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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5sub2 1/8] arm64: add support for module PLTs
Date: Thu, 25 Feb 2016 16:46:31 +0000	[thread overview]
Message-ID: <20160225164630.GF16546@arm.com> (raw)
In-Reply-To: <CAKv+Gu-REUdVJF-_wGU=LRaVRZqsD9bgny9S52pMLp+Es4E-1A@mail.gmail.com>

On Thu, Feb 25, 2016 at 05:43:35PM +0100, Ard Biesheuvel wrote:
> On 25 February 2016 at 17:42, Will Deacon <will.deacon@arm.com> wrote:
> > On Thu, Feb 25, 2016 at 05:33:25PM +0100, Ard Biesheuvel wrote:
> >> AFAIK, gcc never uses x18 (the platform register) so we may be able to
> >> use that instead. We'd need confirmation from the toolchain guys,
> >> though ...
> >
> > In fact, a better thing to do is probably for the atomic code to
> > save/restore those register explicitly and then remove them from the
> > cflags above.
> >
> > I'll try hacking something together...
> >
> 
> That would be more correct, indeed. Also, the PLT can only use br
> <reg> so it will always enter the callee with the preserved value
> stacked, and so the callee needs to be modified in any case.

Wait -- why does the callee need to be modified here? It has no idea
about whether or not it was invoked via a PLT.

Also, can I rely on the PLT not clobbering the condition code?

Will

  reply	other threads:[~2016-02-25 16:46 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-01 13:09 [PATCH v5sub2 0/8] arm64: implement virtual KASLR Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 1/8] arm64: add support for module PLTs Ard Biesheuvel
2016-02-04 15:13   ` Catalin Marinas
2016-02-04 15:31     ` Ard Biesheuvel
2016-02-05 15:42       ` Catalin Marinas
2016-02-05 15:53         ` Ard Biesheuvel
2016-02-05 16:00           ` Catalin Marinas
2016-02-05 16:20             ` Ard Biesheuvel
2016-02-05 16:46               ` Catalin Marinas
2016-02-05 16:54                 ` Ard Biesheuvel
2016-02-05 17:21                   ` Catalin Marinas
2016-02-05 20:39                   ` Kees Cook
2016-02-08 10:12                     ` [PATCH] arm64: allow the module region to be randomized independently Ard Biesheuvel
2016-02-08 18:13                       ` Catalin Marinas
2016-02-08 18:29                         ` Ard Biesheuvel
2016-02-09 10:03                         ` Ard Biesheuvel
2016-02-09 10:45                           ` Catalin Marinas
2016-02-25 16:07   ` [PATCH v5sub2 1/8] arm64: add support for module PLTs Will Deacon
2016-02-25 16:12     ` Ard Biesheuvel
2016-02-25 16:13       ` Ard Biesheuvel
2016-02-25 16:26       ` Will Deacon
2016-02-25 16:33         ` Ard Biesheuvel
2016-02-25 16:42           ` Will Deacon
2016-02-25 16:43             ` Ard Biesheuvel
2016-02-25 16:46               ` Will Deacon [this message]
2016-02-25 16:49                 ` Ard Biesheuvel
2016-02-25 16:50                   ` Ard Biesheuvel
2016-02-25 16:56                     ` Will Deacon
2016-02-25 17:31                       ` Ard Biesheuvel
2016-02-25 18:29                         ` Will Deacon
2016-02-01 13:09 ` [PATCH v5sub2 2/8] arm64: avoid R_AARCH64_ABS64 relocations for Image header fields Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 3/8] arm64: avoid dynamic relocations in early boot code Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 4/8] arm64: make asm/elf.h available to asm files Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 5/8] scripts/sortextable: add support for ET_DYN binaries Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 6/8] arm64: add support for building vmlinux as a relocatable PIE binary Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 7/8] arm64: add support for kernel ASLR Ard Biesheuvel
2016-02-01 13:09 ` [PATCH v5sub2 8/8] arm64: kaslr: randomize the linear region Ard Biesheuvel
2016-02-01 13:35 ` [PATCH v5sub2 0/8] arm64: implement virtual KASLR Ard Biesheuvel
2016-02-05 17:32   ` Catalin Marinas
2016-02-05 17:38     ` Ard Biesheuvel
2016-02-05 17:46       ` Catalin Marinas
2016-02-05 20:42       ` Kees Cook
2016-02-08 12:14         ` Catalin Marinas
2016-02-08 14:30           ` Ard Biesheuvel
2016-02-08 16:19             ` Catalin Marinas
2016-02-08 16:20               ` Ard Biesheuvel
2016-02-08 16:46                 ` Catalin Marinas

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