[3/3] gdb: remove target_ops parameter from gdbarch_core_read_description

  Following the previous patch ("gdb: change order of core_target
initialization"), it is no longer necessary for the core target to pass
a pointer to itself to gdbarch_core_read_description.  Implementations
of this method can just do regular calls to target_read_auxv, through
the inferior target stack.

This allows removing the target_ops parameter in
gdbarch_core_read_description and a bunch of functions called
downstream.  Some auxv-related functions received the auxv data as a
parameter, since they could not assume it could be read from the current
inferior, that is also no longer needed.

Regression tested.  I also tested manually against an AArch64 MTE test
case that Luis Machado sent me a while ago when we were working on this
auxv caching issue, the desired behavior of reporting the MTE tags when
opening the code still worked.

Change-Id: I1e00361209028e9b65dde085d383cf950a7b5e3a
---
 gdb/aarch64-fbsd-tdep.c   |  3 +--
 gdb/aarch64-linux-tdep.c  |  8 +++-----
 gdb/amd64-fbsd-tdep.c     |  4 +---
 gdb/amd64-linux-tdep.c    |  4 +---
 gdb/arc-linux-tdep.c      |  4 +---
 gdb/arm-fbsd-tdep.c       | 24 +++++-------------------
 gdb/arm-fbsd-tdep.h       | 15 +++++----------
 gdb/arm-linux-tdep.c      |  7 ++-----
 gdb/auxv.c                | 11 ++---------
 gdb/auxv.h                |  4 ----
 gdb/corelow.c             |  2 +-
 gdb/gdbarch-components.py |  2 +-
 gdb/gdbarch-gen.h         |  4 ++--
 gdb/gdbarch.c             |  4 ++--
 gdb/i386-fbsd-tdep.c      |  4 +---
 gdb/i386-linux-tdep.c     |  4 +---
 gdb/linux-tdep.c          | 24 ++++++++++--------------
 gdb/linux-tdep.h          | 14 ++++++--------
 gdb/mips-linux-tdep.c     |  4 +---
 gdb/ppc-linux-tdep.c      |  7 ++-----
 gdb/s390-linux-tdep.c     |  6 ++----
 21 files changed, 50 insertions(+), 109 deletions(-)
  

On 11/28/22 6:50 PM, Simon Marchi via Gdb-patches wrote:
> Following the previous patch ("gdb: change order of core_target
> initialization"), it is no longer necessary for the core target to pass
> a pointer to itself to gdbarch_core_read_description.  Implementations
> of this method can just do regular calls to target_read_auxv, through
> the inferior target stack.
> 
> This allows removing the target_ops parameter in
> gdbarch_core_read_description and a bunch of functions called
> downstream.  Some auxv-related functions received the auxv data as a
> parameter, since they could not assume it could be read from the current
> inferior, that is also no longer needed.
> 
> Regression tested.  I also tested manually against an AArch64 MTE test
> case that Luis Machado sent me a while ago when we were working on this
> auxv caching issue, the desired behavior of reporting the MTE tags when
> opening the code still worked.
> 
> Change-Id: I1e00361209028e9b65dde085d383cf950a7b5e3a
> ---
>   gdb/aarch64-fbsd-tdep.c   |  3 +--
>   gdb/aarch64-linux-tdep.c  |  8 +++-----
>   gdb/amd64-fbsd-tdep.c     |  4 +---
>   gdb/amd64-linux-tdep.c    |  4 +---
>   gdb/arc-linux-tdep.c      |  4 +---
>   gdb/arm-fbsd-tdep.c       | 24 +++++-------------------
>   gdb/arm-fbsd-tdep.h       | 15 +++++----------
>   gdb/arm-linux-tdep.c      |  7 ++-----
>   gdb/auxv.c                | 11 ++---------
>   gdb/auxv.h                |  4 ----
>   gdb/corelow.c             |  2 +-
>   gdb/gdbarch-components.py |  2 +-
>   gdb/gdbarch-gen.h         |  4 ++--
>   gdb/gdbarch.c             |  4 ++--
>   gdb/i386-fbsd-tdep.c      |  4 +---
>   gdb/i386-linux-tdep.c     |  4 +---
>   gdb/linux-tdep.c          | 24 ++++++++++--------------
>   gdb/linux-tdep.h          | 14 ++++++--------
>   gdb/mips-linux-tdep.c     |  4 +---
>   gdb/ppc-linux-tdep.c      |  7 ++-----
>   gdb/s390-linux-tdep.c     |  6 ++----
>   21 files changed, 50 insertions(+), 109 deletions(-)
> 
> diff --git a/gdb/arm-fbsd-tdep.c b/gdb/arm-fbsd-tdep.c
> index 75ee08eba506..4ea238de7c7f 100644
> --- a/gdb/arm-fbsd-tdep.c
> +++ b/gdb/arm-fbsd-tdep.c
> @@ -215,10 +215,11 @@ arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
>   /* See arm-fbsd-tdep.h.  */
>   
>   const struct target_desc *
> -arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
> -				target_ops *target, gdbarch *gdbarch, bool tls)
> +arm_fbsd_read_description_auxv (gdbarch *gdbarch, bool tls)
>   {
>     CORE_ADDR arm_hwcap = 0;
> +  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
> +  target_ops *target = current_inferior ()->top_target ();
>   
>     if (!auxv.has_value ()
>         || target_auxv_search (*auxv, target, gdbarch, AT_FREEBSD_HWCAP,
> @@ -239,29 +240,14 @@ arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
>     return arm_read_description (ARM_FP_TYPE_NONE, tls);
>   }
>   
> -/* See arm-fbsd-tdep.h.  */
> -
> -const struct target_desc *
> -arm_fbsd_read_description_auxv (bool tls)
> -{
> -  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
> -  return arm_fbsd_read_description_auxv (auxv,
> -					 current_inferior ()->top_target (),
> -					 current_inferior ()->gdbarch,
> -					 tls);
> -}
> -

