libucontext 1.3.2

also fix MCONTEXT_PC and MCONTEXT_GREGS so they actually read and write to/from
the correct addresses in the ucontext structure.

.gitignore

@@ -1,4 +1,3 @@
-include/libucontext/bits.h
 *.o
 examples/cooperative_threading
 test_libucontext

.woodpecker.yml

@@ -0,0 +1,40 @@
+pipeline:
+  build-x86_64:
+    image: alpine
+    commands:
+      - apk add --no-cache build-base
+      - make check ARCH=x86_64
+    when:
+      platform: linux/amd64
+
+  build-s390x:
+    image: alpine
+    commands:
+      - apk add --no-cache build-base
+      - make check ARCH=s390x
+    when:
+      platform: linux/s390x
+
+  build-ppc64le:
+    image: alpine
+    commands:
+      - apk add --no-cache build-base
+      - make check ARCH=ppc64le
+    when:
+      platform: linux/ppc64le
+
+  build-armv7:
+    image: alpine
+    commands:
+      - apk add --no-cache build-base
+      - make check ARCH=arm
+    when:
+      platform: linux/arm
+
+  build-aarch64:
+    image: alpine
+    commands:
+      - apk add --no-cache build-base
+      - make check ARCH=aarch64
+    when:
+      platform: linux/arm64

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2018-2020 Ariadne Conill <ariadne@dereferenced.org>
+Copyright (c) 2018-2022 Ariadne Conill <ariadne@dereferenced.org>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above

Makefile

@@ -10,48 +10,99 @@ endif
 ifeq ($(ARCH),$(filter $(ARCH),ppc64le))
 	override ARCH = ppc64
 endif
+ifeq ($(ARCH),$(filter $(ARCH),armv7l))
+	override ARCH = arm
+endif
+ifeq ($(ARCH),$(filter $(ARCH),arm64))
+	override ARCH = aarch64
+endif
 
-LIBDIR := /lib
-INCLUDEDIR := /usr/include
-PKGCONFIGDIR := /usr/lib/pkgconfig
-CFLAGS := -ggdb3 -O2 -Wall
+prefix = /usr
+libdir = ${prefix}/lib
+shared_libdir = ${libdir}
+static_libdir = ${libdir}
+includedir = ${prefix}/include
+pkgconfigdir = ${prefix}/lib/pkgconfig
+
+CFLAGS ?= -ggdb3 -O2 -Wall
 CPPFLAGS := -Iinclude -Iarch/${ARCH} -Iarch/common
-EXPORT_UNPREFIXED := yes
+ifneq ($(shell uname),Darwin)
+	EXPORT_UNPREFIXED := yes
+else
+	# Darwin does not support aliases
+	EXPORT_UNPREFIXED := no
+	CPPFLAGS += -D_XOPEN_SOURCE
+endif
 FREESTANDING := no
 
 ifeq ($(FREESTANDING),yes)
-	CFLAGS += -DFREESTANDING -isystem arch/${ARCH}/freestanding
-	EXPORT_UNPREFIXED = no
+	CPPFLAGS += -DFREESTANDING
+	EXPORT_UNPREFIXED = no -Iarch/${ARCH}/include
+else
+	CPPFLAGS += -Iarch/common/include
+endif
+
+# ARM hard float support is presently broken.
+FORCE_SOFT_FLOAT := yes
+
+ifeq ($(FORCE_SOFT_FLOAT),yes)
+        CPPFLAGS += -DFORCE_SOFT_FLOAT
+endif
+
+FORCE_HARD_FLOAT := no
+
+ifeq ($(FORCE_HARD_FLOAT),yes)
+        CPPFLAGS += -DFORCE_HARD_FLOAT
 endif
 
 ifeq ($(EXPORT_UNPREFIXED),yes)
-	CFLAGS += -DEXPORT_UNPREFIXED
+	CPPFLAGS += -DEXPORT_UNPREFIXED
 endif
 
 LIBUCONTEXT_C_SRC = $(wildcard arch/${ARCH}/*.c)
 LIBUCONTEXT_S_SRC = $(wildcard arch/${ARCH}/*.S)
 
+ifeq ($(shell test -d arch/${ARCH}/include; echo $?),0)
+	CPPFLAGS += -Iarch/${ARCH}/include
+endif
+
 LIBUCONTEXT_VERSION := $(shell head -n 1 VERSION)
 LIBUCONTEXT_OBJ = ${LIBUCONTEXT_C_SRC:.c=.o} ${LIBUCONTEXT_S_SRC:.S=.o}
 LIBUCONTEXT_SOVERSION = 1
-LIBUCONTEXT_NAME = libucontext.so
+ifeq ($(shell uname),Darwin)
+	LIBUCONTEXT_NAME = libucontext.dylib
+	LIBUCONTEXT_SONAME = libucontext.${LIBUCONTEXT_SOVERSION}.dylib
+	LIBUCONTEXT_POSIX_NAME = libucontext_posix.dylib
+	LIBUCONTEXT_POSIX_SONAME = libucontext_posix.${LIBUCONTEXT_SOVERSION}.dylib
+	LIBUCONTEXT_LINKER_FLAGS = -Wl,-dynamiclib,-install_name,${LIBUCONTEXT_SONAME},-current_version,${LIBUCONTEXT_SOVERSION},-compatibility_version,${LIBUCONTEXT_SOVERSION}
+	LIBUCONTEXT_POSIX_LINKER_FLAGS = -Wl,-dynamiclib,-install_name,${LIBUCONTEXT_POSIX_SONAME},-current_version,${LIBUCONTEXT_SOVERSION},-compatibility_version,${LIBUCONTEXT_SOVERSION}
+else
+	LIBUCONTEXT_NAME = libucontext.so
+	LIBUCONTEXT_SONAME = libucontext.so.${LIBUCONTEXT_SOVERSION}
+	LIBUCONTEXT_POSIX_NAME = libucontext_posix.so
+	LIBUCONTEXT_POSIX_SONAME = libucontext_posix.so.${LIBUCONTEXT_SOVERSION}
+	LIBUCONTEXT_LINKER_FLAGS = -shared -Wl,-soname,${LIBUCONTEXT_SONAME} -Wl,-z,noexecstack
+	LIBUCONTEXT_POSIX_LINKER_FLAGS = -shared -Wl,-soname,${LIBUCONTEXT_POSIX_SONAME} -Wl,-z,noexecstack
+	ASFLAGS = -Wa,--noexecstack
+endif
 LIBUCONTEXT_STATIC_NAME = libucontext.a
 LIBUCONTEXT_PC = libucontext.pc
-LIBUCONTEXT_SONAME = libucontext.so.${LIBUCONTEXT_SOVERSION}
-LIBUCONTEXT_PATH = ${LIBDIR}/${LIBUCONTEXT_SONAME}
-LIBUCONTEXT_STATIC_PATH = ${LIBDIR}/${LIBUCONTEXT_STATIC_NAME}
+LIBUCONTEXT_PATH = ${shared_libdir}/${LIBUCONTEXT_SONAME}
+LIBUCONTEXT_STATIC_PATH = ${static_libdir}/${LIBUCONTEXT_STATIC_NAME}
 LIBUCONTEXT_HEADERS = \
-	include/libucontext/libucontext.h \
-	include/libucontext/bits.h
+	include/libucontext/libucontext.h
+ifeq ($(FREESTANDING),yes)
+LIBUCONTEXT_HEADERS += arch/${ARCH}/include/libucontext/bits.h
+else
+LIBUCONTEXT_HEADERS += arch/common/include/libucontext/bits.h
+endif
 LIBUCONTEXT_EXAMPLES = \
 	examples/cooperative_threading
-LIBUCONTEXT_POSIX_NAME = libucontext_posix.so
 LIBUCONTEXT_POSIX_STATIC_NAME = libucontext_posix.a
 LIBUCONTEXT_POSIX_C_SRC = libucontext_posix.c
 LIBUCONTEXT_POSIX_OBJ = ${LIBUCONTEXT_POSIX_C_SRC:.c=.o}
-LIBUCONTEXT_POSIX_SONAME = libucontext_posix.so.${LIBUCONTEXT_SOVERSION}
-LIBUCONTEXT_POSIX_PATH = ${LIBDIR}/${LIBUCONTEXT_POSIX_SONAME}
-LIBUCONTEXT_POSIX_STATIC_PATH = ${LIBDIR}/${LIBUCONTEXT_POSIX_STATIC_NAME}
+LIBUCONTEXT_POSIX_PATH = ${shared_libdir}/${LIBUCONTEXT_POSIX_SONAME}
+LIBUCONTEXT_POSIX_STATIC_PATH = ${static_libdir}/${LIBUCONTEXT_POSIX_STATIC_NAME}
 
 ifeq ($(FREESTANDING),yes)
 	LIBUCONTEXT_POSIX_NAME =
@@ -61,8 +112,7 @@ endif
 all: ${LIBUCONTEXT_SONAME} ${LIBUCONTEXT_STATIC_NAME} ${LIBUCONTEXT_POSIX_NAME} ${LIBUCONTEXT_POSIX_STATIC_NAME} ${LIBUCONTEXT_PC}
 
 ${LIBUCONTEXT_POSIX_NAME}: ${LIBUCONTEXT_NAME} ${LIBUCONTEXT_POSIX_OBJ}
-	$(CC) -fPIC -o ${LIBUCONTEXT_POSIX_NAME} -Wl,-soname,${LIBUCONTEXT_POSIX_SONAME} \
-		-shared ${LIBUCONTEXT_POSIX_OBJ} ${LDFLAGS}
+	$(CC) -fPIC -o ${LIBUCONTEXT_POSIX_NAME} ${LIBUCONTEXT_POSIX_LINKER_FLAGS} ${LIBUCONTEXT_POSIX_OBJ} -L. -lucontext ${LDFLAGS}
 
 ${LIBUCONTEXT_POSIX_STATIC_NAME}: ${LIBUCONTEXT_STATIC_NAME} ${LIBUCONTEXT_POSIX_OBJ}
 	$(AR) rcs ${LIBUCONTEXT_POSIX_STATIC_NAME} ${LIBUCONTEXT_POSIX_OBJ}
@@ -70,20 +120,20 @@ ${LIBUCONTEXT_POSIX_STATIC_NAME}: ${LIBUCONTEXT_STATIC_NAME} ${LIBUCONTEXT_POSIX
 ${LIBUCONTEXT_POSIX_SONAME}: ${LIBUCONTEXT_POSIX_NAME}
 	ln -sf ${LIBUCONTEXT_POSIX_NAME} ${LIBUCONTEXT_POSIX_SONAME}
 
