From: Borislav Petkov <bp@alien8•de>
To: "Jason A. Donenfeld" <Jason@zx2c4•com>
Cc: linux-s390@vger•kernel.org, "H . Peter Anvin" <hpa@zytor•com>,
Arnd Bergmann <arnd@arndb•de>, Will Deacon <will@kernel•org>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
Catalin Marinas <catalin.marinas@arm•com>,
Heiko Carstens <hca@linux•ibm.com>,
x86@kernel•org, linux-kernel@vger•kernel.org,
Alexander Gordeev <agordeev@linux•ibm.com>,
linuxppc-dev@lists•ozlabs.org,
Thomas Gleixner <tglx@linutronix•de>,
linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH] random: remove CONFIG_ARCH_RANDOM and "nordrand"
Date: Tue, 5 Jul 2022 21:36:20 +0200 [thread overview]
Message-ID: <YsSStCQQf008hF2F@zn.tnic> (raw)
In-Reply-To: <20220705190121.293703-1-Jason@zx2c4.com>
On Tue, Jul 05, 2022 at 09:01:21PM +0200, Jason A. Donenfeld wrote:
> @@ -26,7 +18,6 @@ __setup("nordrand", x86_rdrand_setup);
> */
> #define SANITY_CHECK_LOOPS 8
>
> -#ifdef CONFIG_ARCH_RANDOM
> void x86_init_rdrand(struct cpuinfo_x86 *c)
> {
> unsigned int changed = 0;
> @@ -59,8 +50,6 @@ void x86_init_rdrand(struct cpuinfo_x86 *c)
> }
>
> if (WARN_ON_ONCE(!changed))
> - pr_emerg(
> -"RDRAND gives funky smelling output, might consider not using it by booting with \"nordrand\"");
> + pr_emerg("RDRAND gives funky smelling output; update microcode or firmware.");
It is highly unlikely to get a BIOS or microcode update for that matter,
for old systems:
7879fc4bdc75 ("x86/rdrand: Sanity-check RDRAND output")
so I guess here you're better off saying that the kernel simply disables
rdrand support and do
clear_cpu_cap(c, X86_FEATURE_RDRAND);
here too.
If I read the commit message above correctly, it sounds like RDRAND
output is not that important anyway...
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-07-05 19:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 19:01 [PATCH] random: remove CONFIG_ARCH_RANDOM and "nordrand" Jason A. Donenfeld
2022-07-05 19:36 ` Borislav Petkov [this message]
2022-07-05 19:44 ` Jason A. Donenfeld
2022-07-05 19:57 ` Borislav Petkov
2022-07-05 21:50 ` H. Peter Anvin
2022-07-05 22:00 ` Borislav Petkov
2022-07-05 23:11 ` H. Peter Anvin
2022-07-06 12:23 ` Borislav Petkov
2022-07-06 16:42 ` H. Peter Anvin
2022-07-06 0:28 ` Jason A. Donenfeld
2022-07-06 0:32 ` [PATCH v2] random: remove CONFIG_ARCH_RANDOM Jason A. Donenfeld
2022-07-06 6:41 ` Greg Kroah-Hartman
2022-07-06 8:40 ` Heiko Carstens
2022-07-06 10:54 ` [PATCH v3] " Jason A. Donenfeld
2022-07-06 12:35 ` Borislav Petkov
2022-07-06 13:55 ` Jason A. Donenfeld
2022-07-06 14:35 ` [PATCH v4] " Jason A. Donenfeld
2022-07-08 0:40 ` [PATCH v5] " Jason A. Donenfeld
2022-07-13 15:46 ` Catalin Marinas
2022-07-18 12:53 ` Michael Ellerman
2022-08-12 13:50 ` Geert Uytterhoeven
2022-07-06 12:30 ` [PATCH] random: remove CONFIG_ARCH_RANDOM and "nordrand" Borislav Petkov
2022-07-06 14:55 ` Theodore Ts'o
2022-07-06 15:24 ` Jason A. Donenfeld
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