This function is used by arm-fbsd-nat.c in the read_description target
method.  Probably that function just needs to be updated to pass in the
gdbarch explicitly rather than keeping this wrapper method though:

diff --git a/gdb/arm-fbsd-nat.c b/gdb/arm-fbsd-nat.c
index 340b8e0d710..0ed3104d12d 100644
--- a/gdb/arm-fbsd-nat.c
+++ b/gdb/arm-fbsd-nat.c
@@ -96,7 +96,7 @@ arm_fbsd_nat_target::read_description ()
  #ifdef PT_GETREGSET
    tls = have_regset (inferior_ptid, NT_ARM_TLS) != 0;
  #endif
-  desc = arm_fbsd_read_description_auxv (tls);
+  desc = arm_fbsd_read_description_auxv (current_inferior ()->gdbarch, tls);
    if (desc == NULL)
      desc = this->beneath ()->read_description ();
    return desc;
  

On 11/29/22 14:16, John Baldwin wrote:
> On 11/28/22 6:50 PM, Simon Marchi via Gdb-patches wrote:
>> Following the previous patch ("gdb: change order of core_target
>> initialization"), it is no longer necessary for the core target to pass
>> a pointer to itself to gdbarch_core_read_description.  Implementations
>> of this method can just do regular calls to target_read_auxv, through
>> the inferior target stack.
>>
>> This allows removing the target_ops parameter in
>> gdbarch_core_read_description and a bunch of functions called
>> downstream.  Some auxv-related functions received the auxv data as a
>> parameter, since they could not assume it could be read from the current
>> inferior, that is also no longer needed.
>>
>> Regression tested.  I also tested manually against an AArch64 MTE test
>> case that Luis Machado sent me a while ago when we were working on this
>> auxv caching issue, the desired behavior of reporting the MTE tags when
>> opening the code still worked.
>>
>> Change-Id: I1e00361209028e9b65dde085d383cf950a7b5e3a
>> ---
>>   gdb/aarch64-fbsd-tdep.c   |  3 +--
>>   gdb/aarch64-linux-tdep.c  |  8 +++-----
>>   gdb/amd64-fbsd-tdep.c     |  4 +---
>>   gdb/amd64-linux-tdep.c    |  4 +---
>>   gdb/arc-linux-tdep.c      |  4 +---
>>   gdb/arm-fbsd-tdep.c       | 24 +++++-------------------
>>   gdb/arm-fbsd-tdep.h       | 15 +++++----------
>>   gdb/arm-linux-tdep.c      |  7 ++-----
>>   gdb/auxv.c                | 11 ++---------
>>   gdb/auxv.h                |  4 ----
>>   gdb/corelow.c             |  2 +-
>>   gdb/gdbarch-components.py |  2 +-
>>   gdb/gdbarch-gen.h         |  4 ++--
>>   gdb/gdbarch.c             |  4 ++--
>>   gdb/i386-fbsd-tdep.c      |  4 +---
>>   gdb/i386-linux-tdep.c     |  4 +---
>>   gdb/linux-tdep.c          | 24 ++++++++++--------------
>>   gdb/linux-tdep.h          | 14 ++++++--------
>>   gdb/mips-linux-tdep.c     |  4 +---
>>   gdb/ppc-linux-tdep.c      |  7 ++-----
>>   gdb/s390-linux-tdep.c     |  6 ++----
>>   21 files changed, 50 insertions(+), 109 deletions(-)
>>
>> diff --git a/gdb/arm-fbsd-tdep.c b/gdb/arm-fbsd-tdep.c
>> index 75ee08eba506..4ea238de7c7f 100644
>> --- a/gdb/arm-fbsd-tdep.c
>> +++ b/gdb/arm-fbsd-tdep.c
>> @@ -215,10 +215,11 @@ arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
>>   /* See arm-fbsd-tdep.h.  */
>>     const struct target_desc *
>> -arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
>> -                target_ops *target, gdbarch *gdbarch, bool tls)
>> +arm_fbsd_read_description_auxv (gdbarch *gdbarch, bool tls)
>>   {
>>     CORE_ADDR arm_hwcap = 0;
>> +  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
>> +  target_ops *target = current_inferior ()->top_target ();
>>       if (!auxv.has_value ()
>>         || target_auxv_search (*auxv, target, gdbarch, AT_FREEBSD_HWCAP,
>> @@ -239,29 +240,14 @@ arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
>>     return arm_read_description (ARM_FP_TYPE_NONE, tls);
>>   }
>>   -/* See arm-fbsd-tdep.h.  */
>> -
>> -const struct target_desc *
>> -arm_fbsd_read_description_auxv (bool tls)
>> -{
>> -  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
>> -  return arm_fbsd_read_description_auxv (auxv,
>> -                     current_inferior ()->top_target (),
>> -                     current_inferior ()->gdbarch,
>> -                     tls);
>> -}
>> -
> 
> This function is used by arm-fbsd-nat.c in the read_description target
> method.  Probably that function just needs to be updated to pass in the
> gdbarch explicitly rather than keeping this wrapper method though:
> 
> diff --git a/gdb/arm-fbsd-nat.c b/gdb/arm-fbsd-nat.c
> index 340b8e0d710..0ed3104d12d 100644
> --- a/gdb/arm-fbsd-nat.c
> +++ b/gdb/arm-fbsd-nat.c
> @@ -96,7 +96,7 @@ arm_fbsd_nat_target::read_description ()
>  #ifdef PT_GETREGSET
>    tls = have_regset (inferior_ptid, NT_ARM_TLS) != 0;
>  #endif
> -  desc = arm_fbsd_read_description_auxv (tls);
> +  desc = arm_fbsd_read_description_auxv (current_inferior ()->gdbarch, tls);
>    if (desc == NULL)
>      desc = this->beneath ()->read_description ();
>    return desc;

