ARM: 8793/1: signal: replace __put_user_error with __put_user

BugLink: https://bugs.launchpad.net/bugs/1852110

Commit 18ea66bd upstream.

With Spectre-v1.1 mitigations, __put_user_error is pointless. In an attempt
to remove it, replace its references in frame setups with __put_user.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

arch/arm/kernel/signal.c

@@ -302,7 +302,7 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
 	if (err == 0)
 		err |= preserve_vfp_context(&aux->vfp);
 #endif
-	__put_user_error(0, &aux->end_magic, err);
+	err |= __put_user(0, &aux->end_magic);
 
 	return err;
 }
@@ -434,7 +434,7 @@ setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 	/*
 	 * Set uc.uc_flags to a value which sc.trap_no would never have.
 	 */
-	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
+	err = __put_user(0x5ac3c35a, &frame->uc.uc_flags);
 
 	err |= setup_sigframe(frame, regs, set);
 	if (err == 0)
@@ -454,8 +454,8 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 
 	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 
-	__put_user_error(0, &frame->sig.uc.uc_flags, err);
-	__put_user_error(NULL, &frame->sig.uc.uc_link, err);
+	err |= __put_user(0, &frame->sig.uc.uc_flags);
+	err |= __put_user(NULL, &frame->sig.uc.uc_link);
 
 	err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp);
 	err |= setup_sigframe(&frame->sig, regs, set);