From: Johannes Berg <johannes@sipsolutions.net>
To: Kees Cook <kees@kernel.org>, Richard Weinberger <richard@nod.at>
Cc: kernel test robot <lkp@intel.com>,
Nathan Chancellor <nathan@kernel.org>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
llvm@lists.linux.dev, linux-um@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v3] gcov: Disable GCOV_PROFILE_ALL on 32-bit UML with Clang 20/21
Date: Thu, 09 Apr 2026 16:47:32 +0200 [thread overview]
Message-ID: <5cf1d83227fd5a6af784f0b11fcdebf9a0bc9f94.camel@sipsolutions.net> (raw)
In-Reply-To: <20260409052038.make.995-kees@kernel.org>
Hi,
Maybe the subject should say "um:" instead of "gcov:" now?
(I'm assuming you want us to apply it to uml tree.)
> Prevent the bad combination by disabling UML's ARCH_HAS_GCOV_PROFILE_ALL
> on 32-bit when using Clang 20.x or 21.x.
You say 20.x or 21.x,
> + # Clang 20 & 21 miscompute __builtin_object_size() under -fprofile-arcs
> + # on 32-bit, causing spurious compile-time errors in check_copy_size().
> + select ARCH_HAS_GCOV_PROFILE_ALL if !(!64BIT && CLANG_VERSION >= 200000 && CLANG_VERSION < 220100)
and I see that 22.0 doesn't even exist, and maybe that's a general
pattern, but it still looks confusing? Wouldn't it be better simpler to
say < 220000? At least to me that more obviously is "up to 21.x". After
all, 20.0 also didn't exist, and you did >=200000, not >200000 or
>=200100?
johannes
next prev parent reply other threads:[~2026-04-09 14:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-09 5:20 [PATCH v3] gcov: Disable GCOV_PROFILE_ALL on 32-bit UML with Clang 20/21 Kees Cook
2026-04-09 14:47 ` Johannes Berg [this message]
2026-04-09 18:26 ` Nathan Chancellor
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