Woops, thanks for pointing it out.  Actually, I'll leave the
one-parameter version there and adapt it, so no change should be needed
in the nat file.

Thanks,

Simon
  

Here's a slightly updated patch.  I realized we could do further
simplifications in target_auxv_search and callers.


From 868f295627164596ea8c868e6ad07e86e44ee7a1 Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@polymtl.ca>
Date: Mon, 28 Nov 2022 16:09:25 -0500
Subject: [PATCH 3/3] gdb: remove target_ops parameter from
 gdbarch_core_read_description

Following the previous patch ("gdb: change order of core_target
initialization"), it is no longer necessary for the core target to pass
a pointer to itself to gdbarch_core_read_description.  Implementations
of this method can just do regular calls to target_read_auxv, through
the inferior target stack.

This allows removing the target_ops parameter in
gdbarch_core_read_description and a bunch of functions called
downstream.  Some auxv-related functions received the auxv data as a
parameter, since they could not assume it could be read from the current
inferior, that is also no longer needed.

Regression tested.  I also tested manually against an AArch64 MTE test
case that Luis Machado sent me a while ago when we were working on this
auxv caching issue, the desired behavior of reporting the MTE tags when
opening the code still worked.

Change-Id: I1e00361209028e9b65dde085d383cf950a7b5e3a
---
 gdb/aarch64-fbsd-tdep.c   |  3 +--
 gdb/aarch64-linux-tdep.c  |  8 +++-----
 gdb/amd64-fbsd-tdep.c     |  4 +---
 gdb/amd64-linux-tdep.c    |  4 +---
 gdb/arc-linux-tdep.c      |  4 +---
 gdb/arm-fbsd-tdep.c       | 20 +++++--------------
 gdb/arm-fbsd-tdep.h       | 12 ++++++------
 gdb/arm-linux-tdep.c      |  7 ++-----
 gdb/auxv.c                | 41 ++++++++++++++-------------------------
 gdb/auxv.h                | 14 ++++---------
 gdb/corelow.c             |  2 +-
 gdb/gdbarch-components.py |  2 +-
 gdb/gdbarch-gen.h         |  4 ++--
 gdb/gdbarch.c             |  4 ++--
 gdb/i386-fbsd-tdep.c      |  4 +---
 gdb/i386-linux-tdep.c     |  4 +---
 gdb/linux-tdep.c          | 25 +++++++++---------------
 gdb/linux-tdep.h          | 14 ++++++-------
 gdb/mips-linux-tdep.c     |  4 +---
 gdb/ppc-linux-tdep.c      |  7 ++-----
 gdb/s390-linux-tdep.c     |  6 ++----
 21 files changed, 67 insertions(+), 126 deletions(-)

