elf.h: Add aarch64 bti/pac dynamic tag constants

  From: Mark Wielaard <mark@klomp.org>

Constants double checked against binutils and the ELF for the Arm 64-bit
Architecture (AArch64) Release 2020Q2 document.
---
 elf/elf.h | 2 ++
 1 file changed, 2 insertions(+)
  

* Mark Wielaard via Libc-alpha:

> From: Mark Wielaard <mark@klomp.org>
>
> Constants double checked against binutils and the ELF for the Arm 64-bit
> Architecture (AArch64) Release 2020Q2 document.
> ---
>  elf/elf.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/elf/elf.h b/elf/elf.h
> index 197b557d15..ff9f1dadd5 100644
> --- a/elf/elf.h
> +++ b/elf/elf.h
> @@ -2875,6 +2875,8 @@ enum
>  #define R_AARCH64_IRELATIVE	1032	/* STT_GNU_IFUNC relocation.  */
>  
>  /* AArch64 specific values for the Dyn d_tag field.  */
> +#define DT_AARCH64_BTI_PLT	(DT_LOPROC + 1)
> +#define DT_AARCH64_PAC_PLT	(DT_LOPROC + 3)
>  #define DT_AARCH64_VARIANT_PCS	(DT_LOPROC + 5)
>  #define DT_AARCH64_NUM		6

I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned that in
the commit message?  There's no PAC PLT with glibc, and people are
expected to use BIND_NOW.

(I hope I remember this correctly.)

Thanks,
Florian
  

Hi Florian,

On Fri, 2020-08-28 at 20:03 +0200, Florian Weimer wrote:
> I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned that
> in the commit message?  There's no PAC PLT with glibc, and people are
> expected to use BIND_NOW.

OK, how about with the attached commit message?

Thanks,

Mark
  

* Mark Wielaard:

> Hi Florian,
>
> On Fri, 2020-08-28 at 20:03 +0200, Florian Weimer wrote:
>> I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned that
>> in the commit message?  There's no PAC PLT with glibc, and people are
>> expected to use BIND_NOW.
>
> OK, how about with the attached commit message?

Yes, this is what I had in mind, but please wait for an ack from an
AArch64 maintainer.

Thanks,
Florian
  

On Fri, 2020-08-28 at 21:04 +0200, Florian Weimer wrote:
> * Mark Wielaard:
> > On Fri, 2020-08-28 at 20:03 +0200, Florian Weimer wrote:
> > > I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned
> > > that
> > > in the commit message?  There's no PAC PLT with glibc, and people
> > > are
> > > expected to use BIND_NOW.
> > 
> > OK, how about with the attached commit message?
> 
> Yes, this is what I had in mind, but please wait for an ack from an
> AArch64 maintainer.

OK. Ping. Any AArch64 maintainer want to ack or nack this commit?

Thanks,

Mark
  

* Mark Wielaard <mark@klomp.org> [2020-09-02 13:28:02 +0200]:
> On Fri, 2020-08-28 at 21:04 +0200, Florian Weimer wrote:
> > * Mark Wielaard:
> > > On Fri, 2020-08-28 at 20:03 +0200, Florian Weimer wrote:
> > > > I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned
> > > > that
> > > > in the commit message?  There's no PAC PLT with glibc, and people
> > > > are
> > > > expected to use BIND_NOW.
> > > 
> > > OK, how about with the attached commit message?
> > 
> > Yes, this is what I had in mind, but please wait for an ack from an
> > AArch64 maintainer.
> 
> OK. Ping. Any AArch64 maintainer want to ack or nack this commit?

i'm on a long holiday, i will be back on sept 21.

the patch looks good, but i wont use my @arm.com
email until i'm back.

> 
> Thanks,
> 
> Mark

> From 3b925f004607cebc167af907c053bd7ef7146a3b Mon Sep 17 00:00:00 2001
> From: Mark Wielaard <mark@klomp.org>
> Date: Fri, 28 Aug 2020 18:44:16 +0200
> Subject: [PATCH] elf.h: Add aarch64 bti/pac dynamic tag constants
> 
> Constants double checked against binutils and the ELF for the Arm 64-bit
> Architecture (AArch64) Release 2020Q2 document.
> 
> Only BTI PLT is used in glibc, there's no PAC PLT with glibc, and people
> are expected to use BIND_NOW.
> ---
>  elf/elf.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/elf/elf.h b/elf/elf.h
> index 197b557d15..ff9f1dadd5 100644
> --- a/elf/elf.h
> +++ b/elf/elf.h
> @@ -2875,6 +2875,8 @@ enum
>  #define R_AARCH64_IRELATIVE	1032	/* STT_GNU_IFUNC relocation.  */
>  
>  /* AArch64 specific values for the Dyn d_tag field.  */
> +#define DT_AARCH64_BTI_PLT	(DT_LOPROC + 1)
> +#define DT_AARCH64_PAC_PLT	(DT_LOPROC + 3)
>  #define DT_AARCH64_VARIANT_PCS	(DT_LOPROC + 5)
>  #define DT_AARCH64_NUM		6
>  
> -- 
> 2.18.4
>
  

On Sun, 2020-09-06 at 22:21 +0200, Szabolcs Nagy wrote:
> * Mark Wielaard <mark@klomp.org> [2020-09-02 13:28:02 +0200]:
> > On Fri, 2020-08-28 at 21:04 +0200, Florian Weimer wrote:
> > > * Mark Wielaard:
> > > > On Fri, 2020-08-28 at 20:03 +0200, Florian Weimer wrote:
> > > > > I think DT_AARCH64_PAC_PLT isn't really used, so maybe mentioned
> > > > > that in the commit message?  There's no PAC PLT with glibc, and
> > > > > people are expected to use BIND_NOW.
> > > > 
> > > > OK, how about with the attached commit message?
> > > 
> > > Yes, this is what I had in mind, but please wait for an ack from an
> > > AArch64 maintainer.
> > 
> > OK. Ping. Any AArch64 maintainer want to ack or nack this commit?
> 
> i'm on a long holiday, i will be back on sept 21.
> 
> the patch looks good

Thanks pushed. Have a nice holiday.

Cheers,

Mark