Merge branch 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/smap support from Ingo Molnar:
 "This adds support for the SMAP (Supervisor Mode Access Prevention) CPU
  feature on Intel CPUs: a hardware feature that prevents unintended
  user-space data access from kernel privileged code.

  It's turned on automatically when possible.

  This, in combination with SMEP, makes it even harder to exploit kernel
  bugs such as NULL pointer dereferences."

Fix up trivial conflict in arch/x86/kernel/entry_64.S due to newly added
includes right next to each other.

* 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, smep, smap: Make the switching functions one-way
  x86, suspend: On wakeup always initialize cr4 and EFER
  x86-32: Start out eflags and cr4 clean
  x86, smap: Do not abuse the [f][x]rstor_checking() functions for user space
  x86-32, smap: Add STAC/CLAC instructions to 32-bit kernel entry
  x86, smap: Reduce the SMAP overhead for signal handling
  x86, smap: A page fault due to SMAP is an oops
  x86, smap: Turn on Supervisor Mode Access Prevention
  x86, smap: Add STAC and CLAC instructions to control user space access
  x86, uaccess: Merge prototypes for clear_user/__clear_user
  x86, smap: Add a header file with macros for STAC/CLAC
  x86, alternative: Add header guards to <asm/alternative-asm.h>
  x86, alternative: Use .pushsection/.popsection
  x86, smap: Add CR4 bit for SMAP
  x86-32, mm: The WP test should be done on a kernel page

7 files changed, 108 insertions, 49 deletions

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 1b8e5a03d942..11676cf65aee 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -43,17 +43,22 @@ int acpi_suspend_lowlevel(void)
 
         header->video_mode = saved_video_mode;
 
+        header->pmode_behavior = 0;
+
 #ifndef CONFIG_64BIT
         store_gdt((struct desc_ptr *)&header->pmode_gdt);
 
-        if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low,
-                       &header->pmode_efer_high))
-                header->pmode_efer_low = header->pmode_efer_high = 0;
+        if (!rdmsr_safe(MSR_EFER,
+                        &header->pmode_efer_low,
+                        &header->pmode_efer_high))
+                header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
 #endif /* !CONFIG_64BIT */
 
         header->pmode_cr0 = read_cr0();
-        header->pmode_cr4 = read_cr4_safe();
-        header->pmode_behavior = 0;
+        if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
+                header->pmode_cr4 = read_cr4();
+                header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
+        }
         if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
                         &header->pmode_misc_en_low,
                         &header->pmode_misc_en_high))
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 532691b6c8fe..7505f7b13e71 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -259,23 +259,36 @@ static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 }
 #endif
 
-static int disable_smep __cpuinitdata;
 static __init int setup_disable_smep(char *arg)
 {
-        disable_smep = 1;
+        setup_clear_cpu_cap(X86_FEATURE_SMEP);
         return 1;
 }
 __setup("nosmep", setup_disable_smep);
 
-static __cpuinit void setup_smep(struct cpuinfo_x86 *c)
+static __always_inline void setup_smep(struct cpuinfo_x86 *c)
 {
-        if (cpu_has(c, X86_FEATURE_SMEP)) {
-                if (unlikely(disable_smep)) {
-                        setup_clear_cpu_cap(X86_FEATURE_SMEP);
-                        clear_in_cr4(X86_CR4_SMEP);
-                } else
-                        set_in_cr4(X86_CR4_SMEP);
-        }
+        if (cpu_has(c, X86_FEATURE_SMEP))
+                set_in_cr4(X86_CR4_SMEP);
+}
+
+static __init int setup_disable_smap(char *arg)
+{
+        setup_clear_cpu_cap(X86_FEATURE_SMAP);
+        return 1;
+}
+__setup("nosmap", setup_disable_smap);
+
+static __always_inline void setup_smap(struct cpuinfo_x86 *c)
+{
+        unsigned long eflags;
+
+        /* This should have been cleared long ago */
+        raw_local_save_flags(eflags);
+        BUG_ON(eflags & X86_EFLAGS_AC);
+
+        if (cpu_has(c, X86_FEATURE_SMAP))
+                set_in_cr4(X86_CR4_SMAP);
 }
 
 /*
@@ -712,8 +725,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
         c->cpu_index = 0;
         filter_cpuid_features(c, false);
 
-        setup_smep(c);
-
         if (this_cpu->c_bsp_init)
                 this_cpu->c_bsp_init(c);
 }
@@ -798,8 +809,6 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
                 c->phys_proc_id = c->initial_apicid;
         }
 
-        setup_smep(c);
-
         get_model_name(c); /* Default name */
 
         detect_nopl(c);
@@ -864,6 +873,10 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
         /* Disable the PN if appropriate */
         squash_the_stupid_serial_number(c);
 
