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From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 15/18] x86: use non-set_fs based maccess routines
Date: Wed, 13 May 2020 18:00:35 +0200	[thread overview]
Message-ID: <20200513160038.2482415-16-hch@lst.de> (raw)
In-Reply-To: <20200513160038.2482415-1-hch@lst.de>

Provide arch_kernel_read and arch_kernel_write routines to implement the
maccess routines without messing with set_fs and without stac/clac that
opens up access to user space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/uaccess.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index d8f283b9a569c..765e18417b3ba 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -523,5 +523,21 @@ do {									\
 	unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label);	\
 } while (0)
 
+#define HAVE_ARCH_PROBE_KERNEL
+
+#define arch_kernel_read(dst, src, type, err_label)			\
+do {									\
+        int __kr_err;							\
+									\
+	__get_user_size(*((type *)dst), (__force type __user *)src,	\
+			sizeof(type), __kr_err);			\
+        if (unlikely(__kr_err))						\
+		goto err_label;						\
+} while (0)
+
+#define arch_kernel_write(dst, src, type, err_label)			\
+	__put_user_size(*((type *)(src)), (__force type __user *)(dst),	\
+			sizeof(type), err_label)
+
 #endif /* _ASM_X86_UACCESS_H */
 
-- 
2.26.2



  parent reply	other threads:[~2020-05-13 16:16 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-13 16:00 clean up and streamline probe_kernel_* and friends v2 Christoph Hellwig
2020-05-13 16:00 ` [PATCH 01/18] maccess: unexport probe_kernel_write and probe_user_write Christoph Hellwig
2020-05-13 16:00 ` [PATCH 02/18] maccess: remove various unused weak aliases Christoph Hellwig
2020-05-13 16:00 ` [PATCH 03/18] maccess: remove duplicate kerneldoc comments Christoph Hellwig
2020-05-13 16:00 ` [PATCH 04/18] maccess: clarify " Christoph Hellwig
2020-05-13 16:00 ` [PATCH 05/18] maccess: update the top of file comment Christoph Hellwig
2020-05-13 16:00 ` [PATCH 06/18] maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 07/18] maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 08/18] maccess: rename strnlen_unsafe_user to strnlen_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 09/18] maccess: remove probe_read_common and probe_write_common Christoph Hellwig
2020-05-13 16:00 ` [PATCH 10/18] maccess: unify the probe kernel arch hooks Christoph Hellwig
2020-05-14  1:13   ` Masami Hiramatsu
2020-05-19  5:46     ` Christoph Hellwig
2020-05-13 16:00 ` [PATCH 11/18] maccess: remove strncpy_from_unsafe Christoph Hellwig
2020-05-13 19:11   ` Linus Torvalds
2020-05-13 19:28     ` Christoph Hellwig
     [not found]       ` <0c1a7066-b269-9695-b94a-bb5f4f20ebd8@iogearbox.net>
2020-05-13 23:03         ` Linus Torvalds
2020-05-13 23:20         ` Masami Hiramatsu
2020-05-13 23:59           ` Linus Torvalds
2020-05-14  1:00             ` Masami Hiramatsu
2020-05-14  2:43               ` Linus Torvalds
2020-05-14  9:44                 ` Masami Hiramatsu
2020-05-13 23:28         ` Al Viro
     [not found]           ` <866cbe54-a027-04eb-65db-c6423d16b924@iogearbox.net>
2020-05-14 10:01             ` David Laight
2020-05-13 16:00 ` [PATCH 12/18] maccess: always use strict semantics for probe_kernel_read Christoph Hellwig
2020-05-13 16:00 ` [PATCH 13/18] maccess: move user access routines together Christoph Hellwig
2020-05-13 16:00 ` [PATCH 14/18] maccess: allow architectures to provide kernel probing directly Christoph Hellwig
2020-05-13 19:36   ` Linus Torvalds
2020-05-13 19:40     ` Christoph Hellwig
2020-05-13 19:48       ` Linus Torvalds
2020-05-13 19:54         ` Christoph Hellwig
2020-05-16  3:42   ` Masami Hiramatsu
2020-05-18 15:09     ` Christoph Hellwig
2020-05-13 16:00 ` Christoph Hellwig [this message]
2020-05-13 16:00 ` [PATCH 16/18] maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 17/18] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 18/18] maccess: rename probe_kernel_address to get_kernel_nofault Christoph Hellwig
2020-05-13 19:37 ` clean up and streamline probe_kernel_* and friends v2 Linus Torvalds
     [not found] ` <10c58b09-5ece-e49f-a7c8-2aa6dfd22fb4@iogearbox.net>
2020-05-13 23:20   ` Linus Torvalds
2020-05-19  5:50   ` Christoph Hellwig

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