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

None of the call sites cares about the return code. All they are interested
in is success or fail.
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/20210908132525.851280949@linutronix.de

arch/x86/ia32/ia32_signal.c

@@ -57,8 +57,8 @@ static inline void reload_segments(struct sigcontext_32 *sc)
 /*
  * Do a signal return; undo the signal stack.
  */
-static int ia32_restore_sigcontext(struct pt_regs *regs,
-				   struct sigcontext_32 __user *usc)
+static bool ia32_restore_sigcontext(struct pt_regs *regs,
+				    struct sigcontext_32 __user *usc)
 {
 	struct sigcontext_32 sc;
 
@@ -66,7 +66,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	current->restart_block.fn = do_no_restart_syscall;
 
 	if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
-		return -EFAULT;
+		return false;
 
 	/* Get only the ia32 registers. */
 	regs->bx = sc.bx;
@@ -94,7 +94,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	 * normal case.
 	 */
 	reload_segments(&sc);
-	return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
+	return !fpu__restore_sig(compat_ptr(sc.fpstate), 1);
 }
 
 COMPAT_SYSCALL_DEFINE0(sigreturn)
@@ -111,7 +111,7 @@ COMPAT_SYSCALL_DEFINE0(sigreturn)
 
 	set_current_blocked(&set);
 
-	if (ia32_restore_sigcontext(regs, &frame->sc))
+	if (!ia32_restore_sigcontext(regs, &frame->sc))
 		goto badframe;
 	return regs->ax;
 
@@ -135,7 +135,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 
 	set_current_blocked(&set);
 
-	if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+	if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
 
 	if (compat_restore_altstack(&frame->uc.uc_stack))

arch/x86/kernel/signal.c

@@ -79,9 +79,9 @@ static void force_valid_ss(struct pt_regs *regs)
 # define CONTEXT_COPY_SIZE	sizeof(struct sigcontext)
 #endif
 
-static int restore_sigcontext(struct pt_regs *regs,
-			      struct sigcontext __user *usc,
-			      unsigned long uc_flags)
+static bool restore_sigcontext(struct pt_regs *regs,
+			       struct sigcontext __user *usc,
+			       unsigned long uc_flags)
 {
 	struct sigcontext sc;
 
@@ -89,7 +89,7 @@ static int restore_sigcontext(struct pt_regs *regs,
 	current->restart_block.fn = do_no_restart_syscall;
 
 	if (copy_from_user(&sc, usc, CONTEXT_COPY_SIZE))
-		return -EFAULT;
+		return false;
 
 #ifdef CONFIG_X86_32
 	set_user_gs(regs, sc.gs);
@@ -136,8 +136,8 @@ static int restore_sigcontext(struct pt_regs *regs,
 		force_valid_ss(regs);
 #endif
 
-	return fpu__restore_sig((void __user *)sc.fpstate,
-			       IS_ENABLED(CONFIG_X86_32));
+	return !fpu__restore_sig((void __user *)sc.fpstate,
+				 IS_ENABLED(CONFIG_X86_32));
 }
 
 static __always_inline int
@@ -641,7 +641,7 @@ SYSCALL_DEFINE0(sigreturn)
 	 * x86_32 has no uc_flags bits relevant to restore_sigcontext.
 	 * Save a few cycles by skipping the __get_user.
 	 */
-	if (restore_sigcontext(regs, &frame->sc, 0))
+	if (!restore_sigcontext(regs, &frame->sc, 0))
 		goto badframe;
 	return regs->ax;
 
@@ -669,7 +669,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 
 	set_current_blocked(&set);
 
-	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
 		goto badframe;
 
 	if (restore_altstack(&frame->uc.uc_stack))
@@ -927,7 +927,7 @@ COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
 
 	set_current_blocked(&set);
 
-	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
+	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
 		goto badframe;
 
 	if (compat_restore_altstack(&frame->uc.uc_stack))