+        /* Set up SMEP/SMAP */
+        setup_smep(c);
+        setup_smap(c);
+
         /*
          * The vendor-specific functions might have changed features.
          * Now we do "generic changes."
@@ -1114,7 +1127,8 @@ void syscall_init(void)
 
         /* Flags to clear on syscall */
         wrmsrl(MSR_SYSCALL_MASK,
-               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
+               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
+               X86_EFLAGS_IOPL|X86_EFLAGS_AC);
 }
 
 /*
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index f438a44bf8f9..0750e3ba87c0 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -57,6 +57,7 @@
 #include <asm/cpufeature.h>
 #include <asm/alternative-asm.h>
 #include <asm/asm.h>
+#include <asm/smap.h>
 
 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
 #include <linux/elf-em.h>
@@ -407,7 +408,9 @@ sysenter_past_esp:
  */
         cmpl $__PAGE_OFFSET-3,%ebp
         jae syscall_fault
+        ASM_STAC
 1:      movl (%ebp),%ebp
+        ASM_CLAC
         movl %ebp,PT_EBP(%esp)
         _ASM_EXTABLE(1b,syscall_fault)
 
@@ -488,6 +491,7 @@ ENDPROC(ia32_sysenter_target)
         # system call handler stub
 ENTRY(system_call)
         RING0_INT_FRAME                 # can't unwind into user space anyway
+        ASM_CLAC
         pushl_cfi %eax                  # save orig_eax
         SAVE_ALL
         GET_THREAD_INFO(%ebp)
@@ -670,6 +674,7 @@ END(syscall_exit_work)
 
         RING0_INT_FRAME                 # can't unwind into user space anyway
 syscall_fault:
+        ASM_CLAC
         GET_THREAD_INFO(%ebp)
         movl $-EFAULT,PT_EAX(%esp)
         jmp resume_userspace
@@ -825,6 +830,7 @@ END(interrupt)
  */
         .p2align CONFIG_X86_L1_CACHE_SHIFT
 common_interrupt:
+        ASM_CLAC
         addl $-0x80,(%esp)      /* Adjust vector into the [-256,-1] range */
         SAVE_ALL
         TRACE_IRQS_OFF
@@ -841,6 +847,7 @@ ENDPROC(common_interrupt)
 #define BUILD_INTERRUPT3(name, nr, fn)  \
 ENTRY(name)                             \
         RING0_INT_FRAME;                \
+        ASM_CLAC;                       \
         pushl_cfi $~(nr);               \
         SAVE_ALL;                       \
         TRACE_IRQS_OFF                  \
@@ -857,6 +864,7 @@ ENDPROC(name)
 
 ENTRY(coprocessor_error)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_coprocessor_error
         jmp error_code
@@ -865,6 +873,7 @@ END(coprocessor_error)
 
 ENTRY(simd_coprocessor_error)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
 #ifdef CONFIG_X86_INVD_BUG
         /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
@@ -886,6 +895,7 @@ END(simd_coprocessor_error)
 
 ENTRY(device_not_available)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $-1                   # mark this as an int
         pushl_cfi $do_device_not_available
         jmp error_code
@@ -906,6 +916,7 @@ END(native_irq_enable_sysexit)
 
 ENTRY(overflow)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_overflow
         jmp error_code
@@ -914,6 +925,7 @@ END(overflow)
 
 ENTRY(bounds)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_bounds
         jmp error_code
@@ -922,6 +934,7 @@ END(bounds)
 
 ENTRY(invalid_op)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_invalid_op
         jmp error_code
@@ -930,6 +943,7 @@ END(invalid_op)
 
 ENTRY(coprocessor_segment_overrun)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_coprocessor_segment_overrun
         jmp error_code
@@ -938,6 +952,7 @@ END(coprocessor_segment_overrun)
 
 ENTRY(invalid_TSS)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_invalid_TSS
         jmp error_code
         CFI_ENDPROC
@@ -945,6 +960,7 @@ END(invalid_TSS)
 
 ENTRY(segment_not_present)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_segment_not_present
         jmp error_code
         CFI_ENDPROC
@@ -952,6 +968,7 @@ END(segment_not_present)
 
 ENTRY(stack_segment)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_stack_segment
         jmp error_code
         CFI_ENDPROC
@@ -959,6 +976,7 @@ END(stack_segment)
 
 ENTRY(alignment_check)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_alignment_check
         jmp error_code
         CFI_ENDPROC
@@ -966,6 +984,7 @@ END(alignment_check)
 
