![Alex Shi](/assets/img/avatar_default.png)
Since percpu_xxx() serial functions are duplicated with this_cpu_xxx(). Removing percpu_xxx() definition and replacing them by this_cpu_xxx() in code. There is no function change in this patch, just preparation for later percpu_xxx serial function removing. On x86 machine the this_cpu_xxx() serial functions are same as __this_cpu_xxx() without no unnecessary premmpt enable/disable. Thanks for Stephen Rothwell, he found and fixed a i386 build error in the patch. Also thanks for Andrew Morton, he kept updating the patchset in Linus' tree. Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Christoph Lameter <cl@gentwo.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
831 lines
19 KiB
C
831 lines
19 KiB
C
/*
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* Copyright (C) 1994 Linus Torvalds
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*
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* Pentium III FXSR, SSE support
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* General FPU state handling cleanups
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* Gareth Hughes <gareth@valinux.com>, May 2000
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*/
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#include <linux/module.h>
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#include <linux/regset.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <asm/sigcontext.h>
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#include <asm/processor.h>
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#include <asm/math_emu.h>
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#include <asm/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/i387.h>
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#include <asm/fpu-internal.h>
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#include <asm/user.h>
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#ifdef CONFIG_X86_64
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# include <asm/sigcontext32.h>
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# include <asm/user32.h>
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#else
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# define save_i387_xstate_ia32 save_i387_xstate
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# define restore_i387_xstate_ia32 restore_i387_xstate
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# define _fpstate_ia32 _fpstate
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# define _xstate_ia32 _xstate
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# define sig_xstate_ia32_size sig_xstate_size
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# define fx_sw_reserved_ia32 fx_sw_reserved
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# define user_i387_ia32_struct user_i387_struct
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# define user32_fxsr_struct user_fxsr_struct
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#endif
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/*
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* Were we in an interrupt that interrupted kernel mode?
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*
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* We can do a kernel_fpu_begin/end() pair *ONLY* if that
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* pair does nothing at all: the thread must not have fpu (so
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* that we don't try to save the FPU state), and TS must
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* be set (so that the clts/stts pair does nothing that is
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* visible in the interrupted kernel thread).
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*/
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static inline bool interrupted_kernel_fpu_idle(void)
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{
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return !__thread_has_fpu(current) &&
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(read_cr0() & X86_CR0_TS);
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}
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/*
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* Were we in user mode (or vm86 mode) when we were
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* interrupted?
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*
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* Doing kernel_fpu_begin/end() is ok if we are running
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* in an interrupt context from user mode - we'll just
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* save the FPU state as required.
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*/
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static inline bool interrupted_user_mode(void)
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{
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struct pt_regs *regs = get_irq_regs();
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return regs && user_mode_vm(regs);
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}
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/*
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* Can we use the FPU in kernel mode with the
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* whole "kernel_fpu_begin/end()" sequence?
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*
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* It's always ok in process context (ie "not interrupt")
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* but it is sometimes ok even from an irq.
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*/
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bool irq_fpu_usable(void)
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{
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return !in_interrupt() ||
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interrupted_user_mode() ||
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interrupted_kernel_fpu_idle();
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}
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EXPORT_SYMBOL(irq_fpu_usable);
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void kernel_fpu_begin(void)
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{
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struct task_struct *me = current;
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WARN_ON_ONCE(!irq_fpu_usable());
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preempt_disable();
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if (__thread_has_fpu(me)) {
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__save_init_fpu(me);
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__thread_clear_has_fpu(me);
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/* We do 'stts()' in kernel_fpu_end() */
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} else {
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this_cpu_write(fpu_owner_task, NULL);
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clts();
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}
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}
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EXPORT_SYMBOL(kernel_fpu_begin);
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void kernel_fpu_end(void)
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{
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stts();
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preempt_enable();
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}
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EXPORT_SYMBOL(kernel_fpu_end);
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void unlazy_fpu(struct task_struct *tsk)
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{
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preempt_disable();
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if (__thread_has_fpu(tsk)) {
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__save_init_fpu(tsk);
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__thread_fpu_end(tsk);
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} else
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tsk->fpu_counter = 0;
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preempt_enable();
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}
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EXPORT_SYMBOL(unlazy_fpu);
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#ifdef CONFIG_MATH_EMULATION
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# define HAVE_HWFP (boot_cpu_data.hard_math)
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#else
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# define HAVE_HWFP 1
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#endif
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static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
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unsigned int xstate_size;
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EXPORT_SYMBOL_GPL(xstate_size);
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unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
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static struct i387_fxsave_struct fx_scratch __cpuinitdata;
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static void __cpuinit mxcsr_feature_mask_init(void)
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{
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unsigned long mask = 0;
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clts();
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if (cpu_has_fxsr) {
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memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
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asm volatile("fxsave %0" : : "m" (fx_scratch));
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mask = fx_scratch.mxcsr_mask;
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if (mask == 0)
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mask = 0x0000ffbf;
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}
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mxcsr_feature_mask &= mask;
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stts();
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}
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static void __cpuinit init_thread_xstate(void)
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{
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/*
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* Note that xstate_size might be overwriten later during
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* xsave_init().
