From: Christoph Hellwig <hch@lst.de>
To: Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Arnd Bergmann <arnd@arndb.de>,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org
Subject: [PATCH 1/8] maccess: add a generic __{get,put}_kernel_nofault for nommu
Date: Fri, 4 Sep 2020 18:52:09 +0200 [thread overview]
Message-ID: <20200904165216.1799796-2-hch@lst.de> (raw)
In-Reply-To: <20200904165216.1799796-1-hch@lst.de>
Nommu architectures do not have page tables and thus no page faults.
Implement the maccess helpers using get_unaligned and put_unaligned and
enable them unconditionally for !CONFIG_MMU.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/asm-generic/uaccess.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index ba68ee4dabfaa7..cc3b2c8b68fab4 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -9,6 +9,26 @@
*/
#include <linux/string.h>
+#ifndef CONFIG_MMU
+#include <asm/unaligned.h>
+
+#define __get_kernel_nofault(dst, src, type, err_label) \
+do { \
+ *((type *)dst) = get_unaligned((type *)(src)); \
+ if (0) /* make sure the label looks used to the compiler */ \
+ goto err_label; \
+} while (0)
+
+#define __put_kernel_nofault(dst, src, type, err_label) \
+do { \
+ put_unaligned(*((type *)src), (type *)(dst)); \
+ if (0) /* make sure the label looks used to the compiler */ \
+ goto err_label; \
+} while (0)
+
+#define HAVE_GET_KERNEL_NOFAULT 1
+#endif /* !CONFIG_MMU */
+
#ifdef CONFIG_UACCESS_MEMCPY
static inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user * from, unsigned long n)
--
2.28.0
next prev parent reply other threads:[~2020-09-04 16:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 16:52 remove set_fs for riscv Christoph Hellwig
2020-09-04 16:52 ` Christoph Hellwig [this message]
2020-09-04 16:52 ` [PATCH 2/8] uaccess: provide a generic TASK_SIZE_MAX definition Christoph Hellwig
2020-09-04 16:52 ` [PATCH 3/8] asm-generic: fix unaligned access hamdling in raw_copy_{from,to}_user Christoph Hellwig
2020-09-04 18:04 ` Arnd Bergmann
2020-09-05 7:14 ` Christoph Hellwig
2020-09-04 18:06 ` Al Viro
2020-09-04 22:35 ` Al Viro
2020-09-05 14:41 ` Al Viro
2020-09-07 8:07 ` Arnd Bergmann
2020-09-07 19:00 ` [PATCH 3/8] asm-generic: fix unaligned access hamdling in raw_copy_{from, to}_user Sean Anderson
2020-09-04 16:52 ` [PATCH 4/8] asm-generic: prepare uaccess.h for a set_fs-less world Christoph Hellwig
2020-09-04 16:52 ` [PATCH 5/8] riscv: use memcpy based uaccess for nommu again Christoph Hellwig
2020-09-04 16:52 ` [PATCH 6/8] riscv: refactor __get_user and __put_user Christoph Hellwig
2020-09-04 16:52 ` [PATCH 7/8] riscv: implement __get_kernel_nofault and __put_user_nofault Christoph Hellwig
2020-09-04 16:52 ` [PATCH 8/8] riscv: remove address space overrides using set_fs() Christoph Hellwig
2020-09-04 18:15 ` remove set_fs for riscv Arnd Bergmann
2020-09-05 7:17 ` Christoph Hellwig
2020-09-05 12:17 ` Arnd Bergmann
2020-09-06 22:14 ` Arnd Bergmann
2020-09-07 6:03 ` Christoph Hellwig
2020-09-07 14:58 ` Arnd Bergmann
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