Patch "powerpc/fsl: Add nospectre_v2 command line argument" has been added to the 4.19-stable tree

[gregkh at linuxfoundation.org]

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

    powerpc/fsl: Add nospectre_v2 command line argument

to the 4.19-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-fsl-add-nospectre_v2-command-line-argument.patch
and it can be found in the queue-4.19 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 16:04:51 CET 2019
From: Michael Ellerman <mpe at ellerman.id.au>
Date: Fri, 29 Mar 2019 22:26:12 +1100
Subject: powerpc/fsl: Add nospectre_v2 command line argument
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: <20190329112620.14489-25-mpe at ellerman.id.au>

From: Diana Craciun <diana.craciun at nxp.com>

commit f633a8ad636efb5d4bba1a047d4a0f1ef719aa06 upstream.

When the command line argument is present, the Spectre variant 2
mitigations are disabled.

Signed-off-by: Diana Craciun <diana.craciun at nxp.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 arch/powerpc/include/asm/setup.h |    5 +++++
 arch/powerpc/kernel/security.c   |   21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)

--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -67,6 +67,11 @@ void do_barrier_nospec_fixups_range(bool
 static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
 #endif
 
+#ifdef CONFIG_PPC_FSL_BOOK3E
+void setup_spectre_v2(void);
+#else
+static inline void setup_spectre_v2(void) {};
+#endif
 void do_btb_flush_fixups(void);
 
 #endif /* !__ASSEMBLY__ */
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -26,6 +26,10 @@ static enum count_cache_flush_type count
 
 bool barrier_nospec_enabled;
 static bool no_nospec;
+static bool btb_flush_enabled;
+#ifdef CONFIG_PPC_FSL_BOOK3E
+static bool no_spectrev2;
+#endif
 
 static void enable_barrier_nospec(bool enable)
 {
@@ -101,6 +105,23 @@ static __init int barrier_nospec_debugfs
 device_initcall(barrier_nospec_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
 
+#ifdef CONFIG_PPC_FSL_BOOK3E
+static int __init handle_nospectre_v2(char *p)
+{
+	no_spectrev2 = true;
+
+	return 0;
+}
+early_param("nospectre_v2", handle_nospectre_v2);
+void setup_spectre_v2(void)
+{
+	if (no_spectrev2)
+		do_btb_flush_fixups();
+	else
+		btb_flush_enabled = true;
+}
+#endif /* CONFIG_PPC_FSL_BOOK3E */
+
 #ifdef CONFIG_PPC_BOOK3S_64
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
 {


Patches currently in stable-queue which might be from mpe at ellerman.id.au are

queue-4.19/powerpc-fsl-emulate-sprn_bucsr-register.patch
queue-4.19/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-64bit.patch
queue-4.19/powerpc-fsl-update-spectre-v2-reporting.patch
queue-4.19/powerpc-fsl-add-macro-to-flush-the-branch-predictor.patch
queue-4.19/powerpc-security-fix-spectre_v2-reporting.patch
queue-4.19/powerpc-fsl-fix-the-flush-of-branch-predictor.patch
queue-4.19/powerpc-fsl-enable-runtime-patching-if-nospectre_v2-boot-arg-is-used.patch
queue-4.19/powerpc-fsl-fixed-warning-orphan-section-__btb_flush_fixup.patch
queue-4.19/powerpc-fsl-add-nospectre_v2-command-line-argument.patch
queue-4.19/powerpc-fsl-add-infrastructure-to-fixup-branch-predictor-flush.patch
queue-4.19/powerpc-fsl-flush-the-branch-predictor-at-each-kernel-entry-32-bit.patch
queue-4.19/powerpc-fsl-flush-branch-predictor-when-entering-kvm.patch