From: Ingo Molnar <mingo@kernel.org>
To: Tony Luck <tony.luck@gmail.com>
Cc: "Mika Penttilä" <mika.penttila@nextfour.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Borislav Petkov" <bp@alien8.de>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
"H. Peter Anvin" <hpa@zytor.com>,
"Andy Lutomirski" <luto@amacapital.net>,
"Williams, Dan J" <dan.j.williams@intel.com>
Subject: Re: [PATCH v14] x86, mce: Add memcpy_mcsafe()
Date: Sat, 12 Mar 2016 18:16:48 +0100 [thread overview]
Message-ID: <20160312171648.GA12167@gmail.com> (raw)
In-Reply-To: <CA+8MBbKn5DU22RHPYR=vKWpKd1aBu4dm5p57R5U5WTb7KCpMVQ@mail.gmail.com>
* Tony Luck <tony.luck@gmail.com> wrote:
> On Thu, Mar 10, 2016 at 11:37 AM, Luck, Tony <tony.luck@intel.com> wrote:
> >> But you return 0 == false for success and 1 == true for failure.
> >
> > Aaargh! -ETOOMUCHSHELLSCRIPTPROGRAMMING
> >
> > -Tony
>
> Options to fix this:
> 1) Just change the comments in the code.
> This seems like it would confuse people as I thing most people
> would expect the "true" return to mean the copy succeeded.
> 2) Reverse the return values.
> Better that option 1 - but doesn't leave scope to return a count
> if some future user does want to know where the copy failed.
> 3) Change the return type back from "bool" to "int"
> 0 == success, non-zero == fail (with option to put the non-copied
> byte count in later).
> 4) Something else
Please use the copy_*_user() memory copying API semantics, which are: return
negative code (-EFAULT) on error, 0 on success.
Don't return 1 and please don't use bools for any memory copy library
functionality.
Thanks,
Ingo
next prev parent reply other threads:[~2016-03-12 17:17 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 18:20 [PATCH v11 0/4] Machine check recovery when kernel accesses poison Tony Luck
2016-02-17 18:20 ` [PATCH v11 1/4] x86: Expand exception table to allow new handling options Tony Luck
2016-02-18 10:19 ` [tip:ras/core] x86/mm: Expand the exception table logic " tip-bot for Tony Luck
2016-02-17 18:20 ` [PATCH v11 4/4] x86: Create a new synthetic cpu capability for machine check recovery Tony Luck
2016-02-18 10:19 ` [tip:x86/asm] x86/cpufeature: " tip-bot for Tony Luck
2016-02-17 18:20 ` [PATCH v11 3/4] x86, mce: Add __mcsafe_copy() Tony Luck
2016-02-18 8:21 ` Ingo Molnar
2016-02-18 9:59 ` Peter Zijlstra
2016-02-18 10:19 ` Ingo Molnar
2016-02-18 10:29 ` Borislav Petkov
2016-02-18 10:35 ` Peter Zijlstra
2016-02-18 14:59 ` Luck, Tony
2016-02-19 7:58 ` Ingo Molnar
2016-02-19 8:43 ` Peter Zijlstra
2016-02-19 9:51 ` Ingo Molnar
2016-02-18 10:29 ` Borislav Petkov
2016-02-18 10:34 ` Ingo Molnar
2016-02-18 10:36 ` Borislav Petkov
2016-02-18 18:48 ` Ingo Molnar
2016-02-18 21:14 ` [PATCH v12] x86, mce: Add memcpy_trap() Luck, Tony
2016-02-19 9:10 ` Ingo Molnar
2016-02-19 17:53 ` [PATCH v13] " Luck, Tony
2016-02-24 17:38 ` Tony Luck
2016-02-24 18:35 ` Linus Torvalds
2016-02-24 19:27 ` Tony Luck
2016-02-24 19:37 ` Linus Torvalds
2016-02-25 8:56 ` Ingo Molnar
2016-02-25 19:33 ` Luck, Tony
2016-02-25 20:39 ` Linus Torvalds
2016-02-25 22:11 ` Andy Lutomirski
2016-02-18 19:47 ` [PATCH v14] x86, mce: Add memcpy_mcsafe() Tony Luck
2016-03-02 20:47 ` Luck, Tony
2016-03-08 17:37 ` [tip:ras/core] x86/mm, x86/mce: " tip-bot for Tony Luck
2016-03-10 19:26 ` [PATCH v14] x86, mce: " Mika Penttilä
2016-03-10 19:37 ` Luck, Tony
2016-03-11 22:10 ` Tony Luck
2016-03-11 22:14 ` Dan Williams
2016-03-12 17:16 ` Ingo Molnar [this message]
2016-03-13 1:12 ` Linus Torvalds
2016-03-13 9:25 ` Ingo Molnar
2016-03-14 22:33 ` [PATCH] x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() Tony Luck
2016-03-16 8:06 ` [tip:x86/urgent] " tip-bot for Tony Luck
2016-02-26 0:58 ` [PATCH v13] x86, mce: Add memcpy_trap() Linus Torvalds
2016-02-26 1:19 ` Andy Lutomirski
2016-02-26 2:38 ` Linus Torvalds
2016-02-18 18:12 ` [PATCH v11 3/4] x86, mce: Add __mcsafe_copy() Linus Torvalds
2016-02-18 18:51 ` Ingo Molnar
2016-02-18 18:52 ` Luck, Tony
2016-02-18 20:14 ` Ingo Molnar
2016-02-18 21:33 ` Dan Williams
2016-02-17 18:20 ` [PATCH v11 2/4] x86, mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries Tony Luck
2016-02-18 10:19 ` [tip:ras/core] x86/mce: " tip-bot for Tony Luck
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