From: Luis Machado <luis.machado@arm.com>
To: Simon Marchi <simark@simark.ca>,
gdb-patches@sourceware.org, binutils@sourceware.org
Subject: Re: [PATCH] Disable year 2038 support on 32-bit hosts by default
Date: Mon, 1 Aug 2022 15:17:15 +0100 [thread overview]
Message-ID: <4224183e-e2c1-9a98-7e41-61a58e49aa29@arm.com> (raw)
In-Reply-To: <959a19b9-b2c3-6638-e0b9-b66ca8328574@simark.ca>
On 8/1/22 15:08, Simon Marchi wrote:
>
>
> On 2022-08-01 03:51, Luis Machado via Gdb-patches wrote:
>> With a recent import of gnulib, code has been pulled that tests and enables
>> 64-bit time_t by default on 32-bit hosts that support it.
>>
>> Although gdb can use the gnulib support, bfd doesn't use gnulib and currently
>> doesn't do these checks.
>>
>> As a consequence, if we have a 32-bit host that supports 64-bit time_t, we'll
>> have a mismatch between gdb's notion of time_t and bfd's notion of time_t.
>>
>> This will lead to mismatches in the struct stat size, leading to memory
>> corruption and crashes.
>>
>> This patch disables the year 2038 check for now, which makes things work
>> reliably again.
>>
>> I'd consider this a temporary fix until we have proper bfd checks for the year
>> 2038, if it makes sense. 64-bit hosts seems to be more common these days, so
>> I'm not sure how important it is to have this support enabled and how soon
>> we want to enable it.
>
> I don't understand: why offer a --enable-year2038 switch if using it
> would produce a broken build?
That switch is already offered by gnulib since the recent import, and it is on by default. So in practice it produces a broken build for 32-bit hosts
running a distro that understands 64-bit time_t. It's been broken for a while now.
What I'm suggesting is having a temporary fix so default builds aren't silently broken due to a mismatch in stat size between GDB and BFD.
It isn't clear to me if we really want to switch to 64-bit time_t for 32-bit hosts at this point. There is potential for more breakage.
next prev parent reply other threads:[~2022-08-01 14:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 7:51 Luis Machado
2022-08-01 14:08 ` Simon Marchi
2022-08-01 14:17 ` Luis Machado [this message]
2022-08-01 15:37 ` Simon Marchi
2022-08-01 15:58 ` Eli Zaretskii
2022-08-02 6:42 ` Luis Machado
2022-08-08 11:34 ` Luis Machado
2022-08-08 11:58 ` Eli Zaretskii
2022-08-08 12:04 ` Luis Machado
2022-08-08 12:38 ` Eli Zaretskii
2022-08-08 17:55 ` Paul Eggert
2022-08-08 18:00 ` Luis Machado
2022-08-08 18:01 ` Luis Machado
2022-08-09 15:49 ` Paul Eggert
2022-08-09 15:59 ` Luis Machado
2022-08-09 16:13 ` Paul Eggert
2022-08-10 9:41 ` Nick Clifton
2022-08-10 10:14 ` Luis Machado
2022-08-09 16:29 ` Eli Zaretskii
2022-08-09 17:02 ` Paul Eggert
2022-08-10 8:38 ` Alan Modra
2022-08-08 14:51 ` Nick Clifton
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