From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
Boqun Feng <boqun.feng@gmail.com>
Cc: 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>,
Will Deacon <will.deacon@arm.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Joel Fernandes <joelaf@google.com>, Shuah Khan <shuah@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Paul Burton <paul.burton@mips.com>,
James Hogan <jhogan@kernel.org>,
Ralf Baechle <ralf@linux-mips.org>,
linux-mips@linux-mips.org
Subject: [RFC PATCH for 5.2 10/10] rseq/selftests: mips: use break instruction for RSEQ_SIG
Date: Wed, 24 Apr 2019 11:25:02 -0400 [thread overview]
Message-ID: <20190424152502.14246-11-mathieu.desnoyers@efficios.com> (raw)
In-Reply-To: <20190424152502.14246-1-mathieu.desnoyers@efficios.com>
Use break as guard instruction for the restartable sequence abort
handler.
Previously, the chosen signature was simply data, based on the
assumption that it could always sit in a literal pool. However,
some compilation environments favor disabling literal pool. Therefore,
ensure the signature is a valid uncommon trap instruction.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Paul Burton <paul.burton@mips.com>
CC: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
---
tools/testing/selftests/rseq/rseq-mips.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index fe3eabcdcbe5..eb53a6adfbbb 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -7,7 +7,11 @@
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
-#define RSEQ_SIG 0x53053053
+/*
+ * RSEQ_SIG uses the break instruction. The instruction pattern is
+ * 0350000d break 0x350
+ */
+#define RSEQ_SIG 0x0350000d
#define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory")
#define rseq_smp_rmb() rseq_smp_mb()
--
2.11.0
next prev parent reply other threads:[~2019-04-24 15:26 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
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 ` Mathieu Desnoyers [this message]
2019-04-24 22:06 ` [RFC PATCH for 5.2 10/10] rseq/selftests: mips: use break instruction for RSEQ_SIG 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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