Subject: Patch "powerpc/64s: Patch barrier_nospec in modules" has been added to the 4.4-stable tree

From: <[email-masked]>
Date: Mon, 29 Apr 2019 11:51:24 +0200

This is a note to let you know that I've just added the patch titled

    powerpc/64s: Patch barrier_nospec in modules

to the 4.4-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-patch-barrier_nospec-in-modules.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email-masked]> know about it.

>From foo@baz Mon 29 Apr 2019 11:38:37 AM CEST
From: Michael Ellerman <[email-masked]>
Date: Mon, 22 Apr 2019 00:20:12 +1000
Subject: powerpc/64s: Patch barrier_nospec in modules
To: [email-masked], [email-masked]
Cc: [email-masked], [email-masked], [email-masked], [email-masked], [email-masked]
Message-ID: <[email-masked]>

From: Michal Suchanek <[email-masked]>

commit 815069ca57c142eb71d27439bc27f41a433a67b3 upstream.

Note that unlike RFI which is patched only in kernel the nospec state
reflects settings at the time the module was loaded.

Iterating all modules and re-patching every time the settings change
is not implemented.

Based on lwsync patching.

Signed-off-by: Michal Suchanek <[email-masked]>
Signed-off-by: Michael Ellerman <[email-masked]>
Signed-off-by: Greg Kroah-Hartman <[email-masked]>
---
 arch/powerpc/include/asm/setup.h  |    7 +++++++
 arch/powerpc/kernel/module.c      |    6 ++++++
 arch/powerpc/kernel/security.c    |    2 +-
 arch/powerpc/lib/feature-fixups.c |   16 +++++++++++++---
 4 files changed, 27 insertions(+), 4 deletions(-)

--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -39,6 +39,13 @@ 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);
+extern bool barrier_nospec_enabled;
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void do_barrier_nospec_fixups_range(bool enable, void *start, void *end);
+#else
+static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
+#endif
 
 #endif /* !__ASSEMBLY__ */
 
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -67,6 +67,12 @@ int module_finalize(const Elf_Ehdr *hdr,
 		do_feature_fixups(powerpc_firmware_features,
 				  (void *)sect->sh_addr,
 				  (void *)sect->sh_addr + sect->sh_size);
+
+	sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
+	if (sect != NULL)
+		do_barrier_nospec_fixups_range(barrier_nospec_enabled,
+				  (void *)sect->sh_addr,
+				  (void *)sect->sh_addr + sect->sh_size);
 #endif
 
 	sect = find_section(hdr, sechdrs, "__lwsync_fixup");
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -16,7 +16,7 @@
 
 unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
 
-static bool barrier_nospec_enabled;
+bool barrier_nospec_enabled;
 
 static void enable_barrier_nospec(bool enable)
 {
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -275,14 +275,14 @@ void do_rfi_flush_fixups(enum l1d_flush_
 						: "unknown");
 }
 
-void do_barrier_nospec_fixups(bool enable)
+void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
 {
 	unsigned int instr, *dest;
 	long *start, *end;
 	int i;
 
-	start = PTRRELOC(&__start___barrier_nospec_fixup),
-	end = PTRRELOC(&__stop___barrier_nospec_fixup);
+	start = fixup_start;
+	end = fixup_end;
 
 	instr = 0x60000000; /* nop */
 
@@ -301,6 +301,16 @@ void do_barrier_nospec_fixups(bool enabl
 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
 }
 
+void do_barrier_nospec_fixups(bool enable)
+{
+	void *start, *end;
+
+	start = PTRRELOC(&__start___barrier_nospec_fixup),
+	end = PTRRELOC(&__stop___barrier_nospec_fixup);
+
+	do_barrier_nospec_fixups_range(enable, start, end);
+}
+
 #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 [email-masked] are

