Re: [RFC PATCH 53/56] drivers/cpu: Re-patch mitigations through sysfs
From: Nikolay Borisov
Date: Mon Oct 27 2025 - 08:25:30 EST
On 10/13/25 17:34, David Kaplan wrote:
Create a new file at /sys/devices/system/cpu/mitigations that prints the
current set of mitigation options and can be written to in order to
re-select mitigations.
Only options related to mitigations are handled, with the file initially
returning the relevant options from the command line. When the file is
written, any existing selections are discarded and the new options are
evaluated.
Signed-off-by: David Kaplan <david.kaplan@xxxxxxx>
---
.../ABI/testing/sysfs-devices-system-cpu | 8 ++
drivers/base/cpu.c | 113 ++++++++++++++++++
include/linux/cpu.h | 3 +
3 files changed, 124 insertions(+)
<snip>
+
+ssize_t cpu_show_mitigation_options(struct device *dev, struct device_attribute *attr, char *buf);
+ssize_t cpu_show_mitigation_options(struct device *dev, struct device_attribute *attr, char *buf)
Make it static
+{
+ return sysfs_emit(buf, saved_opts);
+}
+
+ssize_t cpu_write_mitigation_options(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count);
+
+void __weak cpu_prepare_repatch_alternatives(void)
+{
+}
+
+void __weak cpu_update_alternatives(void)
+{
+}
+
+void __weak cpu_select_mitigations(void)
+{
+}
+
+ssize_t cpu_write_mitigation_options(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
Ditto
<snip>