testing, gdbstub and plugin updates

- update MAINTAINERS with pointers to foo/next
   - add NOFETCH to help test custom docker builds
   - update microblaze toolchain with atomic fixes
   - update tsan build and documentation
   - don't restrict build-environment by arch unless needed
   - add cross-modifying code test
   - add tracepoints for cpu_step_atomic fallbacks
   - fix defaults for loongarch cross build
   - make check-[dco|patch] a little more verbose
   - fix gdbstub bug preventing aarch64_be-linux-user starting
   - add basic test for aarch64_be
   - clean up some gdbstub test scripts
   - fix qemu_plugin_reset
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCgAdFiEEZoWumedRZ7yvyN81+9DbCVqeKkQFAmcaDeQACgkQ+9DbCVqe
 KkRTlQgAlFaP1Nxa8y6pRZSL0WY9J3Znf5e2GDnVN3nJbfx1wZg7oZ4/dWieDF/Y
 /9jLfMi8nDJ51tzH24PSASbHQ1xnblhuUfhRMwqAFhSwsZUb0VzdeGdq+FIyXQ5w
 Cy2Ubz7g81qP/x9JRCCUGFfXaM1LSizsY1lNioRsDd533WJLkvxWucmpSN3XhxHJ
 rEa3xI/qAcUah4G3yww47L+DmlKnJQcsihShRBC6Am2tWqxbz+1kBUaVfaVVo1if
 IPN+bBk4eI1EHdRRyWJSsq3nELzqW4FJ3+9V0ifsOFW2KGsnkhbl0qUxqDmW5aBb
 P9flEdpTfSiCbqp+IKG9vxJKuf/BGw==
 =5Wui
 -----END PGP SIGNATURE-----

Merge tag 'pull-maintainer-oct-misc-241024-1' of https://gitlab.com/stsquad/qemu into staging

testing, gdbstub and plugin updates

  - update MAINTAINERS with pointers to foo/next
  - add NOFETCH to help test custom docker builds
  - update microblaze toolchain with atomic fixes
  - update tsan build and documentation
  - don't restrict build-environment by arch unless needed
  - add cross-modifying code test
  - add tracepoints for cpu_step_atomic fallbacks
  - fix defaults for loongarch cross build
  - make check-[dco|patch] a little more verbose
  - fix gdbstub bug preventing aarch64_be-linux-user starting
  - add basic test for aarch64_be
  - clean up some gdbstub test scripts
  - fix qemu_plugin_reset

# -----BEGIN PGP SIGNATURE-----
#
# iQEzBAABCgAdFiEEZoWumedRZ7yvyN81+9DbCVqeKkQFAmcaDeQACgkQ+9DbCVqe
# KkRTlQgAlFaP1Nxa8y6pRZSL0WY9J3Znf5e2GDnVN3nJbfx1wZg7oZ4/dWieDF/Y
# /9jLfMi8nDJ51tzH24PSASbHQ1xnblhuUfhRMwqAFhSwsZUb0VzdeGdq+FIyXQ5w
# Cy2Ubz7g81qP/x9JRCCUGFfXaM1LSizsY1lNioRsDd533WJLkvxWucmpSN3XhxHJ
# rEa3xI/qAcUah4G3yww47L+DmlKnJQcsihShRBC6Am2tWqxbz+1kBUaVfaVVo1if
# IPN+bBk4eI1EHdRRyWJSsq3nELzqW4FJ3+9V0ifsOFW2KGsnkhbl0qUxqDmW5aBb
# P9flEdpTfSiCbqp+IKG9vxJKuf/BGw==
# =5Wui
# -----END PGP SIGNATURE-----
# gpg: Signature made Thu 24 Oct 2024 10:05:40 BST
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* tag 'pull-maintainer-oct-misc-241024-1' of https://gitlab.com/stsquad/qemu:
  plugins: fix qemu_plugin_reset
  MAINTAINERS: mention my plugins/next tree
  testing: Enhance gdb probe script
  tests/tcg/aarch64: Use raw strings for regexes in test-mte.py
  tests/tcg: enable basic testing for aarch64_be-linux-user
  config/targets: update aarch64_be-linux-user gdb XML list
  MAINTAINERS: mention my gdbstub/next tree
  gitlab: make check-[dco|patch] a little more verbose
  dockerfiles: fix default targets for debian-loongarch-cross
  accel/tcg: add tracepoints for cpu_loop_exit_atomic
  tests/tcg/x86_64: Add cross-modifying code test
  scripts/ci: remove architecture checks for build-environment updates
  docs/devel: update tsan build documentation
  meson: hide tsan related warnings
  MAINTAINERS: mention my testing/next tree
  tests/docker: add NOFETCH env variable for testing
  tests/docker: Fix microblaze atomics

