Commit 782e69ef authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Thomas Gleixner

powerpc/speculation: Support 'mitigations=' cmdline option

Configure powerpc CPU runtime speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Meltdown, Spectre
v1, Spectre v2, and Speculative Store Bypass.

The default behavior is unchanged.
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: default avatarJiri 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/245a606e1a42a558a310220312d9b6adb9159df6.1555085500.git.jpoimboe@redhat.com
parent d68be4c4
...@@ -2514,7 +2514,7 @@ ...@@ -2514,7 +2514,7 @@
http://repo.or.cz/w/linux-2.6/mini2440.git http://repo.or.cz/w/linux-2.6/mini2440.git
mitigations= mitigations=
[X86] Control optional mitigations for CPU [X86,PPC] Control optional mitigations for CPU
vulnerabilities. This is a set of curated, vulnerabilities. This is a set of curated,
arch-independent options, each of which is an arch-independent options, each of which is an
aggregation of existing arch-specific options. aggregation of existing arch-specific options.
...@@ -2523,10 +2523,11 @@ ...@@ -2523,10 +2523,11 @@
Disable all optional CPU mitigations. This Disable all optional CPU mitigations. This
improves system performance, but it may also improves system performance, but it may also
expose users to several CPU vulnerabilities. expose users to several CPU vulnerabilities.
Equivalent to: nopti [X86] Equivalent to: nopti [X86,PPC]
nospectre_v2 [X86] nospectre_v1 [PPC]
nospectre_v2 [X86,PPC]
spectre_v2_user=off [X86] spectre_v2_user=off [X86]
spec_store_bypass_disable=off [X86] spec_store_bypass_disable=off [X86,PPC]
l1tf=off [X86] l1tf=off [X86]
auto (default) auto (default)
......
...@@ -57,7 +57,7 @@ void setup_barrier_nospec(void) ...@@ -57,7 +57,7 @@ void setup_barrier_nospec(void)
enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR); security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
if (!no_nospec) if (!no_nospec && !cpu_mitigations_off())
enable_barrier_nospec(enable); enable_barrier_nospec(enable);
} }
...@@ -116,7 +116,7 @@ static int __init handle_nospectre_v2(char *p) ...@@ -116,7 +116,7 @@ static int __init handle_nospectre_v2(char *p)
early_param("nospectre_v2", handle_nospectre_v2); early_param("nospectre_v2", handle_nospectre_v2);
void setup_spectre_v2(void) void setup_spectre_v2(void)
{ {
if (no_spectrev2) if (no_spectrev2 || cpu_mitigations_off())
do_btb_flush_fixups(); do_btb_flush_fixups();
else else
btb_flush_enabled = true; btb_flush_enabled = true;
...@@ -307,7 +307,7 @@ void setup_stf_barrier(void) ...@@ -307,7 +307,7 @@ void setup_stf_barrier(void)
stf_enabled_flush_types = type; stf_enabled_flush_types = type;
if (!no_stf_barrier) if (!no_stf_barrier && !cpu_mitigations_off())
stf_barrier_enable(enable); stf_barrier_enable(enable);
} }
......
...@@ -958,7 +958,7 @@ void setup_rfi_flush(enum l1d_flush_type types, bool enable) ...@@ -958,7 +958,7 @@ void setup_rfi_flush(enum l1d_flush_type types, bool enable)
enabled_flush_types = types; enabled_flush_types = types;
if (!no_rfi_flush) if (!no_rfi_flush && !cpu_mitigations_off())
rfi_flush_enable(enable); rfi_flush_enable(enable);
} }
......
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