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From:   Wang Qing <wangqing@vivo.com>
To:     Vineet Gupta <vgupta@synopsys.com>, Jens Axboe <axboe@kernel.dk>,
        Wang Qing <wangqing@vivo.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] arc: kernel: Return -EFAULT if copy_to_user() fails
Date:   Mon,  1 Mar 2021 20:05:48 +0800
Message-Id: <1614600349-15662-1-git-send-email-wangqing@vivo.com>
Precedence: bulk

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Signed-off-by: Wang Qing <wangqing@vivo.com>
---
 arch/arc/kernel/signal.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index a78d8f7..fdbe06c
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -96,7 +96,7 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
 			     sizeof(sf->uc.uc_mcontext.regs.scratch));
 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
 
-	return err;
+	return err ? -EFAULT : 0;
 }
 
 static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
@@ -110,7 +110,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
 				&(sf->uc.uc_mcontext.regs.scratch),
 				sizeof(sf->uc.uc_mcontext.regs.scratch));
 	if (err)
-		return err;
+		return -EFAULT;
 
 	set_current_blocked(&set);
 	regs->bta	= uregs.scratch.bta;
-- 
2.7.4