diff options
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 46 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 5 |
2 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index c72cb2269adc..c3ec56279767 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -352,6 +352,45 @@ struct fpstate { /* @regs is dynamically sized! Don't add anything after @regs! */ } __aligned(64); +struct fpu_state_perm { + /* + * @__state_perm: + * + * This bitmap indicates the permission for state components, which + * are available to a thread group. The permission prctl() sets the + * enabled state bits in thread_group_leader()->thread.fpu. + * + * All run time operations use the per thread information in the + * currently active fpu.fpstate which contains the xfeature masks + * and sizes for kernel and user space. + * + * This master permission field is only to be used when + * task.fpu.fpstate based checks fail to validate whether the task + * is allowed to expand it's xfeatures set which requires to + * allocate a larger sized fpstate buffer. + * + * Do not access this field directly. Use the provided helper + * function. Unlocked access is possible for quick checks. + */ + u64 __state_perm; + + /* + * @__state_size: + * + * The size required for @__state_perm. Only valid to access + * with sighand locked. + */ + unsigned int __state_size; + + /* + * @__user_state_size: + * + * The size required for @__state_perm user part. Only valid to + * access with sighand locked. + */ + unsigned int __user_state_size; +}; + /* * Highest level per task FPU state data structure that * contains the FPU register state plus various FPU @@ -396,6 +435,13 @@ struct fpu { struct fpstate *__task_fpstate; /* + * @perm: + * + * Permission related information + */ + struct fpu_state_perm perm; + + /* * @__fpstate: * * Initial in-memory storage for FPU registers which are saved in diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 9c475e2efd4d..b05f6a3b2057 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -412,6 +412,11 @@ void fpstate_reset(struct fpu *fpu) /* Set the fpstate pointer to the default fpstate */ fpu->fpstate = &fpu->__fpstate; __fpstate_reset(fpu->fpstate); + + /* Initialize the permission related info in fpu */ + fpu->perm.__state_perm = fpu_kernel_cfg.default_features; + fpu->perm.__state_size = fpu_kernel_cfg.default_size; + fpu->perm.__user_state_size = fpu_user_cfg.default_size; } /* Clone current's FPU state on fork */ |