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From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will@kernel.org>
Cc: Arnd Bergmann <arnd@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
	clang-built-linux@googlegroups.com
Subject: Re: [PATCH] arm64: make atomic helpers __always_inline
Date: Fri, 8 Jan 2021 21:39:53 +0100	[thread overview]
Message-ID: <X/jDGbwDNcVrZdDJ@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210108093258.GB4031@willie-the-truck>

On Fri, Jan 08, 2021 at 09:32:58AM +0000, Will Deacon wrote:
> Hi Arnd,
> 
> On Fri, Jan 08, 2021 at 10:19:56AM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> > 
> > With UBSAN enabled and building with clang, there are occasionally
> > warnings like
> > 
> > WARNING: modpost: vmlinux.o(.text+0xc533ec): Section mismatch in reference from the function arch_atomic64_or() to the variable .init.data:numa_nodes_parsed
> > The function arch_atomic64_or() references
> > the variable __initdata numa_nodes_parsed.
> > This is often because arch_atomic64_or lacks a __initdata
> > annotation or the annotation of numa_nodes_parsed is wrong.
> > 
> > for functions that end up not being inlined as intended but operating
> > on __initdata variables. Mark these as __always_inline, along with
> > the corresponding asm-generic wrappers.
> 
> Hmm, I don't fully grok this. Why does it matter if a non '__init' function
> is called with a pointer to some '__initdata'? Or is the reference coming
> from somewhere else? (where?).

FWIW the x86 atomics are __always_inline in part due to the noinstr
crud, which I imagine resulted in much the same 'fun'.

  parent reply	other threads:[~2021-01-08 20:43 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-08  9:19 [PATCH] arm64: make atomic helpers __always_inline Arnd Bergmann
2021-01-08  9:32 ` Will Deacon
2021-01-08 10:26   ` Arnd Bergmann
2021-01-08 18:50     ` Will Deacon
2021-01-08 20:04       ` Arnd Bergmann
2021-01-08 21:23     ` Nick Desaulniers
2021-01-08 20:39   ` Peter Zijlstra [this message]
2021-01-12 10:23     ` Mark Rutland
2021-01-13 13:44       ` Will Deacon
2021-01-13 16:06 ` Catalin Marinas

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