Re: null iv parameter passed to combo_init()

On Sun, Jan 9, 2022 at 1:27 PM Zhihong Yu <zyu(at)yugabyte(dot)com> wrote:

>
>
> On Sun, Jan 9, 2022 at 12:38 PM Zhihong Yu <zyu(at)yugabyte(dot)com> wrote:
>
>>
>>
>> On Sun, Jan 9, 2022 at 8:48 AM Noah Misch <noah(at)leadboat(dot)com> wrote:
>>
>>> On Sun, Jan 09, 2022 at 04:37:32AM -0800, Zhihong Yu wrote:
>>> > On Sat, Jan 8, 2022 at 11:32 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> > > Noah Misch <noah(at)leadboat(dot)com> writes:
>>> > > > On further thought, I would write it this way:
>>> > >
>>> > > > - else
>>> > > > + else if (ivlen != 0)
>>> > > > memcpy(ivbuf, iv, ivlen);
>>> > >
>>> > > FWIW, I liked the "ivlen > 0" formulation better. They should be
>>> > > equivalent, because ivlen is unsigned, but it just seems like "> 0"
>>> > > is more natural.
>>>
>>> If I were considering the one code site in isolation, I'd pick "ivlen >
>>> 0".
>>> But of the four sites identified so far, three have signed length
>>> variables.
>>> Since we're likely to get more examples of this pattern, some signed and
>>> some
>>> unsigned, I'd rather use a style that does the optimal thing whether or
>>> not
>>> the variable is signed. What do you think?
>>>
>>> > Patch v4 is attached.
>>>
>>> Does this pass the test procedure shown upthread?
>>>
>> Hi,
>> I installed gcc 4.9.3
>>
>> When I ran:
>> ./configure CFLAGS='-fsanitize=undefined
>> -fsanitize-undefined-trap-on-error'
>>
>> I saw:
>>
>> configure:3977: $? = 0
>> configure:3966: gcc -V >&5
>> gcc: error: unrecognized command line option '-V'
>> gcc: fatal error: no input files
>> compilation terminated.
>> configure:3977: $? = 1
>> configure:3966: gcc -qversion >&5
>> gcc: error: unrecognized command line option '-qversion'
>> gcc: fatal error: no input files
>> compilation terminated.
>> configure:3977: $? = 1
>> configure:3997: checking whether the C compiler works
>> configure:4019: gcc -fsanitize=undefined
>> -fsanitize-undefined-trap-on-error conftest.c >&5
>> gcc: error: unrecognized command line option
>> '-fsanitize-undefined-trap-on-error'
>> configure:4023: $? = 1
>> configure:4061: result: no
>>
>> I wonder if a higher version gcc is needed.
>>
>> FYI
>>
>
> After installing gcc-11, ./configure passed (with 0003-memcpy-null.patch).
> In the output of `make check-world`, I don't see `runtime error`.
> Though there was a crash (maybe specific to my machine):
>
> Core was generated by
> `/nfusr/dev-server/zyu/postgres/tmp_install/usr/local/pgsql/bin/postgres
> --singl'.
> Program terminated with signal SIGILL, Illegal instruction.
> #0 0x000000000050642d in write_item.cold ()
> Missing separate debuginfos, use: debuginfo-install
> glibc-2.17-325.el7_9.x86_64 nss-pam-ldapd-0.8.13-25.el7.x86_64
> sssd-client-1.16.5-10.el7_9.10.x86_64
> (gdb) bt
> #0 0x000000000050642d in write_item.cold ()
> #1 0x0000000000ba9d1b in write_relcache_init_file ()
> #2 0x0000000000bb58f7 in RelationCacheInitializePhase3 ()
> #3 0x0000000000bd5cb5 in InitPostgres ()
> #4 0x0000000000a0a9ea in PostgresMain ()
>
> FYI
>
Hi,
Earlier I was using devtoolset-11 which had an `Illegal instruction` error.

I compiled / installed gcc-11 from source (which took whole afternoon).
`make check-world` passed with patch v3.
In tmp_install/log/install.log, I saw:

gcc -Wall -Wmissing-prototypes -Wpointer-arith
-Wdeclaration-after-statement -Werror=vla -Wendif-labels
-Wmissing-format-attribute -Wimplicit-fallthrough=3 -Wcast-function-type
-Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard
-Wno-format-truncation -Wno-stringop-truncation -fsanitize=undefined
-fsanitize-undefined-trap-on-error -I../../src/port -DFRONTEND
-I../../src/include -D_GNU_SOURCE -c -o path.o path.c
rm -f libpgport.a

Cheers