diff options
author | Ingo Molnar <mingo@kernel.org> | 2025-05-13 11:37:29 +0300 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2025-05-13 11:37:29 +0300 |
commit | ec8f353f5262acff120a0dc83b714d899ee94b7f (patch) | |
tree | a5eab4c8ced9b7ea467da00aa5166a8c59d813d0 | |
parent | 2fb8414e644b133a9c3250f408232af99da256a4 (diff) | |
parent | 32d5fa804dc9bd7cf6651a1378ba616d332e7444 (diff) | |
download | linux-ec8f353f5262acff120a0dc83b714d899ee94b7f.tar.xz |
Merge branch 'x86/fpu' into x86/core, to merge dependent commits
Prepare to resolve conflicts with an upstream series of fixes that conflict
with pending x86 changes:
6f5bf947bab0 Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Signed-off-by: Ingo Molnar <mingo@kernel.org>
31 files changed, 294 insertions, 236 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index bc81b9d1aeca..478ab362fda2 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -481,6 +481,7 @@ #define X86_FEATURE_AMD_HTR_CORES (21*32+ 6) /* Heterogeneous Core Topology */ #define X86_FEATURE_AMD_WORKLOAD_CLASS (21*32+ 7) /* Workload Classification */ #define X86_FEATURE_PREFER_YMM (21*32+ 8) /* Avoid ZMM registers due to downclocking */ +#define X86_FEATURE_APX (21*32+ 9) /* Advanced Performance Extensions */ /* * BUG word(s) diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h index 77d20555e04d..d535a97c7284 100644 --- a/arch/x86/include/asm/entry-common.h +++ b/arch/x86/include/asm/entry-common.h @@ -53,7 +53,6 @@ static inline void arch_exit_work(unsigned long ti_work) if (unlikely(ti_work & _TIF_IO_BITMAP)) tss_update_io_bitmap(); - fpregs_assert_state_consistent(); if (unlikely(ti_work & _TIF_NEED_FPU_LOAD)) switch_fpu_return(); } @@ -61,7 +60,9 @@ static inline void arch_exit_work(unsigned long ti_work) static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, unsigned long ti_work) { - if (IS_ENABLED(CONFIG_X86_DEBUG_FPU) || unlikely(ti_work)) + fpregs_assert_state_consistent(); + + if (unlikely(ti_work)) arch_exit_work(ti_work); fred_update_rsp0(); diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index f42de5f05e7e..8e6848f55dcd 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -136,7 +136,7 @@ static inline void fpstate_free(struct fpu *fpu) { } #endif /* fpstate-related functions which are exported to KVM */ -extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature); +extern void fpstate_clear_xstate_component(struct fpstate *fpstate, unsigned int xfeature); extern u64 xstate_get_guest_group_perm(void); diff --git a/arch/x86/include/asm/fpu/sched.h b/arch/x86/include/asm/fpu/sched.h index c485f1944c5f..c060549c6c94 100644 --- a/arch/x86/include/asm/fpu/sched.h +++ b/arch/x86/include/asm/fpu/sched.h @@ -10,7 +10,7 @@ #include <asm/trace/fpu.h> extern void save_fpregs_to_fpstate(struct fpu *fpu); -extern void fpu__drop(struct fpu *fpu); +extern void fpu__drop(struct task_struct *tsk); extern int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal, unsigned long shstk_addr); extern void fpu_flush_thread(void); @@ -18,31 +18,25 @@ extern void fpu_flush_thread(void); /* * FPU state switching for scheduling. * - * This is a two-stage process: + * switch_fpu() saves the old state and sets TIF_NEED_FPU_LOAD if + * TIF_NEED_FPU_LOAD is not set. This is done within the context + * of the old process. * - * - switch_fpu_prepare() saves the old state. - * This is done within the context of the old process. - * - * - switch_fpu_finish() sets TIF_NEED_FPU_LOAD; the floating point state - * will get loaded on return to userspace, or when the kernel needs it. - * - * If TIF_NEED_FPU_LOAD is cleared then the CPU's FPU registers - * are saved in the current thread's FPU register state. - * - * If TIF_NEED_FPU_LOAD is set then CPU's FPU registers may not - * hold current()'s FPU registers. It is required to load the + * Once TIF_NEED_FPU_LOAD is set, it is required to load the * registers before returning to userland or using the content * otherwise. * * The FPU context is only stored/restored for a user task and * PF_KTHREAD is used to distinguish between kernel and user threads. */ -static inline void switch_fpu_prepare(struct task_struct *old, int cpu) +static inline void switch_fpu(struct task_struct *old, int cpu) { - if (cpu_feature_enabled(X86_FEATURE_FPU) && + if (!test_tsk_thread_flag(old, TIF_NEED_FPU_LOAD) && + cpu_feature_enabled(X86_FEATURE_FPU) && !(old->flags & (PF_KTHREAD | PF_USER_WORKER))) { - struct fpu *old_fpu = &old->thread.fpu; + struct fpu *old_fpu = x86_task_fpu(old); + set_tsk_thread_flag(old, TIF_NEED_FPU_LOAD); save_fpregs_to_fpstate(old_fpu); /* * The save operation preserved register state, so the @@ -50,7 +44,7 @@ static inline void switch_fpu_prepare(struct task_struct *old, int cpu) * current CPU number in @old_fpu, so the next return * to user space can avoid the FPU register restore * when is returns on the same CPU and still owns the - * context. + * context. See fpregs_restore_userregs(). */ old_fpu->last_cpu = cpu; @@ -58,14 +52,4 @@ static inline void switch_fpu_prepare(struct task_struct *old, int cpu) } } -/* - * Delay loading of the complete FPU state until the return to userland. - * PKRU is handled separately. - */ -static inline void switch_fpu_finish(struct task_struct *new) -{ - if (cpu_feature_enabled(X86_FEATURE_FPU)) - set_tsk_thread_flag(new, TIF_NEED_FPU_LOAD); -} - #endif /* _ASM_X86_FPU_SCHED_H */ diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index de16862bf230..1c94121acd3d 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -125,6 +125,7 @@ enum xfeature { XFEATURE_RSRVD_COMP_16, XFEATURE_XTILE_CFG, XFEATURE_XTILE_DATA, + XFEATURE_APX, XFEATURE_MAX, }; @@ -145,6 +146,7 @@ enum xfeature { #define XFEATURE_MASK_LBR (1 << XFEATURE_LBR) #define XFEATURE_MASK_XTILE_CFG (1 << XFEATURE_XTILE_CFG) #define XFEATURE_MASK_XTILE_DATA (1 << XFEATURE_XTILE_DATA) +#define XFEATURE_MASK_APX (1 << XFEATURE_APX) #define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE) #define XFEATURE_MASK_AVX512 (XFEATURE_MASK_OPMASK \ @@ -304,6 +306,13 @@ struct xtile_data { } __packed; /* + * State component 19: 8B extended general purpose register. + */ +struct apx_state { + u64 egpr[16]; +} __packed; + +/* * State component 10 is supervisor state used for context-switching the * PASID state. */ @@ -407,9 +416,11 @@ struct fpu_state_perm { /* * @__state_perm: * - * This bitmap indicates the permission for state components, which - * are available to a thread group. The permission prctl() sets the - * enabled state bits in thread_group_leader()->thread.fpu. + * This bitmap