scripts/gdb: provide linux constants

Some macro's and defines are needed when parsing memory, and without
compiling the kernel as -g3 they are not available in the debug-symbols.

We use the pre-processor here to extract constants to a dedicated module
for the linux debugger extensions

Top level Kbuild is used to call in and generate the constants file,
while maintaining dependencies on autogenerated files in
include/generated

Link: http://lkml.kernel.org/r/bc3df9c25f57ea72177c066a51a446fc19e2c27f.1462865983.git.jan.kiszka@siemens.com
Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kieran Bingham 2016-05-23 16:24:40 -07:00 committed by Linus Torvalds
parent 0c22fde8b0
commit f197d75fca
4 changed files with 54 additions and 1 deletions

10
Kbuild
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@ -5,6 +5,7 @@
# 2) Generate timeconst.h
# 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
# 4) Check for missing system calls
# 5) Generate constants.py (may need bounds.h)
# Default sed regexp - multiline due to syntax constraints
define sed-y
@ -96,5 +97,14 @@ quiet_cmd_syscalls = CALL $<
missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
$(call cmd,syscalls)
#####
# 5) Generate constants for Python GDB integration
#
extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
@$(MAKE) $(build)=scripts/gdb/linux $@
# Keep these three files during make clean
no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)

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@ -8,4 +8,14 @@ ifneq ($(KBUILD_SRC),)
endif
@:
clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py)
quiet_cmd_gen_constants_py = GEN $@
cmd_gen_constants_py = \
$(CPP) -E -x c -P $(c_flags) $< > $@ ;\
sed -i '1,/<!-- end-c-headers -->/d;' $@
$(obj)/constants.py: $(SRCTREE)/$(obj)/constants.py.in
$(call if_changed,gen_constants_py)
build_constants_py: $(obj)/constants.py
clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) $(obj)/constants.py

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@ -0,0 +1,32 @@
/*
* gdb helper commands and functions for Linux kernel debugging
*
* Kernel constants derived from include files.
*
* Copyright (c) 2016 Linaro Ltd
*
* Authors:
* Kieran Bingham <kieran.bingham@linaro.org>
*
* This work is licensed under the terms of the GNU GPL version 2.
*
*/
/* We need to stringify expanded macros so that they can be parsed */
#define STRING(x) #x
#define XSTRING(x) STRING(x)
#define LX_VALUE(x) LX_##x = x
#define LX_GDBPARSED(x) LX_##x = gdb.parse_and_eval(XSTRING(x))
/*
* IS_ENABLED generates (a || b) which is not compatible with python
* We can only switch on configuration items we know are available
* Therefore - IS_BUILTIN() is more appropriate
*/
#define LX_CONFIG(x) LX_##x = IS_BUILTIN(x)
/* The build system will take care of deleting everything above this marker */
<!-- end-c-headers -->
import gdb

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@ -30,3 +30,4 @@ else:
import linux.cpus
import linux.lists
import linux.proc
import linux.constants