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

.gitlab-ci.d/check-dco.py

@@ -19,10 +19,9 @@ cwd = os.getcwd()
 reponame = os.path.basename(cwd)
 repourl = "https://gitlab.com/%s/%s.git" % (namespace, reponame)
 
+print(f"adding upstream git repo @ {repourl}")
 subprocess.check_call(["git", "remote", "add", "check-dco", repourl])
-subprocess.check_call(["git", "fetch", "check-dco", "master"],
+subprocess.check_call(["git", "fetch", "check-dco", "master"])
-                      stdout=subprocess.DEVNULL,
-                      stderr=subprocess.DEVNULL)
 
 ancestor = subprocess.check_output(["git", "merge-base",
                                     "check-dco/master", "HEAD"],

.gitlab-ci.d/check-patch.py

@@ -19,13 +19,12 @@ cwd = os.getcwd()
 reponame = os.path.basename(cwd)
 repourl = "https://gitlab.com/%s/%s.git" % (namespace, reponame)
 
+print(f"adding upstream git repo @ {repourl}")
 # GitLab CI environment does not give us any direct info about the
 # base for the user's branch. We thus need to figure out a common
 # ancestor between the user's branch and current git master.
 subprocess.check_call(["git", "remote", "add", "check-patch", repourl])
-subprocess.check_call(["git", "fetch", "check-patch", "master"],
+subprocess.check_call(["git", "fetch", "check-patch", "master"])
-                      stdout=subprocess.DEVNULL,
-                      stderr=subprocess.DEVNULL)
 
 ancestor = subprocess.check_output(["git", "merge-base",
                                     "check-patch/master", "HEAD"],

MAINTAINERS

@@ -2985,6 +2985,7 @@ F: gdb-xml/
 F: tests/tcg/multiarch/gdbstub/*
 F: scripts/feature_to_c.py
 F: scripts/probe-gdb-support.py
+T: git https://gitlab.com/stsquad/qemu gdbstub/next
 
 Memory API
 M: Paolo Bonzini <pbonzini@redhat.com>
@@ -3708,6 +3709,7 @@ F: include/tcg/
 
 TCG Plugins
 M: Alex Bennée <alex.bennee@linaro.org>
+T: git https://gitlab.com/stsquad/qemu plugins/next
 R: Alexandre Iooss <erdnaxe@crans.org>
 R: Mahmoud Mandour <ma.mandourr@gmail.com>
 R: Pierrick Bouvier <pierrick.bouvier@linaro.org>
@@ -4081,6 +4083,7 @@ Build and test automation
 -------------------------
 Build and test automation, general continuous integration
 M: Alex Bennée <alex.bennee@linaro.org>
+T: git https://gitlab.com/stsquad/qemu testing/next
 M: Philippe Mathieu-Daudé <philmd@linaro.org>
 M: Thomas Huth <thuth@redhat.com>
 R: Wainer dos Santos Moschetta <wainersm@redhat.com>

accel/tcg/ldst_atomicity.c.inc

@@ -168,6 +168,7 @@ static uint64_t load_atomic8_or_exit(CPUState *cpu, uintptr_t ra, void *pv)
 #endif
 
     /* Ultimate fallback: re-execute in serial context. */
+    trace_load_atom8_or_exit_fallback(ra);
     cpu_loop_exit_atomic(cpu, ra);
 }
 