diff --git a/gdb/aarch64-fbsd-tdep.c b/gdb/aarch64-fbsd-tdep.c
index 39d193551059..b76ca24aacfd 100644
--- a/gdb/aarch64-fbsd-tdep.c
+++ b/gdb/aarch64-fbsd-tdep.c
@@ -195,8 +195,7 @@ aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* Implement the "core_read_description" gdbarch method.  */
 
 static const struct target_desc *
-aarch64_fbsd_core_read_description (struct gdbarch *gdbarch,
-				    struct target_ops *target, bfd *abfd)
+aarch64_fbsd_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");
 
diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
index a321aee036a0..fb9875f5701d 100644
--- a/gdb/aarch64-linux-tdep.c
+++ b/gdb/aarch64-linux-tdep.c
@@ -776,13 +776,11 @@ aarch64_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* Implement the "core_read_description" gdbarch method.  */
 
 static const struct target_desc *
-aarch64_linux_core_read_description (struct gdbarch *gdbarch,
-				     struct target_ops *target, bfd *abfd)
+aarch64_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv_raw (target);
-  CORE_ADDR hwcap = linux_get_hwcap (auxv, target, gdbarch);
-  CORE_ADDR hwcap2 = linux_get_hwcap2 (auxv, target, gdbarch);
+  CORE_ADDR hwcap = linux_get_hwcap (gdbarch);
+  CORE_ADDR hwcap2 = linux_get_hwcap2 (gdbarch);
 
   aarch64_features features;
   features.vq = aarch64_linux_core_read_vq (gdbarch, abfd);
diff --git a/gdb/amd64-fbsd-tdep.c b/gdb/amd64-fbsd-tdep.c
index 960bb0b5942f..90dad4cce98e 100644
--- a/gdb/amd64-fbsd-tdep.c
+++ b/gdb/amd64-fbsd-tdep.c
@@ -220,9 +220,7 @@ static const struct tramp_frame amd64_fbsd_sigframe =
 /* Implement the core_read_description gdbarch method.  */
 
 static const struct target_desc *
-amd64fbsd_core_read_description (struct gdbarch *gdbarch,
-				 struct target_ops *target,
-				 bfd *abfd)
+amd64fbsd_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   return amd64_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 }
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index 07c1669f91e0..ace20ed738bd 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -1613,9 +1613,7 @@ amd64_linux_read_description (uint64_t xcr0_features_bit, bool is_x32)
 /* Get Linux/x86 target description from core dump.  */
 
 static const struct target_desc *
-amd64_linux_core_read_description (struct gdbarch *gdbarch,
-				  struct target_ops *target,
-				  bfd *abfd)
+amd64_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   /* Linux/x86-64.  */
   uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
diff --git a/gdb/arc-linux-tdep.c b/gdb/arc-linux-tdep.c
index da7f4758c195..805251d5f4fe 100644
--- a/gdb/arc-linux-tdep.c
+++ b/gdb/arc-linux-tdep.c
@@ -679,9 +679,7 @@ arc_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* Implement the `core_read_description` gdbarch method.  */
 
 static const struct target_desc *
-arc_linux_core_read_description (struct gdbarch *gdbarch,
-				 struct target_ops *target,
-				 bfd *abfd)
+arc_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   arc_arch_features features
     = arc_arch_features_create (abfd,
diff --git a/gdb/arm-fbsd-tdep.c b/gdb/arm-fbsd-tdep.c
index 75ee08eba506..cd8b55997d7d 100644
--- a/gdb/arm-fbsd-tdep.c
+++ b/gdb/arm-fbsd-tdep.c
@@ -215,14 +215,11 @@ arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* See arm-fbsd-tdep.h.  */
 
 const struct target_desc *
-arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
-				target_ops *target, gdbarch *gdbarch, bool tls)
+arm_fbsd_read_description_auxv (gdbarch *gdbarch, bool tls)
 {
   CORE_ADDR arm_hwcap = 0;
 
-  if (!auxv.has_value ()
-      || target_auxv_search (*auxv, target, gdbarch, AT_FREEBSD_HWCAP,
-			     &arm_hwcap) != 1)
+  if (target_auxv_search (gdbarch, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
     return arm_read_description (ARM_FP_TYPE_NONE, tls);
 
   if (arm_hwcap & HWCAP_VFP)
@@ -244,24 +241,17 @@ arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
 const struct target_desc *
 arm_fbsd_read_description_auxv (bool tls)
 {
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
-  return arm_fbsd_read_description_auxv (auxv,
-					 current_inferior ()->top_target (),
-					 current_inferior ()->gdbarch,
-					 tls);
+  return arm_fbsd_read_description_auxv (current_inferior ()->gdbarch, tls);
 }
 
