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
| ||
|
Date: Mon, 13 Jan 2020 15:01:52 +0000 From: Will Deacon <will@...nel.org> To: Arnd Bergmann <arnd@...db.de> Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, linux-arch <linux-arch@...r.kernel.org>, Android Kernel Team <kernel-team@...roid.com>, Michael Ellerman <mpe@...erman.id.au>, Peter Zijlstra <peterz@...radead.org>, Linus Torvalds <torvalds@...ux-foundation.org>, Segher Boessenkool <segher@...nel.crashing.org>, Christian Borntraeger <borntraeger@...ibm.com>, Luc Van Oostenryck <luc.vanoostenryck@...il.com> Subject: Re: [RFC PATCH 7/8] locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros On Fri, Jan 10, 2020 at 08:42:37PM +0100, Arnd Bergmann wrote: > On Fri, Jan 10, 2020 at 5:57 PM Will Deacon <will@...nel.org> wrote: > > > @@ -128,10 +128,10 @@ do { \ > > #ifndef __smp_load_acquire > > #define __smp_load_acquire(p) \ > > ({ \ > > - typeof(*p) ___p1 = READ_ONCE(*p); \ > > + __unqual_scalar_typeof(*p) ___p1 = READ_ONCE(*p); \ > > compiletime_assert_atomic_type(*p); \ > > __smp_mb(); \ > > - ___p1; \ > > + (typeof(*p))___p1; \ > > }) > > Doesn't that last (typeof(*p))___p1 mean you put the potential > 'volatile' back on the assignment after you went through the > effort of taking it out? Yes, but that's ok wrt codegen since the local variable isn't volatile, and I definitely ran into issues with 'const' if I returned the unqualified type here. Will
Powered by blists - more mailing lists