From: David Laight <David.Laight@ACULAB.COM>
To: 'Borislav Petkov' <bp@alien8.de>, LKML <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 00/11] treewide: Fix a bunch of shift overflows
Date: Wed, 6 Apr 2022 09:23:38 +0000 [thread overview]
Message-ID: <4d8265050e2446e295ac60e5c0e4bcee@AcuMS.aculab.com> (raw)
In-Reply-To: <20220405151517.29753-1-bp@alien8.de>
From: Borislav Petkov
> Sent: 05 April 2022 16:15
...
> Due to some recent changes which added -fsanitize-shift to the build
> options of an allmodconfig, it started failing here with an old gcc
> because getting an overflow while shifting is undefined C99 behavior.
Annoyingly it is extremely unlikely that a 2s compliment
system would ever generate anything other than the expected
value - ie the value obtained by doing the calculation
with unsigned values and then getting the result cast back
to signed (which is IIRC implementation defined).
It isn't as though there are many 1s compliment systems out
there, and probably even fewer 'sign overpunch' ones.
Never mind trying to find a working C compiler for them.
What sort of crack are the C standards body and compiler
people actually smoking?
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-04-06 13:01 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-05 15:15 Borislav Petkov
2022-04-05 15:15 ` [PATCH 01/11] scsi: aacraid: Fix undefined behavior due to shift overflowing the constant Borislav Petkov
2022-04-25 18:47 ` Randy Dunlap
2022-04-26 3:05 ` Martin K. Petersen
2022-05-03 0:51 ` Martin K. Petersen
2022-04-05 15:15 ` [PATCH 02/11] ALSA: usb-audio: " Borislav Petkov
2022-04-05 15:32 ` Takashi Iwai
2022-04-05 16:06 ` Borislav Petkov
2022-04-05 16:16 ` Takashi Iwai
2022-04-05 15:15 ` [PATCH 03/11] bnx2x: " Borislav Petkov
2022-04-05 19:53 ` Jakub Kicinski
2022-04-05 19:59 ` Borislav Petkov
2022-04-05 15:15 ` [PATCH 04/11] drm/r128: " Borislav Petkov
2022-04-25 18:46 ` Randy Dunlap
2022-05-19 13:05 ` Daniel Vetter
2022-06-16 16:06 ` Randy Dunlap
2022-06-24 20:13 ` Daniel Vetter
2022-04-05 15:15 ` [PATCH 05/11] i2c: ismt: " Borislav Petkov
2022-04-05 21:18 ` Seth Heasley
2022-04-05 15:15 ` [PATCH 06/11] brcmfmac: sdio: " Borislav Petkov
2022-04-05 15:25 ` Kalle Valo
2022-04-05 16:06 ` Borislav Petkov
2022-04-05 16:37 ` Kalle Valo
2022-04-05 16:55 ` [RESEND PATCH " Borislav Petkov
2022-04-05 19:11 ` Arend van Spriel
2022-04-10 12:20 ` Kalle Valo
2022-04-05 15:15 ` [PATCH 07/11] usb: typec: tcpm: " Borislav Petkov
2022-04-05 15:15 ` [PATCH 08/11] mt76: " Borislav Petkov
2022-04-06 5:43 ` Kalle Valo
2022-04-10 12:20 ` Kalle Valo
2022-04-05 15:15 ` [PATCH 09/11] perf/imx_ddr: " Borislav Petkov
2022-04-08 10:47 ` Will Deacon
2022-04-08 11:01 ` Borislav Petkov
2022-04-05 15:15 ` [PATCH 10/11] IB/mlx5: " Borislav Petkov
2022-04-05 18:31 ` Leon Romanovsky
2022-04-05 19:42 ` Borislav Petkov
2022-04-06 7:17 ` Leon Romanovsky
2022-04-05 15:15 ` [PATCH 11/11] drm/i915: " Borislav Petkov
2022-05-17 23:05 ` Randy Dunlap
2022-05-18 7:44 ` Borislav Petkov
2022-05-18 11:39 ` Jani Nikula
2022-04-06 9:23 ` David Laight [this message]
2022-04-08 13:58 ` [PATCH 00/11] treewide: Fix a bunch of shift overflows Will Deacon
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