x86/fpu: Rename sanitize_i387_state() to fpstate_sanitize_xstate()

So the sanitize_i387_state() function has the following purpose:
on CPUs that support optimized xstate saving instructions, an
FPU fpstate might end up having partially uninitialized data.

This function initializes that data.

Note that the function name is a misnomer and confusing on two levels,
not only is it not i387 specific at all, but it is the exact opposite:
it only matters on xstate CPUs.

So rename sanitize_i387_state() and __sanitize_i387_state() to
fpstate_sanitize_xstate() and __fpstate_sanitize_xstate(),
to clearly express the purpose and usage of the function.

We'll further clean up this function in the next patch.

Cc: Andy Lutomirski <luto@amacapital.net>
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: Peter Zijlstra <peterz@infradead.org>
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 161b51bf267e5a97a18060950a8a816915a2143f..6b6fa46037f87e795939224a8cc0d202c009c4df 100644 (file)
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -139,13 +139,13 @@ static inline void fx_finit(struct i387_fxsave_struct *fx)
        fx->mxcsr = MXCSR_DEFAULT;
 }
 
-extern void __sanitize_i387_state(struct task_struct *);
+extern void __fpstate_sanitize_xstate(struct task_struct *);
 
-static inline void sanitize_i387_state(struct task_struct *tsk)
+static inline void fpstate_sanitize_xstate(struct task_struct *tsk)
 {
        if (!use_xsaveopt())
                return;
-       __sanitize_i387_state(tsk);
+       __fpstate_sanitize_xstate(tsk);
 }
 
 #define user_insn(insn, output, input...)                              \

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index edbb5d04a55810b6381d7c1ea84ecb8d35e4edcf..561a3532abc2f64a1d8da6d6e7084ed7231adef8 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -395,7 +395,7 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
                return -ENODEV;
 
        fpu__activate_stopped(fpu);
-       sanitize_i387_state(target);
+       fpstate_sanitize_xstate(target);
 
        return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                   &fpu->state.fxsave, 0, -1);
@@ -412,7 +412,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
                return -ENODEV;
 
        fpu__activate_stopped(fpu);
-       sanitize_i387_state(target);
+       fpstate_sanitize_xstate(target);
 
        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                 &fpu->state.fxsave, 0, -1);
@@ -644,7 +644,7 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
                                           &fpu->state.fsave, 0,
                                           -1);
 
-       sanitize_i387_state(target);
+       fpstate_sanitize_xstate(target);
 
        if (kbuf && pos == 0 && count == sizeof(env)) {
                convert_from_fxsr(kbuf, target);
@@ -666,7 +666,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 
        fpu__activate_stopped(fpu);
 
-       sanitize_i387_state(target);
+       fpstate_sanitize_xstate(target);
 
        if (!static_cpu_has(X86_FEATURE_FPU))
                return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c087f2d0f2d128aae66d139b70ff41b9911a77df..fc2ff1239fea604267986b32b5bf1256ef0ddeea 100644 (file)
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -92,7 +92,7 @@ EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
  * if the corresponding header bit is zero. This is to ensure that user-space doesn't
  * see some stale state in the memory layout during signal handling, debugging etc.
  */
-void __sanitize_i387_state(struct task_struct *tsk)
+void __fpstate_sanitize_xstate(struct task_struct *tsk)
 {
        struct i387_fxsave_struct *fx = &tsk->thread.fpu.state.fxsave;
        int feature_bit;
@@ -318,7 +318,7 @@ int save_xstate_sig(void __user *buf, void __user *buf_fx, int size)
                if (ia32_fxstate)
                        fpu_fxsave(&tsk->thread.fpu);
        } else {
-               sanitize_i387_state(tsk);
+               fpstate_sanitize_xstate(tsk);
                if (__copy_to_user(buf_fx, xsave, xstate_size))
                        return -1;
        }