From: Andi Kleen <ak@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>, Andi Kleen <andi@firstfloor.org>,
the arch/x86 maintainers <x86@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>
Subject: Re: [PATCH 01/17] kbuild: Disable -Waddress-of-packed-member for gcc 9
Date: Fri, 22 Mar 2019 09:58:26 -0700 [thread overview]
Message-ID: <20190322165826.GE24002@tassilo.jf.intel.com> (raw)
In-Reply-To: <20190322163954.GG7905@worktop.programming.kicks-ass.net>
> Lol... we're actively moving away from the C standard on many places.
Yes and also packed is not part of the C standard.
> Why does the silly compiler think it is a problem to take the address of
> a member of a packed structure? That sounds like something that's
> perfectly fine and useful.
Probably because a pointer reference doesn't do whatever magic
may be needed on architectures with poor misalignment handling.
In theory you would need memcpy().
In practice it's likely a lot of false positives, like
the architectures with poor misalignment handling are usually
in SOCs without PCI and they don't have the devices
with the problematic drivers.
-Andi
next prev parent reply other threads:[~2019-03-22 16:58 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 21:59 Fixes and cleanup from LTO tree Andi Kleen
2019-03-21 21:59 ` [PATCH 01/17] kbuild: Disable -Waddress-of-packed-member for gcc 9 Andi Kleen
2019-03-22 13:58 ` Arnd Bergmann
2019-03-22 16:31 ` Andi Kleen
2019-03-22 16:39 ` Peter Zijlstra
2019-03-22 16:57 ` Arnd Bergmann
2019-03-22 16:58 ` Andi Kleen [this message]
2019-03-25 16:27 ` David Laight
2019-04-01 1:04 ` Masahiro Yamada
2019-03-21 21:59 ` [PATCH 02/17] x86, lto: Mark all top level asm statements as .text Andi Kleen
2019-03-26 17:03 ` Thomas Gleixner
2019-03-26 21:38 ` Andi Kleen
2019-03-26 22:25 ` Thomas Gleixner
2019-03-27 0:55 ` Andi Kleen
2019-03-27 1:08 ` Andi Kleen
2019-03-27 14:20 ` Thomas Gleixner
2019-03-27 14:39 ` Ingo Molnar
2019-03-27 14:59 ` Andi Kleen
2019-03-27 15:08 ` Thomas Gleixner
2019-03-27 15:45 ` Andi Kleen
2019-03-27 19:08 ` Thomas Gleixner
2019-03-27 20:40 ` Andi Kleen
2019-03-27 21:55 ` Thomas Gleixner
2019-03-27 22:29 ` Andi Kleen
2019-03-27 22:50 ` Thomas Gleixner
2019-04-02 8:54 ` Thomas Gleixner
2019-03-21 21:59 ` [PATCH 03/17] x86: Don't inline __const_udelay Andi Kleen
2019-03-21 21:59 ` [PATCH 04/17] init: Add __noreorder and mark initcalls __noreorder Andi Kleen
2019-03-21 21:59 ` [PATCH 05/17] Use C version for SYSCALL_ALIAS Andi Kleen
2019-03-21 21:59 ` [PATCH 06/17] locking/core: Mark spinlocks noinline when inline spinlocks are disabled Andi Kleen
2019-03-21 21:59 ` [PATCH 07/17] amdkfd: Fix extern declaration Andi Kleen
2019-03-21 22:00 ` [PATCH 08/17] x86/speculation: Fix __initconst in bugs.c Andi Kleen
2019-03-26 17:24 ` Thomas Gleixner
2019-03-21 22:00 ` [PATCH 09/17] x86/kvm: Make steal_time visible Andi Kleen
2019-03-21 22:00 ` [PATCH 10/17] delta: Fix buffer overrun in delta_ipc_open Andi Kleen
2019-04-01 13:37 ` Hugues FRUCHET
2019-04-01 16:54 ` Andi Kleen
2019-04-02 9:56 ` Hugues FRUCHET
2019-03-21 22:00 ` [PATCH 11/17] x86/kprobes: Make trampoline_handler global and visible Andi Kleen
2019-03-23 9:45 ` Masami Hiramatsu
2019-03-23 14:35 ` Andi Kleen
2019-03-25 1:53 ` Masami Hiramatsu
2019-03-21 22:00 ` [PATCH 12/17] afs: Avoid section confusion in CM_NAME Andi Kleen
2019-03-22 8:34 ` David Howells
2019-03-21 22:00 ` [PATCH 13/17] ASoC: AMD: Fix incorrect extern Andi Kleen
2019-03-21 22:00 ` [PATCH 14/17] crypto: Don't mark AES tables const and cacheline_aligned Andi Kleen
2019-03-26 8:42 ` Rasmus Villemoes
2019-03-26 18:30 ` Andi Kleen
2019-03-21 22:00 ` [PATCH 15/17] x86/hyperv: Make hv_vcpu_is_preempted visible Andi Kleen
2019-03-26 8:15 ` Yi Sun
2019-03-21 22:00 ` [PATCH 16/17] x86/xen: Mark xen_vcpu_stolen as __visible Andi Kleen
2019-03-21 22:00 ` [PATCH 17/17] dm: Fix const confusion in dm Andi Kleen
2019-03-26 17:00 ` Fixes and cleanup from LTO tree Thomas Gleixner
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