Re: [AArch64][1/6] Add new "pauth" feature and native support

[Eli Zaretskii <eliz@gnu.org>]

> From: Jiong Wang <jiong.wang@foss.arm.com>
> Date: Wed, 9 Aug 2017 13:21:33 +0100
> 
> This patch teach GDB to return the new ARMv8.3-A Pointer Authentication feature
> description when there is related support.
> 
>    * A new "pauth" feature description file is added.
>      The new pointer authentication feature, "pauth", contains two virtual
>      registers, "pauth_dmask" and "pauth_cmask".  Their values are supplied by
>      kernel to GDB through ptrace interface.  They are masks to indicate which
>      bits will be signature when data pointer or code pointer is signed.  Those
>      bits will be set to "1" in the mask.
> 
>    * HWCAP is used to detect whether the hardware support exists.
>      Currently we only support return address signing with A key, so using ptrace
>      trial read would not be reliable as it will return successfully when other
>      keys are used inside kernel.
> 
> The change on include/elf/common.h needs approval from Binutils maintainers.
> 
> gdb/
> 2017-08-09  Jiong Wang<jiong.wang@arm.com>
>              Yao Qi<yao.qi@linaro.org>
> 
> 	* aarch64-linux-nat.c (fetch_pauth_masks_from_thread): New
> 	function.
> 	(aarch64_linux_fetch_inferior_registers): Support pauth
> 	description.
> 	(aarch64_linux_read_description): Likewise.
> 	* aarch64-tdep.c: #include "features/aarch64-pauth.c".
> 	(aarch64_pauth_register_names): New register names array for
> 	pauth.
> 	(aarch64_cannot_store_register): New function.
> 	(aarch64_tdep_has_pauth_p): New function.
> 	(aarch64_gdbarch_init): Handle pauth description.  Initialize
> 	the optional "regnum" field.  Register cannot_store_register hook.
> 	(_initialize_aarch64_tdep): Call initialize_tdesc_aarch64_pauth.
> 	* aarch64-tdep.h (struct aarch64_optional_regnum): New structure
> 	type.
> 	(struct gdbarch_tdep) <regnum>: New field.
>   	(tdesc_aarch64_pauth): New variable declaration.
> 	(aarch64_tdep_has_pauth_p): New function declaration.
> 	* nat/aarch64-linux.c: Include <sys/auxv.h>.
> 	(aarch64_host_hwcap): New function.
> 	* nat/aarch64-linux.h (HWCAP_APIA): New macro.
> 	(aarch64_host_hwcap): New function declaration.
> 	* features/Makefile (WHICH): Add aarch64-pauth.
> 	(XMLTOC): Add aarch64-pauth.xml.
> 	* features/aarch64-pauth-core.xml: New file.
> 	* features/aarch64-pauth.c: Generated.
> 	* features/aarch64-pauth.xml: New file.
> 	* regformats/aarch64-pauth.dat: Generated.
> 
> include/
> 	* elf/common.h (NT_ARM_PAC_MASK): New.
> 
> gdb/doc/
> 	* gdb.texinfo (AArch64 Features): New feature
> 	"org.gnu.gdb.aarch64.pauth".

Thanks, the patch for gdb.texinfo is approved.