From: Keno Fischer <keno@juliacomputing.com>
To: Dave Martin <Dave.Martin@arm.com>
Cc: Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Kyle Huey <khuey@pernos.co>, Oleg Nesterov <oleg@redhat.com>,
linux-arm-kernel@lists.infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: arm64: Register modification during syscall entry/exit stop
Date: Sun, 31 May 2020 12:20:51 -0400 [thread overview]
Message-ID: <CABV8kRwhsPhhqUXS46Rwh-xDEDY2q=KSd-xz1W-pu4Gy4KVp8Q@mail.gmail.com> (raw)
In-Reply-To: <20200527101929.GT5031@arm.com>
> Can't PTRACE_SYSEMU be emulated by using PTRACE_SYSCALL, cancelling the
> syscall at the syscall enter stop, then modifying the regs at the
> syscall exit stop?
Yes, it can. The idea behind SYSEMU is to be able to save half the
ptrace traps that would require, in theory making the ptracer
a decent amount faster. That said, the x7 issue is orthogonal to
SYSEMU, you'd have the same issues if you used PTRACE_SYSCALL.
Keno
next prev parent reply other threads:[~2020-05-31 16:21 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 1:05 arm64: Register modification during syscall entry/exit stop Keno Fischer
2020-05-19 8:15 ` Will Deacon
2020-05-19 8:37 ` Keno Fischer
2020-05-20 17:41 ` Will Deacon
2020-05-23 5:35 ` Keno Fischer
2020-05-24 6:56 ` Keno Fischer
2020-05-27 9:55 ` Will Deacon
2020-05-27 10:19 ` Dave Martin
2020-05-31 9:33 ` Will Deacon
2020-05-31 16:13 ` Keno Fischer
2020-06-01 9:14 ` Dave Martin
2020-06-01 9:23 ` Keno Fischer
2020-06-01 9:52 ` Dave Martin
2020-05-31 16:20 ` Keno Fischer [this message]
2020-06-01 9:23 ` Dave Martin
2020-06-01 9:40 ` Keno Fischer
2020-06-01 9:59 ` Dave Martin
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