From: Alan Modra <amodra@gmail.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: binutils@sourceware.org
Subject: Re: PR28977 tc-i386.c internal error in parse_register
Date: Fri, 18 Mar 2022 18:02:02 +1030 [thread overview]
Message-ID: <YjQ1ctJsSt4mA+p7@squeak.grove.modra.org> (raw)
In-Reply-To: <2da05d25-9304-bb71-1fee-9370a0171331@suse.com>
On Fri, Mar 18, 2022 at 08:12:46AM +0100, Jan Beulich wrote:
> On 18.03.2022 07:56, Alan Modra via Binutils wrote:
> > PR 28977
> > * config/tc-i386.c (parse_register): Handle X_op not O_register
> > as for a non-reg_section symbol. Simplify array bounds check.
>
> Hmm, isn't it that ...
>
> > --- a/gas/config/tc-i386.c
> > +++ b/gas/config/tc-i386.c
> > @@ -12952,17 +12952,18 @@ parse_register (char *reg_string, char **end_op)
> > {
>
> ... the if() right outside of context here is pointing at the actual
> problem? Why would "s=%rdx % %rcx" result in a reg_section expression?
> Imo this clearly ought to be expr_section.
Perhaps, but we are off in the weeds anyway.
The original fuzzer input had a completely crazy expression for "s".
s=%ymm5%%%!%%%%!%%%%%%%\x1d%%%%%%%%%%%%%%��������������������������%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%!%ebp%%%%%%%%%%%%%%%%%%M%%%%%%[s<��%[s<�����%%%%%��������������/+�������������%%%%[s<��%[s<�����%%%%'%%%%%%%%%%%%%%%%;%%%%%%!%%%%!%%%%%%%%%%%%%#NO
My testcase was a little tidier but still gives:
mad.s: Error: invalid operands (*GAS `reg' section* and *GAS `reg' section* sections) for `%' when setting `s'
The aim of the patch is to stop an abort *before* we decide the
expression is invalid. i386 parse_register was being called via
md_parse_name in gas/expr.c:operand.
--
Alan Modra
Australia Development Lab, IBM
next prev parent reply other threads:[~2022-03-18 7:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-18 6:56 Alan Modra
2022-03-18 7:12 ` Jan Beulich
2022-03-18 7:32 ` Alan Modra [this message]
2022-03-18 9:39 ` Jan Beulich
2022-03-18 12:03 ` Alan Modra
2022-03-21 16:59 ` Jan Beulich
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