From: Borislav Petkov <bp@alien8.de>
To: X86 ML <x86@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirsky <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Dave Hansen <dave.hansen@intel.com>,
Greg KH <gregkh@linuxfoundation.org>,
keescook@google.com, hughd@google.com,
Brian Gerst <brgerst@gmail.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
David Laight <David.Laight@aculab.com>,
Eduardo Valentin <eduval@amazon.com>,
aliguori@amazon.com, Will Deacon <will.deacon@arm.com>,
daniel.gruss@iaik.tugraz.at
Subject: [PATCH] x86/pti: Add pti= cmdline option and documentation
Date: Tue, 12 Dec 2017 14:39:52 +0100 [thread overview]
Message-ID: <20171212133952.10177-1-bp@alien8.de> (raw)
From: Borislav Petkov <bp@suse.de>
Keep the "nopti" for traditional reasons.
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: keescook@google.com
Cc: hughd@google.com
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: aliguori@amazon.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: daniel.gruss@iaik.tugraz.at
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
arch/x86/mm/pti.c | 18 ++++++++++++++++++
2 files changed, 24 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5dfd26265484..520fdec15bbb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3255,6 +3255,12 @@
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
+ pti= [X86_64]
+ Control user/kernel address space isolation:
+ on - enable
+ off - disable
+ auto - default setting
+
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
default number.
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index f48645d2f3fd..4afa16b444b2 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -51,15 +51,33 @@
void __init pti_check_boottime_disable(void)
{
bool enable = true;
+ char arg[5];
+
+ if (cmdline_find_option(boot_command_line, "pti", arg, sizeof(arg))) {
+ if (!strncmp(arg, "on", 2))
+ goto enable;
+
+ if (!strncmp(arg, "off", 3)) {
+ pr_info("disabled on command line.\n");
+ return;
+ }
+
+ if (!strncmp(arg, "auto", 4))
+ goto skip;
+ }
if (cmdline_find_option_bool(boot_command_line, "nopti")) {
pr_info("disabled on command line.\n");
enable = false;
}
+
+skip:
if (hypervisor_is_type(X86_HYPER_XEN_PV)) {
pr_info("disabled on XEN_PV.\n");
enable = false;
}
+
+enable:
if (enable)
setup_force_cpu_bug(X86_BUG_CPU_SECURE_MODE_PTI);
}
--
2.13.0
next reply other threads:[~2017-12-12 13:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-12 13:39 Borislav Petkov [this message]
2017-12-12 13:46 ` [PATCH] x86/pti: Add pti= cmdline option and documentation Juergen Gross
2017-12-12 14:28 ` Will Deacon
2017-12-14 15:18 ` Will Deacon
2017-12-18 12:33 ` Ingo Molnar
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