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*/
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if (!HAVE_HWFP) {
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/*
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* Disable xsave as we do not support it if i387
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* emulation is enabled.
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*/
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setup_clear_cpu_cap(X86_FEATURE_XSAVE);
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setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
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xstate_size = sizeof(struct i387_soft_struct);
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return;
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}
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if (cpu_has_fxsr)
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xstate_size = sizeof(struct i387_fxsave_struct);
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else
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xstate_size = sizeof(struct i387_fsave_struct);
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}
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/*
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* Called at bootup to set up the initial FPU state that is later cloned
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* into all processes.
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*/
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void __cpuinit fpu_init(void)
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{
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unsigned long cr0;
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unsigned long cr4_mask = 0;
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if (cpu_has_fxsr)
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cr4_mask |= X86_CR4_OSFXSR;
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if (cpu_has_xmm)
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cr4_mask |= X86_CR4_OSXMMEXCPT;
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if (cr4_mask)
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set_in_cr4(cr4_mask);
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cr0 = read_cr0();
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cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
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if (!HAVE_HWFP)
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cr0 |= X86_CR0_EM;
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write_cr0(cr0);
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if (!smp_processor_id())
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init_thread_xstate();
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mxcsr_feature_mask_init();
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/* clean state in init */
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current_thread_info()->status = 0;
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clear_used_math();
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}
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void fpu_finit(struct fpu *fpu)
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{
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if (!HAVE_HWFP) {
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finit_soft_fpu(&fpu->state->soft);
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return;
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}
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if (cpu_has_fxsr) {
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struct i387_fxsave_struct *fx = &fpu->state->fxsave;
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memset(fx, 0, xstate_size);
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fx->cwd = 0x37f;
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if (cpu_has_xmm)
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fx->mxcsr = MXCSR_DEFAULT;
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} else {
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struct i387_fsave_struct *fp = &fpu->state->fsave;
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memset(fp, 0, xstate_size);
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fp->cwd = 0xffff037fu;
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fp->swd = 0xffff0000u;
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fp->twd = 0xffffffffu;
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fp->fos = 0xffff0000u;
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}
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}
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EXPORT_SYMBOL_GPL(fpu_finit);
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/*
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* The _current_ task is using the FPU for the first time
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* so initialize it and set the mxcsr to its default
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* value at reset if we support XMM instructions and then
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* remember the current task has used the FPU.
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*/
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int init_fpu(struct task_struct *tsk)
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{
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int ret;
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if (tsk_used_math(tsk)) {
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if (HAVE_HWFP && tsk == current)
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unlazy_fpu(tsk);
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tsk->thread.fpu.last_cpu = ~0;
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return 0;
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}
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/*
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* Memory allocation at the first usage of the FPU and other state.
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*/
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ret = fpu_alloc(&tsk->thread.fpu);
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if (ret)
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return ret;
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fpu_finit(&tsk->thread.fpu);
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set_stopped_child_used_math(tsk);
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return 0;
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}
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EXPORT_SYMBOL_GPL(init_fpu);
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/*
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* The xstateregs_active() routine is the same as the fpregs_active() routine,
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* as the "regset->n" for the xstate regset will be updated based on the feature
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* capabilites supported by the xsave.
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*/
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int fpregs_active(struct task_struct *target, const struct user_regset *regset)
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{
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return tsk_used_math(target) ? regset->n : 0;
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}
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int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
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{
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return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
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}
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int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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int ret;
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if (!cpu_has_fxsr)
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return -ENODEV;
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ret = init_fpu(target);
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if (ret)
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return ret;
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sanitize_i387_state(target);
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return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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&target->thread.fpu.state->fxsave, 0, -1);
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}
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int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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int ret;
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if (!cpu_has_fxsr)
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return -ENODEV;
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ret = init_fpu(target);
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if (ret)
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return ret;
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sanitize_i387_state(target);
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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&target->thread.fpu.state->fxsave, 0, -1);
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/*
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* mxcsr reserved bits must be masked to zero for security reasons.
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*/
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target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
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/*
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* update the header bits in the xsave header, indicating the
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* presence of FP and SSE state.
