From: Arnd Bergmann <arnd@arndb.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 21/31] arm64: 32-bit (compat) applications support
Date: Thu, 13 Sep 2012 11:03:27 +0000 [thread overview]
Message-ID: <201209131103.27387.arnd@arndb.de> (raw)
In-Reply-To: <20120913090732.GA25131@arm.com>
On Thursday 13 September 2012, Catalin Marinas wrote:
> Here they are. For converting the other architectures, I'll post
> separate patches as I don't want to add an extra dependency to the
> arm64 series.
Ok, thanks!
> diff --git a/kernel/compat.c b/kernel/compat.c
> index c28a306..5f07388 100644
> --- a/kernel/compat.c
> +++ b/kernel/compat.c
> @@ -1215,6 +1215,50 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info)
> return 0;
> }
>
> +#ifdef __ARCH_WANT_COMPAT_SYS_SENDFILE
> +asmlinkage int compat_sys_sendfile(int out_fd, int in_fd,
> + compat_off_t __user *offset, s32 count)
> +{
> + mm_segment_t old_fs = get_fs();
> + int ret;
> + off_t of;
> +
> + if (offset && get_user(of, offset))
> + return -EFAULT;
> +
> + set_fs(KERNEL_DS);
> + ret = sys_sendfile(out_fd, in_fd,
> + offset ? (off_t __user *)&of : NULL, count);
> + set_fs(old_fs);
> +
> + if (offset && put_user(of, offset))
> + return -EFAULT;
> + return ret;
> +}
> +#endif /* __ARCH_WANT_COMPAT_SYS_SENDFILE */
Looking at this code in detail now, I think it's better to move the functions to
fs/read_write.c and get rid of the get_fs/set_fs hack, like
asmlinkage int compat_sys_sendfile(int out_fd, int in_fd,
compat_off_t __user *offset, s32 count)
{
loff_t pos;
compat_off_t off;
ssize_t ret;
if (offset) {
if (unlikely(get_user(off, offset)))
return -EFAULT;
pos = off;
ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
if (unlikely(put_user(pos, offset)))
return -EFAULT;
return ret;
}
return do_sendfile(out_fd, in_fd, NULL, count, 0);
}
This implementation is smaller and more efficient than the common one.
Same for compat_sys_sendfile64, although I don't think there is ever
a case where loff_t is defined differently from compat_loff_t, so
you can probably just use the native sys_sendfile64 for the compat
case.
>
> +#ifdef __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL
> +asmlinkage int compat_sys_sched_rr_get_interval(compat_pid_t pid,
> + struct compat_timespec __user *interval)
> +{
> + struct timespec t;
> + int ret;
> + mm_segment_t old_fs = get_fs();
> +
> + set_fs(KERNEL_DS);
> + ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
> + set_fs(old_fs);
> + if (put_compat_timespec(&t, interval))
> + return -EFAULT;
> + return ret;
> +}
> +#endif /* __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL */
> +
This one looks reasonable. It would be nice to kill the get_fs/set_fs but here
it would just make the native code slower or duplicate a lot of it.
Acked-by: Arnd Bergmann <arnd@arndb.de>
next prev parent reply other threads:[~2012-09-13 11:03 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-07 16:26 [PATCH v3 00/31] AArch64 Linux kernel port Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 01/31] arm64: Assembly macros and definitions Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 02/31] arm64: Kernel booting and initialisation Catalin Marinas
2012-09-07 19:07 ` Arnd Bergmann
2012-09-09 17:20 ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-09 23:29 ` Nicolas Pitre
2012-09-10 5:53 ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-10 12:51 ` Catalin Marinas
2012-09-10 13:53 ` Arnd Bergmann
2012-09-10 14:12 ` Nicolas Pitre
2012-09-10 14:48 ` Arnd Bergmann
2012-09-10 14:53 ` Catalin Marinas
2012-09-10 15:00 ` Nicolas Pitre
2012-09-10 15:21 ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-10 16:08 ` Catalin Marinas
2012-09-10 16:29 ` Nicolas Pitre
2012-09-10 20:28 ` Jon Masters
2012-09-10 16:11 ` Catalin Marinas
2012-09-12 12:08 ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-12 13:49 ` Catalin Marinas
2012-09-13 15:56 ` Christopher Covington
2012-09-13 17:11 ` Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 03/31] arm64: Exception handling Catalin Marinas
2012-09-07 19:09 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 04/31] arm64: MMU definitions Catalin Marinas
2012-09-07 19:10 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 05/31] arm64: MMU initialisation Catalin Marinas
