From 68cffbbd4406b4efe1aa6e18460b1d7ca02549f1 Mon Sep 17 00:00:00 2001 From: Luis Machado Date: Thu, 31 Mar 2022 11:42:35 +0100 Subject: [AArch64] MTE corefile support Teach GDB how to dump memory tags for AArch64 when using the gcore command and how to read memory tag data back from a core file generated by GDB (via gcore) or by the Linux kernel. The format is documented in the Linux Kernel documentation [1]. Each tagged memory range (listed in /proc//smaps) gets dumped to its own PT_AARCH64_MEMTAG_MTE segment. A section named ".memtag" is created for each of those segments when reading the core file back. To save a little bit of space, given MTE tags only take 4 bits, the memory tags are stored packed as 2 tags per byte. When reading the data back, the tags are unpacked. I've added a new testcase to exercise the feature. Build-tested with --enable-targets=all and regression tested on aarch64-linux Ubuntu 20.04. [1] Documentation/arm64/memory-tagging-extension.rst (Core Dump Support) --- gdb/memtag.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 gdb/memtag.h (limited to 'gdb/memtag.h') diff --git a/gdb/memtag.h b/gdb/memtag.h new file mode 100644 index 0000000..fe908c1 --- /dev/null +++ b/gdb/memtag.h @@ -0,0 +1,50 @@ +/* GDB generic memory tagging definitions. + Copyright (C) 2022 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 . */ + +#ifndef MEMTAG_H +#define MEMTAG_H + +#include "bfd.h" + +struct memtag_section_info +{ + /* The start address of the tagged memory range. */ + CORE_ADDR start_address; + /* The final address of the tagged memory range. */ + CORE_ADDR end_address; + /* The section containing tags for the memory range + [start_address, end_address). */ + asection *memtag_section; +}; + +/* Helper function to walk through memory tag sections in a core file. + + Return TRUE if there is a "memtag" section containing ADDRESS. Return FALSE + otherwise. + + If SECTION is provided, search from that section onwards. If SECTION is + nullptr, then start a new search. + + If a "memtag" section containing ADDRESS is found, fill INFO with data + about such section. Otherwise leave it unchanged. */ + +bool get_next_core_memtag_section (bfd *abfd, asection *section, + CORE_ADDR address, + memtag_section_info &info); + +#endif /* MEMTAG_H */ -- cgit v1.1