From: Kieran Bingham <kieranbingham@gmail.com>
To: Jeff Mahoney <jeffm@suse.com>, Doug Evans <dje@google.com>,
Ales Novak <alnovak@suse.cz>
Cc: gdb-patches <gdb-patches@sourceware.org>,
Peter Griffin <peter.griffin@linaro.org>,
Lee Jones <lee.jones@linaro.org>
Subject: Re: [PATCH 2/4] Add Jeff Mahoney's py-crash patches.
Date: Tue, 02 Feb 2016 08:25:00 -0000 [thread overview]
Message-ID: <56B067E5.8070606@gmail.com> (raw)
In-Reply-To: <56B01AB9.90005@suse.com>
On 02/02/16 02:55, Jeff Mahoney wrote:
> On 2/1/16 5:22 PM, Doug Evans wrote:
>> On Sun, Jan 31, 2016 at 1:44 PM, Ales Novak <alnovak@suse.cz>
>> wrote:
>>> --- gdb/Makefile.in | 12 ++
>>> gdb/python/py-minsymbol.c | 353
>>> +++++++++++++++++++++++++++++++++++++ gdb/python/py-objfile.c
>>> | 29 +++- gdb/python/py-section.c | 401
>>> +++++++++++++++++++++++++++++++++++++++++++
>>> gdb/python/py-symbol.c | 52 ++++--
>>> gdb/python/python-internal.h | 14 ++ gdb/python/python.c
>>> | 7 +- 7 files changed, 853 insertions(+), 15 deletions(-)
>>> create mode 100644 gdb/python/py-minsymbol.c create mode 100644
>>> gdb/python/py-section.c
>
>
>> Hi.
>
> Hi Doug -
>
>> Part of what this patch is doing is exporting bfd to python. E.g.,
>> all the SEC_* constants.
>
>> As a rule we absolutely discourage people from using bfd outside
>> of the the binutils+gdb source tree. Either this rule needs to
>> change, or I don't think we can allow this patch. I'd be interested
>> to hear what others in the community think.
>
> That's unfortunate. The Linux kernel uses ELF sections for a number
> of purposes. Most notably is the definition of per-cpu variables.
> Without the ELF section, we can't resolve the addresses for the
> variables. So, from our perspective, it's a requirement.
Jeff,
I haven't yet looked into your code specifically to check your per-cpu
implementation detail yet, so I'll just speculate for a moment:
Have you seen that we can obtain per_cpu variable from
linux.git/scripts/gdb/linux/cpus.py ?
def per_cpu(var_ptr, cpu):
if cpu == -1:
cpu = get_current_cpu()
if utils.is_target_arch("sparc:v9"):
offset = gdb.parse_and_eval(
"trap_block[{0}].__per_cpu_base".format(str(cpu)))
else:
try:
offset = gdb.parse_and_eval(
"__per_cpu_offset[{0}]".format(str(cpu)))
except gdb.error:
# !CONFIG_SMP case
offset = 0
pointer = var_ptr.cast(utils.get_long_type()) + offset
return pointer.cast(var_ptr.type).dereference()
>> For myself, I would much rather export ELF separately (e.g., a
>> separate python API one can use independent of any particular tool,
>> including gdb), and then have gdb provide the necessary glue to use
>> this API. [I can imagine some compromises being needed, at least
>> for now; e.g., it'd be cumbersome to read in all ELF symbols
>> twice. But fixing that is just an optimization.]
>
> Ok, that's doable. As it is, the section code mixes GDB and BFD
> pretty heavily. It shouldn't be too difficult to separate the two out
> and push the section stuff into a new BFD python interface and
> associate the objfiles with it.
Some of our further work (/stretch goals) on Linux Kernel Awareness,
will also utilise this so I will be interested to see how it goes.
