gdbserver: pass osabi to GDB in more target descriptions

Problem Description
-------------------

On a Windows machine I built gdbserver, configured for the target
'x86_64-w64-mingw32', then on a GNU/Linux machine I built GDB with
support for all target (--enable-targets=all).

On the Windows machine I start gdbserver with a small test binary:

  $ gdbserver 192.168.129.25:54321 C:\some\directory\executable.exe

On the GNU/Linux machine I start GDB without the test binary, and
connect to gdbserver.

As I have not given GDB the test binary, my expectation is that GDB
would connect to gdbserver and then download the file over the remote
protocol, but instead I was presented with this message:

  (gdb) target remote 192.168.129.25:54321
  Remote debugging using 192.168.129.25:54321
  warning: C:\some\directory\executable.exe: No such file or directory.
  0x00007ffa3e1e1741 in ?? ()
  (gdb)

What I found is that if I told GDB where to find the binary, like
this:

  (gdb) file target:C:/some/directory/executable.exe
  A program is being debugged already.
  Are you sure you want to change the file? (y or n) y
  Reading C:/some/directory/executable.exe from remote target...
  warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead.
  Reading C:/some/directory/executable.exe from remote target...
  Reading symbols from target:C:/some/directory/executable.exe...
  (gdb)

then GDB would download the executable.

The Actual Issue
----------------

I tracked the problem down to exec_file_find (solib.c).  The remote
target was passing an absolute Windows filename (beginning with "C:/"
in this case), but in exec_file_find GDB was failing the
IS_TARGET_ABSOLUTE_PATH call, and so was treating the filename as
relative.

The IS_TARGET_ABSOLUTE_PATH call was failing because GDB thought that
the file system kind was "unix", and as the filename didn't start with
a "/" it assumed the filename was not absolute.

But I'm connecting to a Windows target and 'target-file-system-kind'
was set to "auto", so GDB should be figuring out that the target
file-system is "dos-based".

Looking in effective_target_file_system_kind (filesystem.c), we find
that the logic of "auto" is delegated to the current gdbarch.  However
in windows-tdep.c we see:

  set_gdbarch_has_dos_based_file_system (gdbarch, 1);

So if we are using a Windows gdbarch we should have "dos-based"
filesystems.  What this means is that after connecting to the remote
target GDB has selected the wrong gdbarch.

What's happening is that the target description sent back by the
remote target only includes the x86-64 registers.  There's no
information about which OS we're on.  As a consequence, GDB picks the
first x86-64 gdbarch which can handle the provided register set, which
happens to be a GNU/Linux gdbarch.

And indeed, there doesn't appear to be anywhere in gdbserver that sets
the osabi on the target descriptions. Some target descriptions do have
their osabi set when the description is created, e.g. in:

  gdb/arch/amd64.c	- Sets GNU/Linux osabi when appropriate.
  gdb/arch/i386.c	- Likewise.
  gdb/arch/tic6x.c	- Always set GNU/Linux osabi.

There are also some cases in gdb/features/*.c where the tdesc is set,
but these locations are only called from GDB, not from gdbserver.

This means that many target descriptions are created without an osabi,
gdbserver does nothing to fix this, and the description is returned to
GDB without an osabi included.  This leaves GDB having to guess what
the target osabi is, and in some cases, GDB can get this wrong.

Proposed Solution
-----------------

I propose to change init_target_desc so that it requires an gdb_osabi
to be passed in, this will then be used to set the target_desc osabi
field.

I believe that within gdbserver init_target_desc is called for every
target_desc, so this should mean that every target_desc has an
opportunity to set the osabi to something sane.

I did consider passing the osabi into the code which creates the
target_desc objects, but that would require updating far more code, as
each target has its own code for creating target descriptions.
The approach taken here requires minimal changes and forces every
user of init_target_desc to think about what the correct osabi is.

