diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 621f4b6cac4a33525edbbf00bac4a280781490be..8946f89761cc3d63e9eebee6a3a26323f8655f14 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -210,13 +210,6 @@ static void __init fpu__init_system_xstate_size_legacy(void) fpstate_reset(¤t->thread.fpu); } -static void __init fpu__init_init_fpstate(void) -{ - /* Bring init_fpstate size and features up to date */ - init_fpstate.size = fpu_kernel_cfg.max_size; - init_fpstate.xfeatures = fpu_kernel_cfg.max_features; -} - /* * Called on the boot CPU once per system bootup, to set up the initial * FPU state that is later cloned into all processes: @@ -236,5 +229,4 @@ void __init fpu__init_system(struct cpuinfo_x86 *c) fpu__init_system_xstate_size_legacy(); fpu__init_system_xstate(fpu_kernel_cfg.max_size); fpu__init_task_struct_size(); - fpu__init_init_fpstate(); } diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 6bc883a330eb5d8b8656230e2209f4b5742d71e9..37607b6132a369ec3df2c0bbee9e3432bbb49456 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -362,7 +362,7 @@ 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 @@ -677,20 +677,6 @@ 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: */ @@ -715,10 +701,6 @@ 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; @@ -865,6 +847,19 @@ 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(); /* @@ -1120,6 +1115,15 @@ 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