diff options
Diffstat (limited to 'arch/x86/kernel/i387.c')
| -rw-r--r-- | arch/x86/kernel/i387.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 29251f5668b1..56b6e726fb60 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -247,6 +247,37 @@ void fpu_finit(struct fpu *fpu) EXPORT_SYMBOL_GPL(fpu_finit); /* + * Allocate the backing store for the current task's FPU registers + * and initialize the registers themselves as well. + * + * Can fail. + */ +int fpstate_alloc_init(struct task_struct *curr) +{ + int ret; + + if (WARN_ON_ONCE(curr != current)) + return -EINVAL; + if (WARN_ON_ONCE(curr->flags & PF_USED_MATH)) + return -EINVAL; + + /* + * Memory allocation at the first usage of the FPU and other state. + */ + ret = fpu_alloc(&curr->thread.fpu); + if (ret) + return ret; + + fpu_finit(&curr->thread.fpu); + + /* Safe to do for the current task: */ + curr->flags |= PF_USED_MATH; + + return 0; +} +EXPORT_SYMBOL_GPL(fpstate_alloc_init); + +/* * The _current_ task is using the FPU for the first time * so initialize it and set the mxcsr to its default * value at reset if we support XMM instructions and then |