In some cases, e.g. amd64, where the osabi is already set when the
target_desc is created, the init_target_desc call will override the
current value, however, we should always be replacing it with the same
actual value.  i.e. if the target_desc is created with the osabi set
to GNU/Linux, then this should only happen when gdbserver is built for
GNU/Linux, in which case the init_target_desc should also be setting
the osabi to GNU/Linux.

The Tricky Bits
---------------

Some targets, like amd64, use a features based approach for creating
target_desc objects, there's a function in arch/amd64.c which creates
a target_desc, adds features too it, and returns the new target_desc.
This target_desc is then passed to an init_target_desc call within
gdbserver.  This is the easy case to handle.

Then there are other targets which instead have a fixed set of xml
files, each of which is converted into a .dat file, which is then used
to generate a .cc file, which is compiled into gdbserver.  The
generated .cc file creates the target_desc object and calls
init_target_desc on it.  In this case though the target description
that is sent to GDB isn't generated from the target_desc object, but
is instead the contents of the fixed xml file.  For this case the
osabi which we pass to init_target_desc should match the osabi that
exists in the fixed xml file.

Luckily, in the previous commit I copied the osabi information from
the fixed xml files into the .dat files.  So in this commit I have
extended regdat.sh to read the osabi from the .dat file and use it in
the generated init_target_desc call.

The problem with some of these .dat base targets is that their fixed
xml files don't currently contain any osabi information, and the file
names don't indicate that they are Linux only (despite them currently
only being used from gdbserver for Linux targets), so I don't
currently feel confident adding any osabi information to these files.
An example would be features/rs6000/powerpc-64.xml.  For now I've just
ignored these cases.  The init_target_desc will use GDB_OSABI_UNKNOWN
which is the default.  This means that for these targets nothing
changes from the current behaviour.  But many other targets do now
pass the osabi back.  Targets that do pass the osabi back are
improved with this commit.

Conclusion
----------

Now when I connect to the Windows remote the target description
returned includes the osabi name.  With this extra information GDB
selects the correct gdbarch object, which means that GDB understands
the target has a "dos-based" file-system.  With that correct GDB
understands that the filename it was given is absolute, and so fetches
the file from the remote as we'd like.

gdb/features/Makefile

@@ -191,6 +191,8 @@ $(outdir)/%.dat: %.xml number-regs.xsl sort-regs.xsl gdbserver-regs.xsl
 	echo "xmltarget:$(<F)" >> $(outdir)/$*.tmp
 	echo "expedite:$(if $($*-expedite),$($*-expedite),$($(firstword $(subst -, ,$(notdir $*)))-expedite))" \
 	  >> $(outdir)/$*.tmp
+	$(XSLTPROC) --path "$(PWD)" --xinclude print-osabi.xsl $< \
+	  >> $(outdir)/$*.tmp
 	$(XSLTPROC) --path "$(PWD)" --xinclude number-regs.xsl $< | \
 	  $(XSLTPROC) sort-regs.xsl - | \
 	  $(XSLTPROC) gdbserver-regs.xsl - >> $(outdir)/$*.tmp

gdb/features/mips64-dsp-linux.c

@@ -11,6 +11,8 @@ initialize_tdesc_mips64_dsp_linux (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("mips"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.mips.cpu");

gdb/features/mips64-dsp-linux.xml

@@ -8,6 +8,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>mips</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="mips64-cpu.xml"/>
   <xi:include href="mips64-cp0.xml"/>
   <xi:include href="mips64-fpu.xml"/>

gdb/features/mips64-linux.c

@@ -11,6 +11,8 @@ initialize_tdesc_mips64_linux (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("mips"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.mips.cpu");

gdb/features/mips64-linux.xml

@@ -8,6 +8,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>mips</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="mips64-cpu.xml"/>
   <xi:include href="mips64-cp0.xml"/>
   <xi:include href="mips64-fpu.xml"/>