@@ -212,6 +213,7 @@ static Int128 load_atomic16_or_exit(CPUState *cpu, uintptr_t ra, void *pv)
     }
 
     /* Ultimate fallback: re-execute in serial context. */
+    trace_load_atom16_or_exit_fallback(ra);
     cpu_loop_exit_atomic(cpu, ra);
 }
 
@@ -519,6 +521,7 @@ static uint64_t load_atom_8(CPUState *cpu, uintptr_t ra,
         if (HAVE_al8) {
             return load_atom_extract_al8x2(pv);
         }
+        trace_load_atom8_fallback(memop, ra);
         cpu_loop_exit_atomic(cpu, ra);
     default:
         g_assert_not_reached();
@@ -563,6 +566,7 @@ static Int128 load_atom_16(CPUState *cpu, uintptr_t ra,
         break;
     case MO_64:
         if (!HAVE_al8) {
+            trace_load_atom16_fallback(memop, ra);
             cpu_loop_exit_atomic(cpu, ra);
         }
         a = load_atomic8(pv);
@@ -570,6 +574,7 @@ static Int128 load_atom_16(CPUState *cpu, uintptr_t ra,
         break;
     case -MO_64:
         if (!HAVE_al8) {
+            trace_load_atom16_fallback(memop, ra);
             cpu_loop_exit_atomic(cpu, ra);
         }
         a = load_atom_extract_al8x2(pv);
@@ -897,6 +902,7 @@ static void store_atom_2(CPUState *cpu, uintptr_t ra,
         g_assert_not_reached();
     }
 
+    trace_store_atom2_fallback(memop, ra);
     cpu_loop_exit_atomic(cpu, ra);
 }
 
@@ -961,6 +967,7 @@ static void store_atom_4(CPUState *cpu, uintptr_t ra,
                 return;
             }
         }
+        trace_store_atom4_fallback(memop, ra);
         cpu_loop_exit_atomic(cpu, ra);
     default:
         g_assert_not_reached();
@@ -1029,6 +1036,7 @@ static void store_atom_8(CPUState *cpu, uintptr_t ra,
     default:
         g_assert_not_reached();
     }
+    trace_store_atom8_fallback(memop, ra);
     cpu_loop_exit_atomic(cpu, ra);
 }
 
@@ -1107,5 +1115,6 @@ static void store_atom_16(CPUState *cpu, uintptr_t ra,
     default:
         g_assert_not_reached();
     }
+    trace_store_atom16_fallback(memop, ra);
     cpu_loop_exit_atomic(cpu, ra);
 }

accel/tcg/plugin-gen.c

@@ -467,4 +467,8 @@ void plugin_gen_tb_end(CPUState *cpu, size_t num_insns)
 
     /* inject the instrumentation at the appropriate places */
     plugin_gen_inject(ptb);
+
+    /* reset plugin translation state (plugin_tb is reused between blocks) */
+    tcg_ctx->plugin_db = NULL;
+    tcg_ctx->plugin_insn = NULL;
 }

accel/tcg/trace-events

@@ -12,3 +12,15 @@ memory_notdirty_set_dirty(uint64_t vaddr) "0x%" PRIx64
 
 # translate-all.c
 translate_block(void *tb, uintptr_t pc, const void *tb_code) "tb:%p, pc:0x%"PRIxPTR", tb_code:%p"
+
+# ldst_atomicity
+load_atom2_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+load_atom4_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+load_atom8_or_exit_fallback(uintptr_t ra) "ra:0x%"PRIxPTR""
+load_atom8_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+load_atom16_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+load_atom16_or_exit_fallback(uintptr_t ra) "ra:0x%"PRIxPTR""
+store_atom2_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+store_atom4_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+store_atom8_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""
+store_atom16_fallback(uint32_t memop, uintptr_t ra) "mop:0x%"PRIx32", ra:0x%"PRIxPTR""

accel/tcg/user-exec.c

@@ -29,7 +29,7 @@
 #include "exec/page-protection.h"
 #include "exec/helper-proto.h"
 #include "qemu/atomic128.h"
-#include "trace/trace-root.h"
+#include "trace.h"
 #include "tcg/tcg-ldst.h"
 #include "internal-common.h"
 #include "internal-target.h"

