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On Mon, 2020-05-25 at 19:49 +0200, Alexis Ballier wrote: |
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> On Mon, 25 May 2020 11:26:26 -0400 |
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> Mike Gilbert <floppym@g.o> wrote: |
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> |
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> > On Mon, May 25, 2020 at 9:13 AM Alexis Ballier <aballier@g.o> |
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> > wrote: |
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> > > On Sun, 24 May 2020 20:25:11 +0000 (UTC) |
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> > > "Thomas Deutschmann" <whissi@g.o> wrote: |
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> > > |
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> > > > commit: 6e149596cc76f1bbcee6720828c8c8c92420f2a3 |
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> > > > Author: Thomas Deutschmann <whissi <AT> gentoo <DOT> org> |
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> > > > AuthorDate: Sun May 24 19:47:08 2020 +0000 |
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> > > > Commit: Thomas Deutschmann <whissi <AT> gentoo <DOT> org> |
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> > > > CommitDate: Sun May 24 20:23:53 2020 +0000 |
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> > > > URL: |
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> > > > https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=6e149596 |
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> > > > |
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> > > > media-libs/x265: drop USE=pic |
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> > > > |
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> > > > Gentoo's toolchain uses PIC by default. Since USE=asm was added, |
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> > > > we no longer need a USE flag to control that behavior. |
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> > > |
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> > > You got it wrong here it seems: USE=pic does not control whether |
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> > > the toolchain produces PIC or not. Shared libs always are, and have |
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> > > always been, built that way on Gentoo. |
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> > > In this case, USE=pic means "no matter what it costs, I do not want |
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> > > textrels", for the cases of hand written assembly that has to be |
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> > > rewritten to support PIC. And, still in this case, this costs a lot |
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> > > of performance, so it is enabled by default on hardened profiles |
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> > > and not others. |
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> > > Textrels work fine (on some architectures), they disallow W^X and |
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> > > force each process using the shared lib to make a "copy" at runtime |
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> > > in order to resolve relocations, so are not desirable but sometimes |
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> > > the cost outweights the gain. |
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> > > |
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> > > Plus, profiles/features/hardened enables pic by default but knows |
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> > > nothing about USE=asm so this is a regression for them. |
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> > |
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> > The USE flag toggles use of assembly, not use of PIC. The default USE |
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> > value in the hardened profile should not drive decisions on what we |
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> > name USE flags. |
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> |
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> ... but using a global well documented useflag instead of a local |
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> invention should drive such decisions. |
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|
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What 'global well documented useflag'? |
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|
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-- |
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Best regards, |
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Michał Górny |
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