Commit 585d730d authored Oct 18, 2019 by Ilya Leoshkevich Committed by Linus Torvalds Oct 19, 2019

scripts/gdb: fix debugging modules on s390

Currently lx-symbols assumes that module text is always located at
module->core_layout->base, but s390 uses the following layout:

  +------+  <- module->core_layout->base
  | GOT  |
  +------+  <- module->core_layout->base + module->arch->plt_offset
  | PLT  |
  +------+  <- module->core_layout->base + module->arch->plt_offset +
  | TEXT |     module->arch->plt_size
  +------+

Therefore, when trying to debug modules on s390, all the symbol
addresses are skewed by plt_offset + plt_size.

Fix by adding plt_offset + plt_size to module_addr in
load_module_symbols().

Link: http://lkml.kernel.org/r/20191017085917.81791-1-iii@linux.ibm.com


Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent aa5de305

scripts/gdb/linux/symbols.py

+7 −1

Original line number	Diff line number	Diff line
		@@ -15,7 +15,7 @@ import gdb
		import os
		import re

		from linux import modules
		from linux import modules, utils


		if hasattr(gdb, 'Breakpoint'):
		@@ -116,6 +116,12 @@ lx-symbols command."""
		module_file = self._get_module_file(module_name)

		if module_file:
		if utils.is_target_arch('s390'):
		# Module text is preceded by PLT stubs on s390.
		module_arch = module['arch']
		plt_offset = int(module_arch['plt_offset'])
		plt_size = int(module_arch['plt_size'])
		module_addr = hex(int(module_addr, 0) + plt_offset + plt_size)
		gdb.write("loading @{addr}: {filename}\n".format(
		addr=module_addr, filename=module_file))
		cmdline = "add-symbol-file {filename} {addr}{sections}".format(

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