From 91d93d0e206432b9fe4c88e64577b93aef018f98 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 27 Apr 2015 06:46:52 +0200 Subject: [PATCH] x86/fpu: Remove failure return from fpstate_alloc_init() Remove the failure code and propagate this down to callers. Note that this function still has an 'init' aspect, which must be called. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/internal.h | 2 +- arch/x86/kernel/fpu/core.c | 37 ++++++----------------------- arch/x86/kernel/fpu/xsave.c | 4 ++-- arch/x86/kvm/x86.c | 4 ++-- arch/x86/math-emu/fpu_entry.c | 8 ++----- 5 files changed, 14 insertions(+), 41 deletions(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 9454f21f0edf..1d0c5cee29eb 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -44,7 +44,7 @@ extern void fpu__init_system_xstate(void); extern void fpu__init_cpu_xstate(void); extern void fpu__init_system(struct cpuinfo_x86 *c); -extern int fpstate_alloc_init(struct fpu *fpu); +extern void fpstate_alloc_init(struct fpu *fpu); extern void fpstate_init(struct fpu *fpu); extern void fpu__clear(struct task_struct *tsk); diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 6b8d3e1b6ef8..b44ac5090641 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -259,26 +259,17 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) } /* - * Allocate the backing store for the current task's FPU registers - * and initialize the registers themselves as well. - * - * Can fail. + * Initialize the current task's in-memory FPU context: */ -int fpstate_alloc_init(struct fpu *fpu) +void fpstate_alloc_init(struct fpu *fpu) { - int ret; - - if (WARN_ON_ONCE(fpu != ¤t->thread.fpu)) - return -EINVAL; - if (WARN_ON_ONCE(fpu->fpstate_active)) - return -EINVAL; + WARN_ON_ONCE(fpu != ¤t->thread.fpu); + WARN_ON_ONCE(fpu->fpstate_active); fpstate_init(fpu); /* Safe to do for the current task: */ fpu->fpstate_active = 1; - - return 0; } EXPORT_SYMBOL_GPL(fpstate_alloc_init); @@ -340,20 +331,8 @@ void fpu__restore(void) struct task_struct *tsk = current; struct fpu *fpu = &tsk->thread.fpu; - if (!fpu->fpstate_active) { - local_irq_enable(); - /* - * does a slab alloc which can sleep - */ - if (fpstate_alloc_init(fpu)) { - /* - * ran out of memory! - */ - do_group_exit(SIGKILL); - return; - } - local_irq_disable(); - } + if (!fpu->fpstate_active) + fpstate_alloc_init(fpu); /* Avoid __kernel_fpu_begin() right after fpregs_activate() */ kernel_fpu_disable(); @@ -379,9 +358,7 @@ void fpu__clear(struct task_struct *tsk) drop_fpu(fpu); } else { if (!fpu->fpstate_active) { - /* kthread execs. TODO: cleanup this horror. */ - if (WARN_ON(fpstate_alloc_init(fpu))) - force_sig(SIGKILL, tsk); + fpstate_alloc_init(fpu); user_fpu_begin(); } restore_init_xstate(); diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c index c7d48eb0a194..dd2cef08a1a4 100644 --- a/arch/x86/kernel/fpu/xsave.c +++ b/arch/x86/kernel/fpu/xsave.c @@ -358,8 +358,8 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) if (!access_ok(VERIFY_READ, buf, size)) return -EACCES; - if (!fpu->fpstate_active && fpstate_alloc_init(fpu)) - return -1; + if (!fpu->fpstate_active) + fpstate_alloc_init(fpu); if (!static_cpu_has(X86_FEATURE_FPU)) return fpregs_soft_set(current, NULL, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 68529251e897..707f4e27ee91 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6601,8 +6601,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) int r; sigset_t sigsaved; - if (!fpu->fpstate_active && fpstate_alloc_init(fpu)) - return -ENOMEM; + if (!fpu->fpstate_active) + fpstate_alloc_init(fpu); if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved); diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c index 5e003704ebfa..99ddfc274df3 100644 --- a/arch/x86/math-emu/fpu_entry.c +++ b/arch/x86/math-emu/fpu_entry.c @@ -149,12 +149,8 @@ void math_emulate(struct math_emu_info *info) struct desc_struct code_descriptor; struct fpu *fpu = ¤t->thread.fpu; - if (!fpu->fpstate_active) { - if (fpstate_alloc_init(fpu)) { - do_group_exit(SIGKILL); - return; - } - } + if (!fpu->fpstate_active) + fpstate_alloc_init(fpu); #ifdef RE_ENTRANT_CHECKING if (emulating) { -- 2.20.1