 ENTRY(divide_error)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0                    # no error code
         pushl_cfi $do_divide_error
         jmp error_code
@@ -975,6 +994,7 @@ END(divide_error)
 #ifdef CONFIG_X86_MCE
 ENTRY(machine_check)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi machine_check_vector
         jmp error_code
@@ -984,6 +1004,7 @@ END(machine_check)
 
 ENTRY(spurious_interrupt_bug)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $0
         pushl_cfi $do_spurious_interrupt_bug
         jmp error_code
@@ -1273,6 +1294,7 @@ return_to_handler:
 
 ENTRY(page_fault)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_page_fault
         ALIGN
 error_code:
@@ -1345,6 +1367,7 @@ END(page_fault)
 
 ENTRY(debug)
         RING0_INT_FRAME
+        ASM_CLAC
         cmpl $ia32_sysenter_target,(%esp)
         jne debug_stack_correct
         FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
@@ -1369,6 +1392,7 @@ END(debug)
  */
 ENTRY(nmi)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi %eax
         movl %ss, %eax
         cmpw $__ESPFIX_SS, %ax
@@ -1439,6 +1463,7 @@ END(nmi)
 
 ENTRY(int3)
         RING0_INT_FRAME
+        ASM_CLAC
         pushl_cfi $-1                   # mark this as an int
         SAVE_ALL
         TRACE_IRQS_OFF
@@ -1459,6 +1484,7 @@ END(general_protection)
 #ifdef CONFIG_KVM_GUEST
 ENTRY(async_page_fault)
         RING0_EC_FRAME
+        ASM_CLAC
         pushl_cfi $do_async_page_fault
         jmp error_code
         CFI_ENDPROC
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 066334be7b74..44531acd9a81 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -57,6 +57,7 @@
 #include <asm/percpu.h>
 #include <asm/asm.h>
 #include <asm/rcu.h>
+#include <asm/smap.h>
 #include <linux/err.h>
 
 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this.  */
@@ -568,7 +569,8 @@ END(ret_from_fork)
  * System call entry. Up to 6 arguments in registers are supported.
  *
  * SYSCALL does not save anything on the stack and does not change the
- * stack pointer.
+ * stack pointer.  However, it does mask the flags register for us, so
+ * CLD and CLAC are not needed.
  */
 
 /*
@@ -987,6 +989,7 @@ END(interrupt)
          */
         .p2align CONFIG_X86_L1_CACHE_SHIFT
 common_interrupt:
+        ASM_CLAC
         XCPT_FRAME
         addq $-0x80,(%rsp)              /* Adjust vector to [-256,-1] range */
         interrupt do_IRQ
@@ -1126,6 +1129,7 @@ END(common_interrupt)
  */
 .macro apicinterrupt num sym do_sym
 ENTRY(\sym)
+        ASM_CLAC
         INTR_FRAME
         pushq_cfi $~(\num)
 .Lcommon_\sym:
@@ -1180,6 +1184,7 @@ apicinterrupt IRQ_WORK_VECTOR \
  */
 .macro zeroentry sym do_sym
 ENTRY(\sym)
+        ASM_CLAC
         INTR_FRAME
         PARAVIRT_ADJUST_EXCEPTION_FRAME
         pushq_cfi $-1           /* ORIG_RAX: no syscall to restart */
@@ -1197,6 +1202,7 @@ END(\sym)
 
 .macro paranoidzeroentry sym do_sym
 ENTRY(\sym)
+        ASM_CLAC
         INTR_FRAME
         PARAVIRT_ADJUST_EXCEPTION_FRAME
         pushq_cfi $-1           /* ORIG_RAX: no syscall to restart */
@@ -1215,6 +1221,7 @@ END(\sym)
 #define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
 .macro paranoidzeroentry_ist sym do_sym ist
 ENTRY(\sym)
+        ASM_CLAC
         INTR_FRAME
         PARAVIRT_ADJUST_EXCEPTION_FRAME
         pushq_cfi $-1           /* ORIG_RAX: no syscall to restart */
@@ -1234,6 +1241,7 @@ END(\sym)
 
 .macro errorentry sym do_sym
 ENTRY(\sym)
+        ASM_CLAC
         XCPT_FRAME
         PARAVIRT_ADJUST_EXCEPTION_FRAME
         subq $ORIG_RAX-R15, %rsp
@@ -1252,6 +1260,7 @@ END(\sym)
         /* error code is on the stack already */
 .macro paranoiderrorentry sym do_sym
 ENTRY(\sym)
+        ASM_CLAC
         XCPT_FRAME
         PARAVIRT_ADJUST_EXCEPTION_FRAME
         subq $ORIG_RAX-R15, %rsp
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index d42ab17b7397..957a47aec64e 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -287,27 +287,28 @@ ENTRY(startup_32_smp)
         leal -__PAGE_OFFSET(%ecx),%esp
 
