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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/include/asm/fpu/internal.h | 6 +++--- arch/x86/kernel/fpu/core.c | 8 ++++---- arch/x86/kernel/fpu/xstate.c | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 161b51bf267e..6b6fa46037f8 100644 --- 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 8ae4c2450c2b..9ccf2b838de0 100644 --- 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 c087f2d0f2d1..fc2ff1239fea 100644 --- 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; } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