indicates the permission for state components + * available to a thread group, including both user and supervisor + * components and software-defined bits like FPU_GUEST_PERM_LOCKED. + * The permission prctl() sets the enabled state bits in + * thread_group_leader()->thread.fpu. * * All run time operations use the per thread information in the * currently active fpu.fpstate which contains the xfeature masks @@ -525,13 +536,6 @@ struct fpu_guest { u64 xfeatures; /* - * @perm: xfeature bitmap of features which are - * permitted to be enabled for the guest - * vCPU. - */ - u64 perm; - - /* * @xfd_err: Save the guest value. */ u64 xfd_err; diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 7f39fe7980c5..b308a76afbb7 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -32,7 +32,8 @@ XFEATURE_MASK_PKRU | \ XFEATURE_MASK_BNDREGS | \ XFEATURE_MASK_BNDCSR | \ - XFEATURE_MASK_XTILE) + XFEATURE_MASK_XTILE | \ + XFEATURE_MASK_APX) /* * Features which are restored when returning to user space. diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 0973bed22172..50d34698036d 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -514,15 +514,14 @@ struct thread_struct { struct thread_shstk shstk; #endif - - /* Floating point and extended processor state */ - struct fpu fpu; - /* - * WARNING: 'fpu' is dynamically-sized. It *MUST* be at - * the end. - */ }; +#ifdef CONFIG_X86_DEBUG_FPU +extern struct fpu *x86_task_fpu(struct task_struct *task); +#else +# define x86_task_fpu(task) ((struct fpu *)((void *)(task) + sizeof(*(task)))) +#endif + extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size); static inline void arch_thread_struct_whitelist(unsigned long *offset, diff --git a/arch/x86/include/asm/trace/fpu.h b/arch/x86/include/asm/trace/fpu.h index 4645a6334063..0454d5e60e5d 100644 --- a/arch/x86/include/asm/trace/fpu.h +++ b/arch/x86/include/asm/trace/fpu.h @@ -74,11 +74,6 @@ DEFINE_EVENT(x86_fpu, x86_fpu_dropped, TP_ARGS(fpu) ); -DEFINE_EVENT(x86_fpu, x86_fpu_copy_src, - TP_PROTO(struct fpu *fpu), - TP_ARGS(fpu) -); - DEFINE_EVENT(x86_fpu, x86_fpu_copy_dst, TP_PROTO(struct fpu *fpu), TP_ARGS(fpu) diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 94c062cddfa4..46efcbd6afa4 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -28,6 +28,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_PKU, X86_FEATURE_XSAVE }, { X86_FEATURE_MPX, X86_FEATURE_XSAVE }, { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE }, + { X86_FEATURE_APX, X86_FEATURE_XSAVE }, { X86_FEATURE_CMOV, X86_FEATURE_FXSR }, { X86_FEATURE_MMX, X86_FEATURE_FXSR }, { X86_FEATURE_MMXEXT, X86_FEATURE_MMX }, diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index c75c57b32b74..dbf6d71bdf18 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -27,6 +27,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 }, { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 }, { X86_FEATURE_INTEL_PPIN, CPUID_EBX, 0, 0x00000007, 1 }, + { X86_FEATURE_APX, CPUID_EDX, 21, 0x00000007, 1 }, { X86_FEATURE_RRSBA_CTRL, CPUID_EDX, 2, 0x00000007, 2 }, { X86_FEATURE_BHI_CTRL, CPUID_EDX, 4, 0x00000007, 2 }, { X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 }, diff --git a/arch/x86/kernel/fpu/context.h b/arch/x86/kernel/fpu/context.h index f6d856bd50bc..10d0a720659c 100644 --- a/arch/x86/kernel/fpu/context.h +++ b/arch/x86/kernel/fpu/context.h @@ -53,7 +53,7 @@ static inline void fpregs_activate(struct fpu *fpu) /* Internal helper for switch_fpu_return() and signal frame setup */ static inline void fpregs_restore_userregs(void) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); int cpu = smp_processor_id(); if (WARN_ON_ONCE(current->flags & (PF_KTHREAD | PF_USER_WORKER))) @@ -67,7 +67,7 @@ static inline void fpregs_restore_userregs(void) * If PKRU is enabled, then the PKRU value is already * correct because it was either set in switch_to() or in * flush_thread(). So it is excluded because it might be - * not up to date in current->thread.fpu.xsave state. + * not up to date in current->thread.fpu->xsave state. * * XFD state is handled in restore_fpregs_from_fpstate(). */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 91d6341f281f..1cda5b78540b 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -51,6 +51,16 @@ static DEFINE_PER_CPU(bool, in_kernel_fpu); */ DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); +#ifdef CONFIG_X86_DEBUG_FPU +struct fpu *x86_task_fpu(struct task_struct *task) +{ + if (WARN_ON_ONCE(task->flags & PF_KTHREAD)) + return NULL; + + return (void *)task + sizeof(*task); +} +#endif + /* * Can we use the FPU in kernel mode with the * whole "kernel_fpu_begin/end()" sequence? @@ -202,7 +212,7 @@ void fpu_reset_from_exception_fixup(void) #if IS_ENABLED(CONFIG_KVM) static void __fpstate_reset(struct fpstate *fpstate, u64 xfd); -static void fpu_init_guest_permissions(struct fpu_guest *gfpu) +static void fpu_lock_guest_permissions(void) { struct fpu_state_perm *fpuperm; u64 perm; @@ -211,15 +221,13 @@ static void fpu_init_guest_permissions(struct fpu_guest *gfpu) return; spin_lock_irq(¤t->sighand->siglock); - fpuperm = ¤t->group_leader->thread.fpu.guest_perm; + fpuperm = &x86_task_fpu(current->group_leader)->guest_perm; perm = fpuperm->__state_perm; /* First fpstate allocation locks down permissions. */ WRITE_ONCE(fpuperm->__state_perm, perm | FPU_GUEST_PERM_LOCKED); spin_unlock_irq(¤t->sighand->siglock); - - gfpu->perm = perm & ~FPU_GUEST_PERM_LOCKED; } bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) @@ -240,7 +248,6 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) gfpu->fpstate = fpstate; gfpu->xfeatures = fpu_kernel_cfg.default_features; - gfpu->perm = fpu_kernel_cfg.default_features; /* * KVM sets the FP+SSE bits in the XSAVE header when copying FPU state @@ -255,7 +262,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) if (WARN_ON_ONCE(fpu_user_cfg.default_size > gfpu->uabi_size)) gfpu->uabi_size = fpu_user_cfg.default_size; - fpu_init_guest_permissions(gfpu); + fpu_lock_guest_permissions(); return true; } @@ -263,16 +270,16 @@ EXPORT_SYMBOL_GPL(fpu_alloc_guest_fpstate); void fpu_free_guest_fpstate(struct fpu_guest *gfpu) { - struct fpstate *fps = gfpu->fpstate; + struct fpstate *fpstate = gfpu->fpstate; - if (!fps) + if (!fpstate) return; - if (WARN_ON_ONCE(!fps->is_valloc || !fps->is_guest || fps->in_use)) + if (WARN_ON_ONCE(!fpstate->is_valloc || !fpstate->is_guest || fpstate->in_use)) return; gfpu->fpstate = NULL; - vfree(fps); + vfree(fpstate); } EXPORT_SYMBOL_GPL(fpu_free_guest_fpstate); @@ -323,12 +330,12 @@ EXPORT_SYMBOL_GPL(fpu_update_guest_xfd); */ void fpu_sync_guest_vmexit_xfd_state(void) { - struct fpstate *fps = current->thread.fpu.fpstate; + struct fpstate *fpstate = x86_task_fpu(current)->fpstate; lockdep_assert_irqs_disabled(); if (fpu_state_size_dynamic()) { - rdmsrl(MSR_IA32_XFD, fps->xfd); - __this_cpu_write(xfd_state, fps->xfd); + rdmsrl(MSR_IA32_XFD, fpstate->xfd); + __this_cpu_write(xfd_state, fpstate->xfd); } } EXPORT_SYMBOL_GPL(fpu_sync_guest_vmexit_xfd_state); @@ -337,7 +344,7 @@ EXPORT_SYMBOL_GPL(fpu_sync_guest_vmexit_xfd_state); int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest) { struct fpstate *guest_fps = guest_fpu->fpstate; - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); struct fpstate *cur_fps = fpu->fpstate; fpregs_lock(); @@ -438,7 +445,7 @@ void kernel_fpu_begin_mask(unsigned int kfpu_mask) if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER)) && !test_thread_flag(TIF_NEED_FPU_LOAD)) { set_thread_flag(TIF_NEED_FPU_LOAD); - save_fpregs_to_fpstate(¤t->thread.fpu); + save_fpregs_to_fpstate(x86_task_fpu(current)); } __cpu_invalidate_fpregs_state(); @@ -467,7 +474,7 @@ EXPORT_SYMBOL_GPL(kernel_fpu_end); */ void fpu_sync_fpstate(struct fpu *fpu) { - WARN_ON_FPU(fpu != ¤t->thread.fpu); + WARN_ON_FPU(fpu != x86_task_fpu(current)); fpregs_lock(); trace_x86_fpu_before_save(fpu); @@ -552,7 +559,7 @@ void fpstate_reset(struct fpu *fpu) static inline void fpu_inherit_perms(struct fpu *dst_fpu) { if (fpu_state_size_dynamic()) { - struct fpu *src_fpu = ¤t->group_leader->thread.fpu; + struct fpu *src_fpu = x86_task_fpu(current->group_leader); spin_lock_irq(¤t->sighand->siglock); /* Fork also inherits the permissions of the parent */ @@ -572,7 +579,7 @@ static int update_fpu_shstk(struct task_struct *dst, unsigned long ssp) if (!ssp) return 0; - xstate = get_xsave_addr(&dst->thread.fpu.fpstate->regs.xsave, + xstate = get_xsave_addr(&x86_task_fpu(dst)->fpstate->regs.xsave, XFEATURE_CET_USER); /* @@ -593,8 +600,16 @@ static int update_fpu_shstk(struct task_struct *dst, unsigned long ssp) int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal, unsigned long ssp) { - struct fpu *src_fpu = ¤t->thread.fpu; - struct fpu *dst_fpu = &dst->thread.fpu; + /* + * We allocate the new FPU structure right after the end of the task struct. + * task allocation size already took this into account. + * + * This is safe because task_struct size is a multiple of cacheline size, + * thus x86_task_fpu() will always be cacheline aligned as well. + */ + struct fpu *dst_fpu = (void *)dst + sizeof(*dst); + + BUILD_BUG_ON(sizeof(*dst) % SMP_CACHE_BYTES != 0); /* The new task's FPU state cannot be valid in the hardware. */ dst_fpu->last_cpu = -1; @@ -657,19 +672,22 @@ int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal, if (update_fpu_shstk(dst, ssp)) return 1; - trace_x86_fpu_copy_src(src_fpu); trace_x86_fpu_copy_dst(dst_fpu); return 0; } /* - * Whitelist the FPU register state embedded into task_struct for hardened - * usercopy. + * While struct fpu is no longer part of struct thread_struct, it is still + * allocated after struct task_struct in the "task_struct" kmem cache. But + * since FPU is expected to be part of struct thread_struct, we have to + * adjust for it here. */ void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size) { - *offset = offsetof(struct thread_struct, fpu.__fpstate.regs); + /* The allocation follows struct task_struct. */ + *offset = sizeof(struct task_struct) - offsetof(struct task_struct, thread); + *offset += offsetof(struct fpu, __fpstate.regs); *size = fpu_kernel_cfg.default_size; } @@ -682,11 +700,18 @@ void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size) * a state-restore is coming: either an explicit one, * or a reschedule. */ -void fpu__drop(struct fpu *fpu) +void fpu__drop(struct task_struct *tsk) { + struct fpu *fpu; + + if (test_tsk_thread_flag(tsk, TIF_NEED_FPU_LOAD)) + return; + + fpu = x86_task_fpu(tsk); + preempt_disable(); - if (fpu == ¤t->thread.fpu) { + if (fpu == x86_task_fpu(current)) { /* Ignore delayed exceptions from user space */ asm volatile("1: fwait\n" "2:\n" @@ -718,9 +743,9 @@ static inline void restore_fpregs_from_init_fpstate(u64 features_mask) /* * Reset current->fpu memory state to the init values. */ -static void fpu_reset_fpregs(void) +static void fpu_reset_fpstate_regs(void) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); fpregs_lock(); __fpu_invalidate_fpregs_state(fpu); @@ -749,11 +774,11 @@ static void fpu_reset_fpregs(void) */ void fpu__clear_user_states(struct fpu *fpu) { - WARN_ON_FPU(fpu != ¤t->thread.fpu); + WARN_ON_FPU(fpu != x86_task_fpu(current)); fpregs_lock(); if (!cpu_feature_enabled(X86_FEATURE_FPU)) { - fpu_reset_fpregs(); + fpu_reset_fpstate_regs(); fpregs_unlock(); return; } @@ -782,8 +807,8 @@ void fpu__clear_user_states(struct fpu *fpu) void fpu_flush_thread(void) { - fpstate_reset(¤t->thread.fpu); - fpu_reset_fpregs(); + fpstate_reset(x86_task_fpu(current)); + fpu_reset_fpstate_regs(); } /* * Load FPU context before returning to userspace. @@ -823,7 +848,7 @@ void fpregs_lock_and_load(void) */ void fpregs_assert_state_consistent(void) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); if (test_thread_flag(TIF_NEED_FPU_LOAD)) return; @@ -835,7 +860,7 @@ EXPORT_SYMBOL_GPL(fpregs_assert_state_consistent); void fpregs_mark_activate(void) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); fpregs_activate(fpu); fpu->last_cpu = smp_processor_id(); diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 998a08f17e33..6bb3e35c40e2 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -38,7 +38,7 @@ static void fpu__init_cpu_generic(void) /* Flush out any pending x87 state: */ #ifdef CONFIG_MATH_EMULATION if (!boot_cpu_has(X86_FEATURE_FPU)) - fpstate_init_soft(¤t->thread.fpu.fpstate->regs.soft); + ; else #endif asm volatile ("fninit"); @@ -73,6 +73,8 @@ static bool __init fpu__probe_without_cpuid(void) static void __init fpu__init_system_early_generic(void) { + set_thread_flag(TIF_NEED_FPU_LOAD); + if (!boot_cpu_has(X86_FEATURE_CPUID) && !test_bit(X86_FEATURE_FPU, (unsigned long *)cpu_caps_cleared)) { if (fpu__probe_without_cpuid()) @@ -94,7 +96,6 @@ static void __init fpu__init_system_early_generic(void) * Boot time FPU feature detection code: */ unsigned int mxcsr_feature_mask __ro_after_init = 0xffffffffu; -EXPORT_SYMBOL_GPL(mxcsr_feature_mask); static void __init fpu__init_system_mxcsr(void) { @@ -150,11 +151,13 @@ static void __init fpu__init_task_struct_size(void) { int task_size = sizeof(struct task_struct); + task_size += sizeof(struct fpu); + /* * Subtract off the static size of the register state. * It potentially has a bunch of padding. */ - task_size -= sizeof(current->thread.fpu.