queue-4.4/powerpc-64s-add-support-for-a-store-forwarding-barrier-at-kernel-entry-exit.patch
queue-4.4/powerpc-64-make-stf-barrier-ppc_book3s_64-specific.patch
queue-4.4/powerpc-pseries-set-or-clear-security-feature-flags.patch
queue-4.4/powerpc-fsl-fix-spectre_v2-mitigations-reporting.patch
queue-4.4/powerpc-64s-patch-barrier_nospec-in-modules.patch
queue-4.4/powerpc-pseries-support-firmware-disable-of-rfi-flush.patch
queue-4.4/powerpc-rfi-flush-call-setup_rfi_flush-after-lpm-migration.patch
queue-4.4/powerpc-pseries-query-hypervisor-for-count-cache-flush-settings.patch
queue-4.4/powerpc-powernv-set-or-clear-security-feature-flags.patch
queue-4.4/powerpc-64s-add-support-for-software-count-cache-flush.patch
queue-4.4/powerpc64s-show-ori31-availability-in-spectre_v1-sysfs-file-not-v2.patch
queue-4.4/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-64bit.patch
queue-4.4/powerpc-fsl-update-spectre-v2-reporting.patch
queue-4.4/powerpc-64s-wire-up-cpu_show_spectre_v2.patch
queue-4.4/powerpc-64-make-meltdown-reporting-book3s-64-specific.patch
queue-4.4/powerpc-rfi-flush-make-it-possible-to-call-setup_rfi_flush-again.patch
queue-4.4/powerpc-64s-add-support-for-ori-barrier_nospec-patching.patch
queue-4.4/powerpc-use-barrier_nospec-in-copy_from_user.patch
queue-4.4/powerpc-64s-fix-section-mismatch-warnings-from-setup_rfi_flush.patch
queue-4.4/powerpc-avoid-code-patching-freed-init-sections.patch
queue-4.4/powerpc-fsl-add-macro-to-flush-the-branch-predictor.patch
queue-4.4/powerpc-xmon-add-rfi-flush-related-fields-to-paca-dump.patch
queue-4.4/powerpc-fsl-add-barrier_nospec-implementation-for-nxp-powerpc-book3e.patch
queue-4.4/powerpc-security-fix-spectre_v2-reporting.patch
queue-4.4/powerpc-add-security-feature-flags-for-spectre-meltdown.patch
queue-4.4/powerpc-powernv-use-the-security-flags-in-pnv_setup_rfi_flush.patch
queue-4.4/powerpc-64-disable-the-speculation-barrier-from-the-command-line.patch
queue-4.4/powerpc-fsl-fix-the-flush-of-branch-predictor.patch
queue-4.4/powerpc-pseries-use-the-security-flags-in-pseries_setup_rfi_flush.patch
queue-4.4/powerpc-64-add-config_ppc_barrier_nospec.patch
queue-4.4/powerpc-64s-move-cpu_show_meltdown.patch
queue-4.4/powerpc-64-use-barrier_nospec-in-syscall-entry.patch
queue-4.4/powerpc-fsl-add-nospectre_v2-command-line-argument.patch
queue-4.4/powerpc-64s-add-new-security-feature-flags-for-count-cache-flush.patch
queue-4.4/powerpc-fsl-add-infrastructure-to-fixup-branch-predictor-flush.patch
queue-4.4/powerpc-rfi-flush-differentiate-enabled-and-patched-flush-types.patch
queue-4.4/powerpc-64s-enhance-the-information-in-cpu_show_spectre_v1.patch
queue-4.4/powerpc-64-call-setup_barrier_nospec-from-setup_arch.patch
queue-4.4/powerpc-rfi-flush-always-enable-fallback-flush-on-pseries.patch
queue-4.4/powerpc-64s-improve-rfi-l1-d-cache-flush-fallback.patch
queue-4.4/powerpc-asm-add-a-patch_site-macro-helpers-for-patching-instructions.patch
queue-4.4/powerpc-pseries-add-new-h_get_cpu_characteristics-flags.patch
queue-4.4/powerpc-64s-enable-barrier_nospec-based-on-firmware-settings.patch
queue-4.4/powerpc-powernv-support-firmware-disable-of-rfi-flush.patch
queue-4.4/powerpc-rfi-flush-move-the-logic-to-avoid-a-redo-into-the-debugfs-code.patch
queue-4.4/powerpc-powernv-query-firmware-for-count-cache-flush-settings.patch
queue-4.4/powerpc-64s-wire-up-cpu_show_spectre_v1.patch
queue-4.4/powerpc-64s-add-barrier_nospec.patch
queue-4.4/powerpc-64s-enhance-the-information-in-cpu_show_meltdown.patch
queue-4.4/powerpc-move-default-security-feature-flags.patch
queue-4.4/powerpc-pseries-fix-clearing-of-security-feature-flags.patch
queue-4.4/powerpc-pseries-restore-default-security-feature-flags-on-setup.patch