scripts/gdb: add infrastructure

This provides the basic infrastructure to load kernel-specific python
helper scripts when debugging the kernel in gdb.

The loading mechanism is based on gdb loading for <objfile>-gdb.py when
opening <objfile>.  Therefore, this places a corresponding link to the
main helper script into the output directory that contains vmlinux.

The main scripts will pull in submodules containing Linux specific gdb
commands and functions.  To avoid polluting the source directory with
compiled python modules, we link to them from the object directory.

Due to gdb.parse_and_eval and string redirection for gdb.execute, we
depend on gdb >= 7.2.

This feature is enabled via CONFIG_GDB_SCRIPTS.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Michal Marek <mmarek@suse.cz>		[kbuild stuff]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kiszka 2015-02-17 13:46:36 -08:00 committed by Linus Torvalds
parent 0445f01a53
commit 3ee7b3fa2c
6 changed files with 51 additions and 1 deletions

View file

@ -926,6 +926,9 @@ ifdef CONFIG_SAMPLES
endif
ifdef CONFIG_BUILD_DOCSRC
$(Q)$(MAKE) $(build)=Documentation
endif
ifdef CONFIG_GDB_SCRIPTS
$(Q)ln -fsn `cd $(srctree) && /bin/pwd`/scripts/gdb/vmlinux-gdb.py
endif
+$(call if_changed,link-vmlinux)
@ -1181,7 +1184,7 @@ MRPROPER_FILES += .config .config.old .version .old_version $(version_h) \
Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
signing_key.priv signing_key.x509 x509.genkey \
extra_certificates signing_key.x509.keyid \
signing_key.x509.signer
signing_key.x509.signer vmlinux-gdb.py
# clean - Delete most, but leave enough to build external modules
#

View file

@ -167,6 +167,17 @@ config DEBUG_INFO_DWARF4
But it significantly improves the success of resolving
variables in gdb on optimized code.
config GDB_SCRIPTS
bool "Provide GDB scripts for kernel debugging"
depends on DEBUG_INFO
help
This creates the required links to GDB helper scripts in the
build directory. If you load vmlinux into gdb, the helper
scripts will be automatically imported by gdb as well, and
additional functions are available to analyze a Linux kernel
instance. See Documentation/gdb-kernel-debugging.txt for further
details.
config ENABLE_WARN_DEPRECATED
bool "Enable __deprecated logic"
default y

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@ -36,6 +36,7 @@ subdir-$(CONFIG_MODVERSIONS) += genksyms
subdir-y += mod
subdir-$(CONFIG_SECURITY_SELINUX) += selinux
subdir-$(CONFIG_DTC) += dtc
subdir-$(CONFIG_GDB_SCRIPTS) += gdb
# Let clean descend into subdirs
subdir- += basic kconfig package

1
scripts/gdb/Makefile Normal file
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@ -0,0 +1 @@
subdir-y := linux

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@ -0,0 +1,11 @@
always := gdb-scripts
SRCTREE := $(shell cd $(srctree) && /bin/pwd)
$(obj)/gdb-scripts:
ifneq ($(KBUILD_SRC),)
$(Q)ln -fsn $(SRCTREE)/$(obj)/*.py $(objtree)/$(obj)
endif
@:
clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py)

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@ -0,0 +1,23 @@
#
# gdb helper commands and functions for Linux kernel debugging
#
# loader module
#
# Copyright (c) Siemens AG, 2012, 2013
#
# Authors:
# Jan Kiszka <jan.kiszka@siemens.com>
#
# This work is licensed under the terms of the GNU GPL version 2.
#
import os
sys.path.insert(0, os.path.dirname(__file__) + "/scripts/gdb")
try:
gdb.parse_and_eval("0")
gdb.execute("", to_string=True)
except:
gdb.write("NOTE: gdb 7.2 or later required for Linux helper scripts to "
"work.\n")