 default_entry:
-
 /*
  *      New page tables may be in 4Mbyte page mode and may
  *      be using the global pages. 
  *
  *      NOTE! If we are on a 486 we may have no cr4 at all!
- *      So we do not try to touch it unless we really have
- *      some bits in it to set.  This won't work if the BSP
- *      implements cr4 but this AP does not -- very unlikely
- *      but be warned!  The same applies to the pse feature
- *      if not equally supported. --macro
- *
- *      NOTE! We have to correct for the fact that we're
- *      not yet offset PAGE_OFFSET..
+ *      Specifically, cr4 exists if and only if CPUID exists,
+ *      which in turn exists if and only if EFLAGS.ID exists.
  */
-#define cr4_bits pa(mmu_cr4_features)
-        movl cr4_bits,%edx
-        andl %edx,%edx
-        jz 6f
-        movl %cr4,%eax          # Turn on paging options (PSE,PAE,..)
-        orl %edx,%eax
+        movl $X86_EFLAGS_ID,%ecx
+        pushl %ecx
+        popfl
+        pushfl
+        popl %eax
+        pushl $0
+        popfl
+        pushfl
+        popl %edx
+        xorl %edx,%eax
+        testl %ecx,%eax
+        jz 6f                   # No ID flag = no CPUID = no CR4
+
+        movl pa(mmu_cr4_features),%eax
         movl %eax,%cr4
 
         testb $X86_CR4_PAE, %al         # check if PAE is enabled
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 3160c26db5e7..b33144c8b309 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -114,11 +114,12 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
                 regs->orig_ax = -1;             /* disable syscall checks */
 
                 get_user_ex(buf, &sc->fpstate);
-                err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
 
                 get_user_ex(*pax, &sc->ax);
         } get_user_catch(err);
 
+        err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
+
         return err;
 }
 
@@ -355,7 +356,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 put_user_ex(sig, &frame->sig);
                 put_user_ex(&frame->info, &frame->pinfo);
                 put_user_ex(&frame->uc, &frame->puc);
-                err |= copy_siginfo_to_user(&frame->info, info);
 
                 /* Create the ucontext.  */
                 if (cpu_has_xsave)
@@ -367,9 +367,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 put_user_ex(sas_ss_flags(regs->sp),
                             &frame->uc.uc_stack.ss_flags);
                 put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
-                err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
-                                        regs, set->sig[0]);
-                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
                 /* Set up to return from userspace.  */
                 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
@@ -386,6 +383,11 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                  */
                 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
         } put_user_catch(err);
+        
+        err |= copy_siginfo_to_user(&frame->info, info);
+        err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+                                regs, set->sig[0]);
+        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
         if (err)
                 return -EFAULT;
@@ -434,8 +436,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 put_user_ex(sas_ss_flags(regs->sp),
                             &frame->uc.uc_stack.ss_flags);
                 put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
-                err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
-                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
                 /* Set up to return from userspace.  If provided, use a stub
                    already in userspace.  */
@@ -448,6 +448,9 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 }
         } put_user_catch(err);
 
+        err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
+        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
         if (err)
                 return -EFAULT;
 
@@ -504,9 +507,6 @@ static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
                             &frame->uc.uc_stack.ss_flags);
                 put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
                 put_user_ex(0, &frame->uc.uc__pad0);
-                err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
-                                        regs, set->sig[0]);
-                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
                 if (ka->sa.sa_flags & SA_RESTORER) {
                         restorer = ka->sa.sa_restorer;
@@ -518,6 +518,10 @@ static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
                 put_user_ex(restorer, &frame->pretcode);
         } put_user_catch(err);
 
+        err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+                                regs, set->sig[0]);
+        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
         if (err)
                 return -EFAULT;
 
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 4e89b3dd408d..ada87a329edc 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -315,7 +315,7 @@ static inline int restore_user_xstate(void __user *buf, u64 xbv, int fx_only)
                 if ((unsigned long)buf % 64 || fx_only) {
                         u64 init_bv = pcntxt_mask & ~XSTATE_FPSSE;
                         xrstor_state(init_xstate_buf, init_bv);
-                        return fxrstor_checking((__force void *) buf);
+                        return fxrstor_user(buf);
                 } else {
                         u64 init_bv = pcntxt_mask & ~xbv;
                         if (unlikely(init_bv))
@@ -323,9 +323,9 @@ static inline int restore_user_xstate(void __user *buf, u64 xbv, int fx_only)
                         return xrestore_user(buf, xbv);
                 }
         } else if (use_fxsr()) {
-                return fxrstor_checking((__force void *) buf);
+                return fxrstor_user(buf);
         } else
-                return frstor_checking((__force void *) buf);
+                return frstor_user(buf);
 }
 
 int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)