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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-04-12 15:39:29 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-05-22 23:15:26 +0100 |
| commit | ac8b5254181b2f0bd51a3d54e89a7bef8e4f1ef9 (patch) | |
| tree | de412b20c6b1ac3ea63f36edebc26ffe3ea9dcad /arch/x86 | |
| parent | 48a145b594abae133543f06168723947b300995a (diff) | |
| download | linux-stable-ac8b5254181b2f0bd51a3d54e89a7bef8e4f1ef9.tar.gz linux-stable-ac8b5254181b2f0bd51a3d54e89a7bef8e4f1ef9.tar.bz2 linux-stable-ac8b5254181b2f0bd51a3d54e89a7bef8e4f1ef9.zip | |
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')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 6 | ||||
| -rw-r--r-- | arch/x86/mm/kaiser.c | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index d25093a5b1b8..b08b7730836a 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -545,7 +545,8 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) char arg[20]; int ret, i; - if (cmdline_find_option_bool(boot_command_line, "nospectre_v2")) + if (cmdline_find_option_bool(boot_command_line, "nospectre_v2") || + cpu_mitigations_off()) return SPECTRE_V2_CMD_NONE; ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg)); @@ -809,7 +810,8 @@ static enum ssb_mitigation_cmd __init ssb_parse_cmdline(void) char arg[20]; int ret, i; - if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable")) { + if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable") || + cpu_mitigations_off()) { return SPEC_STORE_BYPASS_CMD_NONE; } else { ret = cmdline_find_option(boot_command_line, "spec_store_bypass_disable", 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: |