> -Jeff
>
>
>>> ... + if (PyModule_AddIntConstant (gdb_module, "SEC_NO_FLAGS",
>>> SEC_NO_FLAGS) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_ALLOC", SEC_ALLOC) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_LOAD", SEC_LOAD) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module, "SEC_RELOC", SEC_RELOC) < 0
>>> + || PyModule_AddIntConstant (gdb_module, "SEC_READONLY",
>>> SEC_READONLY) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_CODE", SEC_CODE) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_DATA", SEC_DATA) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module, "SEC_ROM", SEC_ROM) < 0 +
>>> || PyModule_AddIntConstant (gdb_module, "SEC_CONSTRUCTOR", +
>>> SEC_CONSTRUCTOR) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_HAS_CONTENTS", +
>>> SEC_HAS_CONTENTS) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_NEVER_LOAD", +
>>> SEC_NEVER_LOAD) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_THREAD_LOCAL", +
>>> SEC_THREAD_LOCAL) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_HAS_GOT_REF", +
>>> SEC_HAS_GOT_REF) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_IS_COMMON", +
>>> SEC_IS_COMMON) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_DEBUGGING", + SEC_DEBUGGING)
>>> < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_IN_MEMORY", + SEC_IN_MEMORY)
>>> < 0 + || PyModule_AddIntConstant (gdb_module, "SEC_EXCLUDE",
>>> SEC_EXCLUDE) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_SORT_ENTRIES", +
>>> SEC_SORT_ENTRIES) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_LINK_ONCE", +
>>> SEC_LINK_ONCE) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_LINK_DUPLICATES", +
>>> SEC_LINK_DUPLICATES) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_LINK_DUPLICATES_DISCARD", +
>>> SEC_LINK_DUPLICATES_DISCARD) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module,
>>> "SEC_LINK_DUPLICATES_ONE_ONLY", +
>>> SEC_LINK_DUPLICATES_ONE_ONLY) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module,
>>> "SEC_LINK_DUPLICATES_SAME_SIZE", +
>>> SEC_LINK_DUPLICATES_SAME_SIZE) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module, "SEC_LINKER_CREATED", +
>>> SEC_LINKER_CREATED) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_KEEP", SEC_KEEP) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module, "SEC_SMALL_DATA", +
>>> SEC_SMALL_DATA) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_MERGE", SEC_MERGE) < 0 + ||
>>> PyModule_AddIntConstant (gdb_module, "SEC_STRNGS", SEC_STRINGS) <
>>> 0 + || PyModule_AddIntConstant (gdb_module, "SEC_GROUP",
>>> SEC_GROUP) < 0 + || PyModule_AddIntConstant (gdb_module,
>>> "SEC_COFF_SHARED_LIBRARY", +
>>> SEC_COFF_SHARED_LIBRARY) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_ELF_REVERSE_COPY", +
>>> SEC_ELF_REVERSE_COPY) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_COFF_SHARED", +
>>> SEC_COFF_SHARED) < 0 + || PyModule_AddIntConstant
>>> (gdb_module, "SEC_COFF_NOREAD", +
>>> SEC_COFF_NOREAD) < 0) + return -1; ...
>
>
>
>
next prev parent reply other threads:[~2016-02-02 8:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-31 21:45 Enable gdb to open Linux kernel dumps Ales Novak
2016-01-31 21:45 ` [PATCH 2/4] Add Jeff Mahoney's py-crash patches Ales Novak
2016-02-01 12:35 ` Kieran Bingham
2016-02-01 22:23 ` Doug Evans
2016-02-02 2:56 ` Jeff Mahoney
2016-02-02 8:25 ` Kieran Bingham [this message]
2016-02-03 17:55 ` Jeff Mahoney
2016-02-03 18:31 ` Doug Evans
2016-02-03 19:29 ` Jeff Mahoney
2016-02-04 17:25 ` Petr Tesarik
2016-02-04 18:32 ` Matt Rice
2016-02-04 22:27 ` Doug Evans
2016-01-31 21:45 ` [PATCH 3/4] Add SLAB allocator understanding Ales Novak
2016-02-01 13:21 ` Kieran Bingham
2016-02-01 22:30 ` Doug Evans
2016-02-02 2:05 ` Ales Novak
2016-02-02 7:22 ` Jan Kiszka
2016-02-02 13:22 ` Petr Tesarik
2016-02-02 14:42 ` Jeff Mahoney
2016-02-02 8:11 ` Kieran Bingham
2016-02-02 10:04 ` Vlastimil Babka
2016-01-31 21:45 ` [PATCH 1/4] Create new target "kdump" which uses libkdumpfile: https://github.com/ptesarik/libkdumpfile to access contents of compressed kernel dump Ales Novak
2016-02-04 12:40 ` Pedro Alves
2016-02-04 12:45 ` Ales Novak
2016-01-31 21:45 ` [PATCH 4/4] Minor cleanups Ales Novak
2016-02-01 11:27 ` Enable gdb to open Linux kernel dumps Kieran Bingham
2016-02-01 11:51 ` Kieran Bingham
2016-02-01 14:32 ` Ales Novak
2016-02-01 15:01 ` Jeff Mahoney
2016-02-02 9:12 ` Kieran Bingham
2016-02-10 3:24 ` Jeff Mahoney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56B067E5.8070606@gmail.com \
--to=kieranbingham@gmail.com \
--cc=alnovak@suse.cz \
--cc=dje@google.com \
--cc=gdb-patches@sourceware.org \
--cc=jeffm@suse.com \
--cc=lee.jones@linaro.org \
--cc=peter.griffin@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).