• Mathieu Desnoyers's avatar
    rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode · 24fa5d1e
    Mathieu Desnoyers authored
    Use ud1 as the guard instruction for the restartable sequence abort
    handler. Its benefit compared to nopl is to trap execution if the
    program ends up trying to execute it by mistake, which makes debugging
    easier.
    
    The 4-byte signature per se is unchanged (it is the instruction
    operand). Only the opcode is changed from nopl to ud1.
    Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
    Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
    CC: Peter Zijlstra <peterz@infradead.org>
    CC: Thomas Gleixner <tglx@linutronix.de>
    CC: Joel Fernandes <joelaf@google.com>
    CC: Catalin Marinas <catalin.marinas@arm.com>
    CC: Dave Watson <davejwatson@fb.com>
    CC: Will Deacon <will.deacon@arm.com>
    CC: Shuah Khan <shuah@kernel.org>
    CC: Andi Kleen <andi@firstfloor.org>
    CC: linux-kselftest@vger.kernel.org
    CC: "H . Peter Anvin" <hpa@zytor.com>
    CC: Chris Lameter <cl@linux.com>
    CC: Russell King <linux@arm.linux.org.uk>
    CC: Michael Kerrisk <mtk.manpages@gmail.com>
    CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
    CC: Paul Turner <pjt@google.com>
    CC: Boqun Feng <boqun.feng@gmail.com>
    CC: Josh Triplett <josh@joshtriplett.org>
    CC: Steven Rostedt <rostedt@goodmis.org>
    CC: Ben Maurer <bmaurer@fb.com>
    CC: linux-api@vger.kernel.org
    CC: Andy Lutomirski <luto@amacapital.net>
    CC: Andrew Morton <akpm@linux-foundation.org>
    CC: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
    24fa5d1e
rseq-x86.h 33.9 KB