diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-04-24 08:23:54 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-05-07 21:12:41 +0200 |
| commit | 4253b0e0627ee3461e64c2495c616f1c8f6b127b (patch) | |
| tree | 3021ba22fe63f5844c30591396a017d8d5dba9e4 | |
| parent | c50c84c3ac4d5db683904bdb3257798b6ef980ae (diff) | |
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: stable@vger.kernel.org # 4.16
Fixes: d424986f1d ("s390: add sysfs attributes for spectre")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/nospec-branch.c | 19 | ||||
| -rw-r--r-- | arch/s390/kernel/nospec-sysfs.c | 21 |
3 files changed, 22 insertions, 19 deletions
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 84ea6225efb4..f92dd8ed3884 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -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 diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 46d49a11663f..834cf29f2599 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -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); diff --git a/arch/s390/kernel/nospec-sysfs.c b/arch/s390/kernel/nospec-sysfs.c new file mode 100644 index 000000000000..8affad5f18cb --- /dev/null +++ b/arch/s390/kernel/nospec-sysfs.c @@ -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"); +} |