[v6,01/21] scripts/gdb: Add infrastructure

Commit Message

Jan Kiszka Oct. 28, 2013, 8:58 a.m. UTC

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 depends on CONFIG_DEBUG_INFO.

CC: Michal Marek <[e-mail]>
CC: [e-mail]
Signed-off-by: Jan Kiszka <[e-mail]>
---
 Makefile                      |  5 ++++-
 scripts/Makefile              |  3 ++-
 scripts/gdb/Makefile          | 11 +++++++++++
 scripts/gdb/linux/Makefile    |  9 +++++++++
 scripts/gdb/linux/__init__.py |  0
 scripts/gdb/vmlinux-gdb.py    | 23 +++++++++++++++++++++++
 6 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 scripts/gdb/Makefile
 create mode 100644 scripts/gdb/linux/Makefile
 create mode 100644 scripts/gdb/linux/__init__.py
 create mode 100644 scripts/gdb/vmlinux-gdb.py

Comments

Andi Kleen Oct. 30, 2013, 5:35 a.m. UTC | #1

> 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.

> This feature depends on CONFIG_DEBUG_INFO.

Could you make this a separate config option? Having the links for
people who don't use gdb would be ugly.

-Andi
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Patch

diff --git a/Makefile b/Makefile
index 868c0eb..0e222d7 100644
--- a/Makefile
+++ b/Makefile
@@ -778,6 +778,9 @@  endif
 ifdef CONFIG_BUILD_DOCSRC
 	$(Q)$(MAKE) $(build)=Documentation
 endif
+ifdef CONFIG_DEBUG_INFO
+	$(Q)ln -fsn $(srctree)/scripts/gdb/vmlinux-gdb.py
+endif
 	+$(call if_changed,link-vmlinux)
 
 # The actual objects are generated when descending, 
@@ -1026,7 +1029,7 @@  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/scripts/Makefile b/scripts/Makefile
index 01e7adb..3204b91 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -37,6 +37,7 @@  subdir-$(CONFIG_MODVERSIONS) += genksyms
 subdir-y                     += mod
 subdir-$(CONFIG_SECURITY_SELINUX) += selinux
 subdir-$(CONFIG_DTC)         += dtc
+subdir-$(CONFIG_DEBUG_INFO)  += gdb
 
 # Let clean descend into subdirs
-subdir-	+= basic kconfig package selinux
+subdir-	+= basic kconfig package selinux gdb
diff --git a/scripts/gdb/Makefile b/scripts/gdb/Makefile
new file mode 100644
index 0000000..c0e2fd3
--- /dev/null
+++ b/scripts/gdb/Makefile
@@ -0,0 +1,11 @@ 
+subdir-y := linux
+
+always := gdb-scripts
+
+$(obj)/gdb-scripts:
+ifneq ($(KBUILD_SRC),)
+	$(Q)ln -fsn $(srctree)/$(obj)/*.py $(objtree)/$(obj)
+endif
+	@:
+
+clean-files := *.pyc $(if $(KBUILD_SRC),*.py)
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile
new file mode 100644
index 0000000..34ccd06
--- /dev/null
+++ b/scripts/gdb/linux/Makefile
@@ -0,0 +1,9 @@ 
+always := gdb-scripts
+
+$(obj)/gdb-scripts:
+ifneq ($(KBUILD_SRC),)
+	$(Q)ln -fsn $(srctree)/$(obj)/*.py $(objtree)/$(obj)
+endif
+	@:
+
+clean-files := *.pyc $(if $(KBUILD_SRC),*.py)
diff --git a/scripts/gdb/linux/__init__.py b/scripts/gdb/linux/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
new file mode 100644
index 0000000..c1d90ce
--- /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 <[e-mail]>
+#
+# 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")