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>

1 files changed, 4 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 33cb15efd257..dd8796caa239 100644
--- a/Makefile
+++ b/Makefile
@@ -927,6 +927,9 @@ 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)
 
 # The actual objects are generated when descending,
@@ -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
 #