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Diffstat (limited to 'arch/x86/kernel/fpu/xstate.c')
-rw-r--r--arch/x86/kernel/fpu/xstate.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c8340156bfd2..59e543b95a3c 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -360,7 +360,7 @@ static void __init setup_init_fpu_buf(void)
print_xstate_features();
- xstate_init_xcomp_bv(&init_fpstate.regs.xsave, fpu_kernel_cfg.max_features);
+ xstate_init_xcomp_bv(&init_fpstate.regs.xsave, init_fpstate.xfeatures);
/*
* Init all the features state with header.xfeatures being 0x0
@@ -678,20 +678,6 @@ static unsigned int __init get_xsave_size_user(void)
return ebx;
}
-/*
- * Will the runtime-enumerated 'xstate_size' fit in the init
- * task's statically-allocated buffer?
- */
-static bool __init is_supported_xstate_size(unsigned int test_xstate_size)
-{
- if (test_xstate_size <= sizeof(init_fpstate.regs))
- return true;
-
- pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n",
- sizeof(init_fpstate.regs), test_xstate_size);
- return false;
-}
-
static int __init init_xstate_size(void)
{
/* Recompute the context size for enabled features: */
@@ -717,10 +703,6 @@ static int __init init_xstate_size(void)
kernel_default_size =
xstate_calculate_size(fpu_kernel_cfg.default_features, compacted);
- /* Ensure we have the space to store all default enabled features. */
- if (!is_supported_xstate_size(kernel_default_size))
- return -EINVAL;
-
if (!paranoid_xstate_size_valid(kernel_size))
return -EINVAL;
@@ -875,6 +857,19 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
update_regset_xstate_info(fpu_user_cfg.max_size,
fpu_user_cfg.max_features);
+ /*
+ * init_fpstate excludes dynamic states as they are large but init
+ * state is zero.
+ */
+ init_fpstate.size = fpu_kernel_cfg.default_size;
+ init_fpstate.xfeatures = fpu_kernel_cfg.default_features;
+
+ if (init_fpstate.size > sizeof(init_fpstate.regs)) {
+ pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d), disabling XSAVE\n",
+ sizeof(init_fpstate.regs), init_fpstate.size);
+ goto out_disable;
+ }
+
setup_init_fpu_buf();
/*
@@ -1130,6 +1125,15 @@ void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate,
*/
mask = fpstate->user_xfeatures;
+ /*
+ * Dynamic features are not present in init_fpstate. When they are
+ * in an all zeros init state, remove those from 'mask' to zero
+ * those features in the user buffer instead of retrieving them
+ * from init_fpstate.
+ */
+ if (fpu_state_size_dynamic())
+ mask &= (header.xfeatures | xinit->header.xcomp_bv);
+
for_each_extended_xfeature(i, mask) {
/*
* If there was a feature or alignment gap, zero the space