_foo_addr} + $offset} \ + "static variable foo is moved by offset" + +# Make sure the address of a global variable is moved by offset. +set new_global_foo_addr [get_var_address global_foo] +gdb_assert {${new_global_foo_addr} == ${global_foo_addr} + $offset} \ + "global variable foo is moved by offset" + +# Make sure the address of a function is moved by offset. +set new_function_foo_addr [get_var_address function_foo] +gdb_assert {${new_function_foo_addr} == ${function_foo_addr} + $offset} \ + "function foo is moved by offset" + # Now try loading the object as an exec-file; we should be able to print # the values of variables after we do this.