From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH 02/10] x86, asm: use bool for bitops and other assembly outputs
Date: Wed, 8 Jun 2016 10:33:40 +0200 [thread overview]
Message-ID: <20160608083340.GC9645@gmail.com> (raw)
In-Reply-To: <20160608082835.GB9645@gmail.com>
* Ingo Molnar <mingo@kernel.org> wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Tue, Jun 07, 2016 at 04:31:01PM -0700, H. Peter Anvin wrote:
> > > From: "H. Peter Anvin" <hpa@zytor.com>
> > >
> > > The gcc people have confirmed that using "bool" when combined with
> > > inline assembly always is treated as a byte-sized operand that can be
> > > assumed to be 0 or 1, which is exactly what the SET instruction
> > > emits. Change the output types and intermediate variables of as many
> > > operations as practical to "bool".
> > >
> > > Signed-off-by: H. Peter Anvin <hpa@zytor.com>
> > > ---
> > > arch/x86/boot/bitops.h | 8 +++++---
> > > arch/x86/boot/boot.h | 8 ++++----
> > > arch/x86/boot/string.c | 2 +-
> > > arch/x86/include/asm/apm.h | 6 +++---
> > > arch/x86/include/asm/archrandom.h | 16 ++++++++--------
> > > arch/x86/include/asm/atomic.h | 8 ++++----
> > > arch/x86/include/asm/atomic64_64.h | 10 +++++-----
> > > arch/x86/include/asm/bitops.h | 28 ++++++++++++++--------------
> > > arch/x86/include/asm/local.h | 8 ++++----
> > > arch/x86/include/asm/percpu.h | 8 ++++----
> > > arch/x86/include/asm/rmwcc.h | 4 ++--
> > > arch/x86/include/asm/rwsem.h | 17 +++++++++--------
> > > include/linux/random.h | 12 ++++++------
> > > 13 files changed, 69 insertions(+), 66 deletions(-)
> >
> > So the only concern I have with this is that the x86 function signatures
> > are now different from the other architectures.
> >
> > Not sure how much if anything that matters..
>
> It does matter:
>
> In file included from arch/x86/kernel/cpu/common.c:21:0:
> ./arch/x86/include/asm/archrandom.h:95:20: error: redefinition of ‘arch_get_random_long’
> static inline bool arch_get_random_long(unsigned long *v)
> In file included from ./arch/x86/include/asm/stackprotector.h:43:0,
> include/linux/random.h:98:20: note: previous definition of ‘arch_get_random_long’ was here
Note that this particular build error was introduced by b0bdba9825fe, a later
patch in this series - but in generaly I'm uneasy about allowing function
signatures diverge between architectures.
Thanks,
Ingo
next prev parent reply other threads:[~2016-06-08 8:33 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-07 23:30 [PATCH 00/10] x86: use gcc 6+ asm flag output feature H. Peter Anvin
2016-06-07 23:31 ` [PATCH 01/10] x86, bitops: remove use of "sbb" to return CF H. Peter Anvin
2016-06-07 23:39 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 02/10] x86, asm: use bool for bitops and other assembly outputs H. Peter Anvin
2016-06-07 23:40 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-08 7:49 ` [PATCH 02/10] " Peter Zijlstra
2016-06-08 8:28 ` Ingo Molnar
2016-06-08 8:33 ` Ingo Molnar [this message]
2016-06-08 8:55 ` H. Peter Anvin
2016-06-08 9:01 ` Ingo Molnar
2016-06-08 9:12 ` H. Peter Anvin
2016-06-08 9:20 ` Ingo Molnar
2016-06-08 9:31 ` H. Peter Anvin
2016-06-08 9:39 ` Peter Zijlstra
2016-06-08 9:43 ` H. Peter Anvin
2016-06-08 9:40 ` H. Peter Anvin
2016-06-08 8:58 ` H. Peter Anvin
2016-06-08 9:06 ` Ingo Molnar
2016-06-07 23:31 ` [PATCH 03/10] x86, asm: change the GEN_*_RMWcc() macros to not quote the condition H. Peter Anvin
2016-06-07 23:40 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 04/10] x86, asm: define CC_SET() and CC_OUT() macros H. Peter Anvin
2016-06-07 23:40 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-08 5:09 ` [PATCH 04/10] " Andy Lutomirski
2016-06-08 19:29 ` H. Peter Anvin
2016-06-08 19:34 ` H. Peter Anvin
2016-06-08 19:35 ` Borislav Petkov
2016-06-07 23:31 ` [PATCH 05/10] x86, asm: change GEN_*_RMWcc() to use CC_SET()/CC_OUT() H. Peter Anvin
2016-06-07 23:41 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 06/10] x86, asm: Use CC_SET()/CC_OUT() in <asm/bitops.h> H. Peter Anvin
2016-06-07 23:41 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 07/10] x86, asm: Use CC_SET()/CC_OUT() in <asm/percpu.h> H. Peter Anvin
2016-06-07 23:42 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 08/10] x86, asm: Use CC_SET()/CC_OUT() in <asm/rwsem.h> H. Peter Anvin
2016-06-07 23:42 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-07 23:31 ` [PATCH 09/10] x86, asm: Use CC_SET()/CC_OUT() and static_cpu_has() in archrandom.h H. Peter Anvin
2016-06-07 23:42 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-08 5:12 ` [PATCH 09/10] " Andy Lutomirski
2016-06-07 23:31 ` [PATCH 10/10] x86, asm, boot: Use CC_SET()/CC_OUT() in arch/x86/boot/boot.h H. Peter Anvin
2016-06-07 23:43 ` [tip:x86/asm] " tip-bot for H. Peter Anvin
2016-06-08 8:00 ` [PATCH 00/10] x86: use gcc 6+ asm flag output feature Peter Zijlstra
2016-06-08 8:56 ` H. Peter Anvin
2016-06-08 8:26 ` Ingo Molnar
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