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*/
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if (cpu_has_xsave)
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target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
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return ret;
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}
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int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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int ret;
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if (!cpu_has_xsave)
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return -ENODEV;
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ret = init_fpu(target);
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if (ret)
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return ret;
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/*
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* Copy the 48bytes defined by the software first into the xstate
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* memory layout in the thread struct, so that we can copy the entire
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* xstateregs to the user using one user_regset_copyout().
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*/
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memcpy(&target->thread.fpu.state->fxsave.sw_reserved,
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xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
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/*
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* Copy the xstate memory layout.
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*/
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ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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&target->thread.fpu.state->xsave, 0, -1);
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return ret;
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}
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int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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int ret;
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struct xsave_hdr_struct *xsave_hdr;
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if (!cpu_has_xsave)
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return -ENODEV;
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ret = init_fpu(target);
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if (ret)
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return ret;
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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&target->thread.fpu.state->xsave, 0, -1);
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/*
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* mxcsr reserved bits must be masked to zero for security reasons.
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*/
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target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
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xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr;
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xsave_hdr->xstate_bv &= pcntxt_mask;
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/*
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* These bits must be zero.
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*/
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xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
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return ret;
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}
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#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
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/*
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* FPU tag word conversions.
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*/
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static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
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{
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unsigned int tmp; /* to avoid 16 bit prefixes in the code */
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/* Transform each pair of bits into 01 (valid) or 00 (empty) */
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tmp = ~twd;
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tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
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/* and move the valid bits to the lower byte. */
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tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
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tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
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tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
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return tmp;
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}
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#define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16)
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#define FP_EXP_TAG_VALID 0
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#define FP_EXP_TAG_ZERO 1
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#define FP_EXP_TAG_SPECIAL 2
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#define FP_EXP_TAG_EMPTY 3
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static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
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{
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struct _fpxreg *st;
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u32 tos = (fxsave->swd >> 11) & 7;
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u32 twd = (unsigned long) fxsave->twd;
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u32 tag;
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u32 ret = 0xffff0000u;
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int i;
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for (i = 0; i < 8; i++, twd >>= 1) {
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if (twd & 0x1) {
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st = FPREG_ADDR(fxsave, (i - tos) & 7);
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switch (st->exponent & 0x7fff) {
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case 0x7fff:
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tag = FP_EXP_TAG_SPECIAL;
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break;
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case 0x0000:
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if (!st->significand[0] &&
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!st->significand[1] &&
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!st->significand[2] &&
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!st->significand[3])
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tag = FP_EXP_TAG_ZERO;
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else
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tag = FP_EXP_TAG_SPECIAL;
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break;
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default:
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if (st->significand[3] & 0x8000)
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tag = FP_EXP_TAG_VALID;
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else
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tag = FP_EXP_TAG_SPECIAL;
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break;
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}
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} else {
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tag = FP_EXP_TAG_EMPTY;
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}
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ret |= tag << (2 * i);
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}
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return ret;
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}
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/*
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* FXSR floating point environment conversions.
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*/
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static void
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convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
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{
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struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
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struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
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struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
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int i;
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env->cwd = fxsave->cwd | 0xffff0000u;
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env->swd = fxsave->swd | 0xffff0000u;
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env->twd = twd_fxsr_to_i387(fxsave);
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#ifdef CONFIG_X86_64
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env->fip = fxsave->rip;
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env->foo = fxsave->rdp;
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/*
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* should be actually ds/cs at fpu exception time, but
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* that information is not available in 64bit mode.
