From: Randy Dunlap <rdunlap@infradead.org>
To: Andi Kleen <andi@firstfloor.org>, tglx@linutronix.de
Cc: gregkh@linuxfoundation.org, dwmw@amazon.co.uk,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
x86@kernel.org, arjan@linux.intel.com,
Andi Kleen <ak@linux.intel.com>,
jeyu@kernel.org
Subject: Re: [PATCH v4] retpoline/module: Warn for missing retpoline in module
Date: Thu, 25 Jan 2018 15:53:36 -0800 [thread overview]
Message-ID: <e3429aa0-ccbc-e814-f67f-cd5b1f23bcbf@infradead.org> (raw)
In-Reply-To: <20180125235028.31211-1-andi@firstfloor.org>
On 01/25/2018 03:50 PM, Andi Kleen wrote:
> diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
> index 390b3dc3d438..8766e13efe80 100644
> --- a/arch/x86/kernel/cpu/bugs.c
> +++ b/arch/x86/kernel/cpu/bugs.c
> @@ -11,6 +11,7 @@
> #include <linux/init.h>
> #include <linux/utsname.h>
> #include <linux/cpu.h>
> +#include <linux/module.h>
>
> #include <asm/nospec-branch.h>
> #include <asm/cmdline.h>
> @@ -94,6 +95,20 @@ static const char *spectre_v2_strings[] = {
>
> static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
>
> +static bool spectre_v2_bad_module;
> +
> +#ifdef RETPOLINE
> +bool retpoline_module_ok(bool has_retpoline)
> +{
> + if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
> + return true;
> +
> + pr_err("system may be vunerable to spectre_v2\n");
vulnerable
> + spectre_v2_bad_module = true;
> + return false;
> +}
> +#endif
> +
> static void __init spec2_print_if_insecure(const char *reason)
> {
> if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
> @@ -278,6 +293,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev,
> if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
> return sprintf(buf, "Not affected\n");
>
> - return sprintf(buf, "%s\n", spectre_v2_strings[spectre_v2_enabled]);
> + return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled],
> + spectre_v2_bad_module ? " but vulnerable module loaded" : "");
> }
> #endif
--
~Randy
next prev parent reply other threads:[~2018-01-25 23:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-25 23:50 [PATCH v4] retpoline/module: Warn for missing retpoline in module Andi Kleen
2018-01-25 23:53 ` Randy Dunlap [this message]
2018-01-26 14:59 ` [tip:x86/pti] module/retpoline: Warn about " tip-bot for Andi Kleen
2018-01-26 17:51 ` Randy Dunlap
2018-01-27 13:40 ` Borislav Petkov
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