 /* Implement the "core_read_description" gdbarch method.  */
 
 static const struct target_desc *
-arm_fbsd_core_read_description (struct gdbarch *gdbarch,
-				struct target_ops *target,
-				bfd *abfd)
+arm_fbsd_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");
 
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv_raw (target);
-  return arm_fbsd_read_description_auxv (auxv, target, gdbarch, tls != nullptr);
+  return arm_fbsd_read_description_auxv (gdbarch, tls != nullptr);
 }
 
 /* Implement the get_thread_local_address gdbarch method.  */
diff --git a/gdb/arm-fbsd-tdep.h b/gdb/arm-fbsd-tdep.h
index b4137eb9a51a..00263fb420b5 100644
--- a/gdb/arm-fbsd-tdep.h
+++ b/gdb/arm-fbsd-tdep.h
@@ -22,6 +22,8 @@
 
 #include "regset.h"
 
+struct gdbarch;
+
 /* The general-purpose regset consists of 13 R registers, plus SP, LR,
    PC, and CPSR registers.  */
 #define ARM_FBSD_SIZEOF_GREGSET  (17 * 4)
@@ -43,15 +45,13 @@ extern const struct regset arm_fbsd_tls_regset;
 #define	HWCAP_VFPv3		0x00002000
 #define	HWCAP_VFPD32		0x00080000
 
-/* Lookup a target description based on the AT_HWCAP value in the auxv data
-   AUXV.  */
+/* Lookup a target description based on the AT_HWCAP value in the current
+   inferior's auxv data.  */
 
 extern const struct target_desc *
-  arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
-				  target_ops *target, gdbarch *gdbarch,
-				  bool tls);
+  arm_fbsd_read_description_auxv (gdbarch *gdbarch, bool tls);
 
-/* Same as the above, but read the auxv data from the current inferior.  */
+/* Same as the above, but get the GDBARCH from the current inferior.  */
 
 extern const struct target_desc *
   arm_fbsd_read_description_auxv (bool tls);
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index 27aca0c39e6b..2f88bb036d15 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -728,12 +728,9 @@ arm_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* Determine target description from core file.  */
 
 static const struct target_desc *
-arm_linux_core_read_description (struct gdbarch *gdbarch,
-				 struct target_ops *target,
-				 bfd *abfd)
+arm_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv_raw (target);
-  CORE_ADDR arm_hwcap = linux_get_hwcap (auxv, target, gdbarch);
+  CORE_ADDR arm_hwcap = linux_get_hwcap (gdbarch);
 
   if (arm_hwcap & HWCAP_VFP)
     {
diff --git a/gdb/auxv.c b/gdb/auxv.c
index 73e84cf144db..62ad2bf84219 100644
--- a/gdb/auxv.c
+++ b/gdb/auxv.c
@@ -315,16 +315,16 @@ svr4_auxv_parse (struct gdbarch *gdbarch, const gdb_byte **readptr,
    Return 1 if an entry was read into *TYPEP and *VALP.  */
 
 static int
-parse_auxv (target_ops *ops, gdbarch *gdbarch, const gdb_byte **readptr,
+parse_auxv (gdbarch *gdbarch, const gdb_byte **readptr,
 	    const gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
 {
   if (gdbarch_auxv_parse_p (gdbarch))
     return gdbarch_auxv_parse (gdbarch, readptr, endptr, typep, valp);
 
-  return ops->auxv_parse (readptr, endptr, typep, valp);
+  return current_inferior ()->top_target ()->auxv_parse
+    (readptr, endptr, typep, valp);
 }
 
-
 /*  Auxiliary Vector information structure.  This is used by GDB
     for caching purposes for each inferior.  This helps reduce the
     overhead of transfering data from a remote target to the local host.  */
@@ -363,7 +363,8 @@ target_read_auxv ()
   if (info == nullptr)
     {
       info = auxv_inferior_data.emplace (inf);
-      info->data = target_read_auxv_raw (inf->top_target ());
+      info->data
+	= target_read_alloc (inf->top_target (), TARGET_OBJECT_AUXV, NULL);
     }
 
   return info->data;
@@ -371,25 +372,20 @@ target_read_auxv ()
 
