Re: [Valgrind-users] How to do handle SIGILL nostop in valgrind?

[Mark W. <ma...@kl...>]

Hi Ellie,

On Sun, Jun 26, 2022 at 10:13:37AM +0200, ellie wrote:
> How do I run openssl programs in valgrind on processors where it causes
> SIGILL? https://www.openssl.org/docs/faq.html#PROG17
> 
> They recommend to use handle SIGILL nostop, but the only mention in the
> valgrind documentation of that seems to be how to do this in gdb, not how to
> do this in valgrind itself.

Valgrind has (see the man page or manual):

       --sigill-diagnostics=<yes|no> [default: yes]
       
           Enable/disable printing of illegal instruction
           diagnostics. Enabled by default, but defaults to disabled
           when --quiet is given. The default can always be explicitly
           overridden by giving this option.

           When enabled, a warning message will be printed, along with
           some diagnostics, whenever an instruction is encountered
           that Valgrind cannot decode or translate, before the
           program is given a SIGILL signal. Often an illegal
           instruction indicates a bug in the program or missing
           support for the particular instruction in Valgrind. But
           some programs do deliberately try to execute an instruction
           that might be missing and trap the SIGILL signal to detect
           processor features. Using this flag makes it possible to
           avoid the diagnostic output that you would otherwise get in
           such cases.

Hope that helps.

Cheers,

Mark