lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <CADVatmO1V8DiAgWMW9EFHwt+ghwfHhueigXh214tUa_=tVxiug@mail.gmail.com> Date: Sun, 17 Jul 2022 21:25:20 +0100 From: Sudip Mukherjee <sudipm.mukherjee@...il.com> To: Linus Torvalds <torvalds@...ux-foundation.org> Cc: Michael Ellerman <mpe@...erman.id.au>, Benjamin Herrenschmidt <benh@...nel.crashing.org>, Paul Mackerras <paulus@...ba.org>, Kees Cook <keescook@...omium.org>, linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>, linux-kernel <linux-kernel@...r.kernel.org>, linux-hardening@...r.kernel.org, Segher Boessenkool <segher@...nel.crashing.org> Subject: Re: mainline build failure of powerpc allmodconfig for prom_init_check On Sun, Jul 17, 2022 at 3:44 PM Linus Torvalds <torvalds@...ux-foundation.org> wrote: > > On Sun, Jul 17, 2022 at 2:13 AM Sudip Mukherjee > <sudipm.mukherjee@...il.com> wrote: > > > > I was trying to check it. With gcc-11 the assembly code generated is > > not using memset, but using __memset. > > But with gcc-12, I can see the assembly code is using memset. One > > example from the assembly: > > You could try making the 'args' array in 'struct prom_args' be marked > 'volatile'. > > Ie something like this: > > --- a/arch/powerpc/kernel/prom_init.c > +++ b/arch/powerpc/kernel/prom_init.c > @@ -115,6 +115,6 @@ struct prom_args { > __be32 service; > __be32 nargs; > __be32 nret; > - __be32 args[10]; > + volatile __be32 args[10]; > }; > > because I think it's just the compilers turning the small loop over > those fields into a "memset()". That didn't work. "Error: External symbol 'memset' referenced from prom_init.c" is still there with this change. And the generated assembly still has the memset for "struct prom_args". -- Regards Sudip
Powered by blists - more mailing lists