Re: [PATCH v2 03/18] ref-filter: make valid_atom as function parameter

From: Christian Couder <christian.couder@gmail.com>
Date: Jan 18, 2018, 14:23 UTC
Message-ID: <CAP8UFD1qPTh_VX8ebazxoeEHRfNjmNwy-baat9Y+GVHrHWQqFA@mail.gmail.com>
In-Reply-To: <CAL21BmneJ4rgCtf8t8LOK=gVv0MR+xam9jFBp7kp33rqEG7f6Q@mail.gmail.com>

On Thu, Jan 18, 2018 at 12:49 PM, Оля Тележная <olyatelezhnaya@gmail.com> wrote:

Show 17 quoted lines

> 2018-01-18 9:20 GMT+03:00 Оля Тележная <olyatelezhnaya@gmail.com>:
>>
>> I think it's important to finish migrating process at first. I mean,
>> now we are preparing and collecting everything in ref-filter, but we
>> make resulting string and print still in cat-file. And I am not sure,
>> but maybe it will not be possible to start using new atoms in cat-file
>> while some part of logic still differs.
>
> I tried to make that part here:
> https://github.com/telezhnaya/git/commit/19a148614f1d4db1f8e628eb4e6d7c819d2da875
> I know that the code is disgusting and there is a memory leak :) I
> just try to reuse ref-filter logic, I will cleanup everything later.
> At first, I try to make it work.
> The problem is that I have segfault, and if I use gdb, I get:
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000000000000000 in ?? ()

Make sure that you compile with debug options like -g3. For example I use:

$ make -j 4 DEVELOPER=1 CFLAGS="-g3"

> I tried to google it, it's my first time when I get that strange
> message, and unfortunately find nothing. So please explain me the
> reason, why I can't find a place of segfault that way.

I get the following:

(gdb) run cat-file --batch < myarg.txt Starting program: /home/ubuntu/bin/git cat-file --batch < myarg.txt [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x00005555556ea7cf in format_ref_array_item (info=0x7fffffffd460,
format=0x7fffffffd6e0,
    final_buf=0x7fffffffd410) at ref-filter.c:2234
2234                    atomv->handler(atomv, &state);
(gdb) bt
#0  0x00005555556ea7cf in format_ref_array_item (info=0x7fffffffd460,
    format=0x7fffffffd6e0, final_buf=0x7fffffffd410) at ref-filter.c:2234
#1  0x00005555556ea91c in show_ref_array_item (info=0x7fffffffd460,
format=0x7fffffffd6e0)
    at ref-filter.c:2256
#2  0x0000555555577ef7 in batch_object_write (
    obj_name=0x555555a66770 "5e1c309dae7f45e0f39b1bf3ac3cd9db12e7d689",
    opt=0x7fffffffd6e0, data=0x7fffffffd5e0) at builtin/cat-file.c:298