From 3ee7b3fa2cd0182628cca8d9bb5ce2d4722e8dc5 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 17 Feb 2015 13:46:36 -0800 Subject: [PATCH] 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 -gdb.py when opening . 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 Acked-by: Michal Marek [kbuild stuff] Cc: Thomas Gleixner Cc: Jason Wessel Cc: Andi Kleen Cc: Ben Widawsky Cc: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Makefile | 5 ++++- lib/Kconfig.debug | 11 +++++++++++ scripts/Makefile | 1 + scripts/gdb/Makefile | 1 + scripts/gdb/linux/Makefile | 11 +++++++++++ scripts/gdb/vmlinux-gdb.py | 23 +++++++++++++++++++++++ 6 files changed, 51 insertions(+), 1 deletion(-) create mode 100644 scripts/gdb/Makefile create mode 100644 scripts/gdb/linux/Makefile create mode 100644 scripts/gdb/vmlinux-gdb.py diff --git a/Makefile b/Makefile index 33cb15efd257..dd8796caa239 100644 --- a/Makefile +++ b/Makefile @@ -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 $(version_h) \ Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \ signing_key.priv signing_key.x509 x509.genkey \ extra_certificates signing_key.x509.keyid \ - signing_key.x509.signer + signing_key.x509.signer vmlinux-gdb.py # clean - Delete most, but leave enough to build external modules # diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ecb3516f6546..c5cefb3c009c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -167,6 +167,17 @@ config DEBUG_INFO_DWARF4 But it significantly improves the success of resolving variables in gdb on optimized code. +config GDB_SCRIPTS + bool "Provide GDB scripts for kernel debugging" + depends on DEBUG_INFO + help + This creates the required links to GDB helper scripts in the + build directory. If you load vmlinux into gdb, the helper + scripts will be automatically imported by gdb as well, and + additional functions are available to analyze a Linux kernel + instance. See Documentation/gdb-kernel-debugging.txt for further + details. + config ENABLE_WARN_DEPRECATED bool "Enable __deprecated logic" default y diff --git a/scripts/Makefile b/scripts/Makefile index 72902b5f2721..2016a64497ab 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -36,6 +36,7 @@ subdir-$(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 diff --git a/scripts/gdb/Makefile b/scripts/gdb/Makefile new file mode 100644 index 000000000000..62f5f65becfd --- /dev/null +++ b/scripts/gdb/Makefile @@ -0,0 +1 @@ +subdir-y := linux diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile new file mode 100644 index 000000000000..6cf1ecf61057 --- /dev/null +++ b/scripts/gdb/linux/Makefile @@ -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) diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py new file mode 100644 index 000000000000..c1d90cea5288 --- /dev/null +++ b/scripts/gdb/vmlinux-gdb.py @@ -0,0 +1,23 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# loader module +# +# Copyright (c) Siemens AG, 2012, 2013 +# +# Authors: +# Jan Kiszka +# +# 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") -- 2.30.2