From: Catalin Marinas <catalin.marinas@arm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>, Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Marc Zyngier <maz@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: [RFC patch 04/15] arm64/entry: Use generic syscall entry function
Date: Fri, 20 Sep 2019 13:21:17 +0100 [thread overview]
Message-ID: <20190920122116.GA21231@arrakis.emea.arm.com> (raw)
In-Reply-To: <20190919150808.830764150@linutronix.de>
On Thu, Sep 19, 2019 at 05:03:18PM +0200, Thomas Gleixner wrote:
> #ifdef CONFIG_ARM64_ERRATUM_1463225
> @@ -97,19 +97,16 @@ static void el0_svc_common(struct pt_reg
>
> regs->orig_x0 = regs->regs[0];
> regs->syscallno = scno;
> + /* Set default error number */
> + regs->regs[0] = -ENOSYS;
I think this corrupts the first argument of all valid syscalls.
SC_ARM64_REGS_TO_ARGS uses regs[0] instead of orig_x0. ptrace should be
fine since it calls syscall_get_arguments() which uses orig_x0.
We could change the SC_ARM64_REGS_TO_ARGS macro though (in theory there
shouldn't be any performance hit as it's already cached).
>
> cortex_a76_erratum_1463225_svc_handler();
> local_daif_restore(DAIF_PROCCTX);
> user_exit();
>
> - if (has_syscall_work(flags)) {
> - /* set default errno for user-issued syscall(-1) */
> - if (scno == NO_SYSCALL)
> - regs->regs[0] = -ENOSYS;
> - scno = syscall_trace_enter(regs);
> - if (scno == NO_SYSCALL)
> - goto trace_exit;
> - }
> + scno = syscall_enter_from_usermode(regs, scno);
> + if (scno == NO_SYSCALL)
> + goto trace_exit;
>
> invoke_syscall(regs, scno, sc_nr, syscall_table);
--
Catalin
next prev parent reply other threads:[~2019-09-20 12:21 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 15:03 [RFC patch 00/15] entry: Provide generic implementation for host and guest entry/exit work Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 01/15] entry: Provide generic syscall entry functionality Thomas Gleixner
2019-09-20 23:38 ` Andy Lutomirski
2019-10-20 11:49 ` Thomas Gleixner
2019-09-23 9:05 ` Mike Rapoport
2019-09-19 15:03 ` [RFC patch 02/15] x86/entry: Remove _TIF_NOHZ from _TIF_WORK_SYSCALL_ENTRY Thomas Gleixner
2019-09-20 23:39 ` Andy Lutomirski
2019-09-23 20:43 ` Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 03/15] x86/entry: Use generic syscall entry function Thomas Gleixner
2019-09-20 23:41 ` Andy Lutomirski
2019-09-23 8:31 ` Peter Zijlstra
2019-09-23 8:40 ` Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 04/15] arm64/entry: " Thomas Gleixner
2019-09-20 12:21 ` Catalin Marinas [this message]
2019-09-19 15:03 ` [RFC patch 05/15] entry: Provide generic syscall exit function Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 06/15] x86/entry: Use generic syscall exit functionality Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 07/15] arm64/syscall: Remove obscure flag check Thomas Gleixner
2019-09-20 14:29 ` Catalin Marinas
2019-09-19 15:03 ` [RFC patch 08/15] arm64/syscall: Use generic syscall exit functionality Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 09/15] entry: Provide generic exit to usermode functionality Thomas Gleixner
2019-09-23 8:30 ` Peter Zijlstra
2019-09-19 15:03 ` [RFC patch 10/15] x86/entry: Move irq tracing to C code Thomas Gleixner
2019-09-23 8:47 ` Peter Zijlstra
2019-09-23 10:27 ` Thomas Gleixner
2019-09-23 11:49 ` Peter Zijlstra
2019-09-23 11:55 ` Peter Zijlstra
2019-09-23 12:10 ` Peter Zijlstra
2019-09-23 17:24 ` Andy Lutomirski
2019-09-26 2:59 ` Josh Poimboeuf
2019-09-19 15:03 ` [RFC patch 11/15] x86/entry: Use generic exit to usermode Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 12/15] arm64/entry: " Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 13/15] arm64/entry: Move FPU restore out of exit_to_usermode() loop Thomas Gleixner
2019-09-19 15:03 ` [RFC patch 14/15] workpending: Provide infrastructure for work before entering a guest Thomas Gleixner
2019-09-19 15:40 ` Paolo Bonzini
2019-09-20 11:48 ` Thomas Gleixner
2019-09-23 18:17 ` Andy Lutomirski
2019-09-26 11:35 ` Miroslav Benes
2019-09-19 15:03 ` [RFC patch 15/15] x86/kvm: Use GENERIC_EXIT_WORKPENDING Thomas Gleixner
2019-09-19 15:40 ` Paolo Bonzini
2019-09-20 15:12 ` [RFC patch 00/15] entry: Provide generic implementation for host and guest entry/exit work Mark Rutland
2019-09-23 20:50 ` Thomas Gleixner
2019-09-23 18:18 ` Andy Lutomirski
2019-09-24 6:50 ` Christian Borntraeger
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