__fpstate.regs); + task_size -= sizeof(union fpregs_state); /* * Add back the dynamically-calculated register state @@ -164,14 +167,9 @@ static void __init fpu__init_task_struct_size(void) /* * We dynamically size 'struct fpu', so we require that - * it be at the end of 'thread_struct' and that - * 'thread_struct' be at the end of 'task_struct'. If - * you hit a compile error here, check the structure to - * see if something got added to the end. + * 'state' be at the end of 'it: */ CHECK_MEMBER_AT_END_OF(struct fpu, __fpstate); - CHECK_MEMBER_AT_END_OF(struct thread_struct, fpu); - CHECK_MEMBER_AT_END_OF(struct task_struct, thread); arch_task_struct_size = task_size; } @@ -204,7 +202,6 @@ static void __init fpu__init_system_xstate_size_legacy(void) fpu_kernel_cfg.default_size = size; fpu_user_cfg.max_size = size; fpu_user_cfg.default_size = size; - fpstate_reset(¤t->thread.fpu); } /* @@ -213,7 +210,6 @@ static void __init fpu__init_system_xstate_size_legacy(void) */ void __init fpu__init_system(void) { - fpstate_reset(¤t->thread.fpu); fpu__init_system_early_generic(); /* diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 887b0b8e21e3..0986c2200adc 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -45,7 +45,7 @@ int regset_xregset_fpregs_active(struct task_struct *target, const struct user_r */ static void sync_fpstate(struct fpu *fpu) { - if (fpu == ¤t->thread.fpu) + if (fpu == x86_task_fpu(current)) fpu_sync_fpstate(fpu); } @@ -63,7 +63,7 @@ static void fpu_force_restore(struct fpu *fpu) * Only stopped child tasks can be used to modify the FPU * state in the fpstate buffer: */ - WARN_ON_FPU(fpu == ¤t->thread.fpu); + WARN_ON_FPU(fpu == x86_task_fpu(current)); __fpu_invalidate_fpregs_state(fpu); } @@ -71,7 +71,7 @@ static void fpu_force_restore(struct fpu *fpu) int xfpregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); if (!cpu_feature_enabled(X86_FEATURE_FXSR)) return -ENODEV; @@ -91,7 +91,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct fxregs_state newstate; int ret; @@ -133,7 +133,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_feature_enabled(X86_FEATURE_XSAVE)) return -ENODEV; - sync_fpstate(&target->thread.fpu); + sync_fpstate(x86_task_fpu(target)); copy_xstate_to_uabi_buf(to, target, XSTATE_COPY_XSAVE); return 0; @@ -143,7 +143,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct xregs_state *tmpbuf = NULL; int ret; @@ -187,7 +187,7 @@ int ssp_active(struct task_struct *target, const struct user_regset *regset) int ssp_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct cet_user_state *cetregs; if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK) || @@ -214,7 +214,7 @@ int ssp_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct xregs_state *xsave = &fpu->fpstate->regs.xsave; struct cet_user_state *cetregs; unsigned long user_ssp; @@ -368,7 +368,7 @@ static void __convert_from_fxsr(struct user_i387_ia32_struct *env, void convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) { - __convert_from_fxsr(env, tsk, &tsk->thread.fpu.fpstate->regs.fxsave); + __convert_from_fxsr(env, tsk, &x86_task_fpu(tsk)->fpstate->regs.fxsave); } void convert_to_fxsr(struct fxregs_state *fxsave, @@ -401,7 +401,7 @@ void convert_to_fxsr(struct fxregs_state *fxsave, int fpregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct user_i387_ia32_struct env; struct fxregs_state fxsave, *fx; @@ -433,7 +433,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct fpu *fpu = &target->thread.fpu; + struct fpu *fpu = x86_task_fpu(target); struct user_i387_ia32_struct env; int ret; diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 6c69cb28b298..c3ec2512f2bb 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -43,13 +43,13 @@ static inline bool check_xstate_in_sigframe(struct fxregs_state __user *fxbuf, * fpstate layout with out copying the extended state information * in the memory layout. */ - if (__get_user(magic2, (__u32 __user *)(fpstate + current->thread.fpu.fpstate->user_size))) + if (__get_user(magic2, (__u32 __user *)(fpstate + x86_task_fpu(current)->fpstate->user_size))) return false; if (likely(magic2 == FP_XSTATE_MAGIC2)) return true; setfx: - trace_x86_fpu_xstate_check_failed(¤t->thread.fpu); + trace_x86_fpu_xstate_check_failed(x86_task_fpu(current)); /* Set the parameters for fx only state */ fx_sw->magic1 = 0; @@ -64,13 +64,13 @@ setfx: static inline bool save_fsave_header(struct task_struct *tsk, void __user *buf) { if (use_fxsr()) { - struct xregs_state *xsave = &tsk->thread.fpu.fpstate->regs.xsave; + struct xregs_state *xsave = &x86_task_fpu(tsk)->fpstate->regs.xsave; struct user_i387_ia32_struct env; struct _fpstate_32 __user *fp = buf; fpregs_lock(); if (!test_thread_flag(TIF_NEED_FPU_LOAD)) - fxsave(&tsk->thread.fpu.fpstate->regs.fxsave); + fxsave(&x86_task_fpu(tsk)->fpstate->regs.fxsave); fpregs_unlock(); convert_from_fxsr(&env, tsk); @@ -114,7 +114,6 @@ static inline bool save_xstate_epilog(void __user *buf, int ia32_frame, { struct xregs_state __user *x = buf; struct _fpx_sw_bytes sw_bytes = {}; - u32 xfeatures; int err; /* Setup the bytes not touched by the [f]xsave and reserved for SW. */ @@ -128,12 +127,6 @@ static inline bool save_xstate_epilog(void __user *buf, int ia32_frame, (__u32 __user *)(buf + fpstate->user_size)); /* - * Read the xfeatures which we copied (directly from the cpu or - * from the state in task struct) to the user buffers. - */ - err |= __get_user(xfeatures, (__u32 __user *)&x->header.xfeatures); - - /* * For legacy compatible, we always set FP/SSE bits in the bit * vector while saving the state to the user context. This will * enable us capturing any changes(during sigreturn) to @@ -144,9 +137,7 @@ static inline bool save_xstate_epilog(void __user *buf, int ia32_frame, * header as well as change any contents in the memory layout. * xrestore as part of sigreturn will capture all the changes. */ - xfeatures |= XFEATURE_MASK_FPSSE; - - err |= __put_user(xfeatures, (__u32 __user *)&x->header.xfeatures); + err |= set_xfeature_in_sigframe(x, XFEATURE_MASK_FPSSE); return !err; } @@ -184,7 +175,7 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf, u32 pk bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size, u32 pkru) { struct task_struct *tsk = current; - struct fpstate *fpstate = tsk->thread.fpu.fpstate; + struct fpstate *fpstate = x86_task_fpu(tsk)->fpstate; bool ia32_fxstate = (buf != buf_fx); int ret; @@ -272,7 +263,7 @@ static int __restore_fpregs_from_user(void __user *buf, u64 ufeatures, */ static bool restore_fpregs_from_user(void __user *buf, u64 xrestore, bool fx_only) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); int ret; /* Restore enabled features only. */ @@ -332,7 +323,7 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, bool ia32_fxstate) { struct task_struct *tsk = current; - struct fpu *fpu = &tsk->thread.fpu; + struct fpu *fpu = x86_task_fpu(tsk); struct user_i387_ia32_struct env; bool success, fx_only = false; union fpregs_state *fpregs; @@ -452,7 +443,7 @@ static inline unsigned int xstate_sigframe_size(struct fpstate *fpstate) */ bool fpu__restore_sig(void __user *buf, int ia32_frame) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); void __user *buf_fx = buf; bool ia32_fxstate = false; bool success = false; @@ -499,7 +490,7 @@ unsigned long fpu__alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long *buf_fx, unsigned long *size) { - unsigned long frame_size = xstate_sigframe_size(current->thread.fpu.fpstate); + unsigned long frame_size = xstate_sigframe_size(x86_task_fpu(current)->fpstate); *buf_fx = sp = round_down(sp - frame_size, 64); if (ia32_frame && use_fxsr()) { diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 6a41d1610d8b..1c8410b68108 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -14,6 +14,7 @@ #include <linux/proc_fs.h> #include <linux/vmalloc.h> #include <linux/coredump.h> +#include <linux/sort.h> #include <asm/fpu/api.h> #include <asm/fpu/regset.h> @@ -62,6 +63,7 @@ static const char *xfeature_names[] = "unknown xstate feature", "AMX Tile config", "AMX Tile data", + "APX registers", "unknown xstate feature", }; @@ -80,6 +82,7 @@ static unsigned short xsave_cpuid_features[] __initdata = { [XFEATURE_CET_USER] = X86_FEATURE_SHSTK, [XFEATURE_XTILE_CFG] = X86_FEATURE_AMX_TILE, [XFEATURE_XTILE_DATA] = X86_FEATURE_AMX_TILE, + [XFEATURE_APX] = X86_FEATURE_APX, }; static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init = @@ -88,6 +91,31 @@ static unsigned int xstate_sizes[XFEATURE_MAX] __ro_after_init = { [ 0 ... XFEATURE_MAX - 1] = -1}; static unsigned int xstate_flags[XFEATURE_MAX] __ro_after_init; +/* + * Ordering of xstate components in uncompacted format: The xfeature + * number does not necessarily indicate its position in the XSAVE buffer. + * This array defines the traversal order of xstate features. + */ +static unsigned int xfeature_uncompact_order[XFEATURE_MAX] __ro_after_init = + { [ 0 ... XFEATURE_MAX - 1] = -1}; + +static inline unsigned int next_xfeature_order(unsigned int i, u64 mask) +{ + for (; xfeature_uncompact_order[i] != -1; i++) { + if (mask & BIT_ULL(xfeature_uncompact_order[i])) + break; + } + + return i; +} + +/* Iterate xstate features in uncompacted order: */ +#define for_each_extended_xfeature_in_order(i, mask) \ + for (i = 0; \ + i = next_xfeature_order(i, mask), \ + xfeature_uncompact_order[i] != -1; \ + i++) + #define XSTATE_FLAG_SUPERVISOR BIT(0) #define XSTATE_FLAG_ALIGNED64 BIT(1) @@ -209,16 +237,20 @@ static bool xfeature_enabled(enum xfeature xfeature) return fpu_kernel_cfg.max_features & BIT_ULL(xfeature); } +static int compare_xstate_offsets(const void *xfeature1, const void *xfeature2) +{ + return xstate_offsets[*(unsigned int *)xfeature1] - + xstate_offsets[*(unsigned int *)xfeature2]; +} + /* * Record the offsets and sizes of various xstates contained - * in the XSAVE state memory layout. + * in the XSAVE state memory layout. Also, create an ordered + * list of xfeatures for handling out-of-order offsets. */ static void __init setup_xstate_cache(void) { - u32 eax, ebx, ecx, edx, i; - /* start at the beginning of the "extended state" */ - unsigned int last_good_offset = offsetof(struct xregs_state, - extended_state_area); + u32 eax, ebx, ecx, edx, xfeature, i = 0; /* * The FP xstates and SSE xstates are legacy states. They are always * in the fixed offsets in the xsave area in either compacted form @@ -232,31 +264,30 @@ static void __init setup_xstate_cache(void) xstate_sizes[XFEATURE_SSE] = sizeof_field(struct fxregs_state, xmm_space); - for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) { - cpuid_count(CPUID_LEAF_XSTATE, i, &eax, &ebx, &ecx, &edx); + for_each_extended_xfeature(xfeature, fpu_kernel_cfg.max_features) { + cpuid_count(CPUID_LEAF_XSTATE, xfeature, &eax, &ebx, &ecx, &edx); - xstate_sizes[i] = eax; - xstate_flags[i] = ecx; + xstate_sizes[xfeature] = eax; + xstate_flags[xfeature] = ecx; /* * If an xfeature is supervisor state, the offset in EBX is * invalid, leave it to -1. */ - if (xfeature_is_supervisor(i)) + if (xfeature_is_supervisor(xfeature)) continue; - xstate_offsets[i] = ebx; + xstate_offsets[xfeature] = ebx; - /* - * In our xstate size checks, we assume that the highest-numbered - * xstate feature has the highest offset in the buffer. Ensure - * it does. - */ - WARN_ONCE(last_good_offset > xstate_offsets[i], - "x86/fpu: misordered xstate at %d\n", last_good_offset); - - last_good_offset = xstate_offsets[i]; + /* Populate the list of xfeatures before sorting */ + xfeature_uncompact_order[i++] = xfeature; } + + /* + * Sort xfeatures by their offsets to support out-of-order + * offsets in the uncompacted format. + */ + sort(xfeature_uncompact_order, i, sizeof(unsigned int), compare_xstate_offsets, NULL); } /* @@ -340,7 +371,8 @@ static __init void os_xrstor_booting(struct xregs_state *xstate) XFEATURE_MASK_BNDCSR | \ XFEATURE_MASK_PASID | \ XFEATURE_MASK_CET_USER | \ - XFEATURE_MASK_XTILE) + XFEATURE_MASK_XTILE | \ + XFEATURE_MASK_APX) /* * setup the xstate image representing the init state @@ -540,6 +572,7 @@ static bool __init check_xstate_against_struct(int nr) case XFEATURE_PASID: return XCHECK_SZ(sz, nr, struct ia32_pasid_state); case XFEATURE_XTILE_CFG: return XCHECK_SZ(sz, nr, struct xtile_cfg); case XFEATURE_CET_USER: return XCHECK_SZ(sz, nr, struct cet_user_state); + case XFEATURE_APX: return XCHECK_SZ(sz, nr, struct apx_state); case XFEATURE_XTILE_DATA: check_xtile_data_against_struct(sz); return true; default: XSTATE_WARN_ON(1, "No structure for xstate: %d\n", nr); @@ -552,13 +585,20 @@ static bool __init check_xstate_against_struct(int nr) static unsigned int xstate_calculate_size(u64 xfeatures, bool compacted) { unsigned int topmost = fls64(xfeatures) - 1; - unsigned int offset = xstate_offsets[topmost]; + unsigned int offset, i; if (topmost <= XFEATURE_SSE) return sizeof(struct xregs_state); - if (compacted) + if (compacted) { offset = xfeature_get_offset(xfeatures, topmost); + } else { + /* Walk through the xfeature order to pick the last */ + for_each_extended_xfeature_in_order(i, xfeatures) + topmost = xfeature_uncompact_order[i]; + offset = xstate_offsets[topmost]; + } + return offset + xstate_sizes[topmost]; } @@ -711,6 +751,8 @@ static int __init init_xstate_size(void) */ static void __init fpu__init_disable_system_xstate(unsigned int legacy_size) { + pr_info("x86/fpu: XSAVE disabled\n"); + fpu_kernel_cfg.max_features = 0; cr4_clear_bits(X86_CR4_OSXSAVE); setup_clear_cpu_cap(X86_FEATURE_XSAVE); @@ -727,7 +769,7 @@ static void __init fpu__init_disable_system_xstate(unsigned int legacy_size) */ init_fpstate.xfd = 0; - fpstate_reset(¤t->thread.fpu); + fpstate_reset(x86_task_fpu(current)); } /* @@ -775,6 +817,17 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) goto out_disable; } + if (fpu_kernel_cfg.max_features & XFEATURE_MASK_APX && + fpu_kernel_cfg.max_features & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) { + /* + * This is a problematic CPU configuration where two + * conflicting state components are both enumerated. + */ + pr_err("x86/fpu: Both APX/MPX present in the CPU's xstate features: 0x%llx.\n", + fpu_kernel_cfg.max_features); + goto out_disable; + } + fpu_kernel_cfg.independent_features = fpu_kernel_cfg.max_features & XFEATURE_MASK_INDEPENDENT; @@ -834,9 +887,6 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) if (err) goto out_disable; - /* Reset the state for the current task */ - fpstate_reset(¤t->thread.fpu); - /* * Update info used for ptrace frames; use standard-format size and no * supervisor xstates: @@ -852,7 +902,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_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", + pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d)\n", sizeof(init_fpstate.regs), init_fpstate.size); goto out_disable; } @@ -864,7 +914,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) * xfeatures mask. */ if (xfeatures != fpu_kernel_cfg.max_features) { - pr_err("x86/fpu: xfeatures modified from 0x%016llx to 0x%016llx during init, disabling XSAVE\n", + pr_err("x86/fpu: xfeatures modified from 0x%016llx to 0x%016llx during init\n", xfeatures, fpu_kernel_cfg.max_features); goto out_disable; } @@ -909,7 +959,7 @@ void fpu__resume_cpu(void) } if (fpu_state_size_dynamic()) - wrmsrl(MSR_IA32_XFD, current->thread.fpu.fpstate->xfd); + wrmsrl(MSR_IA32_XFD, x86_task_fpu(current)->fpstate->xfd); } /* @@ -1071,10 +1121,9 @@ void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate, const unsigned int off_mxcsr = offsetof(struct fxregs_state, mxcsr); struct xregs_state *xinit = &init_fpstate.regs.xsave; struct xregs_state *xsave = &fpstate->regs.xsave; + unsigned int zerofrom, i, xfeature; struct xstate_header header; - unsigned int zerofrom; u64 mask; - int i; memset(&header, 0, sizeof(header)); header.xfeatures = xsave->header.xfeatures; @@ -1143,15 +1192,16 @@ void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate, */ mask = header.xfeatures; - for_each_extended_xfeature(i, mask) { + for_each_extended_xfeature_in_order(i, mask) { + xfeature = xfeature_uncompact_order[i]; /* * If there was a feature or alignment gap, zero the space * in the destination buffer. */ - if (zerofrom < xstate_offsets[i]) - membuf_zero(&to, xstate_offsets[i] - zerofrom); + if (zerofrom < xstate_offsets[xfeature]) + membuf_zero(&to, xstate_offsets[xfeature] - zerofrom); - if (i == XFEATURE_PKRU) { + if (xfeature == XFEATURE_PKRU) { struct pkru_state pkru = {0}; /* * PKRU is not necessarily up to date in the @@ -1161,14 +1211,14 @@ void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate, membuf_write(&to, &pkru, sizeof(pkru)); } else { membuf_write(&to, - __raw_xsave_addr(xsave, i), - xstate_sizes[i]); + __raw_xsave_addr(xsave, xfeature), + xstate_sizes[xfeature]); } /* * Keep track of the last copied state in the non-compacted * target buffer for gap zeroing. */ - zerofrom = xstate_offsets[i] + xstate_sizes[i]; + zerofrom = xstate_offsets[xfeature] + xstate_sizes[xfeature]; } out: @@ -1191,8 +1241,8 @@ out: void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk, enum xstate_copy_mode copy_mode) { - __copy_xstate_to_uabi_buf(to, tsk->thread.fpu.fpstate, - tsk->thread.fpu.fpstate->user_xfeatures, + __copy_xstate_to_uabi_buf(to, x86_task_fpu(tsk)->fpstate, + x86_task_fpu(tsk)->fpstate->user_xfeatures, tsk->thread.pkru, copy_mode); } @@ -1332,7 +1382,7 @@ int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf, u int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void __user *ubuf) { - return copy_uabi_to_xstate(tsk->thread.fpu.fpstate, NULL, ubuf, &tsk->thread.pkru); + return copy_uabi_to_xstate(x86_task_fpu(tsk)->fpstate, NULL, ubuf, &tsk->thread.pkru); } static bool validate_independent_components(u64 mask) @@ -1398,9 +1448,9 @@ void xrstors(struct xregs_state *xstate, u64 mask) } #if IS_ENABLED(CONFIG_KVM) -void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature) +void fpstate_clear_xstate_component(struct fpstate *fpstate, unsigned int xfeature) { - void *addr = get_xsave_addr(&fps->regs.xsave, xfeature); + void *addr = get_xsave_addr(&fpstate->regs.xsave, xfeature); if (addr) memset(addr, 0, xstate_sizes[xfeature]); @@ -1426,7 +1476,7 @@ static bool xstate_op_valid(struct fpstate *fpstate, u64 mask, bool rstor) * The XFD MSR does not match fpstate->xfd. That's invalid when * the passed in fpstate is current's fpstate. */ - if (fpstate->xfd == current->thread.fpu.fpstate->xfd) + if (fpstate->xfd == x86_task_fpu(current)->fpstate->xfd) return false; /* @@ -1503,7 +1553,7 @@ void fpstate_free(struct fpu *fpu) static int fpstate_realloc(u64 xfeatures, unsigned int ksize, unsigned int usize, struct fpu_guest *guest_fpu) { - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); struct fpstate *curfps, *newfps = NULL; unsigned int fpsize; bool in_use; @@ -1596,7 +1646,7 @@ static int __xstate_request_perm(u64 permitted, u64 requested, bool guest) * AVX512. */ bool compacted = cpu_feature_enabled(X86_FEATURE_XCOMPACTED); - struct fpu *fpu = ¤t->group_leader->thread.fpu; + struct fpu *fpu = x86_task_fpu(current->group_leader); struct fpu_state_perm *perm; unsigned int ksize, usize; u64 mask; @@ -1606,16 +1656,20 @@ static int __xstate_request_perm(u64 permitted, u64 requested, bool guest) if ((permitted & requested) == requested) return 0; - /* Calculate the resulting kernel state size */ + /* + * Calculate the resulting kernel state size. Note, @permitted also + * contains supervisor xfeatures even though supervisor are always + * permitted for kernel and guest FPUs, and never permitted for user + * FPUs. + */ mask = permitted | requested; - /* Take supervisor