configs/targets/aarch64_be-linux-user.mak

@@ -1,7 +1,7 @@
 TARGET_ARCH=aarch64
 TARGET_BASE_ARCH=arm
 TARGET_BIG_ENDIAN=y
-TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/aarch64-pauth.xml
+TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/aarch64-pauth.xml gdb-xml/aarch64-mte.xml
 TARGET_HAS_BFLT=y
 CONFIG_SEMIHOSTING=y
 CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

configure

@@ -1418,6 +1418,7 @@ probe_target_compiler() {
   target_arch=${1%%-*}
   case $target_arch in
     aarch64) container_hosts="x86_64 aarch64" ;;
+    aarch64_be) container_hosts="x86_64 aarch64" ;;
     alpha) container_hosts=x86_64 ;;
     arm) container_hosts="x86_64 aarch64" ;;
     hexagon) container_hosts=x86_64 ;;
@@ -1447,6 +1448,10 @@ probe_target_compiler() {
     case $target_arch in
       # debian-all-test-cross architectures
 
+      aarch64_be)
+        container_image=debian-all-test-cross
+        container_cross_prefix=aarch64-linux-gnu-
+        ;;
       hppa|m68k|mips|riscv64|sparc64)
         container_image=debian-all-test-cross
         ;;

docs/devel/testing/main.rst

@@ -628,20 +628,38 @@ Building and Testing with TSan
 It is possible to build and test with TSan, with a few additional steps.
 These steps are normally done automatically in the docker.
 
-There is a one time patch needed in clang-9 or clang-10 at this time:
+TSan is supported for clang and gcc.
+One particularity of sanitizers is that all the code, including shared objects
+dependencies, should be built with it.
+In the case of TSan, any synchronization primitive from glib (GMutex for
+instance) will not be recognized, and will lead to false positives.
+
+To build a tsan version of glib:
 
 .. code::
 
-  sed -i 's/^const/static const/g' \
+   $ git clone --depth=1 --branch=2.81.0 https://github.com/GNOME/glib.git
-      /usr/lib/llvm-10/lib/clang/10.0.0/include/sanitizer/tsan_interface.h
+   $ cd glib
+   $ CFLAGS="-O2 -g -fsanitize=thread" meson build
+   $ ninja -C build
 
 To configure the build for TSan:
 
 .. code::
 
-  ../configure --enable-tsan --cc=clang-10 --cxx=clang++-10 \
+  ../configure --enable-tsan \
                --disable-werror --extra-cflags="-O0"
 
+When executing qemu, don't forget to point to tsan glib:
+
+.. code::
+
+   $ glib_dir=/path/to/glib
+   $ export LD_LIBRARY_PATH=$glib_dir/build/gio:$glib_dir/build/glib:$glib_dir/build/gmodule:$glib_dir/build/gobject:$glib_dir/build/gthread
+   # check correct version is used
+   $ ldd build/qemu-x86_64 | grep glib
+   $ qemu-system-x86_64 ...
+
 The runtime behavior of TSAN is controlled by the TSAN_OPTIONS environment
 variable.
 

meson.build

@@ -538,7 +538,15 @@ if get_option('tsan')
                          prefix: '#include <sanitizer/tsan_interface.h>')
     error('Cannot enable TSAN due to missing fiber annotation interface')
   endif
-  qemu_cflags = ['-fsanitize=thread'] + qemu_cflags
+  tsan_warn_suppress = []
+  # gcc (>=11) will report constructions not supported by tsan:
+  # "error: ‘atomic_thread_fence’ is not supported with ‘-fsanitize=thread’"
+  # https://gcc.gnu.org/gcc-11/changes.html
+  # However, clang does not support this warning and this triggers an error.
+  if cc.has_argument('-Wno-tsan')
+    tsan_warn_suppress = ['-Wno-tsan']
+  endif
+  qemu_cflags = ['-fsanitize=thread'] + tsan_warn_suppress + qemu_cflags
   qemu_ldflags = ['-fsanitize=thread'] + qemu_ldflags
 endif
 

scripts/ci/setup/ubuntu/build-environment.yml

@@ -39,7 +39,6 @@
       when:
         - ansible_facts['distribution'] == 'Ubuntu'
         - ansible_facts['distribution_version'] == '22.04'
-        - ansible_facts['architecture'] == 'aarch64' or ansible_facts['architecture'] == 'x86_64'
 