-${LIBUCONTEXT_STATIC_NAME}: ${LIBUCONTEXT_HEADERS} ${LIBUCONTEXT_OBJ}
+${LIBUCONTEXT_STATIC_NAME}: ${LIBUCONTEXT_OBJ}
 	$(AR) rcs ${LIBUCONTEXT_STATIC_NAME} ${LIBUCONTEXT_OBJ}
 
-${LIBUCONTEXT_NAME}: ${LIBUCONTEXT_HEADERS} ${LIBUCONTEXT_OBJ}
-	$(CC) -fPIC -o ${LIBUCONTEXT_NAME} -Wl,-soname,${LIBUCONTEXT_SONAME} \
-		-shared ${LIBUCONTEXT_OBJ} ${LDFLAGS}
+${LIBUCONTEXT_NAME}: ${LIBUCONTEXT_OBJ}
+	$(CC) -fPIC -o ${LIBUCONTEXT_NAME} ${LIBUCONTEXT_LINKER_FLAGS} ${LIBUCONTEXT_OBJ} ${LDFLAGS}
 
 ${LIBUCONTEXT_SONAME}: ${LIBUCONTEXT_NAME}
 	ln -sf ${LIBUCONTEXT_NAME} ${LIBUCONTEXT_SONAME}
 
 ${LIBUCONTEXT_PC}: libucontext.pc.in
 	sed -e s:@LIBUCONTEXT_VERSION@:${LIBUCONTEXT_VERSION}:g \
-	    -e s:@LIBUCONTEXT_LIBDIR@:${LIBDIR}:g \
-	    -e s:@LIBUCONTEXT_INCLUDEDIR@:${INCLUDEDIR}:g $< > $@
+	    -e s:@LIBUCONTEXT_SHARED_LIBDIR@:${shared_libdir}:g \
+	    -e s:@LIBUCONTEXT_STATIC_LIBDIR@:${static_libdir}:g \
+	    -e s:@LIBUCONTEXT_INCLUDEDIR@:${includedir}:g $< > $@
 
 MANPAGES_SYMLINKS_3 = \
 	libucontext_getcontext.3 \
@@ -102,10 +152,10 @@ MANPAGES = ${MANPAGES_3}
 docs: ${MANPAGES}
 
 .c.o:
-	$(CC) -std=gnu99 -D_BSD_SOURCE -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} -c -o $@ $<
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} -c -o $@ $<
 
 .S.o:
-	$(CC) -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} -c -o $@ $<
+	$(CC) -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} ${ASFLAGS} -c -o $@ $<
 
 ${LIBUCONTEXT_NAME}_clean:
 	rm -f ${LIBUCONTEXT_NAME}
@@ -122,12 +172,12 @@ libucontext_obj_clean:
 ${LIBUCONTEXT_PC}_clean:
 	rm -f ${LIBUCONTEXT_PC}
 
-bits_clean:
-	rm -f include/libucontext/bits.h
-
 ${LIBUCONTEXT_POSIX_NAME}_clean:
 	rm -f ${LIBUCONTEXT_POSIX_NAME}
 
+${LIBUCONTEXT_POSIX_SONAME}_clean:
+	rm -f ${LIBUCONTEXT_POSIX_SONAME}
+
 ${LIBUCONTEXT_POSIX_STATIC_NAME}_clean:
 	rm -f ${LIBUCONTEXT_POSIX_STATIC_NAME}
 
@@ -152,8 +202,8 @@ clean: ${LIBUCONTEXT_NAME}_clean
 clean: ${LIBUCONTEXT_SONAME}_clean
 clean: ${LIBUCONTEXT_STATIC_NAME}_clean
 clean: ${LIBUCONTEXT_PC}_clean
-clean: bits_clean
 clean: ${LIBUCONTEXT_POSIX_NAME}_clean
+clean: ${LIBUCONTEXT_POSIX_SONAME}_clean
 clean: ${LIBUCONTEXT_POSIX_STATIC_NAME}_clean
 clean: libucontext_posix_obj_clean
 clean: libucontext_obj_clean
@@ -163,13 +213,13 @@ clean: docs_clean
 install: all
 	install -D -m755 ${LIBUCONTEXT_NAME} ${DESTDIR}${LIBUCONTEXT_PATH}
 	install -D -m664 ${LIBUCONTEXT_STATIC_NAME} ${DESTDIR}${LIBUCONTEXT_STATIC_PATH}
-	ln -sf ${LIBUCONTEXT_SONAME} ${DESTDIR}${LIBDIR}/${LIBUCONTEXT_NAME}
+	ln -sf ${LIBUCONTEXT_SONAME} ${DESTDIR}${shared_libdir}/${LIBUCONTEXT_NAME}
 	for i in ${LIBUCONTEXT_HEADERS}; do \
 		destfn=$$(echo $$i | sed s:include/::g); \
-		install -D -m644 $$i ${DESTDIR}${INCLUDEDIR}/$$destfn; \
+		install -D -m644 $$i ${DESTDIR}${includedir}/$$destfn; \
 	done
-	install -D -m644 ${LIBUCONTEXT_PC} ${DESTDIR}${PKGCONFIGDIR}/${LIBUCONTEXT_PC}
-	if [ -n ${LIBUCONTEXT_POSIX_NAME} ]; then \
+	install -D -m644 ${LIBUCONTEXT_PC} ${DESTDIR}${pkgconfigdir}/${LIBUCONTEXT_PC}
+	if [ -n "${LIBUCONTEXT_POSIX_NAME}" ]; then \
 		install -D -m755 ${LIBUCONTEXT_POSIX_NAME} ${DESTDIR}${LIBUCONTEXT_POSIX_PATH}; \
 		install -D -m644 ${LIBUCONTEXT_POSIX_STATIC_NAME} ${DESTDIR}${LIBUCONTEXT_POSIX_STATIC_PATH}; \
 	fi
@@ -183,11 +233,11 @@ install_docs: docs
 ifneq (${FREESTANDING},yes)
 check: check_libucontext_posix
 
-check_libucontext_posix: test_libucontext_posix ${LIBUCONTEXT_POSIX_SONAME}
+check_libucontext_posix: test_libucontext_posix ${LIBUCONTEXT_POSIX_SONAME} ${LIBUCONTEXT_SONAME}
 	env LD_LIBRARY_PATH=$(shell pwd) ./test_libucontext_posix
 
 test_libucontext_posix: test_libucontext_posix.c ${LIBUCONTEXT_POSIX_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext -lucontext_posix
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext -lucontext_posix
 endif
 
 ifeq ($(EXPORT_UNPREFIXED),yes)
@@ -197,30 +247,20 @@ check_libucontext_bare_posixabi: test_libucontext_bare_posixabi ${LIBUCONTEXT_SO
 	env LD_LIBRARY_PATH=$(shell pwd) ./test_libucontext_bare_posixabi
 
 test_libucontext_bare_posixabi: test_libucontext_posix.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} test_libucontext_posix.c -o $@ -L. -lucontext
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} test_libucontext_posix.c -o $@ -L. -lucontext
 endif
 
-check: test_libucontext ${LIBUCONTEXT_SONAME}
+check_libucontext: test_libucontext ${LIBUCONTEXT_SONAME}
 	env LD_LIBRARY_PATH=$(shell pwd) ./test_libucontext
 
+check: check_libucontext
+
 test_libucontext: test_libucontext.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
 
 examples: ${LIBUCONTEXT_EXAMPLES}
 examples/cooperative_threading: examples/cooperative_threading.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
-
-ifeq ($(FREESTANDING),no)
-
-include/libucontext/bits.h: arch/common/bits.h
-	cp arch/common/bits.h $@
-
-else
-
-include/libucontext/bits.h: arch/${ARCH}/freestanding/bits.h
-	cp arch/${ARCH}/freestanding/bits.h $@
-
-endif
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
 
 PACKAGE_NAME = libucontext
 PACKAGE_VERSION = ${LIBUCONTEXT_VERSION}

NEWS

@@ -1,3 +1,79 @@
+Changes from 1.3.1 to 1.3.2
+---------------------------
+
+* Rewrite makecontext in C on LoongArch.
+
+* Fix building x86 and loongarch64 variants on Meson.
+  Patch by Volker Christian.
+
+Changes from 1.3 to 1.3.1
+-------------------------
+
+* Disable hard-float support on ARM by default.
+
+* Fix up getcontext/swapcontext return values on LoongArch.
+
+* Fix assembler warnings when building on LoongArch.
+
+Changes from 1.2 to 1.3
+-----------------------
+
+* Fix up getcontext/swapcontext return values across a few ports.
+  Patches contributed for ARM and test suite by Volker Christian.
+
+* Add support for hard-float on ARM.
+  Patches contributed by Richard Campbell.
+
+* Align build system variables with those used by Automake.
+  Patch contributed by Ismael Luceno.
+
+* Fix sporadic parallel build failures.
+  Patches contributed by Jim Hauxwell.
+
+* Ensure frame pointers are omitted when using the C trampoline.
+  Patch contributed by Sören Tempel.
+
+* Define _XOPEN_SOURCE when building on Darwin.
+  Patch contributed by L. Pereira.
+
+* Add support for building the manpages with Meson.
+  Patch contributed by matoro.
+
+* Migrate build from _BSD_SOURCE to _DEFAULT_SOURCE.
+
+Changes from 1.1 to 1.2
+-----------------------
+
+* Added Loongarch64 port.
+
+* Added OpenRISC (or1k) port.
+
+* Fixed various build system issues:
+  - libucontext_posix.so is no longer underlinked
+  - Executable stacks are now disabled when using GNU-like toolchains
+  - CPPFLAGS is used consistently
+  - Users may now build on Darwin without using Meson
+
+* aarch64 now implements the necessary SIMD register save/restore as
+  mandatory in AAPCS64.
+  Patches contributed by Richard Campbell.
+
+Changes from 1.0 to 1.1
+-----------------------
+
+* Added RISC-V RV32 port.
+
+* Cleaned up use of _GNU_SOURCE in C code.
+  Partially from patches contributed by osy.
+
+* Added automatic detection of armv7l architecture.
+  Patch contributed by Leandro Pereira.
+
+* Fixed installation path of libucontext_posix.a.
+
+* Work around deficiency in clang built-in assembler on AArch64 targets.
+  Patch contributed by osy.
+
 Changes from 0.13.1 to 1.0
 --------------------------
 

README.md

@@ -20,15 +20,18 @@ target to do it.
 |--------------|---------------|---------|-----------------------|-------------------|
 |    aarch64   | ✓             |         | ✓                     | ✓                 |
 |      arm     | ✓             |         | ✓                     | ✓                 |
+| loongarch64  | ✓             |         | ✓                     |                   |
 |     m68k     | ✓             |         | ✓                     | ✓                 |
 |     mips     | ✓             |         | ✓                     |                   |
 |    mips64    | ✓             |         | ✓                     |                   |
+|     or1k     | ✓             |         | ✓                     | ✓                 |
 |      ppc     | ✓             | ✓       |                       |                   |
 |     ppc64    | ✓             | ✓       |                       |                   |
+|    riscv32   | ✓             |         | ✓                     | ✓                 |
 |    riscv64   | ✓             |         | ✓                     | ✓                 |
 |     s390x    | ✓             |         | ✓                     |                   |
 |      sh      | ✓             |         | ✓                     | ✓                 |
-|      x86     | ✓             |         | ✓                     | ✓                 |
+|      x86     | ✓             |         | ✓                     |                   |
 |    x86_64    | ✓             |         | ✓                     | ✓                 |
 
 
@@ -70,15 +73,26 @@ $ make DESTDIR=out install_docs
 ```
 
 
+## real-world use cases
+
+`libucontext` is used on almost all musl distributions to provide the legacy `ucontext.h` API.
+Additionally, it is used by:
+
+* [UTM](https://getutm.app) -- friendly qemu distribution for macOS and iOS devices.  UTM uses libucontext
+  as qemu's coroutine backend.
+
+* [Lwan](https://lwan.ws) -- a high-performance embeddable asynchronous web server.  Lwan uses libucontext
+  to provide green threads when building on non-x86 architectures.
+
+
 ## caveats
 
 `libucontext`, while largely functionally equivalent does have some differences over traditional POSIX
 ucontext functions:
 
-* Saving and restoring the signal mask is not implemented.  This is largely a non-issue because most
-  uses of these functions did not modify the signal mask anyway, but saving/restoring the signal mask
-  (even though it is unmodified in basically all cases in practice) induces a significant performance
-  penalty due to having to make kernel syscalls.
+* Saving and restoring the signal mask is not implemented by default in order to avoid kernel syscall
+  overhead.  Use `-lucontext_posix` if you actually need this functionality, which provides a POSIX
+  compliant implementation at the cost of performance.
 
 * Only basic GPR registers are saved and restored when context swapping.  The glibc implementation uses
   hardware capability detection to save/restore other register groups, such as the FPU registers or
@@ -87,4 +101,5 @@ ucontext functions:
   save/restore FPU registers or vector registers may be added in a later release as a build-time
   setting -- for now, we assume a soft-float ABI with no optional processor features.  In practice, this
   does not really matter, code using these functions are unlikely to be impacted by this design
-  assumption.
+  assumption. This is a work in progress, as newer compilers will spill even non-floating-point state
+  through floating point registers when allowed to do so.

VERSION

@@ -1 +1 @@
-1.0
+1.3.2

arch/aarch64/defs.h

@@ -9,6 +9,7 @@
 #define SP_OFFSET	432
 #define PC_OFFSET	440
 #define PSTATE_OFFSET	448
+#define FPSIMD_CONTEXT_OFFSET 464
 
 #ifndef FPSIMD_MAGIC
 # define FPSIMD_MAGIC	0x46508001

arch/aarch64/getcontext.S

@@ -15,26 +15,15 @@
 ALIAS(getcontext, libucontext_getcontext)
 ALIAS(__getcontext, libucontext_getcontext)
 
-FUNC(libucontext_getcontext)
+	.global PROC_NAME(libucontext_getcontext);
+	.align  2;
+	TYPE(libucontext_getcontext)
+	ENT(libucontext_getcontext)
+PROC_NAME(libucontext_getcontext):
 	str	xzr, [x0, #REG_OFFSET(0)]
 
-	/* save GPRs */
-	stp	x0, x1,   [x0, #REG_OFFSET(0)]
+	/* save x2 and x3 for reuse */
 	stp	x2, x3,   [x0, #REG_OFFSET(2)]
-	stp	x4, x5,   [x0, #REG_OFFSET(4)]
-	stp	x6, x7,   [x0, #REG_OFFSET(6)]
-	stp	x8, x9,   [x0, #REG_OFFSET(8)]
-	stp	x10, x11, [x0, #REG_OFFSET(10)]
-	stp	x12, x13, [x0, #REG_OFFSET(12)]
-	stp	x14, x15, [x0, #REG_OFFSET(14)]
-	stp	x16, x17, [x0, #REG_OFFSET(16)]
-	stp	x18, x19, [x0, #REG_OFFSET(18)]
-	stp	x20, x21, [x0, #REG_OFFSET(20)]
-	stp	x22, x23, [x0, #REG_OFFSET(22)]
-	stp	x24, x25, [x0, #REG_OFFSET(24)]
-	stp	x26, x27, [x0, #REG_OFFSET(26)]
-	stp	x28, x29, [x0, #REG_OFFSET(28)]
-	str	x30,      [x0, #REG_OFFSET(30)]
 
 	/* save current program counter in link register */
 	str	x30, [x0, #PC_OFFSET]
@@ -46,8 +35,32 @@ FUNC(libucontext_getcontext)
 	/* save pstate */
 	str	xzr, [x0, #PSTATE_OFFSET]
 
-	/* TODO: SIMD / FPRs */
+	add x2, x0, #FPSIMD_CONTEXT_OFFSET
+	stp q8, q9,   [x2, #144]
+	stp q10, q11, [x2, #176]
+	stp q12, q13, [x2, #208]
+	stp q14, q15, [x2, #240]
 
+	/* save GPRs and return value 0 */
+	mov	x2, x0
 	mov	x0, #0
+
+	stp	x0, x1,   [x2, #REG_OFFSET(0)]
+	/* x2 and x3 have already been saved */
+	stp	x4, x5,   [x2, #REG_OFFSET(4)]
+	stp	x6, x7,   [x2, #REG_OFFSET(6)]
+	stp	x8, x9,   [x2, #REG_OFFSET(8)]
+	stp	x10, x11, [x2, #REG_OFFSET(10)]
+	stp	x12, x13, [x2, #REG_OFFSET(12)]
+	stp	x14, x15, [x2, #REG_OFFSET(14)]
+	stp	x16, x17, [x2, #REG_OFFSET(16)]
+	stp	x18, x19, [x2, #REG_OFFSET(18)]
+	stp	x20, x21, [x2, #REG_OFFSET(20)]
+	stp	x22, x23, [x2, #REG_OFFSET(22)]
+	stp	x24, x25, [x2, #REG_OFFSET(24)]
+	stp	x26, x27, [x2, #REG_OFFSET(26)]
+	stp	x28, x29, [x2, #REG_OFFSET(28)]
+	str	x30,      [x2, #REG_OFFSET(30)]
+
 	ret
 END(libucontext_getcontext)

arch/aarch64/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/aarch64/setcontext.S

@@ -15,7 +15,11 @@
 ALIAS(setcontext, libucontext_setcontext)
 ALIAS(__setcontext, libucontext_setcontext)
 
-FUNC(libucontext_setcontext)
+	.global PROC_NAME(libucontext_setcontext);
+	.align  2;
+	TYPE(libucontext_setcontext)
+	ENT(libucontext_setcontext)
+PROC_NAME(libucontext_setcontext):
 	/* restore GPRs */
 	ldp	x18, x19, [x0, #REG_OFFSET(18)]
 	ldp	x20, x21, [x0, #REG_OFFSET(20)]
@@ -29,7 +33,11 @@ FUNC(libucontext_setcontext)
 	ldr	x2, [x0, #SP_OFFSET]
 	mov	sp, x2
 
-	/* TODO: SIMD / FPRs */
+	add x2, x0, #FPSIMD_CONTEXT_OFFSET
+	ldp q8, q9,   [x2, #144]
+	ldp q10, q11, [x2, #176]
+	ldp q12, q13, [x2, #208]
+	ldp q14, q15, [x2, #240]
 
 	/* save current program counter in link register */
 	ldr	x16, [x0, #PC_OFFSET]

arch/aarch64/swapcontext.S

@@ -15,7 +15,11 @@
 ALIAS(swapcontext, libucontext_swapcontext)
 ALIAS(__swapcontext, libucontext_swapcontext)
 
-FUNC(libucontext_swapcontext)
+	.global PROC_NAME(libucontext_swapcontext);
+	.align  2;
+	TYPE(libucontext_swapcontext)
+	ENT(libucontext_swapcontext)
+PROC_NAME(libucontext_swapcontext):
 	str	xzr, [x0, #REG_OFFSET(0)]
 
 	/* save GPRs */
@@ -45,6 +49,12 @@ FUNC(libucontext_swapcontext)
 	/* save pstate */
 	str	xzr, [x0, #PSTATE_OFFSET]
 
+	add x2, x0, #FPSIMD_CONTEXT_OFFSET
+	stp q8, q9,   [x2, #144]
+	stp q10, q11, [x2, #176]
+	stp q12, q13, [x2, #208]
+	stp q14, q15, [x2, #240]
+
 	/* context to swap to is in x1 so... we move to x0 and call setcontext */
 	/* store our link register in x28 */
 	mov	x28, x30

arch/arm/defs.h

@@ -2,8 +2,11 @@
 
 #define REG_SZ		(4)
 #define MCONTEXT_GREGS	(32)
+#define VFP_MAGIC_OFFSET (232)
+#define VFP_D8_OFFSET (304)
 
-#define TYPE(__proc)
+#define TYPE(__proc)	.type	__proc, %function;
