From: "H. Peter Anvin" <hpa@zytor.com>
To: Thomas Gleixner <tglx@linutronix.de>,
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: Wed, 12 May 2021 15:24:50 -0700 [thread overview]
Message-ID: <C2397A4D-8709-43F9-9967-51538B2B87FE@zytor.com> (raw)
In-Reply-To: <87mtsz619u.ffs@nanos.tec.linutronix.de>
Yes, indeed. I hope my reply to Ingo clarifies it as I'm going to try to wordsmith that into a better piece of text.
On May 12, 2021 3:22:05 PM PDT, Thomas Gleixner <tglx@linutronix.de> wrote:
>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
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
next prev parent reply other threads:[~2021-05-12 22:38 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
2021-05-12 22:24 ` H. Peter Anvin [this message]
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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