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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-04-24 08:23:54 +0200 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-05-07 21:12:41 +0200 |
commit | 4253b0e0627ee3461e64c2495c616f1c8f6b127b (patch) | |
tree | 3021ba22fe63f5844c30591396a017d8d5dba9e4 /arch/s390/kernel/nospec-sysfs.c | |
parent | c50c84c3ac4d5db683904bdb3257798b6ef980ae (diff) | |
download | linux-4253b0e0627ee3461e64c2495c616f1c8f6b127b.tar.bz2 |
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>
Diffstat (limited to 'arch/s390/kernel/nospec-sysfs.c')
-rw-r--r-- | arch/s390/kernel/nospec-sysfs.c | 21 |
1 files changed, 21 insertions, 0 deletions
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"); +} |