+#define END(__proc)
 
 #define FETCH_LINKPTR(dest) \
 	asm("movs    %0, r4" : "=r" ((dest)))

arch/arm/getcontext.S

@@ -22,6 +22,27 @@ FUNC(libucontext_getcontext)
 	str	r13, [r0, #REG_OFFSET(13)]
 	str	r14, [r0, #REG_OFFSET(15)]
 
+#ifndef FORCE_SOFT_FLOAT
+#ifndef FORCE_HARD_FLOAT
+        /* test for vfp, set kernel-defined magic number in uc_regspace */
+        push    {r0-r1,fp,lr}
+        mov     r0, #16
+        bl      getauxval
+        tst     r0, #64
+        pop     {r0-r1,fp,lr}
+	moveq	r2, #0
+	ldrne	r2, =#0x56465001
+	str	r2, [r0, #VFP_MAGIC_OFFSET]
+        beq     1f
+#endif
+	/* if vfp detected, save d8-d15 */
+	.fpu	vfp
+	add	r1, r0, #VFP_D8_OFFSET
+	vstmia	r1, {d8-d15}
+	.fpu	softvfp
+1:
+#endif
+
 	/* return 0 */
 	mov	r0, #0
 	mov	pc, lr

arch/arm/include/libucontext/bits.h

@@ -23,6 +23,8 @@ typedef struct libucontext_ucontext {
 	struct libucontext_ucontext *uc_link;
 	libucontext_stack_t uc_stack;
 	libucontext_mcontext_t uc_mcontext;
+	unsigned long uc_sigmask[128 / sizeof(long)];
+	unsigned long long uc_regspace[64];
 } libucontext_ucontext_t;
 
 #endif

arch/arm/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/arm/setcontext.S

@@ -16,6 +16,22 @@ ALIAS(setcontext, libucontext_setcontext)
 ALIAS(__setcontext, libucontext_setcontext)
 
 FUNC(libucontext_setcontext)
+#ifndef FORCE_SOFT_FLOAT
+#ifndef FORCE_HARD_FLOAT
+	/* test for vfp magic number set by getcontext */
+	ldr	r2, [r0, #VFP_MAGIC_OFFSET]
+	ldr	r3, =#0x56465001
+	cmp	r2, r3
+        bne     1f
+#endif
+	/* if vfp in use, restore d8-d15 from uc_regspace */
+	.fpu	vfp
+	add	r14, r0, #VFP_D8_OFFSET
+	vldmia	r14, {d8-d15}
+	.fpu 	softvfp
+1:
+#endif
+
 	/* copy all of the current registers into the ucontext structure */
 	add	r14, r0, #REG_OFFSET(0)
 	ldmia	r14, {r0-r12}

arch/arm/swapcontext.S

@@ -16,12 +16,34 @@ ALIAS(swapcontext, libucontext_swapcontext)
 ALIAS(__swapcontext, libucontext_swapcontext)
 
 FUNC(libucontext_swapcontext)
-	/* copy all of the current registers into the ucontext structure */
-	add	r2, r0, #REG_OFFSET(0)
-	stmia	r2, {r0-r12}
-	str	r13, [r0,#REG_OFFSET(13)]
-	str	r14, [r0,#REG_OFFSET(15)]
+#ifndef FORCE_SOFT_FLOAT
+#ifndef FORCE_HARD_FLOAT
+	/* test for vfp magic number, copy to other ucontext */
+	ldr	r3, [r1, #VFP_MAGIC_OFFSET]
+	ldr	r4, =#0x56465001
+	str	r3, [r0, #VFP_MAGIC_OFFSET]
+	cmp	r3, r4
+	bne	1f
+#endif
+	/* if vfp in use, save and restore d8-d15 */
+	.fpu	vfp
+	add	r2, r0, #VFP_D8_OFFSET
+	vstmia	r2, {d8-d15}
 
+	add	r14, r1, #VFP_D8_OFFSET
+	vldmia	r14, {d8-d15}
+	.fpu	softvfp
+1:
+#endif
+
+ 	/* copy all of the current registers into the ucontext structure */
+ 	str	r13, [r0,#REG_OFFSET(13)]
+ 	str	r14, [r0,#REG_OFFSET(15)]
+	add	r2, r0, #REG_OFFSET(0)
+	/* copy r0 with value 0 to indicate success (return value 0) */
+	mov r0, #0
+	stmia	r2, {r0-r12}
+	
 	/* load new registers from the second ucontext structure */
 	add	r14, r1, #REG_OFFSET(0)
 	ldmia	r14, {r0-r12}

arch/common/common-defs.h

@@ -40,6 +40,8 @@
 	ENT(__proc)					\
 PROC_NAME(__proc):					\
 	SETUP_FRAME(__proc)
+
+#ifndef END
 #ifdef __clang__
 #define END(__proc)
 #else
@@ -47,6 +49,7 @@ PROC_NAME(__proc):					\
 	.end	__proc;					\
 	.size	__proc,.-__proc;
 #endif
+#endif
 
 #ifdef EXPORT_UNPREFIXED
 #define ALIAS(__alias, __real)				\

arch/common/common-trampoline.c

@@ -14,11 +14,23 @@
 #include <stdlib.h>
 #include <stdio.h>
 
+/* We need to make sure that the C compiler doesn't push any
+ * additional data to the stack frame. Otherwise, assumptions
+ * made by the architecture-specific implementation of the
+ * FETCH_LINKPTR() macro about the location of the linkptr,
+ * relative to the stack pointer, will not hold.
+ *
+ * Hence, we compile this function with -fomit-frame-pointer
+ * and use the register storage-class specifier for all local
+ * vars. Note that the latter is just a "suggestion" (see C99).
+ */
+
 __attribute__ ((visibility ("hidden")))
+__attribute__ ((optimize ("omit-frame-pointer")))
 void
 libucontext_trampoline(void)
 {
-	register libucontext_ucontext_t *uc_link;
+	register libucontext_ucontext_t *uc_link = NULL;
 
 	FETCH_LINKPTR(uc_link);
 

arch/loongarch64/defs.h

@@ -0,0 +1,82 @@
+#ifndef __ARCH_LOONGARCH64_DEFS_H
+#define __ARCH_LOONGARCH64_DEFS_H
+
+#define REG_SZ		(8)
+
+#define REG_R0		(0)
+#define REG_R1		(1)
+#define REG_R2		(2)
+#define REG_R3		(3)
+#define REG_R4		(4)
+#define REG_R5		(5)
+#define REG_R6		(6)
+#define REG_R7		(7)
+#define REG_R8		(8)
+#define REG_R9		(9)
+#define REG_R10		(10)
+#define REG_R11		(11)
+#define REG_R12		(12)
+#define REG_R13		(13)
+#define REG_R14		(14)
+#define REG_R15		(15)
+#define REG_R16		(16)
+#define REG_R17		(17)
+#define REG_R18		(18)
+#define REG_R19		(19)
+#define REG_R20		(20)
+#define REG_R21		(21)
+#define REG_R22		(22)
+#define REG_R23		(23)
+#define REG_R24		(24)
+#define REG_R25		(25)
+#define REG_R26		(26)
+#define REG_R27		(27)
+#define REG_R28		(28)
+#define REG_R29		(29)
+#define REG_R30		(30)
+#define REG_R31		(31)
+
+/* $a0 is $4 , also $v0, same as $5, $a1 and $v1*/
+#define REG_A0		(4)
+
+/* stack pointer is actually $3 */
+#define REG_SP		(3)
+
+/* frame pointer is actually $22 */
+#define REG_FP		(22)
+
+/* $s0 is $23 */
+#define REG_S0		(23)
+
+/* $ra is $1 */
+#define REG_RA		(1)
+
+/* offset to mc_gregs in ucontext_t */
+#define MCONTEXT_GREGS	(184)
+
+/* offset to PC in ucontext_t */
+#define MCONTEXT_PC	(176)
+
+/* offset to uc_link in ucontext_t */
+#define UCONTEXT_UC_LINK	(8)
+
+/* offset to uc_stack.ss_sp in ucontext_t */
+#define UCONTEXT_STACK_PTR	(16)
+
+/* offset to uc_stack.ss_size in ucontext_t */
+#define UCONTEXT_STACK_SIZE	(32)
+
+/* Stack alignment, from Kernel source */
+#define ALSZ		15
+#define ALMASK		~15
+#define FRAMESZ		(((LOCALSZ * REG_SZ) + ALSZ) & ALMASK)
+
+#define PUSH_FRAME(__proc)	\
+	addi.d		$sp, $sp, -FRAMESZ;
+
+#define POP_FRAME(__proc)	\
+	addi.d		$sp, $sp, FRAMESZ;
+
+#include <common-defs.h>
+
+#endif

arch/loongarch64/freestanding/bits.h

@@ -0,0 +1,43 @@
+#ifndef LIBUCONTEXT_BITS_H
+#define LIBUCONTEXT_BITS_H
+
+typedef unsigned long long libucontext_greg_t, libucontext_gregset_t[32];
+
+/* Container for all general registers.  */
+typedef __loongarch_mc_gp_state gregset_t;
+
+/* Container for floating-point state.  */
+typedef union __loongarch_mc_fp_state fpregset_t;
+
+union __loongarch_mc_fp_state {
+    unsigned int   __val32[256 / 32];
+    unsigned long long   __val64[256 / 64];
+};
+
+typedef struct mcontext_t {
+    unsigned long long   __pc;
+    unsigned long long   __gregs[32];
+    unsigned int   __flags;
+
+    unsigned int   __fcsr;
+    unsigned int   __vcsr;
+    unsigned long long   __fcc;
+    union __loongarch_mc_fp_state    __fpregs[32] __attribute__((__aligned__ (32)));
+
+    unsigned int   __reserved;
+} mcontext_t;
+
+typedef struct {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} libucontext_stack_t;
+
+typedef struct libucontext_ucontext {
+	unsigned long uc_flags;
+	struct libucontext_ucontext *uc_link;
+	libucontext_stack_t uc_stack;
+	libucontext_mcontext_t uc_mcontext;
+} libucontext_ucontext_t;
+
+#endif

arch/loongarch64/getcontext.S

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2021 Peng Fan <fanpeng@loongson.cn>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#define LOCALSZ (1)
+
+#include "defs.h"
+
+ALIAS(getcontext, libucontext_getcontext)
+
+FUNC(libucontext_getcontext)
+	/* copy $sp, $fp to temporary registers so we don't clobber them */
+	move	$a2, $sp
+	move	$a3, $fp
+
+	PUSH_FRAME(libucontext_getcontext)
+
+	/* set registers */
+	st.d	$s0, $a0, REG_OFFSET(23)
+	st.d	$s1, $a0, REG_OFFSET(24)
+	st.d	$s2, $a0, REG_OFFSET(25)
+	st.d	$s3, $a0, REG_OFFSET(26)