     - name: Install packages for QEMU on Ubuntu 22.04
       package:
@@ -47,7 +46,6 @@
       when:
         - ansible_facts['distribution'] == 'Ubuntu'
         - ansible_facts['distribution_version'] == '22.04'
-        - ansible_facts['architecture'] == 'aarch64' or ansible_facts['architecture'] == 'x86_64'
 
     - name: Install armhf cross-compile packages to build QEMU on AArch64 Ubuntu 22.04
       package:

scripts/probe-gdb-support.py

@@ -19,58 +19,61 @@
 
 import argparse
 import re
-from subprocess import check_output, STDOUT
+from subprocess import check_output, STDOUT, CalledProcessError
+import sys
 
-# mappings from gdb arch to QEMU target
+# Mappings from gdb arch to QEMU target
-mappings = {
+MAP = {
-    "alpha" : "alpha",
+    "alpha" : ["alpha"],
     "aarch64" : ["aarch64", "aarch64_be"],
-    "armv7": "arm",
+    "armv7": ["arm"],
     "armv8-a" : ["aarch64", "aarch64_be"],
-    "avr" : "avr",
+    "avr" : ["avr"],
     # no hexagon in upstream gdb
-    "hppa1.0" : "hppa",
+    "hppa1.0" : ["hppa"],
-    "i386" : "i386",
+    "i386" : ["i386"],
-    "i386:x86-64" : "x86_64",
+    "i386:x86-64" : ["x86_64"],
-    "Loongarch64" : "loongarch64",
+    "Loongarch64" : ["loongarch64"],
-    "m68k" : "m68k",
+    "m68k" : ["m68k"],
-    "MicroBlaze" : "microblaze",
+    "MicroBlaze" : ["microblaze"],
     "mips:isa64" : ["mips64", "mips64el"],
-    "or1k" : "or1k",
+    "or1k" : ["or1k"],
-    "powerpc:common" : "ppc",
+    "powerpc:common" : ["ppc"],
     "powerpc:common64" : ["ppc64", "ppc64le"],
-    "riscv:rv32" : "riscv32",
+    "riscv:rv32" : ["riscv32"],
-    "riscv:rv64" : "riscv64",
+    "riscv:rv64" : ["riscv64"],
-    "s390:64-bit" : "s390x",
+    "s390:64-bit" : ["s390x"],
     "sh4" : ["sh4", "sh4eb"],
-    "sparc": "sparc",
+    "sparc": ["sparc"],
-    "sparc:v8plus": "sparc32plus",
+    "sparc:v8plus": ["sparc32plus"],
-    "sparc:v9a" : "sparc64",
+    "sparc:v9a" : ["sparc64"],
     # no tricore in upstream gdb
     "xtensa" : ["xtensa", "xtensaeb"]
 }
 
+
 def do_probe(gdb):
-    gdb_out = check_output([gdb,
+    try:
-                            "-ex", "set architecture",
+        gdb_out = check_output([gdb,
-                            "-ex", "quit"], stderr=STDOUT)
+                               "-ex", "set architecture",
+                               "-ex", "quit"], stderr=STDOUT, encoding="utf-8")
+    except (OSError) as e:
+        sys.exit(e)
+    except CalledProcessError as e:
+        sys.exit(f'{e}. Output:\n\n{e.output}')
 
-    m = re.search(r"Valid arguments are (.*)",
+    found_gdb_archs = re.search(r'Valid arguments are (.*)', gdb_out)
-                  gdb_out.decode("utf-8"))
 