gdb/features/print-osabi.xsl

@@ -0,0 +1,39 @@
+<!--
+
+   Copyright (C) 2024 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+-->
+
+<xsl:stylesheet version="1.0"
+		xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+  <xsl:output method="text"/>
+  <xsl:variable name="total" select="count(/target/osabi)"/>
+  <xsl:template match = "/target">
+    <xsl:text>osabi:</xsl:text>
+    <xsl:choose>
+      <xsl:when test="osabi">
+	<xsl:value-of select="osabi"/>
+      </xsl:when>
+      <xsl:otherwise>
+	<xsl:text>unknown</xsl:text>
+      </xsl:otherwise>
+    </xsl:choose>
+    <xsl:text>
+</xsl:text>
+  </xsl:template>
+</xsl:stylesheet>

gdb/features/s390-gs-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_gs_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-gs-linux64.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux32.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux32 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux32.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core32.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux32v1.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux32v1 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux32v1.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core32.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux32v2.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux32v2 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux32v2.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core32.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux64.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux64v1.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux64v1 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux64v1.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-linux64v2.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_linux64v2 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-linux64v2.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-te-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_te_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-te-linux64.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-tevx-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_tevx_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-tevx-linux64.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390-vx-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390_vx_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:31-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390-vx-linux64.xml

@@ -11,6 +11,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:31-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-gs-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_gs_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-gs-linux64.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-linux64.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-linux64v1.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_linux64v1 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-linux64v1.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-linux64v2.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_linux64v2 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-linux64v2.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-te-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_te_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-te-linux64.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-tevx-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_tevx_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-tevx-linux64.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/features/s390x-vx-linux64.c

@@ -11,6 +11,8 @@ initialize_tdesc_s390x_vx_linux64 (void)
   target_desc_up result = allocate_target_description ();
   set_tdesc_architecture (result.get (), bfd_scan_arch ("s390:64-bit"));
 
+  set_tdesc_osabi (result.get (), GDB_OSABI_LINUX);
+
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result.get (), "org.gnu.gdb.s390.core");

gdb/features/s390x-vx-linux64.xml

@@ -10,6 +10,7 @@
 <!DOCTYPE target SYSTEM "gdb-target.dtd">
 <target>
   <architecture>s390:64-bit</architecture>
+  <osabi>GNU/Linux</osabi>
   <xi:include href="s390x-core64.xml"/>
   <xi:include href="s390-acr.xml"/>
   <xi:include href="s390-fpr.xml"/>

gdb/regformats/mips-dsp-linux.dat

@@ -3,6 +3,7 @@
 name:mips_dsp_linux
 xmltarget:mips-dsp-linux.xml
 expedite:r29,pc
+osabi:GNU/Linux
 32:r0
 32:r1
 32:r2

gdb/regformats/mips-linux.dat

@@ -3,6 +3,7 @@
 name:mips_linux
 xmltarget:mips-linux.xml
 expedite:r29,pc
+osabi:GNU/Linux
 32:r0
 32:r1
 32:r2

gdb/regformats/mips64-dsp-linux.dat

@@ -3,6 +3,7 @@
 name:mips64_dsp_linux
 xmltarget:mips64-dsp-linux.xml
 expedite:r29,pc
+osabi:GNU/Linux
 64:r0
 64:r1
 64:r2

gdb/regformats/mips64-linux.dat

@@ -3,6 +3,7 @@
 name:mips64_linux
 xmltarget:mips64-linux.xml
 expedite:r29,pc
+osabi:GNU/Linux
 64:r0
 64:r1
 64:r2

gdb/regformats/nios2-linux.dat

@@ -3,6 +3,7 @@
 name:nios2_linux
 xmltarget:nios2-linux.xml
 expedite:sp,pc
+osabi:GNU/Linux
 32:zero
 32:at
 32:r2

gdb/regformats/or1k-linux.dat

@@ -3,6 +3,7 @@
 name:or1k_linux
 xmltarget:or1k-linux.xml
 expedite:r1,npc
+osabi:GNU/Linux
 32:r0
 32:r1
 32:r2

