[patch V2 04/52] x86/fpu: Mark various FPU states __ro_after_init

Thomas Gleixner
2021-06-14T16:38:06Z

Nothing modifies these after booting.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/kernel/fpu/init.c | 4 ++--
arch/x86/kernel/fpu/xstate.c | 16 ++++++++++------
2 files changed, 12 insertions(+), 8 deletions(-)

--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -89,7 +89,7 @@ static void fpu__init_system_early_gener
/*
* 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_gene
* 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. */
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -59,19 +59,23 @@ static short xsave_cpuid_features[] __in
* This represents the full set of bits that should ever be set in a kernel
* XSAVE buffer, both supervisor and user xstates.
*/
-u64 xfeatures_mask_all __read_mostly;
+u64 xfeatures_mask_all __ro_after_init;

-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.