-    valid_arches = set()
+    targets = set()
+    if found_gdb_archs:
+        gdb_archs = found_gdb_archs.group(1).split(", ")
+        mapped_gdb_archs = [arch for arch in gdb_archs if arch in MAP]
 
-    if m.group(1):
+        targets = {target for arch in mapped_gdb_archs for target in MAP[arch]}
-        for arch in m.group(1).split(", "):
+
-            if arch in mappings:
+    # QEMU targets
-                mapping = mappings[arch]
+    return targets
-                if isinstance(mapping, str):
-                    valid_arches.add(mapping)
-                else:
-                    for entry in mapping:
-                        valid_arches.add(entry)
 
-    return valid_arches
 
 def main() -> None:
     parser = argparse.ArgumentParser(description='Probe GDB Architectures')

tests/docker/Makefile.include

@@ -92,10 +92,10 @@ endif
 docker-image-alpine: NOUSER=1
 
 debian-toolchain-run = \
-	$(if $(NOCACHE), 						\
+	$(if $(NOCACHE)$(NOFETCH),					\
 		$(call quiet-command,					\
 			$(DOCKER_SCRIPT) build -t qemu/$1 -f $< 	\
-			$(if $V,,--quiet) --no-cache 			\
+			$(if $V,,--quiet) $(if $(NOCACHE),--no-cache)	\
 			--registry $(DOCKER_REGISTRY) --extra-files	\
 			$(DOCKER_FILES_DIR)/$1.d/build-toolchain.sh,	\
 			"BUILD", $1),				        \
@@ -177,6 +177,7 @@ docker:
 	@echo '    NETWORK=$$BACKEND     Enable virtual network interface with $$BACKEND.'
 	@echo '    NOUSER=1             Define to disable adding current user to containers passwd.'
 	@echo '    NOCACHE=1            Ignore cache when build images.'
+	@echo '    NOFETCH=1            Do not fetch from the registry.'
 	@echo '    EXECUTABLE=<path>    Include executable in image.'
 	@echo '    EXTRA_FILES="<path> [... <path>]"'
 	@echo '                         Include extra files in image.'

tests/docker/dockerfiles/debian-loongarch-cross.docker

@@ -43,8 +43,8 @@ RUN curl -#SL https://github.com/loongson/build-tools/releases/download/2023.08.
 ENV PATH $PATH:/opt/cross-tools/bin
 ENV LD_LIBRARY_PATH /opt/cross-tools/lib:/opt/cross-tools/loongarch64-unknown-linux-gnu/lib:$LD_LIBRARY_PATH
 
-ENV QEMU_CONFIGURE_OPTS --disable-system --disable-docs --disable-tools
+ENV QEMU_CONFIGURE_OPTS --disable-docs --disable-tools
-ENV DEF_TARGET_LIST loongarch64-linux-user,loongarch-softmmu
+ENV DEF_TARGET_LIST loongarch64-linux-user,loongarch64-softmmu
 ENV MAKE /usr/bin/make
 
 # As a final step configure the user (if env is defined)

tests/docker/dockerfiles/debian-microblaze-cross.d/build-toolchain.sh

@@ -10,6 +10,8 @@ TOOLCHAIN_INSTALL=/usr/local
 TOOLCHAIN_BIN=${TOOLCHAIN_INSTALL}/bin
 CROSS_SYSROOT=${TOOLCHAIN_INSTALL}/$TARGET/sys-root
 
+GCC_PATCH0_URL=https://raw.githubusercontent.com/Xilinx/meta-xilinx/refs/tags/xlnx-rel-v2024.1/meta-microblaze/recipes-devtools/gcc/gcc-12/0009-Patch-microblaze-Fix-atomic-boolean-return-value.patch
+
 export PATH=${TOOLCHAIN_BIN}:$PATH
 
 #
@@ -31,6 +33,12 @@ mv gcc-11.2.0 src-gcc
 mv musl-1.2.2 src-musl
 mv linux-5.10.70 src-linux
 
+#
+# Patch gcc
+#
+
+wget -O - ${GCC_PATCH0_URL} | patch -d src-gcc -p1
+
 mkdir -p bld-hdr bld-binu bld-gcc bld-musl
 mkdir -p ${CROSS_SYSROOT}/usr/include
 

tests/docker/dockerfiles/debian-toolchain.docker

@@ -10,6 +10,8 @@ FROM docker.io/library/debian:11-slim
 # ??? The build-dep isn't working, missing a number of
 # minimal build dependiencies, e.g. libmpc.
 
