From: Fangrui Song <i@maskray.me>
To: Nick Clifton <nickc@redhat.com>
Cc: Alan Modra <amodra@gmail.com>,
binutils@sourceware.org,
Luca Boccassi <luca.boccassi@microsoft.com>
Subject: Re: Output section type (READONLY)
Date: Mon, 31 Jan 2022 19:39:30 -0800 [thread overview]
Message-ID: <20220201033930.ssqtsoha6jaqzsfs@gmail.com> (raw)
In-Reply-To: <653b3fdf-61ed-2c41-5db2-de40bb51e8a0@redhat.com>
On 2022-01-31, Nick Clifton wrote:
>Hi Fangrui,
>
>>Well, READONLY has another behavior that it forces non-SHF_WRITE output
>>even if an input section has the SHF_WRITE flag.
>
>>I find this quite dangerous if an input section has the SHF_WRITE flag.
>>I do not see in what circumstances a user may want this behavior.
>>This just seems very dangerous to use in general.
>
>So basically what you are saying is that if a input section is assigned
>to an output sections with incompatible attributes (presumably because of a
>linker script declaration) then the linker should issue a warning message,
>yes ?
>
>By extension then, this feature should cover not just the readonly section
>attribute, but the NOLOAD attribute as well.
For NOLOAD, .noload (NOLOAD) : { *(.noload) } makes the output .noload
SHT_NOBITS even if there is a non-empty SHT_PROGBITS .noload section.
I don't know whether the linker should issue a warning.
For READONLY, I am thinking more in line with "whether we need this
feature at all"... If no input has SHF_WRITE, the output naturally does
not have SHF_WRITE; if an input has SHF_WRITE, chancing the output to
non-SHF_WRITE is weird and error-prone.
>This sounds like it might be an interesting feature to implement for someone
>looking to gain experience with the binutils.
Ah, sure:)
>Cheers
> Nick
>
>
>
>
next prev parent reply other threads:[~2022-02-01 3:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-29 7:45 Fangrui Song
2022-01-29 16:46 ` Luca Boccassi
2022-01-29 18:51 ` Fangrui Song
2022-01-31 13:33 ` Nick Clifton
2022-02-01 3:39 ` Fangrui Song [this message]
2022-02-01 11:07 ` Nick Clifton
2022-02-01 11:59 ` Luca Boccassi
2022-02-02 7:29 ` Fangrui Song
2022-02-02 16:54 ` Michael Matz
2022-02-02 18:12 ` Luca Boccassi
2022-02-16 17:38 ` Nick Clifton
2022-02-16 19:03 ` Luca Boccassi
2022-02-17 2:12 ` Fangrui Song
2022-02-21 23:04 ` Alan Modra
2022-02-21 23:30 ` Fangrui Song
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