states into account on the host */ - if (!guest) - mask |= xfeatures_mask_supervisor(); ksize = xstate_calculate_size(mask, compacted); - /* Calculate the resulting user state size */ - mask &= XFEATURE_MASK_USER_SUPPORTED; - usize = xstate_calculate_size(mask, false); + /* + * Calculate the resulting user state size. Take care not to clobber + * the supervisor xfeatures in the new mask! + */ + usize = xstate_calculate_size(mask & XFEATURE_MASK_USER_SUPPORTED, false); if (!guest) { ret = validate_sigaltstack(usize); @@ -1699,7 +1753,7 @@ int __xfd_enable_feature(u64 xfd_err, struct fpu_guest *guest_fpu) return -EPERM; } - fpu = ¤t->group_leader->thread.fpu; + fpu = x86_task_fpu(current->group_leader); perm = guest_fpu ? &fpu->guest_perm : &fpu->perm; ksize = perm->__state_size; usize = perm->__user_state_size; @@ -1804,7 +1858,7 @@ long fpu_xstate_prctl(int option, unsigned long arg2) */ static void avx512_status(struct seq_file *m, struct task_struct *task) { - unsigned long timestamp = READ_ONCE(task->thread.fpu.avx512_timestamp); + unsigned long timestamp = READ_ONCE(x86_task_fpu(task)->avx512_timestamp); long delta; if (!timestamp) { diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index 0fd34f53f025..a0256ef34ecb 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -22,7 +22,7 @@ static inline void xstate_init_xcomp_bv(struct xregs_state *xsave, u64 mask) static inline u64 xstate_get_group_perm(bool guest) { - struct fpu *fpu = ¤t->group_leader->thread.fpu; + struct fpu *fpu = x86_task_fpu(current->group_leader); struct fpu_state_perm *perm; /* Pairs with WRITE_ONCE() in xstate_request_perm() */ @@ -69,21 +69,31 @@ static inline u64 xfeatures_mask_independent(void) return fpu_kernel_cfg.independent_features; } +static inline int set_xfeature_in_sigframe(struct xregs_state __user *xbuf, u64 mask) +{ + u64 xfeatures; + int err; + + /* Read the xfeatures value already saved in the user buffer */ + err = __get_user(xfeatures, &xbuf->header.xfeatures); + xfeatures |= mask; + err |= __put_user(xfeatures, &xbuf->header.xfeatures); + + return err; +} + /* * Update the value of PKRU register that was already pushed onto the signal frame. */ -static inline int update_pkru_in_sigframe(struct xregs_state __user *buf, u64 mask, u32 pkru) +static inline int update_pkru_in_sigframe(struct xregs_state __user *buf, u32 pkru) { - u64 xstate_bv; int err; if (unlikely(!cpu_feature_enabled(X86_FEATURE_OSPKE))) return 0; /* Mark PKRU as in-use so that it is restored correctly. */ - xstate_bv = (mask & xfeatures_in_use()) | XFEATURE_MASK_PKRU; - - err = __put_user(xstate_bv, &buf->header.xfeatures); + err = set_xfeature_in_sigframe(buf, XFEATURE_MASK_PKRU); if (err) return err; @@ -288,7 +298,7 @@ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf, u32 pkr * internally, e.g. PKRU. That's user space ABI and also required * to allow the signal handler to modify PKRU. */ - struct fpstate *fpstate = current->thread.fpu.fpstate; + struct fpstate *fpstate = x86_task_fpu(current)->fpstate; u64 mask = fpstate->user_xfeatures; u32 lmask; u32 hmask; @@ -307,7 +317,7 @@ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf, u32 pkr clac(); if (!err) - err = update_pkru_in_sigframe(buf, mask, pkru); + err = update_pkru_in_sigframe(buf, pkru); return err; } @@ -322,7 +332,7 @@ static inline int xrstor_from_user_sigframe(struct xregs_state __user *buf, u64 u32 hmask = mask >> 32; int err; - xfd_validate_state(current->thread.fpu.fpstate, mask, true); + xfd_validate_state(x86_task_fpu(current)->fpstate, mask, true); stac(); XSTATE_OP(XRSTOR, xstate, lmask, hmask, err); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 962c3ce39323..9e6180777565 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -93,17 +93,12 @@ EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid); */ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { - /* init_task is not dynamically sized (incomplete FPU state) */ - if (unlikely(src == &init_task)) - memcpy_and_pad(dst, arch_task_struct_size, src, sizeof(init_task), 0); - else - memcpy(dst, src, arch_task_struct_size); + /* fpu_clone() will initialize the "dst_fpu" memory */ + memcpy_and_pad(dst, arch_task_struct_size, src, sizeof(*dst), 0); #ifdef CONFIG_VM86 dst->thread.vm86 = NULL; #endif - /* Drop the copied pointer to current's fpstate */ - dst->thread.fpu.fpstate = NULL; return 0; } @@ -111,8 +106,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) #ifdef CONFIG_X86_64 void arch_release_task_struct(struct task_struct *tsk) { - if (fpu_state_size_dynamic()) - fpstate_free(&tsk->thread.fpu); + if (fpu_state_size_dynamic() && !(tsk->flags & (PF_KTHREAD | PF_USER_WORKER))) + fpstate_free(x86_task_fpu(tsk)); } #endif @@ -122,7 +117,6 @@ void arch_release_task_struct(struct task_struct *tsk) void exit_thread(struct task_struct *tsk) { struct thread_struct *t = &tsk->thread; - struct fpu *fpu = &t->fpu; if (test_thread_flag(TIF_IO_BITMAP)) io_bitmap_exit(tsk); @@ -130,7 +124,7 @@ void exit_thread(struct task_struct *tsk) free_vm86(t); shstk_free(tsk); - fpu__drop(fpu); + fpu__drop(tsk); } static int set_new_tls(struct task_struct *p, unsigned long tls) diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 4636ef359973..9bd4fa694da5 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -160,8 +160,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */ - if (!test_tsk_thread_flag(prev_p, TIF_NEED_FPU_LOAD)) - switch_fpu_prepare(prev_p, cpu); + switch_fpu(prev_p, cpu); /* * Save away %gs. No need to save %fs, as it was saved on the @@ -208,8 +207,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) raw_cpu_write(current_task, next_p); - switch_fpu_finish(next_p); - /* Load the Intel cache allocation PQR MSR. */ resctrl_sched_in(next_p); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 7196ca7048be..d55310d3133c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -616,8 +616,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) && this_cpu_read(hardirq_stack_inuse)); - if (!test_tsk_thread_flag(prev_p, TIF_NEED_FPU_LOAD)) - switch_fpu_prepare(prev_p, cpu); + switch_fpu(prev_p, cpu); /* We must save %fs and %gs before load_TLS() because * %fs and %gs may be cleared by load_TLS(). @@ -671,8 +670,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) raw_cpu_write(current_task, next_p); raw_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p)); - switch_fpu_finish(next_p); - /* Reload sp0. */ update_task_stack(next_p); diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 5f441039b572..2404233336ab 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -255,7 +255,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) { bool stepping, failed; - struct fpu *fpu = ¤t->thread.fpu; + struct fpu *fpu = x86_task_fpu(current); if (v8086_mode(regs)) save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL); @@ -423,14 +423,14 @@ bool sigaltstack_size_valid(size_t ss_size) if (!fpu_state_size_dynamic() && !strict_sigaltstack_size) return true; - fsize += current->group_leader->thread.fpu.perm.