| Message ID | 1453288550-4706-2-git-send-email-kieran.bingham@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 23/01/16 15:05, Jan Kiszka wrote: > On 2016-01-20 12:15, Kieran Bingham wrote: >> 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 >> >> Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org> >> --- >> >> I've added a 'constants.py' which is automatically generated. This allows >> values not available to the debugger, through #defines to be provided to >> our scripts. >> >> The alternative method for this is to create a c-object file to obtain values >> through symbols instead, and compile segments with -g3 to include macro >> definitions in the debug-info. >> >> I'd appreciate your thoughts on these options. > > I cannot assess your second proposal. How invasive will it be? Is it > promising to reduce the maintenance? What will be the impact of -g3? > > This approach seems pragmatic and sufficient. Would be fine with me > unless the other has significant advantages. At the moment, I believe the current method (generating a constants.py) is my preferred method. It's less intrusive, and can be generated for a kernel which is to be debugged, which perhaps didn't have GDB_SCRIPTS enabled at the time. A c-object file would be more limiting I believe. Kieran
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile index 6cf1ecf61057..50864f408ca8 100644 --- a/scripts/gdb/linux/Makefile +++ b/scripts/gdb/linux/Makefile @@ -2,10 +2,15 @@ always := gdb-scripts SRCTREE := $(shell cd $(srctree) && /bin/pwd) -$(obj)/gdb-scripts: +$(obj)/gdb-scripts: $(obj)/constants.py ifneq ($(KBUILD_SRC),) $(Q)ln -fsn $(SRCTREE)/$(obj)/*.py $(objtree)/$(obj) endif @: -clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) +$(obj)/constants.py: $(SRCTREE)/$(obj)/constants.py.in + @echo " GDB PP $@" + @$(CPP) -E -x c -P $(c_flags) $< > $@ + @sed -i '1,/<!-- end-c-headers -->/d;' $@ + +clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) $(obj)/constants.py diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in new file mode 100644 index 000000000000..d84084ac945b --- /dev/null +++ b/scripts/gdb/linux/constants.py.in @@ -0,0 +1,22 @@ +/* + * 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) + +/* The build system will take care of deleting everything above this marker */ +<!-- end-c-headers --> + +import gdb diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index d5943eca19cd..6e0b0afd888a 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -30,3 +30,4 @@ else: import linux.cpus import linux.lists import linux.proc + import 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 Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org> --- I've added a 'constants.py' which is automatically generated. This allows values not available to the debugger, through #defines to be provided to our scripts. The alternative method for this is to create a c-object file to obtain values through symbols instead, and compile segments with -g3 to include macro definitions in the debug-info. I'd appreciate your thoughts on these options. scripts/gdb/linux/Makefile | 9 +++++++-- scripts/gdb/linux/constants.py.in | 22 ++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 1 + 3 files changed, 30 insertions(+), 2 deletions(-) create mode 100644 scripts/gdb/linux/constants.py.in -- 2.5.0