+	st.d	$s4, $a0, REG_OFFSET(27)
+	st.d	$s5, $a0, REG_OFFSET(28)
+	st.d	$s6, $a0, REG_OFFSET(29)
+	st.d	$s7, $a0, REG_OFFSET(30)
+	st.d	$s8, $a0, REG_OFFSET(31)
+
+	st.d	$a2, $a0, REG_OFFSET(3)
+	st.d	$zero, $a0, REG_OFFSET(4)
+	st.d	$a3, $a0, REG_OFFSET(22)
+	st.d	$ra, $a0, REG_OFFSET(1)
+
+	st.d	$ra, $a0, (MCONTEXT_PC)
+
+	move	$a0, $zero
+
+	POP_FRAME(libucontext_getcontext)
+
+	jr	$ra
+END(libucontext_getcontext)

arch/loongarch64/makecontext.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2024 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <stddef.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "defs.h"
+#include <libucontext/libucontext.h>
+
+
+extern void libucontext_trampoline(void);
+
+
+void
+libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	libucontext_greg_t *sp, *regp;
+	va_list va;
+	int i;
+
+	/* set up and align the stack. */
+	sp = (libucontext_greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	sp -= argc < 8 ? 0 : argc - 8;
+	sp = (libucontext_greg_t *) (((uintptr_t) sp & -16L));
+
+	/* set up the ucontext structure */
+	ucp->uc_mcontext.__gregs[REG_RA] = (libucontext_greg_t) libucontext_trampoline;
+	ucp->uc_mcontext.__gregs[REG_S0] = (libucontext_greg_t) ucp->uc_link;
+	ucp->uc_mcontext.__gregs[REG_SP] = (libucontext_greg_t) sp;
+	ucp->uc_mcontext.__pc            = (libucontext_greg_t) func;
+
+	va_start(va, argc);
+
+	/* first 8 args go in $a0 through $a7. */
+	regp = &(ucp->uc_mcontext.__gregs[REG_A0]);
+
+	for (i = 0; (i < argc && i < 8); i++)
+		*regp++ = va_arg (va, libucontext_greg_t);
+
+	/* remainder overflows into stack */
+	for (; i < argc; i++)
+		*sp++ = va_arg (va, libucontext_greg_t);
+
+	va_end(va);
+}
+
+#ifdef EXPORT_UNPREFIXED
+extern __typeof(libucontext_makecontext) makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+extern __typeof(libucontext_makecontext) __makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+#endif

arch/loongarch64/setcontext.S

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2021 Peng Fan <fanpeng@loongson.cn>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#define LOCALSZ (1)
+
+#include "defs.h"
+
+ALIAS(setcontext, libucontext_setcontext)
+
+FUNC(libucontext_setcontext)
+	PUSH_FRAME(libucontext_setcontext)
+
+	/* move the context to $v0, in LA, $v0 = $a0 = $4 */
+	move	$t5, $a0
+
+	/* load the registers */
+	ld.d	$a0, $t5, REG_OFFSET(4)
+	ld.d	$a1, $t5, REG_OFFSET(5)
+	ld.d	$a2, $t5, REG_OFFSET(6)
+	ld.d	$a3, $t5, REG_OFFSET(7)
+	ld.d	$a4, $t5, REG_OFFSET(8)
+	ld.d	$a5, $t5, REG_OFFSET(9)
+	ld.d	$a6, $t5, REG_OFFSET(10)
+	ld.d	$a7, $t5, REG_OFFSET(11)
+
+	ld.d	$s0, $t5, REG_OFFSET(23)
+	ld.d	$s1, $t5, REG_OFFSET(24)
+	ld.d	$s2, $t5, REG_OFFSET(25)
+	ld.d	$s3, $t5, REG_OFFSET(26)
+	ld.d	$s4, $t5, REG_OFFSET(27)
+	ld.d	$s5, $t5, REG_OFFSET(28)
+	ld.d	$s6, $t5, REG_OFFSET(29)
+	ld.d	$s7, $t5, REG_OFFSET(30)
+	ld.d	$s8, $t5, REG_OFFSET(31)
+
+	ld.d	$sp, $t5, REG_OFFSET(3)
+	ld.d	$fp, $t5, REG_OFFSET(22)
+	ld.d	$ra, $t5, REG_OFFSET(1)
+
+	ld.d	$t8, $t5, (MCONTEXT_PC)
+
+	jr	$t8
+	move	$a0, $zero
+
+	POP_FRAME(libucontext_setcontext)
+END(libucontext_setcontext)

arch/loongarch64/startcontext.S

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2021 Peng Fan <fanpeng@loongson.cn>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#define LOCALSZ (4)
+
+#include "defs.h"
+
+FUNC(libucontext_trampoline)
+
+	/* call setcontext */
+	move	$a0, $s0
+	/* we receive our initial ucontext in $s0, so if $s0 is nil, bail */
+	beqz	$s0, no_linked_context
+
+	la.got	$t8, libucontext_setcontext
+
+	jr	$t8
+
+no_linked_context:
+	move	$a0, $zero
+	la.global	$t8, exit
+	jr	$t8
+
+END(libucontext_trampoline)

arch/loongarch64/swapcontext.S

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2021 Peng Fan <fanpeng@loongson.cn>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#define	LOCALSZ	(4)
+
+#include "defs.h"
+
+#define A1_OFFSET (FRAMESZ - (1 * REG_SZ))
+
+ALIAS(swapcontext, libucontext_swapcontext)
+
+FUNC(libucontext_swapcontext)
+	/* copy $sp, $fp to temporary registers so we don't clobber them */
+	move	$a3, $sp
+	move	$a4, $fp
+
+	move	$t5, $a0
+
+	PUSH_FRAME(libucontext_swapcontext)
+
+	/* set registers */
+	st.d	$s0, $t5, REG_OFFSET(23)
+	st.d	$s1, $t5, REG_OFFSET(24)
+	st.d	$s2, $t5, REG_OFFSET(25)
+	st.d	$s3, $t5, REG_OFFSET(26)
+	st.d	$s4, $t5, REG_OFFSET(27)
+	st.d	$s5, $t5, REG_OFFSET(28)
+	st.d	$s6, $t5, REG_OFFSET(29)
+	st.d	$s7, $t5, REG_OFFSET(30)
+	st.d	$s8, $t5, REG_OFFSET(31)
+
+	st.d	$a3, $t5, REG_OFFSET(3)
+	st.d	$zero, $t5, REG_OFFSET(4)
+	st.d	$a4, $t5, REG_OFFSET(22)
+	st.d	$ra, $t5, REG_OFFSET(1)
+
+	st.d	$ra, $t5, (MCONTEXT_PC)
+
+	/* copy new context address in $a1 to stack */
+	st.d	$a1, $sp, A1_OFFSET
+
+	/* load new context address into $v0 */
+	ld.d	$t4, $sp, A1_OFFSET
+
+	/* load the registers */
+	ld.d	$a0, $t4, REG_OFFSET(4)
+	ld.d	$a1, $t4, REG_OFFSET(5)
+	ld.d	$a2, $t4, REG_OFFSET(6)
+	ld.d	$a3, $t4, REG_OFFSET(7)
+	ld.d	$a4, $t4, REG_OFFSET(8)
+	ld.d	$a5, $t4, REG_OFFSET(9)
+	ld.d	$a6, $t4, REG_OFFSET(10)
+	ld.d	$a7, $t4, REG_OFFSET(11)
+
+	ld.d	$s0, $t4, REG_OFFSET(23)
+	ld.d	$s1, $t4, REG_OFFSET(24)
+	ld.d	$s2, $t4, REG_OFFSET(25)
+	ld.d	$s3, $t4, REG_OFFSET(26)
+	ld.d	$s4, $t4, REG_OFFSET(27)
+	ld.d	$s5, $t4, REG_OFFSET(28)
+	ld.d	$s6, $t4, REG_OFFSET(29)
+	ld.d	$s7, $t4, REG_OFFSET(30)
+	ld.d	$s8, $t4, REG_OFFSET(31)
+
+	ld.d	$sp, $t4, REG_OFFSET(3)
+	ld.d	$fp, $t4, REG_OFFSET(22)
+	ld.d	$ra, $t4, REG_OFFSET(1)
+
+	ld.d	$t8, $t4, (MCONTEXT_PC)
+
+	jr	$t8
+	move	$a0, $zero
+
+fail:
+	la.global	$t8, exit
+
+	POP_FRAME(libucontext_swapcontext)
+
+	jirl	$ra, $t8, 0
+	move	$a0, $zero
+END(libucontext_swapcontext)

arch/m68k/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/or1k/defs.h

@@ -0,0 +1,22 @@
+#ifndef __ARCH_OR1K_DEFS_H
+#define __ARCH_OR1K_DEFS_H
+
+#define REG_SZ		(4)
+#define MCONTEXT_GREGS	(20)
+
+#define REG_SP		(1)
+#define REG_FP		(2)
+#define REG_RA		(9)
+#define REG_SA		(11)
+#define REG_LR		(14)
+#define REG_PC		(33)
+#define REG_SR		(34)
+
+#define PC_OFFSET	REG_OFFSET(REG_PC)
+
+#define FETCH_LINKPTR(dest) \
+	asm("l.ori %0, r14, 0" :: "r" ((dest)))
+
+#include "common-defs.h"
+
+#endif

arch/or1k/getcontext.S

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2022 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(getcontext, libucontext_getcontext)
+ALIAS(__getcontext, libucontext_getcontext)
+
+FUNC(libucontext_getcontext)
+	l.sw		REG_OFFSET(1)(r3), r1			/* store r1 and r2 */
+	l.sw		REG_OFFSET(2)(r3), r2
+
+	l.sw		REG_OFFSET(9)(r3), r9			/* link register */
+	l.sw		REG_OFFSET(11)(r3), r0			/* return value is 0 */
+
+	l.sw		REG_OFFSET(10)(r3), r10			/* store r10 for TLS */
+
+	l.sw		REG_OFFSET(14)(r3), r14			/* store r14 through r30 even */
+	l.sw		REG_OFFSET(16)(r3), r16
+	l.sw		REG_OFFSET(18)(r3), r18
+	l.sw		REG_OFFSET(20)(r3), r20
+	l.sw		REG_OFFSET(22)(r3), r22
+	l.sw		REG_OFFSET(24)(r3), r24
+	l.sw		REG_OFFSET(26)(r3), r26
+	l.sw		REG_OFFSET(28)(r3), r28
+	l.sw		REG_OFFSET(30)(r3), r30
+
+	l.ori		r11, r0, 0
+	l.jr		r9
+END(libucontext_getcontext)

arch/or1k/include/libucontext/bits.h

@@ -0,0 +1,28 @@
+#ifndef LIBUCONTEXT_BITS_H
+#define LIBUCONTEXT_BITS_H
+
+typedef struct sigaltstack {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} libucontext_stack_t;
+
+typedef int libucontext_greg_t, libucontext_gregset_t[32];
+
+typedef struct {
+	struct {
+		libucontext_gregset_t gpr;
+		libucontext_greg_t pc;
+		libucontext_greg_t sr;
+	} regs;
+	unsigned long oldmask;
+} libucontext_mcontext_t;
+
+typedef struct libucontext_ucontext {
+	unsigned long uc_flags;
+	struct libucontext_ucontext *uc_link;
+	libucontext_stack_t uc_stack;
+	libucontext_mcontext_t uc_mcontext;