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*/
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env->fcs = task_pt_regs(tsk)->cs;
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if (tsk == current) {
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savesegment(ds, env->fos);
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} else {
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env->fos = tsk->thread.ds;
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}
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env->fos |= 0xffff0000;
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#else
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env->fip = fxsave->fip;
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env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
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env->foo = fxsave->foo;
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env->fos = fxsave->fos;
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#endif
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for (i = 0; i < 8; ++i)
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memcpy(&to[i], &from[i], sizeof(to[0]));
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}
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static void convert_to_fxsr(struct task_struct *tsk,
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const struct user_i387_ia32_struct *env)
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{
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struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
|
|
struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
|
|
struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
|
|
int i;
|
|
|
|
fxsave->cwd = env->cwd;
|
|
fxsave->swd = env->swd;
|
|
fxsave->twd = twd_i387_to_fxsr(env->twd);
|
|
fxsave->fop = (u16) ((u32) env->fcs >> 16);
|
|
#ifdef CONFIG_X86_64
|
|
fxsave->rip = env->fip;
|
|
fxsave->rdp = env->foo;
|
|
/* cs and ds ignored */
|
|
#else
|
|
fxsave->fip = env->fip;
|
|
fxsave->fcs = (env->fcs & 0xffff);
|
|
fxsave->foo = env->foo;
|
|
fxsave->fos = env->fos;
|
|
#endif
|
|
|
|
for (i = 0; i < 8; ++i)
|
|
memcpy(&to[i], &from[i], sizeof(from[0]));
|
|
}
|
|
|
|
int fpregs_get(struct task_struct *target, const struct user_regset *regset,
|
|
unsigned int pos, unsigned int count,
|
|
void *kbuf, void __user *ubuf)
|
|
{
|
|
struct user_i387_ia32_struct env;
|
|
int ret;
|
|
|
|
ret = init_fpu(target);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (!HAVE_HWFP)
|
|
return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
|
|
|
|
if (!cpu_has_fxsr) {
|
|
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
|
|
&target->thread.fpu.state->fsave, 0,
|
|
-1);
|
|
}
|
|
|
|
sanitize_i387_state(target);
|
|
|
|
if (kbuf && pos == 0 && count == sizeof(env)) {
|
|
convert_from_fxsr(kbuf, target);
|
|
return 0;
|
|
}
|
|
|
|
convert_from_fxsr(&env, target);
|
|
|
|
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
|
|
}
|
|
|
|
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 user_i387_ia32_struct env;
|
|
int ret;
|
|
|
|
ret = init_fpu(target);
|
|
if (ret)
|
|
return ret;
|
|
|
|
sanitize_i387_state(target);
|
|
|
|
if (!HAVE_HWFP)
|
|
return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
|
|
|
|
if (!cpu_has_fxsr) {
|
|
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
|
|
&target->thread.fpu.state->fsave, 0, -1);
|
|
}
|
|
|
|
if (pos > 0 || count < sizeof(env))
|
|
convert_from_fxsr(&env, target);
|
|
|
|
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
|
|
if (!ret)
|
|
convert_to_fxsr(target, &env);
|
|
|
|
/*
|
|
* update the header bit in the xsave header, indicating the
|
|
* presence of FP.
|
|
*/
|
|
if (cpu_has_xsave)
|
|
target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Signal frame handlers.
|
|
*/
|
|
|
|
static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct i387_fsave_struct *fp = &tsk->thread.fpu.state->fsave;
|
|
|
|
fp->status = fp->swd;
|
|
if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
|
|
return -1;
|
|
return 1;
|
|
}
|
|
|
|
static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct i387_fxsave_struct *fx = &tsk->thread.fpu.state->fxsave;
|
|
struct user_i387_ia32_struct env;
|
|
int err = 0;
|
|
|
|
convert_from_fxsr(&env, tsk);
|
|
if (__copy_to_user(buf, &env, sizeof(env)))
|
|
return -1;
|
|
|
|
err |= __put_user(fx->swd, &buf->status);
|
|
err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
|
|
if (err)
|
|
return -1;
|
|
|
|
if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
|
|
return -1;
|
|
return 1;
|
|
}
|
|
|
|
static int save_i387_xsave(void __user *buf)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct _fpstate_ia32 __user *fx = buf;
|
|
int err = 0;
|
|
|
|
|
|
sanitize_i387_state(tsk);
|
|
|
|
/*
|
|
* 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
|
|
* the FP/SSE bits by the legacy applications which don't touch
|
|
* xstate_bv in the xsave header.
|
|
*
|
|
* xsave aware applications can change the xstate_bv in the xsave
|
|
* header as well as change any contents in the memory layout.
|
|
* xrestore as part of sigreturn will capture all the changes.
|
|
*/
|
|
tsk->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
|
|
|
|
if (save_i387_fxsave(fx) < 0)
|
|
return -1;
|
|
|
|
err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
|
|
sizeof(struct _fpx_sw_bytes));
|
|
err |= __put_user(FP_XSTATE_MAGIC2,
|
|
(__u32 __user *) (buf + sig_xstate_ia32_size
|
|
- FP_XSTATE_MAGIC2_SIZE));
|
|
if (err)
|
|
return -1;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int save_i387_xstate_ia32(void __user *buf)
|
|
{
|
|
struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
|
|
struct task_struct *tsk = current;
|
|
|
|
if (!used_math())
|
|
return 0;
|
|
|
|
if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
|
|
return -EACCES;
|
|
/*
|
|
* This will cause a "finit" to be triggered by the next
|
|
* attempted FPU operation by the 'current' process.
