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-arch@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/8] asm-generic: improve the nommu {get,put}_user handling
Date: Mon, 7 Sep 2020 07:58:19 +0200 [thread overview]
Message-ID: <20200907055825.1917151-3-hch@lst.de> (raw)
In-Reply-To: <20200907055825.1917151-1-hch@lst.de>
Instead of reusing raw_{copy,to}_from_user implement separate handlers
using {get,put}_unaligned. This ensures unaligned access is handled
correctly, and avoid the need for the small constant size optimization
in raw_{copy,to}_from_user.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/asm-generic/uaccess.h | 91 ++++++++++++++++++++---------------
1 file changed, 51 insertions(+), 40 deletions(-)
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index ba68ee4dabfaa7..6de5f524e9e631 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -10,28 +10,60 @@
#include <linux/string.h>
#ifdef CONFIG_UACCESS_MEMCPY
-static inline __must_check unsigned long
-raw_copy_from_user(void *to, const void __user * from, unsigned long n)
+#include <asm/unaligned.h>
+
+static inline int __get_user_fn(size_t size, const void __user *from, void *to)
{
- if (__builtin_constant_p(n)) {
- switch(n) {
- case 1:
- *(u8 *)to = *(u8 __force *)from;
- return 0;
- case 2:
- *(u16 *)to = *(u16 __force *)from;
- return 0;
- case 4:
- *(u32 *)to = *(u32 __force *)from;
- return 0;
-#ifdef CONFIG_64BIT
- case 8:
- *(u64 *)to = *(u64 __force *)from;
- return 0;
-#endif
- }
+ BUILD_BUG_ON(!__builtin_constant_p(size));
+
+ switch (size) {
+ case 1:
+ *(u8 *)to = get_unaligned((u8 __force *)from);
+ return 0;
+ case 2:
+ *(u16 *)to = get_unaligned((u16 __force *)from);
+ return 0;
+ case 4:
+ *(u32 *)to = get_unaligned((u32 __force *)from);
+ return 0;
+ case 8:
+ *(u64 *)to = get_unaligned((u64 __force *)from);
+ return 0;
+ default:
+ BUILD_BUG();
+ return 0;
+ }
+
+}
+#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
+
+static inline int __put_user_fn(size_t size, void __user *to, void *from)
+{
+ BUILD_BUG_ON(!__builtin_constant_p(size));
+
+ switch (size) {
+ case 1:
+ put_unaligned(*(u8 *)from, (u8 __force *)to);
+ return 0;
+ case 2:
+ put_unaligned(*(u16 *)from, (u16 __force *)to);
+ return 0;
+ case 4:
+ put_unaligned(*(u32 *)from, (u32 __force *)to);
+ return 0;
+ case 8:
+ put_unaligned(*(u64 *)from, (u64 __force *)to);
+ return 0;
+ default:
+ BUILD_BUG();
+ return 0;
}
+}
+#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
+static inline __must_check unsigned long
+raw_copy_from_user(void *to, const void __user * from, unsigned long n)
+{
memcpy(to, (const void __force *)from, n);
return 0;
}
@@ -39,27 +71,6 @@ raw_copy_from_user(void *to, const void __user * from, unsigned long n)
static inline __must_check unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
- if (__builtin_constant_p(n)) {
- switch(n) {
- case 1:
- *(u8 __force *)to = *(u8 *)from;
- return 0;
- case 2:
- *(u16 __force *)to = *(u16 *)from;
- return 0;
- case 4:
- *(u32 __force *)to = *(u32 *)from;
- return 0;
-#ifdef CONFIG_64BIT
- case 8:
- *(u64 __force *)to = *(u64 *)from;
- return 0;
-#endif
- default:
- break;
- }
- }
-
memcpy((void __force *)to, from, n);
return 0;
}
--
2.28.0
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next prev parent reply other threads:[~2020-09-07 5:58 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 5:58 remove set_fs for riscv v2 Christoph Hellwig
2020-09-07 5:58 ` [PATCH 1/8] uaccess: provide a generic TASK_SIZE_MAX definition Christoph Hellwig
2020-09-07 5:58 ` Christoph Hellwig [this message]
2020-09-07 5:58 ` [PATCH 3/8] asm-generic: add nommu implementations of __{get, put}_kernel_nofault Christoph Hellwig
2020-09-07 5:58 ` [PATCH 4/8] asm-generic: make the set_fs implementation optional Christoph Hellwig
2020-09-07 5:58 ` [PATCH 5/8] riscv: use memcpy based uaccess for nommu again Christoph Hellwig
2020-09-09 4:59 ` Palmer Dabbelt
2020-09-07 5:58 ` [PATCH 6/8] riscv: refactor __get_user and __put_user Christoph Hellwig
2020-09-09 4:59 ` Palmer Dabbelt
2020-09-07 5:58 ` [PATCH 7/8] riscv: implement __get_kernel_nofault and __put_user_nofault Christoph Hellwig
2020-09-09 4:59 ` Palmer Dabbelt
2020-09-07 5:58 ` [PATCH 8/8] riscv: remove address space overrides using set_fs() Christoph Hellwig
2020-09-09 4:59 ` Palmer Dabbelt
2020-09-09 4:59 ` remove set_fs for riscv v2 Palmer Dabbelt
2020-09-09 6:55 ` Christoph Hellwig
2020-09-09 20:38 ` Palmer Dabbelt
2020-09-22 4:37 ` Christoph Hellwig
2020-09-26 17:50 ` Palmer Dabbelt
2020-09-26 19:13 ` Arnd Bergmann
2020-10-04 17:27 ` Palmer Dabbelt
2020-09-28 12:49 ` Christoph Hellwig
2020-09-28 16:45 ` Palmer Dabbelt
2020-09-29 18:03 ` Christoph Hellwig
2020-09-26 6:58 ` Christoph Hellwig
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