From e0349c46cb4fbbb507fa34476bd70f9c82bad359 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Fri, 21 Feb 2025 21:40:34 +0100 Subject: scripts/gdb/linux/symbols.py: address changes to module_sect_attrs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When loading symbols from kernel modules we used to iterate from 0 to module_sect_attrs::nsections, in order to retrieve their name and address. However module_sect_attrs::nsections has been removed from the struct by a previous commit. Re-arrange the iteration by accessing all items in module_sect_attrs::grp::bin_attrs[] until NULL is found (it's a NULL terminated array). At the same time the symbol address cannot be extracted from module_sect_attrs::attrs[]::address anymore because it has also been deleted. Fetch it from module_sect_attrs::grp::bin_attrs[]::private as described in 4b2c11e4aaf7. Link: https://lkml.kernel.org/r/20250221204034.4430-1-antonio@mandelbit.com Fixes: d8959b947a8d ("module: sysfs: Drop member 'module_sect_attrs::nsections'") Fixes: 4b2c11e4aaf7 ("module: sysfs: Drop member 'module_sect_attr::address'") Signed-off-by: Antonio Quartulli Reviewed-by: Jan Kiszka Cc: Thomas Weißschuh Cc: Kieran Bingham Signed-off-by: Andrew Morton --- scripts/gdb/linux/symbols.py | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'scripts/gdb/linux/symbols.py') diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py index f6c1b063775a..15d76f7d8ebc 100644 --- a/scripts/gdb/linux/symbols.py +++ b/scripts/gdb/linux/symbols.py @@ -15,6 +15,7 @@ import gdb import os import re +from itertools import count from linux import modules, utils, constants @@ -95,10 +96,14 @@ lx-symbols command.""" except gdb.error: return str(module_addr) - attrs = sect_attrs['attrs'] - section_name_to_address = { - attrs[n]['battr']['attr']['name'].string(): attrs[n]['address'] - for n in range(int(sect_attrs['nsections']))} + section_name_to_address = {} + for i in count(): + # this is a NULL terminated array + if sect_attrs['grp']['bin_attrs'][i] == 0x0: + break + + attr = sect_attrs['grp']['bin_attrs'][i].dereference() + section_name_to_address[attr['attr']['name'].string()] = attr['private'] textaddr = section_name_to_address.get(".text", module_addr) args = [] -- cgit v1.2.3 From 28939c3e9925735166e7b6e42f9e1dc828093510 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Mon, 3 Mar 2025 12:03:58 +0100 Subject: scripts/gdb/symbols: determine KASLR offset on s390 Use QEMU's qemu.PhyMemMode [1] functionality to read vmcore from the physical memory the same way the existing dump tooling does this. Gracefully handle non-QEMU targets, early boot, and memory corruptions; print a warning if such situation is detected. [1] https://qemu-project.gitlab.io/qemu/system/gdb.html#examining-physical-memory Link: https://lkml.kernel.org/r/20250303110437.79070-1-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Acked-by: Jan Kiszka Cc: Alexander Gordeev Cc: Andrew Donnellan Cc: Christian Borntraeger Cc: Heiko Carstens Cc: Kieran Bingham Cc: Nina Schoetterl-Glausch Cc: Vasily Gorbik Signed-off-by: Andrew Morton --- scripts/gdb/linux/symbols.py | 31 ++++++++++++++++++++++++++++++- scripts/gdb/linux/utils.py | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+), 1 deletion(-) (limited to 'scripts/gdb/linux/symbols.py') diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py index 15d76f7d8ebc..b255177301e9 100644 --- a/scripts/gdb/linux/symbols.py +++ b/scripts/gdb/linux/symbols.py @@ -14,6 +14,7 @@ import gdb import os import re +import struct from itertools import count from linux import modules, utils, constants @@ -54,6 +55,29 @@ if hasattr(gdb, 'Breakpoint'): return False +def get_vmcore_s390(): + with utils.qemu_phy_mem_mode(): + vmcore_info = 0x0e0c + paddr_vmcoreinfo_note = gdb.parse_and_eval("*(unsigned long long *)" + + hex(vmcore_info)) + inferior = gdb.selected_inferior() + elf_note = inferior.read_memory(paddr_vmcoreinfo_note, 12) + n_namesz, n_descsz, n_type = struct.unpack(">III", elf_note) + desc_paddr = paddr_vmcoreinfo_note + len(elf_note) + n_namesz + 1 + return gdb.parse_and_eval("(char *)" + hex(desc_paddr)).string() + + +def get_kerneloffset(): + if utils.is_target_arch('s390'): + try: + vmcore_str = get_vmcore_s390() + except gdb.error as e: + gdb.write("{}\n".format(e)) + return None + return utils.parse_vmcore(vmcore_str).kerneloffset + return None + + class LxSymbols(gdb.Command): """(Re-)load symbols of Linux kernel and currently loaded modules. @@ -160,7 +184,12 @@ lx-symbols command.""" obj.filename.endswith('vmlinux.debug')): orig_vmlinux = obj.filename gdb.execute("symbol-file", to_string=True) - gdb.execute("symbol-file {0}".format(orig_vmlinux)) + kerneloffset = get_kerneloffset() + if kerneloffset is None: + offset_arg = "" + else: + offset_arg = " -o " + hex(kerneloffset) + gdb.execute("symbol-file {0}{1}".format(orig_vmlinux, offset_arg)) self.loaded_modules = [] module_list = modules.module_list() diff --git a/scripts/gdb/linux/utils.py b/scripts/gdb/linux/utils.py index 245ab297ea84..03ebdccf5f69 100644 --- a/scripts/gdb/linux/utils.py +++ b/scripts/gdb/linux/utils.py @@ -11,6 +11,11 @@ # This work is licensed under the terms of the GNU GPL version 2. # +import contextlib +import dataclasses +import re +import typing + import gdb @@ -216,3 +221,33 @@ def gdb_eval_or_none(expresssion): return gdb.parse_and_eval(expresssion) except gdb.error: return None + + +@contextlib.contextmanager +def qemu_phy_mem_mode(): + connection = gdb.selected_inferior().connection + orig = connection.send_packet("qqemu.PhyMemMode") + if orig not in b"01": + raise gdb.error("Unexpected qemu.PhyMemMode") + orig = orig.decode() + if connection.send_packet("Qqemu.PhyMemMode:1") != b"OK": + raise gdb.error("Failed to set qemu.PhyMemMode") + try: + yield + finally: + if connection.send_packet("Qqemu.PhyMemMode:" + orig) != b"OK": + raise gdb.error("Failed to restore qemu.PhyMemMode") + + +@dataclasses.dataclass +class VmCore: + kerneloffset: typing.Optional[int] + + +def parse_vmcore(s): + match = re.search(r"KERNELOFFSET=([0-9a-f]+)", s) + if match is None: + kerneloffset = None + else: + kerneloffset = int(match.group(1), 16) + return VmCore(kerneloffset=kerneloffset) -- cgit v1.2.3