From: "Arnd Bergmann" <arnd@arndb.de>
To: "Jason A . Donenfeld" <Jason@zx2c4.com>,
"Segher Boessenkool" <segher@kernel.crashing.org>
Cc: "Eric Biggers" <ebiggers@kernel.org>,
"Christophe Leroy" <christophe.leroy@csgroup.eu>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Naveen N Rao" <naveen@kernel.org>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Theodore Ts'o" <tytso@mit.edu>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Masami Hiramatsu" <mhiramat@kernel.org>,
"Mathieu Desnoyers" <mathieu.desnoyers@efficios.com>,
"Vincenzo Frascino" <vincenzo.frascino@arm.com>,
shuah <shuah@kernel.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
Linux-Arch <linux-arch@vger.kernel.org>,
linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v2 05/17] vdso: Avoid call to memset() by getrandom
Date: Wed, 28 Aug 2024 12:24:12 +0000 [thread overview]
Message-ID: <fc19bf63-d519-46e2-be70-80202c85ff92@app.fastmail.com> (raw)
In-Reply-To: <Zs8HirKLk-SrwTIu@zx2c4.com>
On Wed, Aug 28, 2024, at 11:18, Jason A. Donenfeld wrote:
> On Tue, Aug 27, 2024 at 05:53:30PM -0500, Segher Boessenkool wrote:
>> On Tue, Aug 27, 2024 at 11:08:19AM -0700, Eric Biggers wrote:
>> >
>> > Is there a compiler flag that could be used to disable the generation of calls
>> > to memset?
>>
>> -fno-tree-loop-distribute-patterns . But, as always, read up on it, see
>> what it actually does (and how it avoids your problem, and mostly: learn
>> what the actual problem *was*!)
>
> This might help with various loops, but it doesn't help with the matter
> that this patch fixes, which is struct initialization. I just tried it
> with the arm64 patch to no avail.
Maybe -ffreestanding can help here? That should cause the vdso to be built
with the assumption that there is no libc, so it would neither add nor
remove standard library calls. Not sure if that causes other problems,
e.g. if the calling conventions are different.
Arnd
next prev parent reply other threads:[~2024-08-28 12:24 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-22 7:13 [PATCH v2 00/17] Wire up getrandom() vDSO implementation on powerpc Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 01/17] asm-generic/unaligned.h: Extract common header for vDSO Christophe Leroy
2024-08-26 7:20 ` Jason A. Donenfeld
2024-08-26 7:32 ` Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 02/17] vdso: Clean header inclusion in getrandom Christophe Leroy
2024-08-26 8:07 ` Jason A. Donenfeld
2024-08-26 8:37 ` Christophe Leroy
2024-08-26 8:58 ` Jason A. Donenfeld
2024-08-26 10:45 ` Christophe Leroy
2024-08-26 13:17 ` Jason A. Donenfeld
2024-08-26 13:24 ` Thomas Gleixner
2024-08-22 7:13 ` [PATCH v2 03/17] vdso: Add __arch_get_k_vdso_rng_data() Christophe Leroy
2024-08-26 7:24 ` Jason A. Donenfeld
2024-08-22 7:13 ` [PATCH v2 04/17] vdso: Add missing c-getrandom-y in Makefile Christophe Leroy
2024-08-26 7:40 ` Jason A. Donenfeld
2024-08-22 7:13 ` [PATCH v2 05/17] vdso: Avoid call to memset() by getrandom Christophe Leroy
2024-08-26 8:01 ` Jason A. Donenfeld
2024-08-27 18:08 ` Eric Biggers
2024-08-27 18:22 ` Jason A. Donenfeld
2024-08-27 22:53 ` Segher Boessenkool
2024-08-28 11:18 ` Jason A. Donenfeld
2024-08-28 12:24 ` Arnd Bergmann [this message]
2024-08-28 12:26 ` Jason A. Donenfeld
2024-08-28 12:51 ` Segher Boessenkool
2024-08-28 12:45 ` Segher Boessenkool
2024-08-28 15:40 ` Ard Biesheuvel
2024-08-28 16:20 ` Segher Boessenkool
2024-08-28 17:12 ` Ard Biesheuvel
2024-08-28 17:25 ` Segher Boessenkool
2024-08-29 17:36 ` Christophe Leroy
2024-08-29 18:02 ` Segher Boessenkool
2024-08-29 18:50 ` Christophe Leroy
2024-08-30 10:01 ` Michael Ellerman
2024-08-28 12:33 ` Segher Boessenkool
2024-08-28 12:51 ` Jason A. Donenfeld
2024-08-22 7:13 ` [PATCH v2 06/17] vdso: Change getrandom's generation to unsigned long Christophe Leroy
2024-08-26 7:50 ` Jason A. Donenfeld
2024-08-26 8:01 ` Christophe Leroy
2024-08-26 8:16 ` Jason A. Donenfeld
2024-08-26 9:43 ` Thomas Gleixner
2024-08-26 9:48 ` Jason A. Donenfeld
2024-08-26 10:20 ` LEROY Christophe
2024-08-22 7:13 ` [PATCH v2 07/17] mm: Define VM_DROPPABLE for powerpc/32 Christophe Leroy
2024-08-26 9:53 ` kernel test robot
2024-08-26 10:13 ` kernel test robot
2024-08-26 21:34 ` kernel test robot
2024-08-22 7:13 ` [PATCH v2 08/17] powerpc: Add little endian variants of LWZX_BE and STWX_BE Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 09/17] powerpc/vdso32: Add crtsavres Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 10/17] powerpc/vdso: Refactor CFLAGS for CVDSO build Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 11/17] powerpc/vdso: Wire up getrandom() vDSO implementation Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 12/17] selftests: vdso: Fix powerpc64 vdso_config Christophe Leroy
2024-08-22 7:13 ` [PATCH v2 13/17] selftests: vdso: Don't hard-code location of vDSO sources Christophe Leroy
2024-08-26 7:26 ` Jason A. Donenfeld
2024-08-22 7:13 ` [PATCH v2 14/17] selftests: vdso: Make test_vdso_getrandom look for the right vDSO function Christophe Leroy
2024-08-26 7:28 ` Jason A. Donenfeld
2024-08-26 7:35 ` LEROY Christophe
2024-08-22 7:13 ` [PATCH v2 15/17] selftests: vdso: Fix build of test_vdso_chacha Christophe Leroy
2024-08-26 7:33 ` Jason A. Donenfeld
2024-08-22 7:13 ` [PATCH v2 16/17] selftests: vdso: Make VDSO function call more generic Christophe Leroy
2024-08-26 7:37 ` Jason A. Donenfeld
2024-08-26 7:48 ` LEROY Christophe
2024-08-22 7:13 ` [PATCH v2 17/17] selftests: vdso: Add support for vdso_test_random for powerpc Christophe Leroy
2024-08-26 7:19 ` [PATCH v2 00/17] Wire up getrandom() vDSO implementation on powerpc Jason A. Donenfeld
2024-08-26 8:23 ` Jason A. Donenfeld
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