Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
To:     LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        "Steven J. Magnani" <steve@digidescorp.com>,
        Michal Simek <monstr@monstr.eu>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Leon Romanovsky <leonro@mellanox.com>,
        Doug Ledford <dledford@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>
From:   Randy Dunlap <rdunlap@infradead.org>
Subject: [PATCH v3] arch/microblaze: add support for get_user() of size 8
 bytes
Message-ID: <5a3e440f-4ec5-65d7-b2a4-c57fec0df973@infradead.org>
Date:   Sun, 1 Sep 2019 07:55:53 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.8.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Randy Dunlap <rdunlap@infradead.org>

arch/microblaze/ is missing support for get_user() of size 8 bytes,
so add it by using __copy_from_user().

Fixes these build errors:
   drivers/infiniband/core/uverbs_main.o: In function `ib_uverbs_write':
   drivers/infiniband/core/.tmp_gl_uverbs_main.o:(.text+0x13a4): undefined reference to `__user_bad'
   drivers/android/binder.o: In function `binder_thread_write':
   drivers/android/.tmp_gl_binder.o:(.text+0xda6c): undefined reference to `__user_bad'
   drivers/android/.tmp_gl_binder.o:(.text+0xda98): undefined reference to `__user_bad'
   drivers/android/.tmp_gl_binder.o:(.text+0xdf10): undefined reference to `__user_bad'
   drivers/android/.tmp_gl_binder.o:(.text+0xe498): undefined reference to `__user_bad'
   drivers/android/binder.o:drivers/android/.tmp_gl_binder.o:(.text+0xea78): more undefined references to `__user_bad' follow

'make allmodconfig' now builds successfully for arch/microblaze/.

Fixes: 538722ca3b76 ("microblaze: fix get_user/put_user side-effects")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven J. Magnani <steve@digidescorp.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Doug Ledford <dledford@redhat.com>
---
v3: fix return value in error case (comments from Linus).

What is a reasonable path for having this patch merged?
I have sent several emails to Micahl Simek but he seems to have
dropped active maintenance of arch/microblaze/.

 arch/microblaze/include/asm/uaccess.h |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- lnx-53-rc6.orig/arch/microblaze/include/asm/uaccess.h
+++ lnx-53-rc6/arch/microblaze/include/asm/uaccess.h
@@ -186,6 +186,11 @@ extern long __user_bad(void);
 			__get_user_asm("lw", __gu_addr, __gu_val,	\
 				       __gu_err);			\
 			break;						\
+		case 8:							\
+			__gu_err = __copy_from_user(&__gu_val, __gu_addr, 8);\
+			if (__gu_err) /* bytes remaining */		\
+				__gu_err = -EFAULT;			\
+			break;						\
 		default:						\
 			__gu_err = __user_bad();			\
 			break;						\
@@ -212,6 +217,11 @@ extern long __user_bad(void);
 	case 4:								\
 		__get_user_asm("lw", (ptr), __gu_val, __gu_err);	\
 		break;							\
+	case 8:								\
+		__gu_err = __copy_from_user(&__gu_val, ptr, 8);		\
+		if (__gu_err) /* bytes remaining */			\
+			__gu_err = -EFAULT;				\
+		break;							\
 	default:							\
 		/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
 	}								\