Patch "[PATCH stable v4.14 01/32] powerpc/64s: Add support for ori barrier_nospec patching" has been added to the 4.14-stable tree
gregkh at linuxfoundation.org
gregkh at linuxfoundation.org
Sat Mar 30 01:54:46 AEDT 2019
This is a note to let you know that I've just added the patch titled
[PATCH stable v4.14 01/32] powerpc/64s: Add support for ori barrier_nospec patching
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-64s-add-support-for-ori-barrier_nospec-patching.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.
>From foo at baz Fri Mar 29 15:53:50 CET 2019
From: Michael Ellerman <mpe at ellerman.id.au>
Date: Fri, 29 Mar 2019 22:25:49 +1100
Subject: [PATCH stable v4.14 01/32] powerpc/64s: Add support for ori barrier_nospec patching
To: stable at vger.kernel.org, gregkh at linuxfoundation.org
Cc: linuxppc-dev at ozlabs.org, diana.craciun at nxp.com, msuchanek at suse.de, christophe.leroy at c-s.fr
Message-ID: <20190329112620.14489-2-mpe at ellerman.id.au>
From: Michael Ellerman <mpe at ellerman.id.au>
From: Michal Suchanek <msuchanek at suse.de>
commit 2eea7f067f495e33b8b116b35b5988ab2b8aec55 upstream.
Based on the RFI patching. This is required to be able to disable the
speculation barrier.
Only one barrier type is supported and it does nothing when the
firmware does not enable it. Also re-patching modules is not supported
So the only meaningful thing that can be done is patching out the
speculation barrier at boot when the user says it is not wanted.
Signed-off-by: Michal Suchanek <msuchanek at suse.de>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
arch/powerpc/include/asm/barrier.h | 2 +-
arch/powerpc/include/asm/feature-fixups.h | 9 +++++++++
arch/powerpc/include/asm/setup.h | 1 +
arch/powerpc/kernel/security.c | 9 +++++++++
arch/powerpc/kernel/vmlinux.lds.S | 7 +++++++
arch/powerpc/lib/feature-fixups.c | 27 +++++++++++++++++++++++++++
6 files changed, 54 insertions(+), 1 deletion(-)
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -81,7 +81,7 @@ do { \
* Prevent execution of subsequent instructions until preceding branches have
* been fully resolved and are no longer executing speculatively.
*/
-#define barrier_nospec_asm ori 31,31,0
+#define barrier_nospec_asm NOSPEC_BARRIER_FIXUP_SECTION; nop
// This also acts as a compiler barrier due to the memory clobber.
#define barrier_nospec() asm (stringify_in_c(barrier_nospec_asm) ::: "memory")
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -211,6 +211,14 @@ label##3: \
FTR_ENTRY_OFFSET 951b-952b; \
.popsection;
+#define NOSPEC_BARRIER_FIXUP_SECTION \
+953: \
+ .pushsection __barrier_nospec_fixup,"a"; \
+ .align 2; \
+954: \
+ FTR_ENTRY_OFFSET 953b-954b; \
+ .popsection;
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -219,6 +227,7 @@ extern long stf_barrier_fallback;
extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup;
extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup;
extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
+extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup;
void apply_feature_fixups(void);
void setup_feature_keys(void);
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -52,6 +52,7 @@ enum l1d_flush_type {
void setup_rfi_flush(enum l1d_flush_type, bool enable);
void do_rfi_flush_fixups(enum l1d_flush_type types);
+void do_barrier_nospec_fixups(bool enable);
#endif /* !__ASSEMBLY__ */
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -10,10 +10,19 @@
#include <asm/debugfs.h>
#include <asm/security_features.h>
+#include <asm/setup.h>
unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
+static bool barrier_nospec_enabled;
+
+static void enable_barrier_nospec(bool enable)
+{
+ barrier_nospec_enabled = enable;
+ do_barrier_nospec_fixups(enable);
+}
+
