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From: Mark Rutland <mark.rutland@arm.com>
To: Will Deacon <will.deacon@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Peter Zijlstra <peterz@infradead.org>,
	"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@amacapital.net>,
	Dave Watson <davejwatson@fb.com>, Paul Turner <pjt@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Russell King <linux@arm.linux.org.uk>,
	Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
	Andi Kleen <andi@firstfloor.org>, Chris Lameter <cl@linux.com>,
	Ben Maurer <bmaurer@fb.com>, Steven Rostedt <rostedt@goodmis.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Michael Kerrisk <mtk.manpages@gmail.com>,
	Joel Fernandes <joelaf@google.com>, Shuah Khan <shuah@kernel.org>,
	linux-kselftest@vger.kernel.org
Subject: Re: [RFC PATCH for 5.2 08/10] rseq/selftests: aarch64 code signature: handle big-endian environment
Date: Wed, 24 Apr 2019 17:51:50 +0100	[thread overview]
Message-ID: <20190424165150.GF21101@lakrids.cambridge.arm.com> (raw)
In-Reply-To: <20190424164538.GC18611@fuggles.cambridge.arm.com>

On Wed, Apr 24, 2019 at 05:45:38PM +0100, Will Deacon wrote:
> On Wed, Apr 24, 2019 at 11:25:00AM -0400, Mathieu Desnoyers wrote:
> > +/*
> > + * aarch64 -mbig-endian generates mixed endianness code vs data:
> > + * little-endian code and big-endian data. Ensure the RSEQ_SIG signature
> > + * matches code endianness.
> > + */
> > +#define RSEQ_SIG_CODE	0xd428bc00	/* BRK #0x45E0.  */
> > +
> > +#ifdef __AARCH64EB__
> > +#define RSEQ_SIG_DATA	0x00bc28d4	/* BRK #0x45E0.  */
> 
> It would be neater to implement swab32 and use that with RSEQ_SIG_CODE,

If possible, marginally neater than that would be using
le32_to_cpu(RSEQ_SIG_CODE), without any ifdeffery necessary.

It looks like that's defined in tools/include/linux/kernel.h, but I'm
not sure if that gets pulled into your include path.

Thanks,
Mark.

  reply	other threads:[~2019-04-24 16:52 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-24 15:24 [RFC PATCH for 5.2 00/10] Restartable Sequences selftests updates Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 01/10] rseq/selftests: Add __rseq_exit_point_array section for debuggers Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 02/10] rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 03/10] rseq/selftests: Use __rseq_handled symbol to coexist with glibc Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 04/10] rseq/selftests: s390: use jg instruction for jumps outside of the asm Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 05/10] rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 06/10] rseq/selftests: s390: use trap4 for RSEQ_SIG Mathieu Desnoyers
2019-04-24 15:24 ` [RFC PATCH for 5.2 07/10] rseq/selftests: arm: use udf instruction " Mathieu Desnoyers
2019-04-24 15:25 ` [RFC PATCH for 5.2 08/10] rseq/selftests: aarch64 code signature: handle big-endian environment Mathieu Desnoyers
2019-04-24 16:40   ` Mark Rutland
2019-04-24 16:44     ` Will Deacon
2019-04-24 16:45     ` Mark Rutland
2019-04-24 16:45   ` Will Deacon
2019-04-24 16:51     ` Mark Rutland [this message]
2019-04-24 17:00       ` Mathieu Desnoyers
2019-04-24 17:02         ` Mathieu Desnoyers
2019-04-24 15:25 ` [RFC PATCH for 5.2 09/10] rseq/selftests: powerpc code signature: generate valid instructions Mathieu Desnoyers
2019-04-24 15:25 ` [RFC PATCH for 5.2 10/10] rseq/selftests: mips: use break instruction for RSEQ_SIG Mathieu Desnoyers
2019-04-24 22:06   ` Paul Burton
2019-04-24 23:12     ` Mathieu Desnoyers
2019-04-24 23:17       ` Paul Burton
2019-04-24 23:22         ` Mathieu Desnoyers
2019-04-25 14:21     ` Mathieu Desnoyers
2019-04-29 22:31       ` Paul Burton

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