gdb/regformats/regdat.sh

@@ -105,7 +105,7 @@ EOF
 }
 
 
-exec > new-$2
+exec > new-$3
 copyright $1
 echo '#include "regdef.h"'
 echo '#include "tdesc.h"'
@@ -118,6 +118,7 @@ xmlarch=x
 xmlosabi=x
 expedite=x
 feature=x
+osabi=unknown
 exec < $1
 while do_read
 do
@@ -143,7 +144,7 @@ do
   elif test "${type}" = "xmlarch"; then
     xmlarch="${entry}"
     continue
-  elif test "${type}" = "osabi"; then
+  elif test "${type}" = "xmlosabi"; then
     xmlosabi="${entry}"
     continue
   elif test "${type}" = "expedite"; then
@@ -152,6 +153,9 @@ do
   elif test "${type}" = "feature"; then
     feature="${entry}"
     continue
+  elif test "${type}" = "osabi"; then
+    osabi="${entry}"
+    continue
   elif test "${name}" = x; then
     echo "$0: $1 does not specify \`\`name''." 1>&2
     exit 1
@@ -188,11 +192,13 @@ else
 fi
 echo
 
+osabi_enum=$(grep "${osabi}" "$2" | sed 's/.*(\([^,]\+\),.*/GDB_OSABI_\1/')
+
 cat <<EOF
   result->xmltarget = xmltarget_${name};
 #endif
 
-  init_target_desc (result, expedite_regs_${name});
+  init_target_desc (result, expedite_regs_${name}, ${osabi_enum});
 
   tdesc_${name} = result;
 }
@@ -200,4 +206,4 @@ EOF
 
 # close things off
 exec 1>&2
-mv -- "new-$2" "$2"
+mv -- "new-$3" "$3"

gdb/regformats/rs6000/powerpc-32.dat

@@ -3,6 +3,7 @@
 name:powerpc_32
 xmltarget:powerpc-32.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_32l
 xmltarget:powerpc-32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_64l
 xmltarget:powerpc-64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-altivec32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_altivec32l
 xmltarget:powerpc-altivec32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-altivec64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_altivec64l
 xmltarget:powerpc-altivec64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-e500l.dat

@@ -3,6 +3,7 @@
 name:powerpc_e500l
 xmltarget:powerpc-e500l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa205-32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_32l
 xmltarget:powerpc-isa205-32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa205-64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_64l
 xmltarget:powerpc-isa205-64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-isa205-altivec32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_altivec32l
 xmltarget:powerpc-isa205-altivec32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa205-altivec64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_altivec64l
 xmltarget:powerpc-isa205-altivec64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-isa205-ppr-dscr-vsx32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_ppr_dscr_vsx32l
 xmltarget:powerpc-isa205-ppr-dscr-vsx32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa205-ppr-dscr-vsx64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_ppr_dscr_vsx64l
 xmltarget:powerpc-isa205-ppr-dscr-vsx64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-isa205-vsx32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_vsx32l
 xmltarget:powerpc-isa205-vsx32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa205-vsx64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa205_vsx64l
 xmltarget:powerpc-isa205-vsx64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-isa207-htm-vsx32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa207_htm_vsx32l
 xmltarget:powerpc-isa207-htm-vsx32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa207-htm-vsx64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa207_htm_vsx64l
 xmltarget:powerpc-isa207-htm-vsx64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-isa207-vsx32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa207_vsx32l
 xmltarget:powerpc-isa207-vsx32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-isa207-vsx64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_isa207_vsx64l
 xmltarget:powerpc-isa207-vsx64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/rs6000/powerpc-vsx32l.dat

@@ -3,6 +3,7 @@
 name:powerpc_vsx32l
 xmltarget:powerpc-vsx32l.xml
 expedite:r1,pc
+osabi:unknown
 32:r0
 32:r1
 32:r2

gdb/regformats/rs6000/powerpc-vsx64l.dat

@@ -3,6 +3,7 @@
 name:powerpc_vsx64l
 xmltarget:powerpc-vsx64l.xml
 expedite:r1,pc
+osabi:unknown
 64:r0
 64:r1
 64:r2

gdb/regformats/s390-gs-linux64.dat

@@ -3,6 +3,7 @@
 name:s390_gs_linux64
 xmltarget:s390-gs-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-linux32.dat

@@ -3,6 +3,7 @@
 name:s390_linux32
 xmltarget:s390-linux32.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0

gdb/regformats/s390-linux32v1.dat

@@ -3,6 +3,7 @@
 name:s390_linux32v1
 xmltarget:s390-linux32v1.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0

gdb/regformats/s390-linux32v2.dat

@@ -3,6 +3,7 @@
 name:s390_linux32v2
 xmltarget:s390-linux32v2.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0

gdb/regformats/s390-linux64.dat

@@ -3,6 +3,7 @@
 name:s390_linux64
 xmltarget:s390-linux64.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-linux64v1.dat

@@ -3,6 +3,7 @@
 name:s390_linux64v1
 xmltarget:s390-linux64v1.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-linux64v2.dat

@@ -3,6 +3,7 @@
 name:s390_linux64v2
 xmltarget:s390-linux64v2.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-te-linux64.dat

@@ -3,6 +3,7 @@
 name:s390_te_linux64
 xmltarget:s390-te-linux64.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-tevx-linux64.dat

@@ -3,6 +3,7 @@
 name:s390_tevx_linux64
 xmltarget:s390-tevx-linux64.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390-vx-linux64.dat

@@ -3,6 +3,7 @@
 name:s390_vx_linux64
 xmltarget:s390-vx-linux64.xml
 expedite:r14l,r15l,pswa
+osabi:GNU/Linux
 32:pswm
 32:pswa
 32:r0h

gdb/regformats/s390x-gs-linux64.dat

@@ -3,6 +3,7 @@
 name:s390x_gs_linux64
 xmltarget:s390x-gs-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-linux64.dat

@@ -3,6 +3,7 @@
 name:s390x_linux64
 xmltarget:s390x-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-linux64v1.dat

@@ -3,6 +3,7 @@
 name:s390x_linux64v1
 xmltarget:s390x-linux64v1.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-linux64v2.dat

@@ -3,6 +3,7 @@
 name:s390x_linux64v2
 xmltarget:s390x-linux64v2.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-te-linux64.dat

@@ -3,6 +3,7 @@
 name:s390x_te_linux64
 xmltarget:s390x-te-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-tevx-linux64.dat

@@ -3,6 +3,7 @@
 name:s390x_tevx_linux64
 xmltarget:s390x-tevx-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/s390x-vx-linux64.dat

@@ -3,6 +3,7 @@
 name:s390x_vx_linux64
 xmltarget:s390x-vx-linux64.xml
 expedite:r14,r15,pswa
+osabi:GNU/Linux
 64:pswm
 64:pswa
 64:r0

gdb/regformats/tic6x-c62x-linux.dat

@@ -4,6 +4,7 @@ name:tic6x_c62x_linux
 feature:1
 xmltarget:tic6x-c62x-linux.xml
 expedite:A15,PC
+osabi:GNU/Linux
 32:A0
 32:A1
 32:A2

gdb/regformats/tic6x-c64x-linux.dat

@@ -4,6 +4,7 @@ name:tic6x_c64x_linux
 feature:1
 xmltarget:tic6x-c64x-linux.xml
 expedite:A15,PC
+osabi:GNU/Linux
 32:A0
 32:A1
 32:A2

gdb/regformats/tic6x-c64xp-linux.dat

@@ -4,6 +4,7 @@ name:tic6x_c64xp_linux
 feature:1
 xmltarget:tic6x-c64xp-linux.xml
 expedite:A15,PC
+osabi:GNU/Linux
 32:A0
 32:A1
 32:A2

gdbserver/Makefile.in

@@ -488,6 +488,7 @@ stamp-xml: $(XML_DIR)/feature_to_c.sh Makefile $(XML_FILES)
 MAKEOVERRIDES =
 
 regdat_sh = $(srcdir)/../gdb/regformats/regdat.sh
+osabi_def = $(srcdir)/../gdbsupport/osabi.def
 
 UST_CFLAGS = \
 	$(ustinc) \
@@ -588,11 +589,11 @@ target/%.o: ../gdb/target/%.c
 # Rules for register format descriptions.  Suffix destination files with
 # -generated to identify and clean them easily.
 
-%-generated.cc: ../gdb/regformats/%.dat $(regdat_sh)
-	$(ECHO_REGDAT) $(SHELL) $(regdat_sh) $< $@
+%-generated.cc: ../gdb/regformats/%.dat $(osabi_def) $(regdat_sh)
+	$(ECHO_REGDAT) $(SHELL) $(regdat_sh) $< $(osabi_def) $@
 
-%-generated.cc: ../gdb/regformats/rs6000/%.dat $(regdat_sh)
-	$(ECHO_REGDAT) $(SHELL) $(regdat_sh) $< $@
+%-generated.cc: ../gdb/regformats/rs6000/%.dat $(osabi_def) $(regdat_sh)
+	$(ECHO_REGDAT) $(SHELL) $(regdat_sh) $< $(osabi_def) $@
 
 # Rule for gdbreplay.o.  This is the same as COMPILE, but includes common-defs.h
 # instead of server.h.

gdbserver/linux-aarch32-tdesc.cc

@@ -34,7 +34,7 @@ aarch32_linux_read_description ()
       tdesc_aarch32 = aarch32_create_target_description (false);
 
       static const char *expedite_regs[] = { "r11", "sp", "pc", 0 };
-      init_target_desc (tdesc_aarch32, expedite_regs);
+      init_target_desc (tdesc_aarch32, expedite_regs, GDB_OSABI_LINUX);
     }
   return tdesc_aarch32;
 }

gdbserver/linux-aarch64-tdesc.cc

@@ -67,7 +67,8 @@ aarch64_linux_read_description (const aarch64_features &features)
 
       expedited_registers.push_back (nullptr);
 
-      init_target_desc (tdesc, (const char **) expedited_registers.data ());
+      init_target_desc (tdesc, (const char **) expedited_registers.data (),
+			GDB_OSABI_LINUX);
 
       tdesc_aarch64_map[features] = tdesc;
     }

gdbserver/linux-arc-low.cc

@@ -114,7 +114,7 @@ arc_linux_read_description (void)
   target_desc_up tdesc = arc_create_target_description (features);
 
   static const char *expedite_regs[] = { "sp", "status32", nullptr };
-  init_target_desc (tdesc.get (), expedite_regs);
+  init_target_desc (tdesc.get (), expedite_regs, GDB_OSABI_LINUX);
 
   return tdesc.release ();
 }

gdbserver/linux-arm-tdesc.cc

@@ -37,7 +37,7 @@ arm_linux_read_description (arm_fp_type fp_type)
       tdesc = arm_create_target_description (fp_type, false);
 
       static const char *expedite_regs[] = { "r11", "sp", "pc", 0 };
-      init_target_desc (tdesc, expedite_regs);
+      init_target_desc (tdesc, expedite_regs, GDB_OSABI_LINUX);
 
       tdesc_arm_list[fp_type] = tdesc;
     }

gdbserver/linux-csky-low.cc

@@ -133,7 +133,7 @@ csky_target::low_arch_setup ()
 
   if (tdesc->expedite_regs.empty ())
     {
-      init_target_desc (tdesc.get (), expedite_regs);
+      init_target_desc (tdesc.get (), expedite_regs, GDB_OSABI_LINUX);
       gdb_assert (!tdesc->expedite_regs.empty ());
     }
 

gdbserver/linux-loongarch-low.cc

@@ -85,7 +85,7 @@ loongarch_target::low_arch_setup ()
 
   if (tdesc->expedite_regs.empty ())
     {
-      init_target_desc (tdesc.get (), expedite_regs);
+      init_target_desc (tdesc.get (), expedite_regs, GDB_OSABI_LINUX);
       gdb_assert (!tdesc->expedite_regs.empty ());
     }
   current_process ()->tdesc = tdesc.release ();

gdbserver/linux-riscv-low.cc

@@ -91,7 +91,7 @@ riscv_target::low_arch_setup ()
 
   if (tdesc->expedite_regs.empty ())
     {
-      init_target_desc (tdesc.get (), expedite_regs);
+      init_target_desc (tdesc.get (), expedite_regs, GDB_OSABI_LINUX);
       gdb_assert (!tdesc->expedite_regs.empty ());
     }
 

gdbserver/linux-x86-tdesc.cc

@@ -26,10 +26,21 @@
 void
 x86_linux_post_init_tdesc (target_desc *tdesc, bool is_64bit)
 {
+  enum gdb_osabi osabi = GDB_OSABI_LINUX;
+
+#ifndef IN_PROCESS_AGENT
+  /* x86 target descriptions are created with the osabi already set.
+     However, init_target_desc requires us to override the already set
+     value.  That's fine, out new string should match the old one.  */
+  gdb_assert (tdesc_osabi_name (tdesc) != nullptr);
+  gdb_assert (strcmp (tdesc_osabi_name (tdesc),
+		      gdbarch_osabi_name (osabi)) == 0);
+#endif /* ! IN_PROCESS_AGENT */
+
 #ifdef __x86_64__
   if (is_64bit)
-    init_target_desc (tdesc, amd64_expedite_regs);
+    init_target_desc (tdesc, amd64_expedite_regs, osabi);
   else
 #endif
-    init_target_desc (tdesc, i386_expedite_regs);
+    init_target_desc (tdesc, i386_expedite_regs, osabi);
 }

gdbserver/netbsd-aarch64-low.cc

@@ -98,7 +98,7 @@ netbsd_aarch64_target::low_arch_setup ()
     = aarch64_create_target_description ({});
 
   static const char *expedite_regs_aarch64[] = { "x29", "sp", "pc", NULL };
-  init_target_desc (tdesc, expedite_regs_aarch64);
+  init_target_desc (tdesc, expedite_regs_aarch64, GDB_OSABI_NETBSD);
 
   current_process ()->tdesc = tdesc;
 }

gdbserver/netbsd-amd64-low.cc

@@ -193,7 +193,7 @@ netbsd_amd64_target::low_arch_setup ()
   target_desc *tdesc
     = amd64_create_target_description (X86_XSTATE_SSE_MASK, false, false, false);
 
-  init_target_desc (tdesc, amd64_expedite_regs);
+  init_target_desc (tdesc, amd64_expedite_regs, GDB_OSABI_NETBSD);
 
   current_process ()->tdesc = tdesc;
 }

gdbserver/netbsd-i386-low.cc

@@ -142,7 +142,7 @@ netbsd_i386_target::low_arch_setup ()
   target_desc *tdesc
     = i386_create_target_description (X86_XSTATE_SSE_MASK, false, false);
 
-  init_target_desc (tdesc, i386_expedite_regs);
+  init_target_desc (tdesc, i386_expedite_regs, GDB_OSABI_NETBSD);
 
   current_process ()->tdesc = tdesc;
 }

gdbserver/tdesc.cc

@@ -53,7 +53,8 @@ void target_desc::accept (tdesc_element_visitor &v) const
 
 void
 init_target_desc (struct target_desc *tdesc,
-		  const char **expedite_regs)
+		  const char **expedite_regs,
+		  enum gdb_osabi osabi)
 {
   int offset = 0;
 
@@ -88,6 +89,8 @@ init_target_desc (struct target_desc *tdesc,
   int expedite_count = 0;
   while (expedite_regs[expedite_count] != nullptr)
     tdesc->expedite_regs.push_back (expedite_regs[expedite_count++]);
+
+  set_tdesc_osabi (tdesc, osabi);
 #endif
 }