|
|
*/
|
|
clear_used_math();
|
|
|
|
if (!HAVE_HWFP) {
|
|
return fpregs_soft_get(current, NULL,
|
|
0, sizeof(struct user_i387_ia32_struct),
|
|
NULL, fp) ? -1 : 1;
|
|
}
|
|
|
|
unlazy_fpu(tsk);
|
|
|
|
if (cpu_has_xsave)
|
|
return save_i387_xsave(fp);
|
|
if (cpu_has_fxsr)
|
|
return save_i387_fxsave(fp);
|
|
else
|
|
return save_i387_fsave(fp);
|
|
}
|
|
|
|
static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
return __copy_from_user(&tsk->thread.fpu.state->fsave, buf,
|
|
sizeof(struct i387_fsave_struct));
|
|
}
|
|
|
|
static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
|
|
unsigned int size)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct user_i387_ia32_struct env;
|
|
int err;
|
|
|
|
err = __copy_from_user(&tsk->thread.fpu.state->fxsave, &buf->_fxsr_env[0],
|
|
size);
|
|
/* mxcsr reserved bits must be masked to zero for security reasons */
|
|
tsk->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
|
|
if (err || __copy_from_user(&env, buf, sizeof(env)))
|
|
return 1;
|
|
convert_to_fxsr(tsk, &env);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int restore_i387_xsave(void __user *buf)
|
|
{
|
|
struct _fpx_sw_bytes fx_sw_user;
|
|
struct _fpstate_ia32 __user *fx_user =
|
|
((struct _fpstate_ia32 __user *) buf);
|
|
struct i387_fxsave_struct __user *fx =
|
|
(struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
|
|
struct xsave_hdr_struct *xsave_hdr =
|
|
¤t->thread.fpu.state->xsave.xsave_hdr;
|
|
u64 mask;
|
|
int err;
|
|
|
|
if (check_for_xstate(fx, buf, &fx_sw_user))
|
|
goto fx_only;
|
|
|
|
mask = fx_sw_user.xstate_bv;
|
|
|
|
err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
|
|
|
|
xsave_hdr->xstate_bv &= pcntxt_mask;
|
|
/*
|
|
* These bits must be zero.
|
|
*/
|
|
xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
|
|
|
|
/*
|
|
* Init the state that is not present in the memory layout
|
|
* and enabled by the OS.
|
|
*/
|
|
mask = ~(pcntxt_mask & ~mask);
|
|
xsave_hdr->xstate_bv &= mask;
|
|
|
|
return err;
|
|
fx_only:
|
|
/*
|
|
* Couldn't find the extended state information in the memory
|
|
* layout. Restore the FP/SSE and init the other extended state
|
|
* enabled by the OS.
|
|
*/
|
|
xsave_hdr->xstate_bv = XSTATE_FPSSE;
|
|
return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
|
|
}
|
|
|
|
int restore_i387_xstate_ia32(void __user *buf)
|
|
{
|
|
int err;
|
|
struct task_struct *tsk = current;
|
|
struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
|
|
|
|
if (HAVE_HWFP)
|
|
clear_fpu(tsk);
|
|
|
|
if (!buf) {
|
|
if (used_math()) {
|
|
clear_fpu(tsk);
|
|
clear_used_math();
|
|
}
|
|
|
|
return 0;
|
|
} else
|
|
if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
|
|
return -EACCES;
|
|
|
|
if (!used_math()) {
|
|
err = init_fpu(tsk);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (HAVE_HWFP) {
|
|
if (cpu_has_xsave)
|
|
err = restore_i387_xsave(buf);
|
|
else if (cpu_has_fxsr)
|
|
err = restore_i387_fxsave(fp, sizeof(struct
|
|
i387_fxsave_struct));
|
|
else
|
|
err = restore_i387_fsave(fp);
|
|
} else {
|
|
err = fpregs_soft_set(current, NULL,
|
|
0, sizeof(struct user_i387_ia32_struct),
|
|
NULL, fp) != 0;
|
|
}
|
|
set_used_math();
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* FPU state for core dumps.
|
|
* This is only used for a.out dumps now.
|
|
* It is declared generically using elf_fpregset_t (which is
|
|
* struct user_i387_struct) but is in fact only used for 32-bit
|
|
* dumps, so on 64-bit it is really struct user_i387_ia32_struct.
|
|
*/
|
|
int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
int fpvalid;
|
|
|
|
fpvalid = !!used_math();
|
|
if (fpvalid)
|
|
fpvalid = !fpregs_get(tsk, NULL,
|
|
0, sizeof(struct user_i387_ia32_struct),
|
|
fpu, NULL);
|
|
|
|
return fpvalid;
|
|
}
|
|
EXPORT_SYMBOL(dump_fpu);
|
|
|
|
#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
|