}
static inline void
-sanitize_restored_xstate(union fpregs_state *state,
- struct user_i387_ia32_struct *ia32_env,
- u64 xfeatures, int fx_only)
+sanitize_restored_user_xstate(union fpregs_state *state,
+ struct user_i387_ia32_struct *ia32_env,
+ u64 user_xfeatures, int fx_only)
{
struct xregs_state *xsave = &state->xsave;
struct xstate_header *header = &xsave->header;
*/
/*
- * Init the state that is not present in the memory
- * layout and not enabled by the OS.
+ * 'user_xfeatures' might have bits clear which are
+ * set in header->xfeatures. This represents features that
+ * were in init state prior to a signal delivery, and need
+ * to be reset back to the init state. Clear any user
+ * feature bits which are set in the kernel buffer to get
+ * them back to the init state.
+ *
+ * Supervisor state is unchanged by input from userspace.
+ * Ensure supervisor state bits stay set and supervisor
+ * state is not modified.
*/
if (fx_only)
header->xfeatures = XFEATURE_MASK_FPSSE;
else
- header->xfeatures &= xfeatures;
+ header->xfeatures &= user_xfeatures |
+ xfeatures_mask_supervisor();
}
if (use_fxsr()) {
struct task_struct *tsk = current;
struct fpu *fpu = &tsk->thread.fpu;
struct user_i387_ia32_struct env;
- u64 xfeatures = 0;
+ u64 user_xfeatures = 0;
int fx_only = 0;
int ret = 0;
trace_x86_fpu_xstate_check_failed(fpu);
} else {
state_size = fx_sw_user.xstate_size;
- xfeatures = fx_sw_user.xfeatures;
+ user_xfeatures = fx_sw_user.xfeatures;
}
}
*/
fpregs_lock();
pagefault_disable();
- ret = copy_user_to_fpregs_zeroing(buf_fx, xfeatures, fx_only);
+ ret = copy_user_to_fpregs_zeroing(buf_fx, user_xfeatures, fx_only);
pagefault_enable();
if (!ret) {
fpregs_mark_activate();
if (use_xsave() && !fx_only) {
- u64 init_bv = xfeatures_mask_user() & ~xfeatures;
+ u64 init_bv = xfeatures_mask_user() & ~user_xfeatures;
if (using_compacted_format()) {
ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
if (ret)
goto err_out;
- sanitize_restored_xstate(&fpu->state, envp, xfeatures, fx_only);
+ sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
+ fx_only);
fpregs_lock();
if (unlikely(init_bv))
copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
- ret = copy_kernel_to_xregs_err(&fpu->state.xsave, xfeatures);
+ ret = copy_kernel_to_xregs_err(&fpu->state.xsave, user_xfeatures);
} else if (use_fxsr()) {
ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size);
goto err_out;
}
- sanitize_restored_xstate(&fpu->state, envp, xfeatures, fx_only);
+ sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
+ fx_only);
fpregs_lock();
if (use_xsave()) {