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authorJosh Poimboeuf <jpoimboe@redhat.com>2019-04-12 15:39:29 -0500
committerBen Hutchings <ben@decadent.org.uk>2019-05-22 23:15:26 +0100
commitac8b5254181b2f0bd51a3d54e89a7bef8e4f1ef9 (patch)
treede412b20c6b1ac3ea63f36edebc26ffe3ea9dcad /arch/x86/mm/kaiser.c
parent48a145b594abae133543f06168723947b300995a (diff)
x86/speculation: Support 'mitigations=' cmdline option
commit d68be4c4d31295ff6ae34a8ddfaa4c1a8ff42812 upstream. Configure x86 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v2, Speculative Store Bypass, and L1TF. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Price <steven.price@arm.com> Cc: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/6616d0ae169308516cfdf5216bedd169f8a8291b.1555085500.git.jpoimboe@redhat.com [bwh: Backported to 3.16: - Drop the auto,nosmt option and the l1tf mitigation selection, which we can't support - Adjust filenames, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/x86/mm/kaiser.c')
-rw-r--r--arch/x86/mm/kaiser.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
index 8a07537dae08..30d1958e0540 100644
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -10,6 +10,7 @@
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
+#include <linux/cpu.h>
#include <xen/xen.h>
#undef pr_fmt
@@ -294,7 +295,8 @@ void __init kaiser_check_boottime_disable(void)
goto skip;
}
- if (cmdline_find_option_bool(boot_command_line, "nopti"))
+ if (cmdline_find_option_bool(boot_command_line, "nopti") ||
+ cpu_mitigations_off())
goto disable;
skip: