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From: Florian Weimer <fweimer@redhat.com>
To: Richard Palethorpe <rpalethorpe@suse.com>
Cc: x86@kernel.org, Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	rpalethorpe@richiejp.com,
	Dominik Brodowski <linux@dominikbrodowski.net>,
	ltp@lists.linux.it
Subject: Re: [PATCH] x86/entry/ia32: Ensure s32 is sign extended to s64
Date: Mon, 27 Sep 2021 20:51:11 +0200	[thread overview]
Message-ID: <875yuletsw.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20210927161955.28494-1-rpalethorpe@suse.com> (Richard Palethorpe's message of "Mon, 27 Sep 2021 17:19:55 +0100")

* Richard Palethorpe:

> +#define __SC_COMPAT_CAST(t, a)						\
> +	(__typeof(__builtin_choose_expr(__TYPE_IS_L(t), 0, 0U)))	\
> +	(unsigned int)a

So this casts to int (triggering sign extension) if the type on the
64-bit kernel side is long?  But not in other cases (unsigned long,
pointer)?  Just double-checking.

Thanks,
Florian


WARNING: multiple messages have this Message-ID (diff)
From: Florian Weimer <fweimer@redhat.com>
To: Richard Palethorpe <rpalethorpe@suse.com>
Cc: linux-s390@vger.kernel.org, rpalethorpe@richiejp.com,
	Arnd Bergmann <arnd@arndb.de>, Vasily Gorbik <gor@linux.ibm.com>,
	linux-api@vger.kernel.org, Heiko Carstens <hca@linux.ibm.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Dominik Brodowski <linux@dominikbrodowski.net>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	ltp@lists.linux.it
Subject: Re: [LTP] [PATCH] x86/entry/ia32: Ensure s32 is sign extended to s64
Date: Mon, 27 Sep 2021 20:51:11 +0200	[thread overview]
Message-ID: <875yuletsw.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20210927161955.28494-1-rpalethorpe@suse.com> (Richard Palethorpe's message of "Mon, 27 Sep 2021 17:19:55 +0100")

* Richard Palethorpe:

> +#define __SC_COMPAT_CAST(t, a)						\
> +	(__typeof(__builtin_choose_expr(__TYPE_IS_L(t), 0, 0U)))	\
> +	(unsigned int)a

So this casts to int (triggering sign extension) if the type on the
64-bit kernel side is long?  But not in other cases (unsigned long,
pointer)?  Just double-checking.

Thanks,
Florian


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

  parent reply	other threads:[~2021-09-27 18:51 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-27 16:19 [PATCH] x86/entry/ia32: Ensure s32 is sign extended to s64 Richard Palethorpe
2021-09-27 16:19 ` [LTP] " Richard Palethorpe via ltp
2021-09-27 18:22 ` Arnd Bergmann
2021-09-27 18:22   ` [LTP] " Arnd Bergmann
2021-09-28  9:02   ` Richard Palethorpe
2021-09-28  9:02     ` [LTP] " Richard Palethorpe
2021-09-27 18:51 ` Florian Weimer [this message]
2021-09-27 18:51   ` Florian Weimer
2021-09-27 19:01   ` Arnd Bergmann
2021-09-27 19:01     ` [LTP] " Arnd Bergmann

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