Luis Machado
bef382e61a
Extend the "x" and "print" commands to make use of memory tagging functionality, if supported by the architecture. The "print" command will point out any possible tag mismatches it finds when dealing with pointers, in case such a pointer is tagged. No additional modifiers are needed. Suppose we have a pointer "p" with value 0x1234 (logical tag 0x0) and that we have an allocation tag of 0x1 for that particular area of memory. This is the expected output: (gdb) p/x p Logical tag (0x0) does not match the allocation tag (0x1). $1 = 0x1234 The "x" command has a new 'm' modifier that will enable displaying of allocation tags alongside the data dump. It will display one allocation tag per line. AArch64 has a tag granule of 16 bytes, which means we can have one tag for every 16 bytes of memory. In this case, this is what the "x" command will display with the new 'm' modifier: (gdb) x/32bxm p <Allocation Tag 0x1 for range [0x1230,0x1240)> 0x1234: 0x01 0x02 0x00 0x00 0x00 0x00 0x00 0x00 0x123c: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 <Allocation Tag 0x1 for range [0x1240,0x1250)> 0x1244: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x124c: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 (gdb) x/4gxm a <Allocation Tag 0x1 for range [0x1230,0x1240)> 0x1234: 0x0000000000000201 0x0000000000000000 <Allocation Tag 0x1 for range [0x1240,0x1250)> 0x1244: 0x0000000000000000 0x0000000000000000 gdb/ChangeLog: 2021-03-24 Luis Machado <luis.machado@linaro.org> * printcmd.c (decode_format): Handle the 'm' modifier. (do_examine): Display allocation tags when required/supported. (should_validate_memtags): New function. (print_command_1): Display memory tag mismatches. * valprint.c (show_memory_tag_violations): New function. (value_print_option_defs): Add new option "memory-tag-violations". (user_print_options) <memory_tag_violations>: Initialize to 1. * valprint.h (struct format_data) <print_tags>: New field. (value_print_options) <memory_tag_violations>: New field. gdb/testsuite/ChangeLog: 2021-03-24 Luis Machado <luis.machado@linaro.org> * gdb.base/options.exp: Adjust for new print options. * gdb.base/with.exp: Likewise.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.