FAILED: patch "[PATCH] s390: move spectre sysfs attribute code" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message May 20, 2018

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2018-05-20 08:29 UTC #0 lore raw

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 4253b0e0627ee3461e64c2495c616f1c8f6b127b Mon Sep 17 00:00:00 2001

From: Martin Schwidefsky <[email protected]>
Date: Tue, 24 Apr 2018 08:23:54 +0200
Subject: [PATCH] s390: move spectre sysfs attribute code

The nospec-branch.c file is compiled without the gcc options to generate expoline thunks. The return branch of the sysfs show functions cpu_show_spectre_v1 and cpu_show_spectre_v2 is an indirect branch as well. These need to be compiled with expolines.

Move the sysfs functions for spectre reporting to a separate file and loose an '.' for one of the messages.

Cc [email protected] # 4.16

Fixes d424986f1d ("s390: add sysfs attributes for spectre")

Signed-off-by Martin Schwidefsky <[email protected]>

arch/s390/kernel/Makefile +1 -0

index 84ea6225efb4..f92dd8ed3884 100644
@@ -65,6 +65,7 @@ obj-y	+= nospec-branch.o
 
 extra-y				+= head.o head64.o vmlinux.lds
 
+obj-$(CONFIG_SYSFS)		+= nospec-sysfs.o
 CFLAGS_REMOVE_nospec-branch.o	+= $(CC_FLAGS_EXPOLINE)
 
 obj-$(CONFIG_MODULES)		+= module.o

arch/s390/kernel/nospec-branch.c +0 ~~-19~~

index 46d49a11663f..834cf29f2599 100644
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/module.h>
 #include <linux/device.h>
-#include <linux/cpu.h>
 #include <asm/nospec-branch.h>
 
 static int __init nobp_setup_early(char *str)

@@ -44,24 +43,6 @@ static int __init nospec_report(void)
 }
 arch_initcall(nospec_report);
 
-#ifdef CONFIG_SYSFS
-ssize_t cpu_show_spectre_v1(struct device *dev,
-			    struct device_attribute *attr, char *buf)
-{
-	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
-}
-
-ssize_t cpu_show_spectre_v2(struct device *dev,
-			    struct device_attribute *attr, char *buf)
-{
-	if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
-		return sprintf(buf, "Mitigation: execute trampolines\n");
-	if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
-		return sprintf(buf, "Mitigation: limited branch prediction.\n");
-	return sprintf(buf, "Vulnerable\n");
-}
-#endif
-
 #ifdef CONFIG_EXPOLINE
 
 int nospec_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF);

arch/s390/kernel/nospec-sysfs.c new file +21 -0

new file mode 100644
index 000000000000..8affad5f18cb
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <asm/facility.h>
+#include <asm/nospec-branch.h>
+
+ssize_t cpu_show_spectre_v1(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+}
+
+ssize_t cpu_show_spectre_v2(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
+		return sprintf(buf, "Mitigation: execute trampolines\n");
+	if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
+		return sprintf(buf, "Mitigation: limited branch prediction\n");
+	return sprintf(buf, "Vulnerable\n");
+}