 /* See auxv.h.  */
 
-gdb::optional<gdb::byte_vector>
-target_read_auxv_raw (target_ops *ops)
-{
-  return target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL);
-}
-
-/* See auxv.h.  */
-
 int
-target_auxv_search (const gdb::byte_vector &auxv, target_ops *ops,
-		    gdbarch *gdbarch, CORE_ADDR match, CORE_ADDR *valp)
+target_auxv_search (gdbarch *gdbarch, CORE_ADDR match, CORE_ADDR *valp)
 {
+  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
+  if (!auxv.has_value ())
+    return 0;
+
   CORE_ADDR type, val;
-  const gdb_byte *data = auxv.data ();
+  const gdb_byte *data = auxv->data ();
   const gdb_byte *ptr = data;
-  size_t len = auxv.size ();
+  size_t len = auxv->size ();
 
   while (1)
-    switch (parse_auxv (ops, gdbarch, &ptr, data + len, &type, &val))
+    switch (parse_auxv (gdbarch, &ptr, data + len, &type, &val))
       {
       case 1:			/* Here's an entry, check it.  */
 	if (type == match)
@@ -410,13 +406,7 @@ target_auxv_search (const gdb::byte_vector &auxv, target_ops *ops,
 int
 target_auxv_search (CORE_ADDR match, CORE_ADDR *valp)
 {
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv ();
-
-  if (!auxv.has_value ())
-    return -1;
-
-  return target_auxv_search (*auxv, current_inferior ()->top_target (),
-			     current_inferior ()->gdbarch, match, valp);
+  return target_auxv_search (current_inferior ()->gdbarch, match, valp);
 }
 
 /* Print the description of a single AUXV entry on the specified file.  */
@@ -573,8 +563,7 @@ fprint_target_auxv (struct ui_file *file)
   const gdb_byte *ptr = data;
   size_t len = auxv->size ();
 
-  while (parse_auxv (current_inferior ()->top_target (),
-		     current_inferior ()->gdbarch,
+  while (parse_auxv (current_inferior ()->gdbarch,
 		     &ptr, data + len, &type, &val) > 0)
     {
       gdbarch_print_auxv_entry (gdbarch, file, type, val);
diff --git a/gdb/auxv.h b/gdb/auxv.h
index 788d187b27a0..6b6ffedf1bdb 100644
--- a/gdb/auxv.h
+++ b/gdb/auxv.h
@@ -50,24 +50,18 @@ extern int svr4_auxv_parse (struct gdbarch *gdbarch, const gdb_byte **readptr,
 
 extern gdb::optional<gdb::byte_vector> target_read_auxv ();
 
-/* Read auxv data from OPS.  */
-
-extern gdb::optional<gdb::byte_vector> target_read_auxv_raw (target_ops *ops);
-
 /* Search AUXV for an entry with a_type matching MATCH.
 
-   OPS and GDBARCH are the target and architecture to use to parse auxv entries.
+   Use GDBARCH to parse auxv entries, instead of the current inferior's arch.
 
    Return zero if no such entry was found, or -1 if there was
    an error getting the information.  On success, return 1 after
    storing the entry's value field in *VALP.  */
 
-extern int target_auxv_search (const gdb::byte_vector &auxv,
-			       target_ops *ops, gdbarch *gdbarch,
-			       CORE_ADDR match, CORE_ADDR *valp);
+extern int target_auxv_search (gdbarch *gdbarch, CORE_ADDR match,
+			       CORE_ADDR *valp);
 
-/* Same as the above, but read the auxv data from the current inferior.  Use
-   the current inferior's top target and arch to parse auxv entries.  */
+/* Same as the above, but get the gdbarch from the current inferior.  */
 
 extern int target_auxv_search (CORE_ADDR match, CORE_ADDR *valp);
 
diff --git a/gdb/corelow.c b/gdb/corelow.c
index 8cd6be436094..bdd23bc2a328 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -1123,7 +1123,7 @@ core_target::read_description ()
     {
       const struct target_desc *result;
 
-      result = gdbarch_core_read_description (m_core_gdbarch, this, core_bfd);
+      result = gdbarch_core_read_description (m_core_gdbarch, core_bfd);
       if (result != NULL)
 	return result;
     }
diff --git a/gdb/gdbarch-components.py b/gdb/gdbarch-components.py
index e7230949aad5..0791f373d7e4 100644
--- a/gdb/gdbarch-components.py
+++ b/gdb/gdbarch-components.py
@@ -1892,7 +1892,7 @@ Refresh overlay mapped state for section OSECT.
 Method(
     type="const struct target_desc *",
     name="core_read_description",
-    params=[("struct target_ops *", "target"), ("bfd *", "abfd")],
+    params=[("bfd *", "abfd")],
     predicate=True,
     invalid=True,
 )
diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h
index a663316df166..4de2b31bc2e3 100644
--- a/gdb/gdbarch-gen.h
+++ b/gdb/gdbarch-gen.h
@@ -1127,8 +1127,8 @@ extern void set_gdbarch_overlay_update (struct gdbarch *gdbarch, gdbarch_overlay
 
 extern bool gdbarch_core_read_description_p (struct gdbarch *gdbarch);
 