+} libucontext_ucontext_t;
+
+#endif

arch/or1k/makecontext.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2022 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <stddef.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "defs.h"
+#include <libucontext/libucontext.h>
+
+
+extern void libucontext_trampoline(void);
+
+
+void
+libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	libucontext_greg_t *sp;
+	va_list va;
+	int i;
+
+	/* set up and align the stack. */
+	sp = (libucontext_greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	sp -= argc < 6 ? 0 : (argc - 6);
+	sp = (libucontext_greg_t *) (((uintptr_t) sp & ~0x3));
+
+	/* set up the ucontext structure */
+	ucp->uc_mcontext.regs.gpr[REG_SP] = (libucontext_greg_t) sp;
+	ucp->uc_mcontext.regs.gpr[REG_RA] = (libucontext_greg_t) &libucontext_trampoline;
+	ucp->uc_mcontext.regs.gpr[REG_FP] = 0;
+	ucp->uc_mcontext.regs.gpr[REG_SA] = (libucontext_greg_t) func;
+	ucp->uc_mcontext.regs.gpr[REG_LR] = (libucontext_greg_t) ucp->uc_link;
+
+	va_start(va, argc);
+
+	/* args less than argv[6] have dedicated registers, else they overflow onto stack */
+	for (i = 0; i < argc; i++)
+	{
+		if (i < 6)
+			ucp->uc_mcontext.regs.gpr[i + 3] = va_arg (va, libucontext_greg_t);
+		else
+			sp[i - 6] = va_arg (va, libucontext_greg_t);
+	}
+
+	va_end(va);
+}
+
+#ifdef EXPORT_UNPREFIXED
+extern __typeof(libucontext_makecontext) makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+extern __typeof(libucontext_makecontext) __makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+#endif

arch/or1k/setcontext.S

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2022 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(setcontext, libucontext_setcontext)
+ALIAS(__setcontext, libucontext_setcontext)
+
+FUNC(libucontext_setcontext)
+	l.ori		r30, r3, 0				/* avoid clobbering r3 by copying to r30 */
+
+	l.lwz		r3, REG_OFFSET(3)(r30)			/* restore r3-r8 (argument registers) */
+	l.lwz		r4, REG_OFFSET(4)(r30)
+	l.lwz		r5, REG_OFFSET(5)(r30)
+	l.lwz		r6, REG_OFFSET(6)(r30)
+	l.lwz		r7, REG_OFFSET(7)(r30)
+	l.lwz		r8, REG_OFFSET(8)(r30)
+
+	l.lwz		r1, REG_OFFSET(1)(r30)			/* restore stack/frame pointers */
+	l.lwz		r2, REG_OFFSET(2)(r30)
+
+	l.lwz		r9, REG_OFFSET(9)(r30)			/* restore link register and starting address register */
+	l.lwz		r11, REG_OFFSET(11)(r30)
+
+	l.lwz		r10, REG_OFFSET(10)(r30)		/* restore TLS register */
+
+	l.lwz		r14, REG_OFFSET(14)(r30)		/* restore r14-r30, even only */
+	l.lwz		r16, REG_OFFSET(16)(r30)
+	l.lwz		r18, REG_OFFSET(18)(r30)
+	l.lwz		r20, REG_OFFSET(20)(r30)
+	l.lwz		r22, REG_OFFSET(22)(r30)
+	l.lwz		r24, REG_OFFSET(24)(r30)
+	l.lwz		r26, REG_OFFSET(26)(r30)
+	l.lwz		r28, REG_OFFSET(28)(r30)
+	l.lwz		r30, REG_OFFSET(30)(r30)
+
+	l.jr		r11					/* jump to new starting address */
+	l.ori		r11, r0, 0
+END(libucontext_setcontext)

arch/or1k/swapcontext.S

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2022 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(swapcontext, libucontext_swapcontext)
+ALIAS(__swapcontext, libucontext_swapcontext)
+
+FUNC(libucontext_swapcontext)
+	/* copy context into r3 like getcontext */
+	l.sw		REG_OFFSET(1)(r3), r1			/* store r1 and r2 */
+	l.sw		REG_OFFSET(2)(r3), r2
+
+	l.sw		REG_OFFSET(9)(r3), r9			/* link register */
+	l.sw		REG_OFFSET(11)(r3), r0			/* return value is zero */
+
+	l.sw		REG_OFFSET(10)(r3), r10			/* store r10 for TLS */
+
+	l.sw		REG_OFFSET(14)(r3), r14			/* store r14 through r30 even */
+	l.sw		REG_OFFSET(16)(r3), r16
+	l.sw		REG_OFFSET(18)(r3), r18
+	l.sw		REG_OFFSET(20)(r3), r20
+	l.sw		REG_OFFSET(22)(r3), r22
+	l.sw		REG_OFFSET(24)(r3), r24
+	l.sw		REG_OFFSET(26)(r3), r26
+	l.sw		REG_OFFSET(28)(r3), r28
+	l.sw		REG_OFFSET(30)(r3), r30
+
+	/* set the new context from r4 */
+	l.ori		r30, r4, 0				/* copy r4 to r30 to avoid clobbering */
+
+	l.lwz		r3, REG_OFFSET(3)(r30)			/* restore r3-r8 (argument registers) */
+	l.lwz		r4, REG_OFFSET(4)(r30)
+	l.lwz		r5, REG_OFFSET(5)(r30)
+	l.lwz		r6, REG_OFFSET(6)(r30)
+	l.lwz		r7, REG_OFFSET(7)(r30)
+	l.lwz		r8, REG_OFFSET(8)(r30)
+
+	l.lwz		r1, REG_OFFSET(1)(r30)			/* restore stack/frame pointers */
+	l.lwz		r2, REG_OFFSET(2)(r30)
+
+	l.lwz		r9, REG_OFFSET(9)(r30)			/* restore link register and starting address register */
+	l.lwz		r11, REG_OFFSET(11)(r30)
+
+	l.lwz		r10, REG_OFFSET(10)(r30)		/* restore TLS register */
+
+	l.lwz		r14, REG_OFFSET(14)(r30)		/* restore r14-r30, even only */
+	l.lwz		r16, REG_OFFSET(16)(r30)
+	l.lwz		r18, REG_OFFSET(18)(r30)
+	l.lwz		r20, REG_OFFSET(20)(r30)
+	l.lwz		r22, REG_OFFSET(22)(r30)
+	l.lwz		r24, REG_OFFSET(24)(r30)
+	l.lwz		r26, REG_OFFSET(26)(r30)
+	l.lwz		r28, REG_OFFSET(28)(r30)
+	l.lwz		r30, REG_OFFSET(30)(r30)
+
+	l.ori		r11, r0, 0
+	l.jr		r9					/* jump to new starting address */
+END(libucontext_swapcontext)

arch/ppc/makecontext.c

@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdarg.h>
 #include <stdint.h>
 

arch/ppc64/makecontext.c

@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdarg.h>
 #include <stdint.h>
 

arch/riscv32/defs.h

@@ -0,0 +1,55 @@
+#ifndef __ARCH_RISCV64_DEFS_H
+#define __ARCH_RISCV64_DEFS_H
+
+#define REG_SZ		(4)
+#define MCONTEXT_GREGS	(160)
+
+/* program counter is saved in x0 as well as x1, similar to mips */
+#ifndef REG_PC
+#define REG_PC		(0)
+#endif
+
+#ifndef REG_RA
+#define REG_RA		(1)
+#endif
+
+#ifndef REG_SP
+#define REG_SP		(2)
+#endif
+
+#ifndef REG_S0
+#define REG_S0		(8)
+#endif
+
+#define REG_S1		(9)
+
+#ifndef REG_A0
+#define REG_A0		(10)
+#endif
+
+#define REG_A1		(11)
+#define REG_A2		(12)
+#define REG_A3		(13)
+#define REG_A4		(14)
+#define REG_A5		(15)
+#define REG_A6		(16)
+#define REG_A7		(17)
+#define REG_S2		(18)
+#define REG_S3		(19)
+#define REG_S4		(20)
+#define REG_S5		(21)
+#define REG_S6		(22)
+#define REG_S7		(23)
+#define REG_S8		(24)
+#define REG_S9		(25)
+#define REG_S10		(26)
+#define REG_S11		(27)
+
+#define PC_OFFSET	REG_OFFSET(REG_PC)
+
+#define FETCH_LINKPTR(dest) \
+	asm("mv	%0, s1" : "=r" ((dest)))
+
+#include "common-defs.h"
+
+#endif

arch/riscv32/getcontext.S

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(getcontext, libucontext_getcontext)
+ALIAS(__getcontext, libucontext_getcontext)
+
+FUNC(libucontext_getcontext)
+	sw ra, REG_OFFSET(REG_PC)(a0)
+	sw ra, REG_OFFSET(REG_RA)(a0)
+	sw sp, REG_OFFSET(REG_SP)(a0)
+
+	/* first saved register block */
+	sw s0, REG_OFFSET(REG_S0)(a0)
+	sw s1, REG_OFFSET(REG_S1)(a0)
+
+	/* return register block */
+	sw x0, REG_OFFSET(REG_A0)(a0)
+	sw x0, REG_OFFSET(REG_A1)(a0)
+
+	/* second saved register block */
+	sw s2, REG_OFFSET(REG_S2)(a0)
+	sw s3, REG_OFFSET(REG_S3)(a0)
+	sw s4, REG_OFFSET(REG_S4)(a0)
+	sw s5, REG_OFFSET(REG_S5)(a0)
+	sw s6, REG_OFFSET(REG_S6)(a0)
+	sw s7, REG_OFFSET(REG_S7)(a0)
+	sw s8, REG_OFFSET(REG_S8)(a0)
+	sw s9, REG_OFFSET(REG_S9)(a0)
+	sw s10, REG_OFFSET(REG_S10)(a0)
+	sw s11, REG_OFFSET(REG_S11)(a0)
+
+	/* done saving, return */
+	mv a0, x0
+	ret
+END(libucontext_getcontext)

arch/riscv32/makecontext.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <stddef.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "defs.h"
+#include <libucontext/libucontext.h>
+
+
+extern void libucontext_trampoline(void);
+
+
+void
+libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	libucontext_greg_t *sp, *regp;
+	va_list va;
+	int i;
+
+	/* set up and align the stack. */
+	sp = (libucontext_greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	sp -= argc < 8 ? 0 : argc - 8;
+	sp = (libucontext_greg_t *) (((uintptr_t) sp & -16L));
+
+	/* set up the ucontext structure */
+	ucp->uc_mcontext.__gregs[REG_RA] = (libucontext_greg_t) libucontext_trampoline;
+	ucp->uc_mcontext.__gregs[REG_S0] = 0;
