From: Randy Dunlap <rdunlap@infradead.org>
To: Arnd Bergmann <arnd@kernel.org>, linux-arch@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Vineet Gupta <vgupta@synopsys.com>, Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 12/13] asm-generic: uaccess: 1-byte access is always aligned
Date: Sat, 15 May 2021 11:41:13 -0700 [thread overview]
Message-ID: <9f763da3-25c6-24e7-91e9-f3016a85f9f7@infradead.org> (raw)
In-Reply-To: <20210514100106.3404011-13-arnd@kernel.org>
On 5/14/21 3:01 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> With the cleaned up version of asm-generic/unaligned.h,
> there is a warning about the get_user/put_user helpers using
> unaligned access for single-byte variables:
>
> include/asm-generic/uaccess.h: In function ‘__get_user_fn’:
> include/asm-generic/unaligned.h:13:15: warning: ‘packed’ attribute ignored for field of type ‘u8’ {aka ‘unsigned char’} [-Wattributes]
> const struct { type x __packed; } *__pptr = (typeof(__pptr))(ptr); \
>
> Change these to use a direct pointer dereference to avoid the
> warnings.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> include/asm-generic/uaccess.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
> index 4973328f3c6e..7e903e450659 100644
> --- a/include/asm-generic/uaccess.h
> +++ b/include/asm-generic/uaccess.h
> @@ -19,7 +19,7 @@ __get_user_fn(size_t size, const void __user *from, void *to)
>
> switch (size) {
> case 1:
> - *(u8 *)to = get_unaligned((u8 __force *)from);
> + *(u8 *)to = *((u8 __force *)from);
> return 0;
> case 2:
> *(u16 *)to = get_unaligned((u16 __force *)from);
> @@ -45,7 +45,7 @@ __put_user_fn(size_t size, void __user *to, void *from)
>
> switch (size) {
> case 1:
> - put_unaligned(*(u8 *)from, (u8 __force *)to);
> + *(*(u8 *)from, (u8 __force *)to);
Should that be from =
?
> return 0;
> case 2:
> put_unaligned(*(u16 *)from, (u16 __force *)to);
>
--
~Randy
next prev parent reply other threads:[~2021-05-15 18:41 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-14 10:00 [PATCH v2 00/13] Unify asm/unaligned.h around struct helper Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 01/13] asm-generic: use asm-generic/unaligned.h for most architectures Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 02/13] openrisc: always use unaligned-struct header Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 03/13] sh: remove unaligned access for sh4a Arnd Bergmann
2021-05-14 10:34 ` John Paul Adrian Glaubitz
2021-05-14 12:22 ` Arnd Bergmann
2021-05-15 15:36 ` John Paul Adrian Glaubitz
2021-05-15 20:10 ` Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 04/13] m68k: select CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 05/13] powerpc: use linux/unaligned/le_struct.h on LE power7 Arnd Bergmann
2021-05-14 11:48 ` Segher Boessenkool
2021-05-14 13:02 ` Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 06/13] asm-generic: unaligned: remove byteshift helpers Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 07/13] asm-generic: unaligned always use struct helpers Arnd Bergmann
2021-05-17 21:53 ` Eric Biggers
2021-05-18 7:25 ` Arnd Bergmann
2021-05-18 14:56 ` Linus Torvalds
2021-05-18 15:41 ` Arnd Bergmann
2021-05-18 16:12 ` Linus Torvalds
2021-05-18 18:09 ` Jason A. Donenfeld
2021-05-18 20:51 ` Arnd Bergmann
2021-05-18 21:31 ` Eric Biggers
2021-05-18 21:14 ` David Laight
2021-05-14 10:00 ` [PATCH v2 08/13] partitions: msdos: fix one-byte get_unaligned() Arnd Bergmann
2021-05-17 10:28 ` Christoph Hellwig
2021-05-17 10:44 ` Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 09/13] apparmor: use get_unaligned() only for multi-byte words Arnd Bergmann
2021-05-14 10:00 ` [PATCH v2 10/13] mwifiex: re-fix for unaligned accesses Arnd Bergmann
2021-05-15 6:22 ` Kalle Valo
2021-05-15 9:01 ` Arnd Bergmann
2021-05-15 18:23 ` Kalle Valo
2021-05-14 10:00 ` [PATCH v2 11/13] netpoll: avoid put_unaligned() on single character Arnd Bergmann
2021-05-14 10:01 ` [PATCH v2 12/13] asm-generic: uaccess: 1-byte access is always aligned Arnd Bergmann
2021-05-15 18:41 ` Randy Dunlap [this message]
2021-05-15 20:16 ` Arnd Bergmann
2021-05-14 10:01 ` [PATCH v2 13/13] asm-generic: simplify asm/unaligned.h Arnd Bergmann
2021-05-14 10:35 ` David Laight
2021-05-14 17:32 ` [PATCH v2 00/13] Unify asm/unaligned.h around struct helper Linus Torvalds
2021-05-14 18:51 ` Vineet Gupta
2021-05-14 19:22 ` Linus Torvalds
2021-05-14 19:45 ` Vineet Gupta
2021-05-14 20:19 ` Linus Torvalds
2021-05-14 19:31 ` Arnd Bergmann
2021-12-16 17:29 ` Ard Biesheuvel
2021-12-16 17:42 ` Linus Torvalds
2021-12-16 17:49 ` David Laight
2021-12-16 18:56 ` Segher Boessenkool
2021-12-17 12:34 ` David Laight
2021-12-17 13:35 ` Segher Boessenkool
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