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From: Thomas Gleixner <tglx@linutronix.de>
To: "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs
Date: Thu, 13 May 2021 00:22:05 +0200	[thread overview]
Message-ID: <87mtsz619u.ffs@nanos.tec.linutronix.de> (raw)
In-Reply-To: <b0ca952a-fd82-7833-ac82-ea8ecad48b53@zytor.com>

On Wed, May 12 2021 at 15:09, H. Peter Anvin wrote:
> On 5/12/21 11:34 AM, Thomas Gleixner wrote:
>>>
>>> That is intentional, as (again) system calls are int.
>> 
>> They are 'int' kernel internally, but _NOT_ at the user space visible
>> side. Again: man syscall
>> 
>>      syscall(long number,...);
>> 
>> So that results in a user ABI change.
>> 
>>> As stated in my reply to Ingo, I'll clean the various descriptions and
>>> try to capture the discussion better.
>> 
>> If we agree to go there then this wants to be a seperate commit which
>> does nothing else than changing this behaviour.
>> 
>
> Good idea.
>
> As far as this being a user ABI change, this is actually a revert to the 
> original x86-64 ABI; see my message to Ingo.

I'm not against that change, but it has to be well justified and the
reasoning wants to be in the changelog. You know the drill :)

Thanks,

        tglx

  reply	other threads:[~2021-05-12 22:36 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 18:53 [RFC v2 PATCH 0/6] x86/entry: cleanups and consistent syscall number handling H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 1/7] x86/entry: unify definitions from calling.h and ptrace-abi.h H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h> tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 2/7] x86/entry: reverse arguments to do_syscall_64() H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Reverse " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 3/7] x86/syscall: unconditionally prototype {ia32,x32}_sys_call_table[] H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/syscall: Unconditionally " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 4/7] x86/syscall: maximize MSR_SYSCALL_MASK H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/syscall: Maximize MSR_SYSCALL_MASK tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 5/7] x86/entry: split PUSH_AND_CLEAR_REGS into two submacros H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Split " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 6/7] x86/regs: syscall_get_nr() returns -1 for a non-system call H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/regs: Syscall_get_nr() " tip-bot2 for H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs H. Peter Anvin
2021-05-12  8:51   ` Ingo Molnar
2021-05-12 17:50     ` H. Peter Anvin
2021-05-12 12:09   ` Thomas Gleixner
2021-05-12 18:21     ` H. Peter Anvin
2021-05-12 18:34       ` Thomas Gleixner
2021-05-12 22:09         ` H. Peter Anvin
2021-05-12 22:22           ` Thomas Gleixner [this message]
2021-05-12 22:24             ` H. Peter Anvin
2021-05-14  0:38             ` H. Peter Anvin
2021-05-14  3:18               ` Andy Lutomirski
2021-05-14  3:23                 ` H. Peter Anvin

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