+RUN sed 's/^deb /deb-src /' </etc/apt/sources.list >/etc/apt/sources.list.d/deb-src.list
+
 RUN apt update && \
     DEBIAN_FRONTEND=noninteractive apt install -yy eatmydata && \
     DEBIAN_FRONTEND=noninteractive eatmydata \
@@ -33,6 +35,11 @@ RUN cd /root && ./build-toolchain.sh
 # and the build trees by restoring the original image,
 # then copying the built toolchain from stage 0.
 FROM docker.io/library/debian:11-slim
+RUN apt update && \
+    DEBIAN_FRONTEND=noninteractive apt install -yy eatmydata && \
+    DEBIAN_FRONTEND=noninteractive eatmydata \
+    apt install -y --no-install-recommends \
+        libmpc3
 COPY --from=0 /usr/local /usr/local
 # As a final step configure the user (if env is defined)
 ARG USER

tests/tcg/Makefile.target

@@ -103,9 +103,14 @@ ifeq ($(filter %-softmmu, $(TARGET)),)
 # then the target. If there are common tests shared between
 # sub-targets (e.g. ARM & AArch64) then it is up to
 # $(TARGET_NAME)/Makefile.target to include the common parent
-# architecture in its VPATH.
+# architecture in its VPATH. However some targets are so minimal we
+# can't even build the multiarch tests.
+ifneq ($(filter $(TARGET_NAME),aarch64_be),)
+-include $(SRC_PATH)/tests/tcg/$(TARGET_NAME)/Makefile.target
+else
 -include $(SRC_PATH)/tests/tcg/multiarch/Makefile.target
 -include $(SRC_PATH)/tests/tcg/$(TARGET_NAME)/Makefile.target
+endif
 
 # Add the common build options
 CFLAGS+=-Wall -Werror -O0 -g -fno-strict-aliasing

tests/tcg/aarch64/gdbstub/test-mte.py

@@ -23,8 +23,8 @@ from sys import argv
 from test_gdbstub import arg_parser, main, report
 
 
-PATTERN_0 = "Memory tags for address 0x[0-9a-f]+ match \\(0x[0-9a-f]+\\)."
+PATTERN_0 = r"Memory tags for address 0x[0-9a-f]+ match \(0x[0-9a-f]+\)."
-PATTERN_1 = ".*(0x[0-9a-f]+)"
+PATTERN_1 = r".*(0x[0-9a-f]+)"
 
 
 def run_test():

tests/tcg/aarch64_be/Makefile.target

@@ -0,0 +1,17 @@
+# -*- Mode: makefile -*-
+#
+# A super basic AArch64 BE makefile. As we don't have any big-endian
+# libc available the best we can do is a basic Hello World.
+
+AARCH64BE_SRC=$(SRC_PATH)/tests/tcg/aarch64_be
+VPATH += $(AARCH64BE_SRC)
+
+AARCH64BE_TEST_SRCS=$(notdir $(wildcard $(AARCH64BE_SRC)/*.c))
+AARCH64BE_TESTS=$(AARCH64BE_TEST_SRCS:.c=)
+#MULTIARCH_TESTS = $(MULTIARCH_SRCS:.c=)
+
+# We need to specify big-endian cflags
+CFLAGS +=-mbig-endian -ffreestanding
+LDFLAGS +=-nostdlib
+
+TESTS += $(AARCH64BE_TESTS)