-typedef const struct target_desc * (gdbarch_core_read_description_ftype) (struct gdbarch *gdbarch, struct target_ops *target, bfd *abfd);
-extern const struct target_desc * gdbarch_core_read_description (struct gdbarch *gdbarch, struct target_ops *target, bfd *abfd);
+typedef const struct target_desc * (gdbarch_core_read_description_ftype) (struct gdbarch *gdbarch, bfd *abfd);
+extern const struct target_desc * gdbarch_core_read_description (struct gdbarch *gdbarch, bfd *abfd);
 extern void set_gdbarch_core_read_description (struct gdbarch *gdbarch, gdbarch_core_read_description_ftype *core_read_description);
 
 /* Set if the address in N_SO or N_FUN stabs may be zero. */
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index ddb8dec1c72d..f6138a42219a 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -4211,13 +4211,13 @@ gdbarch_core_read_description_p (struct gdbarch *gdbarch)
 }
 
 const struct target_desc *
-gdbarch_core_read_description (struct gdbarch *gdbarch, struct target_ops *target, bfd *abfd)
+gdbarch_core_read_description (struct gdbarch *gdbarch, bfd *abfd)
 {
   gdb_assert (gdbarch != NULL);
   gdb_assert (gdbarch->core_read_description != NULL);
   if (gdbarch_debug >= 2)
     gdb_printf (gdb_stdlog, "gdbarch_core_read_description called\n");
-  return gdbarch->core_read_description (gdbarch, target, abfd);
+  return gdbarch->core_read_description (gdbarch, abfd);
 }
 
 void
diff --git a/gdb/i386-fbsd-tdep.c b/gdb/i386-fbsd-tdep.c
index eef124fca0ce..fb3a384d9442 100644
--- a/gdb/i386-fbsd-tdep.c
+++ b/gdb/i386-fbsd-tdep.c
@@ -281,9 +281,7 @@ i386fbsd_core_read_xcr0 (bfd *abfd)
 /* Implement the core_read_description gdbarch method.  */
 
 static const struct target_desc *
-i386fbsd_core_read_description (struct gdbarch *gdbarch,
-				struct target_ops *target,
-				bfd *abfd)
+i386fbsd_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   return i386_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 }
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index 5c2fed39868c..63a56b86a974 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -703,9 +703,7 @@ i386_linux_read_description (uint64_t xcr0)
 /* Get Linux/x86 target description from core dump.  */
 
 static const struct target_desc *
-i386_linux_core_read_description (struct gdbarch *gdbarch,
-				  struct target_ops *target,
-				  bfd *abfd)
+i386_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   /* Linux/i386.  */
   uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index c30d9fb13f8c..99eaec431a5d 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -2661,12 +2661,11 @@ linux_displaced_step_restore_all_in_ptid (inferior *parent_inf, ptid_t ptid)
 /* Helper for linux_get_hwcap and linux_get_hwcap2.  */
 
 static CORE_ADDR
-linux_get_hwcap_helper (const gdb::optional<gdb::byte_vector> &auxv,
-			target_ops *target, gdbarch *gdbarch, CORE_ADDR match)
+linux_get_hwcap_helper (gdbarch *gdbarch, CORE_ADDR match)
 {
   CORE_ADDR field;
-  if (!auxv.has_value ()
-      || target_auxv_search (*auxv, target, gdbarch, match, &field) != 1)
+
+  if (target_auxv_search (gdbarch, match, &field) != 1)
     return 0;
   return field;
 }
@@ -2674,10 +2673,9 @@ linux_get_hwcap_helper (const gdb::optional<gdb::byte_vector> &auxv,
 /* See linux-tdep.h.  */
 
 CORE_ADDR
-linux_get_hwcap (const gdb::optional<gdb::byte_vector> &auxv,
-		 target_ops *target, gdbarch *gdbarch)
+linux_get_hwcap (gdbarch *gdbarch)
 {
-  return linux_get_hwcap_helper (auxv, target, gdbarch, AT_HWCAP);
+  return linux_get_hwcap_helper (gdbarch, AT_HWCAP);
 }
 
 /* See linux-tdep.h.  */
@@ -2685,18 +2683,15 @@ linux_get_hwcap (const gdb::optional<gdb::byte_vector> &auxv,
 CORE_ADDR
 linux_get_hwcap ()
 {
-  return linux_get_hwcap (target_read_auxv (),
-			  current_inferior ()->top_target (),
-			  current_inferior ()->gdbarch);
+  return linux_get_hwcap (current_inferior ()->gdbarch);
 }
 
 /* See linux-tdep.h.  */
 
 CORE_ADDR
-linux_get_hwcap2 (const gdb::optional<gdb::byte_vector> &auxv,
-		  target_ops *target, gdbarch *gdbarch)
+linux_get_hwcap2 (gdbarch *gdbarch)
 {
-  return linux_get_hwcap_helper (auxv, target, gdbarch, AT_HWCAP2);
+  return linux_get_hwcap_helper (gdbarch, AT_HWCAP2);
 }
 