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
bool thread_priv;
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -153,6 +153,13 @@ SECTIONS
*(__rfi_flush_fixup)
__stop___rfi_flush_fixup = .;
}
+
+ . = ALIGN(8);
+ __spec_barrier_fixup : AT(ADDR(__spec_barrier_fixup) - LOAD_OFFSET) {
+ __start___barrier_nospec_fixup = .;
+ *(__barrier_nospec_fixup)
+ __stop___barrier_nospec_fixup = .;
+ }
#endif
EXCEPTION_TABLE(0)
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -277,6 +277,33 @@ void do_rfi_flush_fixups(enum l1d_flush_
(types & L1D_FLUSH_MTTRIG) ? "mttrig type"
: "unknown");
}
+
+void do_barrier_nospec_fixups(bool enable)
+{
+ unsigned int instr, *dest;
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___barrier_nospec_fixup),
+ end = PTRRELOC(&__stop___barrier_nospec_fixup);
+
+ instr = 0x60000000; /* nop */
+
+ if (enable) {
+ pr_info("barrier-nospec: using ORI speculation barrier\n");
+ instr = 0x63ff0000; /* ori 31,31,0 speculation barrier */
+ }
+
+ for (i = 0; start < end; start++, i++) {
+ dest = (void *)start + *start;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+ patch_instruction(dest, instr);
+ }
+
+ printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
+}
+
#endif /* CONFIG_PPC_BOOK3S_64 */
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
Patches currently in stable-queue which might be from mpe at ellerman.id.au are
queue-4.14/powerpc-fsl-emulate-sprn_bucsr-register.patch
queue-4.14/powerpc-64-make-stf-barrier-ppc_book3s_64-specific.patch
queue-4.14/powerpc-fsl-fix-spectre_v2-mitigations-reporting.patch
queue-4.14/powerpc-64s-patch-barrier_nospec-in-modules.patch
queue-4.14/powerpc-pseries-query-hypervisor-for-count-cache-flush-settings.patch
queue-4.14/powerpc-64s-add-support-for-software-count-cache-flush.patch
queue-4.14/powerpc64s-show-ori31-availability-in-spectre_v1-sysfs-file-not-v2.patch
queue-4.14/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-64bit.patch
queue-4.14/powerpc-fsl-update-spectre-v2-reporting.patch
queue-4.14/powerpc-64-make-meltdown-reporting-book3s-64-specific.patch
queue-4.14/powerpc-64s-add-support-for-ori-barrier_nospec-patching.patch
queue-4.14/powerpc-use-barrier_nospec-in-copy_from_user.patch
queue-4.14/powerpc-fsl-sanitize-the-syscall-table-for-nxp-powerpc-32-bit-platforms.patch
queue-4.14/powerpc-fsl-add-macro-to-flush-the-branch-predictor.patch
queue-4.14/powerpc-fsl-add-barrier_nospec-implementation-for-nxp-powerpc-book3e.patch
queue-4.14/powerpc-security-fix-spectre_v2-reporting.patch
queue-4.14/powerpc-64-disable-the-speculation-barrier-from-the-command-line.patch
queue-4.14/powerpc-fsl-fix-the-flush-of-branch-predictor.patch
queue-4.14/powerpc-64-add-config_ppc_barrier_nospec.patch
queue-4.14/powerpc-fsl-enable-runtime-patching-if-nospectre_v2-boot-arg-is-used.patch
queue-4.14/powerpc-64-use-barrier_nospec-in-syscall-entry.patch
queue-4.14/powerpc-fsl-fixed-warning-orphan-section-__btb_flush_fixup.patch
queue-4.14/powerpc-fsl-add-nospectre_v2-command-line-argument.patch
queue-4.14/powerpc-64s-add-new-security-feature-flags-for-count-cache-flush.patch
queue-4.14/powerpc-fsl-add-infrastructure-to-fixup-branch-predictor-flush.patch
queue-4.14/powerpc-64s-enhance-the-information-in-cpu_show_spectre_v1.patch
queue-4.14/powerpc-64-call-setup_barrier_nospec-from-setup_arch.patch
queue-4.14/powerpc-asm-add-a-patch_site-macro-helpers-for-patching-instructions.patch
queue-4.14/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-32-bit.patch
queue-4.14/powerpc-64s-enable-barrier_nospec-based-on-firmware-settings.patch
queue-4.14/powerpc-fsl-flush-branch-predictor-when-entering-kvm.patch
queue-4.14/powerpc-powernv-query-firmware-for-count-cache-flush-settings.patch
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