x86/fpu: Standardize the parameter type of copy_kernel_to_fpregs()

Bring the __copy_fpstate_to_fpregs() and copy_fpstate_to_fpregs() functions
in line with the parameter passing convention of other kernel-to-FPU-registers
copying functions: pass around an in-memory FPU register state pointer,
instead of struct fpu *.

NOTE: This patch also changes the assembly constraint of the FXSAVE-leak
      workaround from 'fpu->fpregs_active' to 'fpstate' - but that is fine,
      as we only need a valid memory address there for the FILDL instruction.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index da71d41227ff9a32c5ff46b125a76d699705a31b..12acbb32a5613f641d4c31afd69960d639cc7010 100644 (file)
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -446,19 +446,19 @@ static inline int copy_fpregs_to_fpstate(struct fpu *fpu)
        return 0;
 }
 
-static inline void __copy_kernel_to_fpregs(struct fpu *fpu)
+static inline void __copy_kernel_to_fpregs(union fpregs_state *fpstate)
 {
        if (use_xsave()) {
-               copy_kernel_to_xregs(&fpu->state.xsave, -1);
+               copy_kernel_to_xregs(&fpstate->xsave, -1);
        } else {
                if (use_fxsr())
-                       copy_kernel_to_fxregs(&fpu->state.fxsave);
+                       copy_kernel_to_fxregs(&fpstate->fxsave);
                else
-                       copy_kernel_to_fregs(&fpu->state.fsave);
+                       copy_kernel_to_fregs(&fpstate->fsave);
        }
 }
 
-static inline void copy_kernel_to_fpregs(struct fpu *fpu)
+static inline void copy_kernel_to_fpregs(union fpregs_state *fpstate)
 {
        /*
         * AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
@@ -470,10 +470,10 @@ static inline void copy_kernel_to_fpregs(struct fpu *fpu)
                        "fnclex\n\t"
                        "emms\n\t"
                        "fildl %P[addr]"        /* set F?P to defined value */
-                       : : [addr] "m" (fpu->fpregs_active));
+                       : : [addr] "m" (fpstate));
        }
 
-       __copy_kernel_to_fpregs(fpu);
+       __copy_kernel_to_fpregs(fpstate);
 }
 
 extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size);
@@ -642,7 +642,7 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
 static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switch)
 {
        if (fpu_switch.preload)
-               copy_kernel_to_fpregs(new_fpu);
+               copy_kernel_to_fpregs(&new_fpu->state);
 }
 
 /*

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 8470df44c06d1b45b928ad9e77b01214b53bca4c..79de954626fd971f1d24553078bed1f199d52267 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -127,7 +127,7 @@ void __kernel_fpu_end(void)
        struct fpu *fpu = &current->thread.fpu;
 
        if (fpu->fpregs_active)
-               copy_kernel_to_fpregs(fpu);
+               copy_kernel_to_fpregs(&fpu->state);
        else
                __fpregs_deactivate_hw();
 
@@ -368,7 +368,7 @@ void fpu__restore(struct fpu *fpu)
        /* Avoid __kernel_fpu_begin() right after fpregs_activate() */
        kernel_fpu_disable();
        fpregs_activate(fpu);
-       copy_kernel_to_fpregs(fpu);
+       copy_kernel_to_fpregs(&fpu->state);
        fpu->counter++;
        kernel_fpu_enable();
 }

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 66871f4937fa3f624f7aff2944ac8c10fdf5baf5..26eaeb522cab214bed15cba35f5be945722d70ae 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7030,7 +7030,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
        kvm_put_guest_xcr0(vcpu);
        vcpu->guest_fpu_loaded = 1;
        __kernel_fpu_begin();
-       __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu);
+       __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state);
        trace_kvm_fpu(1);
 }