 /* See linux-tdep.h.  */
@@ -2704,9 +2699,7 @@ linux_get_hwcap2 (const gdb::optional<gdb::byte_vector> &auxv,
 CORE_ADDR
 linux_get_hwcap2 ()
 {
-  return linux_get_hwcap2 (target_read_auxv (),
-			   current_inferior ()->top_target (),
-			   current_inferior ()->gdbarch);
+  return linux_get_hwcap2 (current_inferior ()->gdbarch);
 }
 
 /* Display whether the gcore command is using the
diff --git a/gdb/linux-tdep.h b/gdb/linux-tdep.h
index 95cc29c828c2..b7a52ccde235 100644
--- a/gdb/linux-tdep.h
+++ b/gdb/linux-tdep.h
@@ -90,23 +90,21 @@ extern void linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
 
 extern int linux_is_uclinux (void);
 
-/* Fetch the AT_HWCAP entry from auxv data AUXV.  Use TARGET and GDBARCH to
-   parse auxv entries.
+/* Fetch the AT_HWCAP entry from the current inferior's auxv data.  Use GDBARCH
+   to parse auxv entries.
 
    On error, 0 is returned.  */
-extern CORE_ADDR linux_get_hwcap (const gdb::optional<gdb::byte_vector> &auxv,
-				  struct target_ops *target, gdbarch *gdbarch);
+extern CORE_ADDR linux_get_hwcap (gdbarch *gdbarch);
 
 /* Same as the above, but obtain all the inputs from the current inferior.  */
 
 extern CORE_ADDR linux_get_hwcap ();
 
-/* Fetch the AT_HWCAP2 entry from auxv data AUXV.  Use TARGET and GDBARCH to
-   parse auxv entries.
+/* Fetch the AT_HWCAP2 entry from the current inferior's auxv data.  Use GDBARCH
+   to parse auxv entries.
 
    On error, 0 is returned.  */
-extern CORE_ADDR linux_get_hwcap2 (const gdb::optional<gdb::byte_vector> &auxv,
-				   struct target_ops *target, gdbarch *gdbarch);
+extern CORE_ADDR linux_get_hwcap2 (gdbarch *gdbarch);
 
 /* Same as the above, but obtain all the inputs from the current inferior.  */
 
diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index 1b3b5f88edbc..534d47fc1ae5 100644
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -554,9 +554,7 @@ mips_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
 }
 
 static const struct target_desc *
-mips_linux_core_read_description (struct gdbarch *gdbarch,
-				  struct target_ops *target,
-				  bfd *abfd)
+mips_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   asection *section = bfd_get_section_by_name (abfd, ".reg");
   if (! section)
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 39d692b2764c..cec3a31d7746 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -1566,9 +1566,7 @@ ppc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 }
 
 static const struct target_desc *
-ppc_linux_core_read_description (struct gdbarch *gdbarch,
-				 struct target_ops *target,
-				 bfd *abfd)
+ppc_linux_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   struct ppc_linux_features features = ppc_linux_no_features;
   asection *altivec = bfd_get_section_by_name (abfd, ".reg-ppc-vmx");
@@ -1601,8 +1599,7 @@ ppc_linux_core_read_description (struct gdbarch *gdbarch,
   if (vsx)
     features.vsx = true;
 
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv_raw (target);
-  CORE_ADDR hwcap = linux_get_hwcap (auxv, target, gdbarch);
+  CORE_ADDR hwcap = linux_get_hwcap (gdbarch);
 
   features.isa205 = ppc_linux_has_isa205 (hwcap);
 
diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c
index 14d71134e0cd..d134332b7b16 100644
--- a/gdb/s390-linux-tdep.c
+++ b/gdb/s390-linux-tdep.c
@@ -328,12 +328,10 @@ s390_iterate_over_regset_sections (struct gdbarch *gdbarch,
 /* Implement core_read_description gdbarch method.  */
 
 static const struct target_desc *
-s390_core_read_description (struct gdbarch *gdbarch,
-			    struct target_ops *target, bfd *abfd)
+s390_core_read_description (gdbarch *gdbarch, bfd *abfd)
 {
   asection *section = bfd_get_section_by_name (abfd, ".reg");
-  gdb::optional<gdb::byte_vector> auxv = target_read_auxv_raw (target);
-  CORE_ADDR hwcap = linux_get_hwcap (auxv, target, gdbarch);
+  CORE_ADDR hwcap = linux_get_hwcap (gdbarch);
   bool high_gprs, v1, v2, te, vx, gs;
 
   if (!section)