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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2024-03-13 01:41:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-13 13:58:59 +0300 |
| commit | 66d5260fc7d5adb115c97f0e011ee13c0caa8ea6 (patch) | |
| tree | d5c5a100b134c307bfe11c7e4af39292ccc044d1 /include/linux/cpu.h | |
| parent | 5fbd9f6c3953215923b8b4116e2d2b8dc4960d9f (diff) | |
| download | linux-66d5260fc7d5adb115c97f0e011ee13c0caa8ea6.tar.xz | |
x86/rfds: Mitigate Register File Data Sampling (RFDS)
commit 8076fcde016c9c0e0660543e67bff86cb48a7c9c upstream.
RFDS is a CPU vulnerability that may allow userspace to infer kernel
stale data previously used in floating point registers, vector registers
and integer registers. RFDS only affects certain Intel Atom processors.
Intel released a microcode update that uses VERW instruction to clear
the affected CPU buffers. Unlike MDS, none of the affected cores support
SMT.
Add RFDS bug infrastructure and enable the VERW based mitigation by
default, that clears the affected buffers just before exiting to
userspace. Also add sysfs reporting and cmdline parameter
"reg_file_data_sampling" to control the mitigation.
For details see:
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
[ pawan: - Resolved conflicts in sysfs reporting.
- s/ATOM_GRACEMONT/ALDERLAKE_N/ATOM_GRACEMONT is called
ALDERLAKE_N in 6.6. ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/cpu.h')
| -rw-r--r-- | include/linux/cpu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 6d7ab016127c..2099226d8623 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -74,6 +74,8 @@ extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, struct device_attribute *attr, char *buf); extern ssize_t cpu_show_gds(struct device *dev, struct device_attribute *attr, char *buf); +extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev, + struct device_attribute *attr, char *buf); extern __printf(4, 5) struct device *cpu_device_create(struct device *parent, void *drvdata, |