x86/fpu: Mark various FPU state variables __ro_after_init

mainline inclusion
from mainline-v5.14-rc1
commit ce578f16
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC
CVE: NA

Intel-SIG: commit ce578f16 x86/fpu: Mark various FPU state variables __ro_after_init.

--------------------------------

Nothing modifies these after booting.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20210623121451.611751529@linutronix.deSigned-off-by: NLin Wang <lin.x.wang@intel.com>

arch/x86/kernel/fpu/init.c

@@ -89,7 +89,7 @@ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c)
 /*
  * Boot time FPU feature detection code:
  */
-unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
+unsigned int mxcsr_feature_mask __ro_after_init = 0xffffffffu;
 EXPORT_SYMBOL_GPL(mxcsr_feature_mask);
 
 static void __init fpu__init_system_mxcsr(void)
@@ -135,7 +135,7 @@ static void __init fpu__init_system_generic(void)
  * This is inherent to the XSAVE architecture which puts all state
  * components into a single, continuous memory block:
  */
-unsigned int fpu_kernel_xstate_size;
+unsigned int fpu_kernel_xstate_size __ro_after_init;
 EXPORT_SYMBOL_GPL(fpu_kernel_xstate_size);
 
 /* Get alignment of the TYPE. */

arch/x86/kernel/fpu/xstate.c

@@ -61,17 +61,21 @@ static short xsave_cpuid_features[] __initdata = {
  */
 u64 xfeatures_mask_all __read_mostly;
 
-static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_sizes[XFEATURE_MAX]   = { [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_comp_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_supervisor_only_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init =
+	{ [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_sizes[XFEATURE_MAX] __ro_after_init =
+	{ [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_comp_offsets[XFEATURE_MAX] __ro_after_init =
+	{ [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_supervisor_only_offsets[XFEATURE_MAX] __ro_after_init =
+	{ [ 0 ... XFEATURE_MAX - 1] = -1};
 
 /*
  * The XSAVE area of kernel can be in standard or compacted format;
  * it is always in standard format for user mode. This is the user
  * mode standard format size used for signal and ptrace frames.
  */
-unsigned int fpu_user_xstate_size;
+unsigned int fpu_user_xstate_size __ro_after_init;
 
 /*
  * Return whether the system supports a given xfeature.