+	ucp->uc_mcontext.__gregs[REG_S1] = (libucontext_greg_t) ucp->uc_link;
+	ucp->uc_mcontext.__gregs[REG_SP] = (libucontext_greg_t) sp;
+	ucp->uc_mcontext.__gregs[REG_PC] = (libucontext_greg_t) func;
+
+	va_start(va, argc);
+
+	/* first 8 args go in $a0 through $a7. */
+	regp = &(ucp->uc_mcontext.__gregs[REG_A0]);
+
+	for (i = 0; (i < argc && i < 8); i++)
+		*regp++ = va_arg (va, libucontext_greg_t);
+
+	/* remainder overflows into stack */
+	for (; i < argc; i++)
+		*sp++ = va_arg (va, libucontext_greg_t);
+
+	va_end(va);
+}
+
+#ifdef EXPORT_UNPREFIXED
+extern __typeof(libucontext_makecontext) makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+extern __typeof(libucontext_makecontext) __makecontext __attribute__((weak, __alias__("libucontext_makecontext")));
+#endif

arch/riscv32/setcontext.S

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(setcontext, libucontext_setcontext)
+ALIAS(__setcontext, libucontext_setcontext)
+
+FUNC(libucontext_setcontext)
+	/* move $a0 to $t0 to avoid clobbering. */
+	mv t0, a0
+
+	lw t1, PC_OFFSET(t0)
+	lw ra, REG_OFFSET(REG_RA)(t0)
+	lw sp, REG_OFFSET(REG_SP)(t0)
+
+	/* first saved register block */
+	lw s0, REG_OFFSET(REG_S0)(t0)
+	lw s1, REG_OFFSET(REG_S1)(t0)
+
+	/* return register block */
+	lw a0, REG_OFFSET(REG_A0)(t0)
+	lw a1, REG_OFFSET(REG_A1)(t0)
+
+	/* argument register block */
+	lw a2, REG_OFFSET(REG_A2)(t0)
+	lw a3, REG_OFFSET(REG_A3)(t0)
+	lw a4, REG_OFFSET(REG_A4)(t0)
+	lw a5, REG_OFFSET(REG_A5)(t0)
+	lw a6, REG_OFFSET(REG_A6)(t0)
+	lw a7, REG_OFFSET(REG_A7)(t0)
+
+	/* second saved register block */
+	lw s2, REG_OFFSET(REG_S2)(t0)
+	lw s3, REG_OFFSET(REG_S3)(t0)
+	lw s4, REG_OFFSET(REG_S4)(t0)
+	lw s5, REG_OFFSET(REG_S5)(t0)
+	lw s6, REG_OFFSET(REG_S6)(t0)
+	lw s7, REG_OFFSET(REG_S7)(t0)
+	lw s8, REG_OFFSET(REG_S8)(t0)
+	lw s9, REG_OFFSET(REG_S9)(t0)
+	lw s10, REG_OFFSET(REG_S10)(t0)
+	lw s11, REG_OFFSET(REG_S11)(t0)
+
+	/* done restoring, jump to new pc in S1 */
+	jr t1
+END(libucontext_setcontext)

arch/riscv32/swapcontext.S

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+ALIAS(swapcontext, libucontext_swapcontext)
+ALIAS(__swapcontext, libucontext_swapcontext)
+
+FUNC(libucontext_swapcontext)
+	/* move $a1 to $t0 to avoid clobbering. */
+	mv t0, a1
+
+	sw ra, REG_OFFSET(REG_PC)(a0)
+	sw ra, REG_OFFSET(REG_RA)(a0)
+	sw sp, REG_OFFSET(REG_SP)(a0)
+
+	/* first saved register block */
+	sw s0, REG_OFFSET(REG_S0)(a0)
+	sw s1, REG_OFFSET(REG_S1)(a0)
+
+	/* return register block */
+	sw x0, REG_OFFSET(REG_A0)(a0)
+	sw x0, REG_OFFSET(REG_A1)(a0)
+
+	/* second saved register block */
+	sw s2, REG_OFFSET(REG_S2)(a0)
+	sw s3, REG_OFFSET(REG_S3)(a0)
+	sw s4, REG_OFFSET(REG_S4)(a0)
+	sw s5, REG_OFFSET(REG_S5)(a0)
+	sw s6, REG_OFFSET(REG_S6)(a0)
+	sw s7, REG_OFFSET(REG_S7)(a0)
+	sw s8, REG_OFFSET(REG_S8)(a0)
+	sw s9, REG_OFFSET(REG_S9)(a0)
+	sw s10, REG_OFFSET(REG_S10)(a0)
+	sw s11, REG_OFFSET(REG_S11)(a0)
+
+	/* restore the other context from $t0. */
+	lw t1, REG_OFFSET(REG_PC)(t0)
+	lw ra, REG_OFFSET(REG_RA)(t0)
+	lw sp, REG_OFFSET(REG_SP)(t0)
+
+	/* first saved register block */
+	lw s0, REG_OFFSET(REG_S0)(t0)
+	lw s1, REG_OFFSET(REG_S1)(t0)
+
+	/* return register block */
+	lw a0, REG_OFFSET(REG_A0)(t0)
+	lw a1, REG_OFFSET(REG_A1)(t0)
+
+	/* argument register block */
+	lw a2, REG_OFFSET(REG_A2)(t0)
+	lw a3, REG_OFFSET(REG_A3)(t0)
+	lw a4, REG_OFFSET(REG_A4)(t0)
+	lw a5, REG_OFFSET(REG_A5)(t0)
+	lw a6, REG_OFFSET(REG_A6)(t0)
+	lw a7, REG_OFFSET(REG_A7)(t0)
+
+	/* second saved register block */
+	lw s2, REG_OFFSET(REG_S2)(t0)
+	lw s3, REG_OFFSET(REG_S3)(t0)
+	lw s4, REG_OFFSET(REG_S4)(t0)
+	lw s5, REG_OFFSET(REG_S5)(t0)
+	lw s6, REG_OFFSET(REG_S6)(t0)
+	lw s7, REG_OFFSET(REG_S7)(t0)
+	lw s8, REG_OFFSET(REG_S8)(t0)
+	lw s9, REG_OFFSET(REG_S9)(t0)
+	lw s10, REG_OFFSET(REG_S10)(t0)
+	lw s11, REG_OFFSET(REG_S11)(t0)
+
+	/* done swapping, jump to new PC in S1 */
+	jr t1
+END(libucontext_swapcontext)

arch/riscv32/trampoline.c

@@ -0,0 +1,3 @@
+#include "defs.h"
+#include <libucontext/libucontext.h>
+#include "common-trampoline.c"

arch/riscv64/getcontext.S

@@ -25,8 +25,8 @@ FUNC(libucontext_getcontext)
 	sd s1, REG_OFFSET(REG_S1)(a0)
 
 	/* return register block */
-	sd a0, REG_OFFSET(REG_A0)(a0)
-	sd a1, REG_OFFSET(REG_A1)(a0)
+	sd x0, REG_OFFSET(REG_A0)(a0)
+	sd x0, REG_OFFSET(REG_A1)(a0)
 
 	/* second saved register block */
 	sd s2, REG_OFFSET(REG_S2)(a0)
@@ -41,5 +41,6 @@ FUNC(libucontext_getcontext)
 	sd s11, REG_OFFSET(REG_S11)(a0)
 
 	/* done saving, return */
+	mv a0, x0
 	ret
 END(libucontext_getcontext)

arch/riscv64/include/libucontext/bits.h

@@ -0,0 +1,48 @@
+#ifndef LIBUCONTEXT_BITS_H
+#define LIBUCONTEXT_BITS_H
+
+typedef unsigned long libucontext_greg_t;
+typedef unsigned long libucontext__riscv_mc_gp_state[32];
+
+struct libucontext__riscv_mc_f_ext_state {
+	unsigned int __f[32];
+	unsigned int __fcsr;
+};
+
+struct libucontext__riscv_mc_d_ext_state {
+	unsigned long long __f[32];
+	unsigned int __fcsr;
+};
+
+struct libucontext__riscv_mc_q_ext_state {
+	unsigned long long __f[64] __attribute__((aligned(16)));
+	unsigned int __fcsr;
+	unsigned int __reserved[3];
+};
+
+union libucontext__riscv_mc_fp_state {
+	struct libucontext__riscv_mc_f_ext_state __f;
+	struct libucontext__riscv_mc_d_ext_state __d;
+	struct libucontext__riscv_mc_q_ext_state __q;
+};
+
+typedef struct libucontext_mcontext {
+	libucontext__riscv_mc_gp_state __gregs;
+	union libucontext__riscv_mc_fp_state __fpregs;
+} libucontext_mcontext_t;
+
+typedef struct {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} libucontext_stack_t;
+
+typedef struct libucontext_ucontext {
+	unsigned long uc_flags;
+	struct libucontext_ucontext *uc_link;
+	libucontext_stack_t uc_stack;
+	unsigned char __pad[128];
+	libucontext_mcontext_t uc_mcontext;
+} libucontext_ucontext_t;
+
+#endif

arch/riscv64/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/riscv64/swapcontext.S

@@ -28,8 +28,8 @@ FUNC(libucontext_swapcontext)
 	sd s1, REG_OFFSET(REG_S1)(a0)
 
 	/* return register block */
-	sd a0, REG_OFFSET(REG_A0)(a0)
-	sd a1, REG_OFFSET(REG_A1)(a0)
+	sd x0, REG_OFFSET(REG_A0)(a0)
+	sd x0, REG_OFFSET(REG_A1)(a0)
 
 	/* second saved register block */
 	sd s2, REG_OFFSET(REG_S2)(a0)

arch/s390x/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/s390x/swapcontext.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020, 2024 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -19,12 +19,14 @@ FUNC(libucontext_swapcontext)
 	lgr	%r1, %r2			/* use %r1 to save current context to */
 	lgr	%r0, %r3			/* use %r0 for source context */
 
+	la	%r2, 0				/* zero out future return value */
+
 	stam	%a0, %a15, AREG_OFFSET(0)(%r1)	/* store access registers */
 	stmg	%r0, %r15, REG_OFFSET(0)(%r1)	/* store general-purpose registers */
 
-	lgr	%r2, %r0			/* swap %r0 to %r2 (XXX: figure out why it hates loading from %r0) */
-	lam	%a2, %a15, AREG_OFFSET(2)(%r2)	/* load access registers, but skip %a0 and %a1 which are for TLS */
-	lmg	%r0, %r15, REG_OFFSET(0)(%r2)	/* load general-purpose registers */
+	lgr	%r5, %r0			/* copy %r0 to %r5 so that %r0 doesn't get clobbered */
+	lam	%a2, %a15, AREG_OFFSET(2)(%r5)	/* load access registers, but skip %a0 and %a1 which are for TLS */
+	lmg	%r0, %r15, REG_OFFSET(0)(%r5)	/* load general-purpose registers */
 
 	br	%r14				/* return to new link register address */
 END(libucontext_swapcontext)

arch/sh/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/x86/defs.h

@@ -1,7 +1,6 @@
 #ifndef __ARCH_X86_DEFS_H
 #define __ARCH_X86_DEFS_H
 
-#ifndef _GNU_SOURCE
 #ifndef REG_GS
 # define REG_GS		(0)
 #endif
@@ -53,15 +52,11 @@
 #ifndef REG_EIP
 # define REG_EIP	(14)
 #endif
-#endif
 
 #define REG_SZ		(4)
 
 #define MCONTEXT_GREGS	(20)
 
