x86/fpu/signal: Change return type of __fpu_restore_sig() to boolean

Now that fpu__restore_sig() returns a boolean get rid of the individual
error codes in __fpu_restore_sig() as well.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210908132525.966197097@linutronix.de

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index d418d28819b9159b7dd65fe9133abffa8c0699a9..912d770363e6cd0645a440c4ea028080d20ccfac 100644 (file)
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -309,8 +309,8 @@ retry:
        return 0;
 }
 
-static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
-                            bool ia32_fxstate)
+static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx,
+                             bool ia32_fxstate)
 {
        int state_size = fpu_kernel_xstate_size;
        struct task_struct *tsk = current;
@@ -318,14 +318,14 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
        struct user_i387_ia32_struct env;
        u64 user_xfeatures = 0;
        bool fx_only = false;
-       int ret;
+       bool success;
+
 
        if (use_xsave()) {
                struct _fpx_sw_bytes fx_sw_user;
 
-               ret = check_xstate_in_sigframe(buf_fx, &fx_sw_user);
-               if (unlikely(ret))
-                       return ret;
+               if (check_xstate_in_sigframe(buf_fx, &fx_sw_user))
+                       return false;
 
                fx_only = !fx_sw_user.magic1;
                state_size = fx_sw_user.xstate_size;
@@ -341,8 +341,8 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
                 * faults. If it does, fall back to the slow path below, going
                 * through the kernel buffer with the enabled pagefault handler.
                 */
-               return restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only,
-                                               state_size);
+               return !restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only,
+                                                state_size);
        }
 
        /*
@@ -350,9 +350,8 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
         * to be ignored for histerical raisins. The legacy state is folded
         * in once the larger state has been copied.
         */
-       ret = __copy_from_user(&env, buf, sizeof(env));
-       if (ret)
-               return ret;
+       if (__copy_from_user(&env, buf, sizeof(env)))
+               return false;
 
        /*
         * By setting TIF_NEED_FPU_LOAD it is ensured that our xstate is
@@ -379,17 +378,16 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
        fpregs_unlock();
 
        if (use_xsave() && !fx_only) {
-               ret = copy_sigframe_from_user_to_xstate(&fpu->state.xsave, buf_fx);
-               if (ret)
-                       return ret;
+               if (copy_sigframe_from_user_to_xstate(&fpu->state.xsave, buf_fx))
+                       return false;
        } else {
                if (__copy_from_user(&fpu->state.fxsave, buf_fx,
                                     sizeof(fpu->state.fxsave)))
-                       return -EFAULT;
+                       return false;
 
                /* Reject invalid MXCSR values. */
                if (fpu->state.fxsave.mxcsr & ~mxcsr_feature_mask)
-                       return -EINVAL;
+                       return false;
 
                /* Enforce XFEATURE_MASK_FPSSE when XSAVE is enabled */
                if (use_xsave())
@@ -413,17 +411,18 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
                u64 mask = user_xfeatures | xfeatures_mask_supervisor();
 
                fpu->state.xsave.header.xfeatures &= mask;
-               ret = os_xrstor_safe(&fpu->state.xsave, xfeatures_mask_all) ? -EINVAL : 0;
+               success = !os_xrstor_safe(&fpu->state.xsave, xfeatures_mask_all);
        } else {
-               ret = fxrstor_safe(&fpu->state.fxsave);
+               success = !fxrstor_safe(&fpu->state.fxsave);
        }
 
-       if (likely(!ret))
+       if (likely(success))
                fpregs_mark_activate();
 
        fpregs_unlock();
-       return ret;
+       return success;
 }
+
 static inline int xstate_sigframe_size(void)
 {
        return use_xsave() ? fpu_user_xstate_size + FP_XSTATE_MAGIC2_SIZE :
@@ -467,7 +466,7 @@ bool fpu__restore_sig(void __user *buf, int ia32_frame)
                                           sizeof(struct user_i387_ia32_struct),
                                           NULL, buf);
        } else {
-               success = !__fpu_restore_sig(buf, buf_fx, ia32_fxstate);
+               success = __fpu_restore_sig(buf, buf_fx, ia32_fxstate);
        }
 
 out: