gdb/testsuite: add tests for unwinding of pseudo registers

This patch adds tests to exercise the previous patches' changes.

All three tests:

 - aarch64-pseudo-unwind
 - amd64-pseudo-unwind
 - arm-pseudo-unwind

follow the same pattern, just with different registers.

The other test, arm-pseudo-unwind-legacy, tests the special case where
the unwind information contains an entry for a register considered a
pseudo-register by GDB.

Change-Id: Ic29ac040c5eb087b4a0d79f9d02f65b7979df30f
Reviewed-By: John Baldwin <jhb@FreeBSD.org>
Reviewed-by: Luis Machado <luis.machado@arm.com>
Approved-By: Luis Machado <luis.machado@arm.com> (aarch64/arm)
Tested-By: Luis Machado <luis.machado@arm.com> (aarch64/arm)

12 files changed, 796 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind-asm.S b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind-asm.S
new file mode 100644
index 0000000..575ed75
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind-asm.S
@@ -0,0 +1,82 @@
+/* Copyright 2018-2023 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/>.  */
+
+.section .note.GNU-stack,"",%progbits
+
+.data
+value_callee:
+.quad 0x2021222324252627
+value_caller:
+.quad 0x1011121314151617
+
+.text
+.global callee
+callee:
+	/* Standard prologue:
+	    - push fp (x29) and lr (x30) to the stack.
+	    - mov sp to fp  */
+.cfi_startproc
+	stp x29, x30, [sp, -16]!
+.cfi_def_cfa 29, 16
+.cfi_offset 29, -16
+.cfi_offset 30, -8
+	mov x29, sp
+
+	/* Save caller's x19 value on the stack.  */
+.cfi_offset 19, -32
+	str x19, [sp, -16]!
+
+	/* Put our own x19 value.  */
+	adr x0, value_callee
+	ldr x19, [x0]
+
+break_here_asm:
+
+	/* Restore caller's x19 value.  */
+	ldr x19, [sp], 16
+
+	/* Standard epilogue:
+	    - pop fp (x29) and lr (x30) from the stack  */
+	ldp x29, x30, [sp], 16
+	ret
+.cfi_endproc
+
+
+.global caller
+caller:
+	/* Standard prologue.  */
+.cfi_startproc
+	stp x29, x30, [sp, -16]!
+.cfi_def_cfa 29, 16
+.cfi_offset x29, -16
+.cfi_offset x30, -8
+	add x29, sp, 0
+
+	/* Put our own x19 value.  */
+	adr x0, value_caller
+	ldr x19, [x0]
+
+	/* Call callee.  */
+	bl callee
+
+	/* Store our x19 value in x0 to return it.  */
+	mov x0, x19
+
+	/* Standard epilogue.  */
+	ldp x29, x30, [sp], 16
+	ret
+.cfi_endproc
diff --git a/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.c b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.c
new file mode 100644
index 0000000..d18876f
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.c
@@ -0,0 +1,33 @@
+/* Copyright 2018-2023 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/>.  */
+
+#include <stdint.h>
+
+uint64_t caller (void);
+
+static void
+break_here_c (uint64_t value)
+{
+}
+
+int
+main (void)
+{
+  uint64_t value = caller ();
+  break_here_c (value);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.exp b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.exp
new file mode 100644
index 0000000..62b3f8c
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.exp
@@ -0,0 +1,88 @@
+# Copyright 2018-2023 Free Software Foundation, Inc.
+
+# 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/>.
+
+# This test is equivalent to amd64-pseudo-unwind, but specific to AArch64.  We
+# use the raw register x19 which is 64 bits long and pseudo register w19, which
+# is the bottom half of x19.
+
+if { ![istarget aarch64-*-* ] } {
+    verbose "Skipping aarch64 pseudo register unwind."
+    return
+}
+
+standard_testfile aarch64-pseudo-unwind.c aarch64-pseudo-unwind-asm.S
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	"${srcfile} ${srcfile2}" {debug}] } {
+    return -1
+}
+
+clean_restart ${binfile}
+
+if ![runto_main] then {
+    fail "could not run to main"
+}
+
+gdb_breakpoint break_here_asm temporary
+gdb_continue_to_breakpoint "continue to callee"
+
+# Verify the value of x19/w19 in the inner frame (callee).
+with_test_prefix "callee, before change" {
+    gdb_test "p/x \$x19" " = 0x2021222324252627"
+    gdb_test "p/x \$w19" " = 0x24252627"
+}
+
+# Verify that we can change the value of the pseudo register (w19) in the inner
+# frame (callee).
+gdb_test_no_output "set \$w19 = 0x34353637"
+
+# Verify the value of x19/w19 in the inner frame (callee) after the change.
+with_test_prefix "callee, after change" {
+    gdb_test "p/x \$x19" " = 0x34353637"
+    gdb_test "p/x \$w19" " = 0x34353637"
+}
+
+# Go up one frame (to caller) and do the same.
+gdb_test "up"
+
+# Verify the value of x19/w19 in the outer frame (caller).
+with_test_prefix "caller, before change" {
+    gdb_test "p/x \$x19" " = 0x1011121314151617"
+    gdb_test "p/x \$w19" " = 0x14151617"
+}
+
+# Verify that we can change the value of the pseudo register (w19) in the outer
+# frame (caller).
+gdb_test_no_output "set \$w19 = 0x44454647"
+
+# Verify the value of x19/w19 in the outer frame (caller) after the change.
+with_test_prefix "caller, after change" {
+    gdb_test "p/x \$x19" " = 0x44454647"
+    gdb_test "p/x \$w19" " = 0x44454647"
+}
+
+# Go back to frame 0 (callee), check that the change to the outer frame didn't
+# mess up anything there.
+gdb_test "down"
+with_test_prefix "callee, after change in caller" {
+    gdb_test "p/x \$x19" " = 0x34353637"
+    gdb_test "p/x \$w19" " = 0x34353637"
+}
+
+# Verify that the value of the saved x19 we changed is correctly seen by the
+# inferior.
+gdb_breakpoint break_here_c temporary
+gdb_continue_to_breakpoint "continue to break_here_c"
+gdb_test "p/x value" " = 0x44454647"
diff --git a/gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S
new file mode 100644
index 0000000..c306b82
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S
@@ -0,0 +1,66 @@
+/* Copyright 2018-2023 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/>.  */
+
+.section .note.GNU-stack,"",%progbits
+
+.text
+.global callee
+callee:
+	/* Standard prologue.  */
+.cfi_startproc
+	push %rbp
+.cfi_def_cfa rbp, 16
+	mov %rsp, %rbp
+
+	/* Save caller's rbx value on the stack.  */
+.cfi_offset rbx, -24
+	push %rbx
+
+	/* Put our own rbx value.  */
+	mov $0x2021222324252627, %rbx
+break_here_asm:
+
+	/* Restore caller's rbx value.  */
+	pop %rbx
+
+	/* Standard epilogue.  */
+	pop %rbp
+	ret
+.cfi_endproc
+
+
+.global caller
+caller:
+.cfi_startproc
+	/* Standard prologue.  */
+	push %rbp
+.cfi_def_cfa_offset 16
+	mov %rsp, %rbp
+
+	/* Put our own rbx value.  */
+	mov $0x1011121314151617, %rbx
+
+	/* Call callee.  */
+	call callee
+
+	/* Store our rbx value in rax to return it.  */
+	mov %rbx, %rax
+
+	/* Standard epilogue.  */
+	pop %rbp
+	ret
+.cfi_endproc
diff --git a/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.c b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.c
new file mode 100644
index 0000000..d18876f
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.c
@@ -0,0 +1,33 @@
+/* Copyright 2018-2023 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/>.  */
+
+#include <stdint.h>
+
+uint64_t caller (void);
+
+static void
+break_here_c (uint64_t value)
+{
+}
+
+int
+main (void)
+{
+  uint64_t value = caller ();
+  break_here_c (value);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.exp b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.exp
new file mode 100644
index 0000000..45e9a3c
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-pseudo-unwind.exp
@@ -0,0 +1,91 @@
+# Copyright 2018-2023 Free Software Foundation, Inc.
+
+# 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/>.
+
+# This test verifies that we can read and write the value of a pseudo register
+# in unwound frames.  For the test, we choose one raw register, rbx, and one
+# pseudo register that is backed by rbx, ebx.  We have two frames (the inner one,
+# #0 and the outer one, #1) that each set a value for rbx.  We verify that we
+# can read both rbx and ebx correctly for each frame, and that when we write to
+# ebx, rbx for that frame is correctly updated.
+
+if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
+    verbose "Skipping amd64 pseudo register unwind."
+    return
+}
+
+standard_testfile amd64-pseudo-unwind.c amd64-pseudo-unwind-asm.S
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	"${srcfile} ${srcfile2}" {debug}] } {
+    return -1
+}
+
+clean_restart ${binfile}
+
+if ![runto_main] then {
+    fail "could not run to main"
+}
+
+gdb_breakpoint break_here_asm temporary
+gdb_continue_to_breakpoint "continue to callee"
+
+# Verify the value of rbx/ebx in the inner frame (callee).
+with_test_prefix "callee, before change" {
+    gdb_test "p/x \$rbx" " = 0x2021222324252627"
+    gdb_test "p/x \$ebx" " = 0x24252627"
+}
+
+# Verify that we can change the value of the pseudo register (ebx) in the inner
+# frame (callee).
+gdb_test_no_output "set \$ebx = 0x34353637"
+
+# Verify the value of rbx/ebx in the inner frame (callee) after the change.
+with_test_prefix "callee, after change" {
+    gdb_test "p/x \$rbx" " = 0x2021222334353637"
+    gdb_test "p/x \$ebx" " = 0x34353637"
+}
+
+# Go up one frame, and do the same.
+gdb_test "up"
+
+# Verify the value of rbx/ebx in the outer frame (caller).
+with_test_prefix "caller, before change" {
+    gdb_test "p/x \$rbx" " = 0x1011121314151617"
+    gdb_test "p/x \$ebx" " = 0x14151617"
+}
+
+# Verify that we can change the value of the pseudo register (ebx) in the outer
+# frame (caller).
+gdb_test_no_output "set \$ebx = 0x44454647"
+
+# Verify the value of rbx/ebx in the outer frame (caller) after the change.
+with_test_prefix "caller, after change" {
+    gdb_test "p/x \$rbx" " = 0x1011121344454647"
+    gdb_test "p/x \$ebx" " = 0x44454647"
+}
+
+# Go back to frame 0 (callee), check that the change to the outer frame didn't
+# mess up anything there.
+gdb_test "down"
+with_test_prefix "callee, after change in caller" {
+    gdb_test "p/x \$rbx" " = 0x2021222334353637"
+    gdb_test "p/x \$ebx" " = 0x34353637"
+}
+
+# Verify that the value of the saved rbx we changed is correctly seen by the
+# inferior.
+gdb_breakpoint break_here_c temporary
+gdb_continue_to_breakpoint "continue to break_here_c"
+gdb_test "p/x value" " = 0x1011121344454647"
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind-asm.S b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-asm.S
new file mode 100644
index 0000000..0e5ad1b
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-asm.S
@@ -0,0 +1,79 @@
+/* Copyright 2018-2023 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/>.  */
+
+.section .note.GNU-stack,"",%progbits
+
+.data
+value_callee:
+.quad 0x2021222324252627
+value_caller:
+.quad 0x1011121314151617
+
+.text
+.arm
+.global callee
+callee:
+	/* Standard prologue.  */
+.cfi_startproc
+	push {fp, lr}
+.cfi_def_cfa fp, 4
+.cfi_offset fp, -8
+.cfi_offset lr, -4
+	add fp, sp, #4
+
+	/* Save caller's d8 value on the stack.  */
+.cfi_offset d8, -16
+	vpush {d8}
+
+	/* Put our own d8 value.  */
+	ldr r0, =value_callee
+	vldr d8, [r0]
+break_here_asm:
+
+	/* Restore caller's d8 value.  */
+	vpop {d8}
+
+	/* Standard epilogue.  */
+	pop {fp, pc}
+.cfi_endproc
+
+
+.global caller
+caller:
+	/* Standard prologue.  */
+.cfi_startproc
+	push {fp, lr}
+.cfi_def_cfa fp, 4
+.cfi_offset fp, -8
+.cfi_offset lr, -4
+	add fp, sp, #4
+
+	/* Put our own d8 value.  */
+	ldr r0, =value_caller
+	vldr d8, [r0]
+
+	/* Call callee.  */
+	bl callee
+
+	/* Store our d8 value in r0-r1 to return it.  */
+	vpush {d8}
+	pop {r0}
+	pop {r1}
+
+	/* Standard epilogue.  */
+	pop {fp, pc}
+.cfi_endproc
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy-asm.S b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy-asm.S
new file mode 100644
index 0000000..786e79a
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy-asm.S
@@ -0,0 +1,84 @@
+/* Copyright 2018-2023 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/>.  */
+
+/* The difference between this and arm-pseudo-unwind is that here, the CFI
+   directives use the obsolete DWARF number for the s16 register (a
+   pseudo-register in GDB), whereas arm-pseudo-unwind uses the number for the d8
+   register (the underlying raw register for s16).  */
+
+.section .note.GNU-stack,"",%progbits
+
+.data
+value_callee:
+.quad 0x20212223
+value_caller:
+.quad 0x10111213
+
+.text
+.arm
+.global callee
+callee:
+.cfi_startproc
+	/* Standard prologue.  */
+	push {fp, lr}
+.cfi_def_cfa fp, 4
+.cfi_offset fp, -8
+.cfi_offset lr, -4
+	add fp, sp, #4
+
+	/* Save caller's s16 value on the stack.  */
+.cfi_offset 80, -12
+	vpush {s16}
+
+	/* Put our own s16 value.  */
+	ldr r0, =value_callee
+	vldr s16, [r0]
+break_here_asm:
+
+	/* Restore caller's s16 value.  */
+	vpop {s16}
+
+	/* Standard epilogue.  */
+	pop {fp, pc}
+.cfi_endproc
+
+
+.global caller
+caller:
+.cfi_startproc
+	/* Standard prologue.  */
+	push {fp, lr}
+.cfi_def_cfa fp, 4
+.cfi_offset fp, -8
+.cfi_offset lr, -4
+	add fp, sp, #4
+
+	/* Put our own s16 value.  */
+	ldr r0, =value_caller
+	vldr s16, [r0]
+
+	/* Call callee.  */
+	bl callee
+
+	/* Store our s16 value in r0-r1 to return it.  */
+	vpush {s16}
+	pop {r0}
+	mov r1, #0
+
+	/* Standard epilogue.  */
+	pop {fp, pc}
+.cfi_endproc
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.c b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.c
new file mode 100644
index 0000000..d18876f
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.c
@@ -0,0 +1,33 @@
+/* Copyright 2018-2023 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/>.  */
+
+#include <stdint.h>
+
+uint64_t caller (void);
+
+static void
+break_here_c (uint64_t value)
+{
+}
+
+int
+main (void)
+{
+  uint64_t value = caller ();
+  break_here_c (value);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.exp b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.exp
new file mode 100644
index 0000000..c3d0979
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.exp
@@ -0,0 +1,86 @@
+# Copyright 2018-2023 Free Software Foundation, Inc.
+
+# 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/>.
+
+# This test is in the same vein as amd64-pseudo-unwind, making sure we can
+# read write pseudo registers in outer frames.  However, it tests a special
+# case where the debug info includes unwind information for a pseudo register
+# but not the underlying raw register.  This can happen for the pseudo register
+# s16, which is the bottom half of the raw register d8.
+#
+# See "DWARF for the ARM architecture":
+#   https://github.com/ARM-software/abi-aa/releases/download/2023Q3/aadwarf32.pdf
+
+if { ![istarget arm*-*-* ] } {
+    verbose "Skipping arm pseudo register unwind."
+    return
+}
+
+standard_testfile arm-pseudo-unwind-legacy.c arm-pseudo-unwind-legacy-asm.S
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	"${srcfile} ${srcfile2}" {debug additional_flags=-marm}] } {
+    return -1
+}
+
+clean_restart ${binfile}
+
+if ![runto_main] then {
+    fail "could not run to main"
+}
+
+gdb_breakpoint break_here_asm temporary
+gdb_continue_to_breakpoint "continue to callee"
+
+# Verify the value of s16 in the inner frame (callee).
+with_test_prefix "callee, before change" {
+    gdb_test "p/x \$s16" " = 0x20212223"
+}
+
+# Verify that we can change the value of s16 in the inner frame (callee).
+gdb_test_no_output "set \$s16 = 1.0"
+
+# Verify the value of s16 in the inner frame (callee) after the change.
+with_test_prefix "callee, after change" {
+    gdb_test "p/x \$s16" " = 0x3f800000"
+}
+
+# Go up one frame, and do the same.
+gdb_test "up"
+
+# Verify the value of s16 in the outer frame (caller).
+with_test_prefix "caller, before change" {
+    gdb_test "p/x \$s16" " = 0x10111213"
+}
+
+# Verify that we can change the value of s16 in the outer frame (caller).
+gdb_test_no_output "set \$s16 = 2.0"
+
+# Verify the value of s16 in the outer frame (caller) after the change.
+with_test_prefix "caller, after change" {
+    gdb_test "p/x \$s16" " = 0x40000000"
+}
+
+# Go back to frame 0 (callee), check that the change to the outer frame didn't
+# mess up anything there.
+gdb_test "down"
+with_test_prefix "callee, after change in caller" {
+    gdb_test "p/x \$s16" " = 0x3f800000"
+}
+
+# Verify that the value of the saved s16 we changed is correctly seen by the
+# inferior.
+gdb_breakpoint break_here_c temporary
+gdb_continue_to_breakpoint "continue to break_here_c"
+gdb_test "p/x value" " = 0x40000000"
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind.c b/gdb/testsuite/gdb.arch/arm-pseudo-unwind.c
new file mode 100644
index 0000000..d18876f
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind.c
@@ -0,0 +1,33 @@
+/* Copyright 2018-2023 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/>.  */
+
+#include <stdint.h>
+
+uint64_t caller (void);
+
+static void
+break_here_c (uint64_t value)
+{
+}
+
+int
+main (void)
+{
+  uint64_t value = caller ();
+  break_here_c (value);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.arch/arm-pseudo-unwind.exp b/gdb/testsuite/gdb.arch/arm-pseudo-unwind.exp
new file mode 100644
index 0000000..bfe81b7
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/arm-pseudo-unwind.exp
@@ -0,0 +1,88 @@
+# Copyright 2018-2023 Free Software Foundation, Inc.
+
+# 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/>.
+
+# This test is equivalent to amd64-pseudo-unwind, but specific to ARM.  We
+# use the raw register d8 which is 64 bits long.  We use pseudo register s16,
+# which is the low 32 bits of d8.
+
+if { ![istarget arm*-*-* ] } {
+    verbose "Skipping arm pseudo register unwind."
+    return
+}
+
+standard_testfile arm-pseudo-unwind.c arm-pseudo-unwind-asm.S
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	"${srcfile} ${srcfile2}" {debug additional_flags=-marm}] } {
+    return -1
+}
+
+clean_restart ${binfile}
+
+if ![runto_main] then {
+    fail "could not run to main"
+}
+
+gdb_breakpoint break_here_asm temporary
+gdb_continue_to_breakpoint "continue to callee"
+
+# Verify the value of d8/s16 in the inner frame (callee).
+with_test_prefix "callee, before change" {
+    gdb_test "p/x \$d8" " = 0x2021222324252627"
+    gdb_test "p/x \$s16" " = 0x24252627"
+}
+
+# Verify that we can change the value of the pseudo register (s16) in the inner
+# frame (callee).
+gdb_test_no_output "set \$s16 = 1.0"
+
+# Verify the value of d8/s16 in the inner frame (callee) after the change.
+with_test_prefix "callee, after change" {
+    gdb_test "p/x \$d8" " = 0x202122233f800000"
+    gdb_test "p/x \$s16" " = 0x3f800000"
+}
+
+# Go up one frame (to caller), and do the same.
+gdb_test "up"
+
+# Verify the value of d8/s16 in the outer frame (caller).
+with_test_prefix "caller, before change" {
+    gdb_test "p/x \$d8" " = 0x1011121314151617"
+    gdb_test "p/x \$s16" " = 0x14151617"
+}
+
+# Verify that we can change the value of the pseudo register (s16) in the outer
+# frame (caller).
+gdb_test_no_output "set \$s16 = 2.0"
+
+# Verify the value of d8/s16 in the outer frame (caller) after the change.
+with_test_prefix "caller, after change" {
+    gdb_test "p/x \$d8" " = 0x1011121340000000"
+    gdb_test "p/x \$s16" " = 0x40000000"
+}
+
+# Go back to frame 0 (callee), check that the change to the outer frame didn't
+# mess up anything there.
+gdb_test "down"
+with_test_prefix "callee, after change in caller" {
+    gdb_test "p/x \$d8" " = 0x202122233f800000"
+    gdb_test "p/x \$s16" " = 0x3f800000"
+}
+
+# Verify that the value of the saved d8 we changed is correctly seen by the
+# inferior.
+gdb_breakpoint break_here_c temporary
+gdb_continue_to_breakpoint "continue to break_here_c"
+gdb_test "p/x value" " = 0x1011121340000000"