Re: [Tinycc-devel] TCC segfault on Fedora 29

[Michael Matz]

Hi,

On Sat, 3 Nov 2018, Christian Jullien wrote:

> BTW, I already reported this BUG in the past:
>
> http://lists.nongnu.org/archive/html/tinycc-devel/2017-10/msg00033.html

I fixed this but that doesn't help the original bug report.  It's 
something specific to Fedora 29' /usr/lib64/crt1.o, so the reporter is 
probably right that it's the update to glibc 2.28 triggering the bug.  As 
I don't have such a new glibc yet I can't reproduce but will given some 
time.  Alternatively: somebody can send me their /usr/lib64/crt*.o files 
from a system where the segfault reproduces.  It's some unhandled 
situation with the section headers in that file.


Ciao,
Michael.

>  
>
>  
>
>  
>
> From: Tinycc-devel [mailto:address@hidden
> On Behalf Of Christian Jullien
> Sent: samedi 3 novembre 2018 16:35
> To: address@hidden
> Subject: Re: [Tinycc-devel] TCC segfault on Fedora 29
>
>  
>
> Main is a special case.
>
> While it is declared as returning an int, it is legal for this function and
> only for this function, to NOT return. In this case, it is as if it
> explicitly returned 0.
>
>  
>
> C.
>
>  
>
> From: Tinycc-devel [mailto:address@hidden
> On Behalf Of Nikolajs Agafonovs
> Sent: samedi 3 novembre 2018 16:28
> To: address@hidden
> Subject: Re: [Tinycc-devel] TCC segfault on Fedora 29
>
>  
>
> You forgot return value of function.
>
>  
>
> сб, 3 нояб. 2018 г., 16:50 藍挺瑋 address@hidden:
>
>       TCC works fine on Fedora 28, but it crashes on Fedora 29. It is
>       easily
>       reproducible because it cannot even compile a simple program.
>
>       $ echo 'int main(){}' > dummy.c
>       $ tcc dummy.c
>       Segmentation fault (core dumped)
>       $ gdb tcc core.\!usr\!bin\!tcc.signal-11.pid-303
>       GNU gdb (GDB) Fedora 8.2-3.fc29
>       Copyright (C) 2018 Free Software Foundation, Inc.
>       License GPLv3+: GNU GPL version 3 or later
>       <http://gnu.org/licenses/gpl.html>
>       This is free software: you are free to change and redistribute
>       it.
>       There is NO WARRANTY, to the extent permitted by law.
>       Type "show copying" and "show warranty" for details.
>       This GDB was configured as "x86_64-redhat-linux-gnu".
>       Type "show configuration" for configuration details.
>       For bug reporting instructions, please see:
>       <http://www.gnu.org/software/gdb/bugs/>.
>       Find the GDB manual and other documentation resources online at:
>           <http://www.gnu.org/software/gdb/documentation/>.
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>       For help, type "help".
>       Type "apropos word" to search for commands related to "word"...
>       Reading symbols from tcc...Reading symbols from
>       /usr/lib/debug/usr/bin/tcc-0.9.27-1.fc29.x86_64.debug...done.
>       done.
>       [New LWP 303]
>
>       warning: Loadable section ".note.gnu.property" outside of ELF
>       segments
>       Core was generated by `tcc dummy.c'.
>       Program terminated with signal SIGSEGV, Segmentation fault.
>       #0  0x000055e93017e05c in tcc_load_object_file
>       (address@hidden, address@hidden,
>       address@hidden) at tccelf.c:2462
>       2462                s->sh_info =
>       sm_table[sh->sh_info].s->sh_num;
>       (gdb) bt
>       #0  0x000055e93017e05c in tcc_load_object_file
>       (address@hidden, address@hidden,
>       address@hidden) at tccelf.c:2462
>       #1  0x000055e93016286c in tcc_add_file_internal
>       (s1=0x55e931cb2260,
>       filename=0x7ffc2cf18c90 "/usr/lib64/crt1.o", flags=64) at
>       libtcc.c:1028
>       #2  0x000055e930162967 in tcc_add_library_internal
>       (address@hidden, address@hidden "%s/%s",
>       address@hidden "crt1.o",
>       address@hidden,
>       paths=<optimized out>,
>           nb_paths=<optimized out>) at libtcc.c:1109
>       #3  0x000055e930162b17 in tcc_add_crt (address@hidden,
>       address@hidden "crt1.o") at
>       libtcc.c:1125
>       #4  0x000055e930162c7f in tcc_set_output_type (s=0x55e931cb2260,
>       output_type=2) at libtcc.c:978
>       #5  0x000055e93015fa4d in main (argc0=2, argv0=0x7ffc2cf19298)
>       at tcc.c:312
>
>       I guess it may be related to the Binutils 2.31 and GLIBC 2.28
>       upgrades
>       in Fedora 29. I also tested the latest version from git, and it
>       crashed
>       in the same way.
>
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