2012-09-07 19:10 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 06/31] arm64: MMU fault handling and page table management Catalin Marinas
2012-09-07 19:11 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 07/31] arm64: Process management Catalin Marinas
2012-09-07 19:20 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 08/31] arm64: CPU support Catalin Marinas
2012-09-07 19:24 ` Arnd Bergmann
2012-09-10 16:43 ` Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 09/31] arm64: Cache maintenance routines Catalin Marinas
2012-09-07 19:28 ` Arnd Bergmann
2012-09-10 16:48 ` Catalin Marinas
2012-09-10 17:29 ` Nicolas Pitre
2012-09-14 16:53 ` Catalin Marinas
2012-09-07 19:35 ` Simon Baatz
2012-09-12 9:29 ` Catalin Marinas
2012-09-12 21:55 ` Simon Baatz
2012-09-13 12:38 ` Catalin Marinas
2012-09-13 20:14 ` Simon Baatz
2012-09-07 16:26 ` [PATCH v3 10/31] arm64: TLB maintenance functionality Catalin Marinas
2012-09-07 19:28 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 11/31] arm64: IRQ handling Catalin Marinas
2012-09-07 19:37 ` Arnd Bergmann
2012-09-12 10:24 ` Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 12/31] arm64: Atomic operations Catalin Marinas
2012-09-07 19:37 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 13/31] arm64: Device specific operations Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 14/31] arm64: DMA mapping API Catalin Marinas
2012-09-07 19:38 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 15/31] arm64: SMP support Catalin Marinas
2012-09-07 19:39 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 16/31] arm64: ELF definitions Catalin Marinas
2012-09-07 19:40 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 17/31] arm64: System calls handling Catalin Marinas
2012-09-07 19:43 ` Arnd Bergmann
2012-09-07 19:54 ` Al Viro
2012-09-10 9:56 ` Catalin Marinas
2012-09-10 13:51 ` Arnd Bergmann
2012-09-10 14:01 ` Catalin Marinas
2012-09-10 14:24 ` Arnd Bergmann
2012-09-10 15:50 ` Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 18/31] arm64: VDSO support Catalin Marinas
2012-09-07 19:44 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 19/31] arm64: Signal handling support Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 20/31] arm64: User access library functions Catalin Marinas
2012-09-07 19:46 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 21/31] arm64: 32-bit (compat) applications support Catalin Marinas
2012-09-07 19:47 ` Arnd Bergmann
2012-09-13 9:07 ` Catalin Marinas
2012-09-13 11:03 ` Arnd Bergmann [this message]
2012-09-13 15:50 ` Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 22/31] arm64: Floating point and SIMD Catalin Marinas
2012-09-07 16:26 ` [PATCH v3 23/31] arm64: Debugging support Catalin Marinas
2012-09-07 19:49 ` Arnd Bergmann
2012-09-07 16:26 ` [PATCH v3 24/31] arm64: Add support for /proc/sys/debug/exception-trace Catalin Marinas
2012-09-07 16:27 ` [PATCH v3 25/31] arm64: Performance counters support Catalin Marinas
2012-09-07 16:27 ` [PATCH v3 26/31] arm64: Miscellaneous library functions Catalin Marinas
2012-09-07 19:52 ` Arnd Bergmann
2012-09-12 21:12 ` Catalin Marinas
2012-09-13 10:48 ` Arnd Bergmann
2012-09-07 16:27 ` [PATCH v3 27/31] arm64: Loadable modules Catalin Marinas
2012-09-07 19:52 ` Arnd Bergmann
2012-09-07 16:27 ` [PATCH v3 28/31] arm64: Generic timers support Catalin Marinas
2012-09-07 19:53 ` Arnd Bergmann
2012-09-08 8:28 ` Shilimkar, Santosh
2012-09-07 16:27 ` [PATCH v3 29/31] arm64: Miscellaneous header files Catalin Marinas
2012-09-07 19:54 ` Arnd Bergmann
2012-09-07 16:27 ` [PATCH v3 30/31] arm64: Build infrastructure Catalin Marinas
2012-09-07 19:55 ` Arnd Bergmann
2012-09-07 16:27 ` [PATCH v3 31/31] arm64: MAINTAINERS update Catalin Marinas
2012-09-09 16:31 ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-10 17:57 ` Nicolas Pitre
2012-09-10 21:17 ` Russell King - ARM Linux
2012-09-10 23:31 ` Nicolas Pitre
2012-09-07 23:25 ` [PATCH v3 00/31] AArch64 Linux kernel port Olof Johansson
2012-09-12 14:54 ` Catalin Marinas
2012-09-08 9:18 ` Santosh Shilimkar
2012-09-08 13:59 ` Nicolas Pitre
2012-09-08 14:42 ` Shilimkar, Santosh
2012-09-10 17:53 ` Nicolas Pitre
2012-09-10 20:22 ` Jon Masters
2012-09-12 11:54 ` Arnd Bergmann
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