tests/tcg/aarch64_be/hello.c

@@ -0,0 +1,35 @@
+/*
+ * Non-libc syscall hello world for Aarch64 BE
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#define __NR_write 64
+#define __NR_exit 93
+
+int write(int fd, char *buf, int len)
+{
+    register int x0 __asm__("x0") = fd;
+    register char *x1 __asm__("x1") = buf;
+    register int x2 __asm__("x2") = len;
+    register int x8 __asm__("x8") = __NR_write;
+
+    asm volatile("svc #0" : : "r"(x0), "r"(x1), "r"(x2), "r"(x8));
+
+    return len;
+}
+
+void exit(int ret)
+{
+    register int x0 __asm__("x0") = ret;
+    register int x8 __asm__("x8") = __NR_exit;
+
+    asm volatile("svc #0" : : "r"(x0), "r"(x8));
+    __builtin_unreachable();
+}
+
+void _start(void)
+{
+    write(1, "Hello World\n", 12);
+    exit(0);
+}

tests/tcg/x86_64/Makefile.target

@@ -17,6 +17,7 @@ X86_64_TESTS += cmpxchg
 X86_64_TESTS += adox
 X86_64_TESTS += test-1648
 X86_64_TESTS += test-2175
+X86_64_TESTS += cross-modifying-code
 TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64
 else
 TESTS=$(MULTIARCH_TESTS)
@@ -27,6 +28,9 @@ adox: CFLAGS=-O2
 run-test-i386-ssse3: QEMU_OPTS += -cpu max
 run-plugin-test-i386-ssse3-%: QEMU_OPTS += -cpu max
 
+cross-modifying-code: CFLAGS+=-pthread
+cross-modifying-code: LDFLAGS+=-pthread
+
 test-x86_64: LDFLAGS+=-lm -lc
 test-x86_64: test-i386.c test-i386.h test-i386-shift.h test-i386-muldiv.h
 	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)

tests/tcg/x86_64/cross-modifying-code.c

@@ -0,0 +1,80 @@
+/*
+ * Test patching code, running in one thread, from another thread.
+ *
+ * Intel SDM calls this "cross-modifying code" and recommends a special
+ * sequence, which requires both threads to cooperate.
+ *
+ * Linux kernel uses a different sequence that does not require cooperation and
+ * involves patching the first byte with int3.
+ *
+ * Finally, there is user-mode software out there that simply uses atomics, and
+ * that seems to be good enough in practice. Test that QEMU has no problems
+ * with this as well.
+ */
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+void add1_or_nop(long *x);
+asm(".pushsection .rwx,\"awx\",@progbits\n"
+    ".globl add1_or_nop\n"
+    /* addq $0x1,(%rdi) */
+    "add1_or_nop: .byte 0x48, 0x83, 0x07, 0x01\n"
+    "ret\n"
+    ".popsection\n");
+
+#define THREAD_WAIT 0
+#define THREAD_PATCH 1
+#define THREAD_STOP 2
+
+static void *thread_func(void *arg)
+{
+    int val = 0x0026748d; /* nop */
+
+    while (true) {
+        switch (__atomic_load_n((int *)arg, __ATOMIC_SEQ_CST)) {
+        case THREAD_WAIT:
+            break;
+        case THREAD_PATCH:
+            val = __atomic_exchange_n((int *)&add1_or_nop, val,
+                                      __ATOMIC_SEQ_CST);
+            break;
+        case THREAD_STOP:
+            return NULL;
+        default:
+            assert(false);
+            __builtin_unreachable();
+        }
+    }
+}
+
+#define INITIAL 42
+#define COUNT 1000000
+
+int main(void)
+{
+    int command = THREAD_WAIT;
+    pthread_t thread;
+    long x = 0;
+    int err;
+    int i;
+
+    err = pthread_create(&thread, NULL, &thread_func, &command);
+    assert(err == 0);
+
+    __atomic_store_n(&command, THREAD_PATCH, __ATOMIC_SEQ_CST);
+    for (i = 0; i < COUNT; i++) {
+        add1_or_nop(&x);
+    }
+    __atomic_store_n(&command, THREAD_STOP, __ATOMIC_SEQ_CST);
+
+    err = pthread_join(thread, NULL);
+    assert(err == 0);
+
+    assert(x >= INITIAL);
+    assert(x <= INITIAL + COUNT);
+
+    return EXIT_SUCCESS;
+}