__user_state_size; + fsize += x86_task_fpu(current->group_leader)->perm.__user_state_size; if (likely(ss_size > fsize)) return true; if (strict_sigaltstack_size) return ss_size > fsize; - mask = current->group_leader->thread.fpu.perm.__state_perm; + mask = x86_task_fpu(current->group_leader)->perm.__state_perm; if (mask & XFEATURE_MASK_USER_DYNAMIC) return ss_size > fsize; diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index d67407c623f3..42e1d6cc48e9 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1295,7 +1295,7 @@ DEFINE_IDTENTRY_RAW(exc_debug) static void math_error(struct pt_regs *regs, int trapnr) { struct task_struct *task = current; - struct fpu *fpu = &task->thread.fpu; + struct fpu *fpu = x86_task_fpu(task); int si_code; char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : "simd exception"; diff --git a/arch/x86/math-emu/fpu_aux.c b/arch/x86/math-emu/fpu_aux.c index d62662bdd460..5f253ae406b6 100644 --- a/arch/x86/math-emu/fpu_aux.c +++ b/arch/x86/math-emu/fpu_aux.c @@ -53,7 +53,7 @@ void fpstate_init_soft(struct swregs_state *soft) void finit(void) { - fpstate_init_soft(¤t->thread.fpu.fpstate->regs.soft); + fpstate_init_soft(&x86_task_fpu(current)->fpstate->regs.soft); } /* diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c index 91c52ead1226..5034df617740 100644 --- a/arch/x86/math-emu/fpu_entry.c +++ b/arch/x86/math-emu/fpu_entry.c @@ -641,7 +641,7 @@ int fpregs_soft_set(struct task_struct *target, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct swregs_state *s387 = &target->thread.fpu.fpstate->regs.soft; + struct swregs_state *s387 = &x86_task_fpu(target)->fpstate->regs.soft; void *space = s387->st_space; int ret; int offset, other, i, tags, regnr, tag, newtop; @@ -692,7 +692,7 @@ int fpregs_soft_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { - struct swregs_state *s387 = &target->thread.fpu.fpstate->regs.soft; + struct swregs_state *s387 = &x86_task_fpu(target)->fpstate->regs.soft; const void *space = s387->st_space; int offset = (S387->ftop & 7) * 10, other = 80 - offset; diff --git a/arch/x86/math-emu/fpu_system.h b/arch/x86/math-emu/fpu_system.h index eec3e4805c75..5e238e930fe3 100644 --- a/arch/x86/math-emu/fpu_system.h +++ b/arch/x86/math-emu/fpu_system.h @@ -73,7 +73,7 @@ static inline bool seg_writable(struct desc_struct *d) return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE; } -#define I387 (¤t->thread.fpu.fpstate->regs) +#define I387 (&x86_task_fpu(current)->fpstate->regs) #define FPU_info (I387->soft.info) #define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs)) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 51986e8a9d35..bf8dab18be97 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -111,7 +111,7 @@ static bool ex_handler_sgx(const struct exception_table_entry *fixup, /* * Handler for when we fail to restore a task's FPU state. We should never get - * here because the FPU state of a task using the FPU (task->thread.fpu.state) + * here because the FPU state of a task using the FPU (struct fpu::fpstate) * should always be valid. However, past bugs have allowed userspace to set * reserved bits in the XSAVE area using PTRACE_SETREGSET or sys_rt_sigreturn(). * These caused XRSTOR to fail when switching to the task, leaking the FPU diff --git a/include/linux/sched.h b/include/linux/sched.h index f96ac1982893..4ecc0c6b1cb0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1646,22 +1646,15 @@ struct task_struct { struct user_event_mm *user_event_mm; #endif - /* - * New fields for task_struct should be added above here, so that - * they are included in the randomized portion of task_struct. - */ - randomized_struct_fields_end - /* CPU-specific state of this task: */ struct thread_struct thread; /* - * WARNING: on x86, 'thread_struct' contains a variable-sized - * structure. It *MUST* be at the end of 'task_struct'. - * - * Do not put anything below here! + * New fields for task_struct should be added above here, so that + * they are included in the randomized portion of task_struct. */ -}; + randomized_struct_fields_end +} __attribute__ ((aligned (64))); #define TASK_REPORT_IDLE (TASK_REPORT + 1) #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 28422c32cc8f..f703fcfe9f7c 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -19,7 +19,7 @@ TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering \ - corrupt_xstate_header amx lam test_shadow_stack avx + corrupt_xstate_header amx lam test_shadow_stack avx apx # Some selftests require 32bit support enabled also on 64bit systems TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall @@ -136,3 +136,4 @@ $(OUTPUT)/nx_stack_64: CFLAGS += -Wl,-z,noexecstack $(OUTPUT)/avx_64: CFLAGS += -mno-avx -mno-avx512f $(OUTPUT)/amx_64: EXTRA_FILES += xstate.c $(OUTPUT)/avx_64: EXTRA_FILES += xstate.c +$(OUTPUT)/apx_64: EXTRA_FILES += xstate.c diff --git a/tools/testing/selftests/x86/apx.c b/tools/testing/selftests/x86/apx.c new file mode 100644 index 000000000000..d9c8d41b8c5a --- /dev/null +++ b/tools/testing/selftests/x86/apx.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include "xstate.h" + +int main(void) +{ + test_xstate(XFEATURE_APX); +} diff --git a/tools/testing/selftests/x86/xstate.c b/tools/testing/selftests/x86/xstate.c index 23c1d6c964ea..97fe4bd8bc77 100644 --- a/tools/testing/selftests/x86/xstate.c +++ b/tools/testing/selftests/x86/xstate.c @@ -31,7 +31,8 @@ (1 << XFEATURE_OPMASK) | \ (1 << XFEATURE_ZMM_Hi256) | \ (1 << XFEATURE_Hi16_ZMM) | \ - (1 << XFEATURE_XTILEDATA)) + (1 << XFEATURE_XTILEDATA) | \ + (1 << XFEATURE_APX)) static inline uint64_t xgetbv(uint32_t index) { diff --git a/tools/testing/selftests/x86/xstate.h b/tools/testing/selftests/x86/xstate.h index 42af36ec852f..e91e3092b5d2 100644 --- a/tools/testing/selftests/x86/xstate.h +++ b/tools/testing/selftests/x86/xstate.h @@ -33,6 +33,7 @@ enum xfeature { XFEATURE_RSRVD_COMP_16, XFEATURE_XTILECFG, XFEATURE_XTILEDATA, + XFEATURE_APX, XFEATURE_MAX, }; @@ -59,6 +60,7 @@ static const char *xfeature_names[] = "unknown xstate feature", "AMX Tile config", "AMX Tile data", + "APX registers", "unknown xstate feature", }; |