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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v10 1/3] arm64: Add __NR_* definitions for compat syscalls
Date: Thu, 29 Jan 2015 09:57:03 +0000	[thread overview]
Message-ID: <20150129095702.GA1626@arm.com> (raw)
In-Reply-To: <CAOZdJXUhpmi0SM5izDYQnx8SHjWjqOFVduV0+boPw6+YCKP5+g@mail.gmail.com>

On Wed, Jan 28, 2015 at 09:31:49PM +0000, Timur Tabi wrote:
> On Fri, Jul 4, 2014 at 2:28 AM, AKASHI Takahiro
> <takahiro.akashi@linaro.org> wrote:
> > +#define __ARM_NR_COMPAT_BASE           0x0f0000
> > +#define __ARM_NR_compat_cacheflush     (__ARM_NR_COMPAT_BASE+2)
> > +#define __ARM_NR_compat_set_tls                (__ARM_NR_COMPAT_BASE+5)
> 
> I know this patch is six months old, but I was wondering if anyone
> knows of any plans to make these syscalls available to 64-bit apps?
> We have a 32-bit app that uses __ARM_NR_compat_cacheflush, and we'd
> like to port that app to 64-bit.  I'm just not sure how to start doing
> that, since there don't appear to be any 64-bit ARM-specific syscalls.

You can issue cache maintenance instructions directly from EL0 in AArch64.
Take a look at DC CVAU, DC CVAC, DC CIVAC, IC IVAU and DC ZVA.

As for the TLS register, that's also writable from EL0 but I wouldn't
recommend messing with it outside of libc.

Will

  parent reply	other threads:[~2015-01-29  9:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-04  7:28 [PATCH v10 0/3] arm64: Add audit support AKASHI Takahiro
2014-07-04  7:28 ` [PATCH v10 1/3] arm64: Add __NR_* definitions for compat syscalls AKASHI Takahiro
2014-07-04 10:06   ` Arnd Bergmann
2014-07-04 10:57     ` Catalin Marinas
2014-07-04 11:05     ` AKASHI Takahiro
2014-07-04 11:17       ` Arnd Bergmann
2015-01-28 21:31   ` Timur Tabi
2015-01-28 21:35     ` Arnd Bergmann
2015-01-29  9:57     ` Will Deacon [this message]
2014-07-04  7:28 ` [PATCH v10 2/3] arm64: Add audit support AKASHI Takahiro
2014-07-04  7:28 ` [PATCH v10 3/3] arm64: audit: Add audit hook in syscall_trace_enter/exit() AKASHI Takahiro
2014-07-10 10:08 ` [PATCH v10 0/3] arm64: Add audit support Catalin Marinas

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