Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / arch / x86 / kernel / fpu / signal.c

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index a4ec653..ec3ae30 100644 (file)
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -307,13 +307,17 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                return 0;
        }
 
-       if (!access_ok(buf, size))
-               return -EACCES;
+       if (!access_ok(buf, size)) {
+               ret = -EACCES;
+               goto out;
+       }
 
-       if (!static_cpu_has(X86_FEATURE_FPU))
-               return fpregs_soft_set(current, NULL,
-                                      0, sizeof(struct user_i387_ia32_struct),
-                                      NULL, buf) != 0;
+       if (!static_cpu_has(X86_FEATURE_FPU)) {
+               ret = fpregs_soft_set(current, NULL, 0,
+                                     sizeof(struct user_i387_ia32_struct),
+                                     NULL, buf);
+               goto out;
+       }
 
        if (use_xsave()) {
                struct _fpx_sw_bytes fx_sw_user;
@@ -369,6 +373,25 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                        fpregs_unlock();
                        return 0;
                }
+
+               /*
+                * The above did an FPU restore operation, restricted to
+                * the user portion of the registers, and failed, but the
+                * microcode might have modified the FPU registers
+                * nevertheless.
+                *
+                * If the FPU registers do not belong to current, then
+                * invalidate the FPU register state otherwise the task might
+                * preempt current and return to user space with corrupted
+                * FPU registers.
+                *
+                * In case current owns the FPU registers then no further
+                * action is required. The fixup below will handle it
+                * correctly.
+                */
+               if (test_thread_flag(TIF_NEED_FPU_LOAD))
+                       __cpu_invalidate_fpregs_state();
+
                fpregs_unlock();
        } else {
                /*
@@ -377,7 +400,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                 */
                ret = __copy_from_user(&env, buf, sizeof(env));
                if (ret)
-                       goto err_out;
+                       goto out;
                envp = &env;
        }
 
@@ -405,16 +428,9 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
        if (use_xsave() && !fx_only) {
                u64 init_bv = xfeatures_mask_user() & ~user_xfeatures;
 
-               if (using_compacted_format()) {
-                       ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
-               } else {
-                       ret = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);
-
-                       if (!ret && state_size > offsetof(struct xregs_state, header))
-                               ret = validate_user_xstate_header(&fpu->state.xsave.header);
-               }
+               ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
                if (ret)
-                       goto err_out;
+                       goto out;
 
                sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
                                              fx_only);
@@ -434,7 +450,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size);
                if (ret) {
                        ret = -EFAULT;
-                       goto err_out;
+                       goto out;
                }
 
                sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
@@ -452,7 +468,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
        } else {
                ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size);
                if (ret)
-                       goto err_out;
+                       goto out;
 
                fpregs_lock();
                ret = copy_kernel_to_fregs_err(&fpu->state.fsave);
@@ -463,7 +479,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                fpregs_deactivate(fpu);
        fpregs_unlock();
 
-err_out:
+out:
        if (ret)
                fpu__clear_user_states(fpu);
        return ret;