-#define FETCH_LINKPTR(dest) \
-	asm("movl (%%esp, %%ebx, 4), %0" : "=r" ((dest)));
-
 #include "common-defs.h"
 
 #endif

arch/x86/makecontext.c

@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

arch/x86/startcontext.S

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include "defs.h"
+
+FUNC(libucontext_trampoline)
+	/* get the proper context into position and test for NULL */
+	leal	(%esp,%ebx,4), %esp
+	cmpl	$0, (%esp)
+
+	/* restore global offset table, exit@plt and libucontext_setcontext@plt need this */
+	call	__i686_get_pc_thunk_bx
+	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
+
+	/* if we have no linked context, lets get out of here */
+	je	no_linked_context
+
+	/* call setcontext to switch to the linked context */
+	call	libucontext_setcontext@plt
+	movl	%eax, (%esp)
+
+no_linked_context:
+	/* we are returning into a null context, it seems, so maybe we should exit */
+	call	exit@plt
+
+	/* something is really hosed, call hlt to force termination */
+	hlt
+
+__i686_get_pc_thunk_bx:
+	mov	(%esp), %ebx
+	ret
+END(libucontext_trampoline)

arch/x86_64/defs.h

@@ -1,29 +1,95 @@
 #ifndef __ARCH_X86_64_DEFS_H
 #define __ARCH_X86_64_DEFS_H
 
-#ifndef _GNU_SOURCE
+#ifndef REG_R8
 # define REG_R8		(0)
+#endif
+
+#ifndef REG_R9
 # define REG_R9		(1)
+#endif
+
+#ifndef REG_R10
 # define REG_R10	(2)
+#endif
+
+#ifndef REG_R11
 # define REG_R11	(3)
+#endif
+
+#ifndef REG_R12
 # define REG_R12	(4)
+#endif
+
+#ifndef REG_R13
 # define REG_R13	(5)
+#endif
+
+#ifndef REG_R14
 # define REG_R14	(6)
+#endif
+
+#ifndef REG_R15
 # define REG_R15	(7)
+#endif
+
+#ifndef REG_RDI
 # define REG_RDI	(8)
+#endif
+
+#ifndef REG_RSI
 # define REG_RSI	(9)
+#endif
+
+#ifndef REG_RBP
 # define REG_RBP	(10)
+#endif
+
+#ifndef REG_RBX
 # define REG_RBX	(11)
+#endif
+
+#ifndef REG_RDX
 # define REG_RDX	(12)
+#endif
+
+#ifndef REG_RAX
 # define REG_RAX	(13)
+#endif
+
+#ifndef REG_RCX
 # define REG_RCX	(14)
+#endif
+
+#ifndef REG_RSP
 # define REG_RSP	(15)
+#endif
+
+#ifndef REG_RIP
 # define REG_RIP	(16)
+#endif
+
+#ifndef REG_EFL
 # define REG_EFL	(17)
+#endif
+
+#ifndef REG_CSGSFS
 # define REG_CSGSFS	(18)
+#endif
+
+#ifndef REG_ERR
 # define REG_ERR	(19)
+#endif
+
+#ifndef REG_TRAPNO
 # define REG_TRAPNO	(20)
+#endif
+
+#ifndef REG_OLDMASK
 # define REG_OLDMASK	(21)
+#endif
+
+#ifndef REG_CR2
 # define REG_CR2	(22)
 #endif
 

arch/x86_64/makecontext.c

@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>

doc/meson.build

@@ -0,0 +1,21 @@
+scdoc = find_program('scdoc', required: true)
+
+custom_target(
+  'libucontext.3',
+  output: 'libucontext.3',
+  input: 'libucontext.scd',
+  command: [ scdoc ],
+  feed: true,
+  capture: true,
+  install: true,
+  install_dir: get_option('mandir') / 'man3'
+)
+
+if meson.version().version_compare('>=0.61.0')
+  foreach link : [ 'get', 'make', 'set', 'swap' ]
+    install_symlink('libucontext_' + link + 'context.3',
+      pointing_to: 'libucontext.3',
+      install_dir: get_option('mandir') / 'man3'
+    )
+  endforeach
+endif

include/libucontext/libucontext.h

@@ -4,9 +4,17 @@
 #include <stddef.h>
 #include <libucontext/bits.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 int  libucontext_getcontext(libucontext_ucontext_t *);
 void libucontext_makecontext(libucontext_ucontext_t *, void (*)(), int, ...);
 int  libucontext_setcontext(const libucontext_ucontext_t *);
 int  libucontext_swapcontext(libucontext_ucontext_t *, const libucontext_ucontext_t *);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif

libucontext.pc.in

@@ -1,8 +1,9 @@
-libdir=@LIBUCONTEXT_LIBDIR@
+libdir=@LIBUCONTEXT_SHARED_LIBDIR@
+static_libdir=@LIBUCONTEXT_STATIC_LIBDIR@
 includedir=@LIBUCONTEXT_INCLUDEDIR@
 
 Name: libucontext
 Version: @LIBUCONTEXT_VERSION@
 Description: ucontext library implementation (standalone)
-Libs: -L${libdir} -lucontext
+Libs: -L${libdir} -L${static_libdir} -lucontext
 Cflags: -I${includedir}

meson.build

@@ -1,12 +1,16 @@
 project(
   'libucontext',
   'c',
-  meson_version : '>=0.55.0',
+  meson_version : '>=0.59.0',
   default_options: ['c_std=gnu11', 'default_library=both'],
   version : run_command('head', files('VERSION')).stdout()
 )
 
-cpu = host_machine.cpu_family()
+cpu = get_option('cpu')
+if cpu == ''
+  cpu = host_machine.cpu_family()
+endif
+
 if cpu == 'sh4'
   cpu = 'sh'
 endif
@@ -36,7 +40,7 @@ if cpu in ['ppc', 'ppc64']
     'arch' / cpu / 'retfromsyscall.c'
   ]
 endif
-if cpu not in ['mips', 'mips64', 'ppc', 'ppc64', 's390x']
+if cpu not in ['loongarch64', 'mips', 'mips64', 'ppc', 'ppc64', 's390x', 'x86']
   project_source_files += [
     'arch' / cpu / 'trampoline.c'
   ]
@@ -52,7 +56,7 @@ project_includes = [
 ]
 
 build_args = [
-  '-D_BSD_SOURCE'
+  '-D_DEFAULT_SOURCE'
 ]
 
 
@@ -70,9 +74,11 @@ if freestanding
   build_args += '-DFREESTANDING'
   build_posix = false
   export_unprefixed = false
-  project_headers += ['arch' / cpu / 'freestanding/bits.h']
+  project_headers += ['arch' / cpu / 'include/libucontext/bits.h']
+  project_includes += ['arch' / cpu / 'include']
 else
-  project_headers += ['arch/common/bits.h']
+  project_headers += ['arch/common/include/libucontext/bits.h']
+  project_includes += ['arch/common/include']
 endif
 
 if export_unprefixed
@@ -138,9 +144,8 @@ endif
 # Docs
 # ====
 
-# TODO: meson.build for docs
-if not meson.is_subproject()
-  #subdir('docs')
+if not meson.is_subproject() and get_option('docs')
+  subdir('doc')
 endif
 
 # ==========

meson_options.txt

@@ -1,4 +1,8 @@
 option('freestanding', type : 'boolean', value : false,
        description: 'Do not use system headers')
 option('export_unprefixed', type : 'boolean', value : true,
-       description: 'Export POSIX 2004 ucontext names as alises')
+       description: 'Export POSIX 2004 ucontext names as alises')
+option('cpu', type : 'string', value : '',
+       description: 'Target CPU architecture for cross compile')
+option('docs', type : 'boolean', value : false,
+       description: 'Build and install man pages')

test_libucontext.c

@@ -9,6 +9,9 @@
 #include <string.h>
 #include <libucontext/libucontext.h>
 
+#define handle_error(msg) \
+           do { perror(msg); exit(EXIT_FAILURE); } while (0)
+
 static libucontext_ucontext_t ctx[3];
 
 
@@ -36,7 +39,8 @@ static void f1 (int a, int b, int c, int d, int e, int f, int g, int h, int i, i
 	printf("looks like all arguments are passed correctly\n");
 
 	printf("swap back to f2\n");
-	libucontext_swapcontext(&ctx[1], &ctx[2]);
+	if (libucontext_swapcontext(&ctx[1], &ctx[2]) != 0)
+		handle_error("libucontext_swapcontext");
 	printf("finish f1\n");
 }
 
@@ -44,7 +48,8 @@ static void f1 (int a, int b, int c, int d, int e, int f, int g, int h, int i, i
 static void f2 (void) {
 	printf("start f2\n");
 	printf("swap to f1\n");
-	libucontext_swapcontext(&ctx[2], &ctx[1]);
+	if (libucontext_swapcontext(&ctx[2], &ctx[1]) != 0)
+		handle_error("libucontext_swapcontext");
 	printf("finish f2, should swap to f1\n");
 }
 
@@ -63,7 +68,8 @@ int main (int argc, const char *argv[]) {
 	printf("setting up context 1\n");
 
 
-	libucontext_getcontext(&ctx[1]);
+	if (libucontext_getcontext(&ctx[1]) != 0)
+		handle_error("libucontext_getcontext");
 	ctx[1].uc_stack.ss_sp = st1;
 	ctx[1].uc_stack.ss_size = sizeof st1;
 	ctx[1].uc_link = &ctx[0];
@@ -83,16 +89,20 @@ int main (int argc, const char *argv[]) {
 	printf("doing initial swapcontext\n");
 
 
-	libucontext_swapcontext(&ctx[0], &ctx[2]);
+	if (libucontext_swapcontext(&ctx[0], &ctx[2]) != 0)
+		handle_error("libucontext_swapcontext");
 
 
 	printf("returned from initial swapcontext\n");
 
 
 	/* test ability to use getcontext/setcontext without makecontext */
-	libucontext_getcontext(&ctx[1]);
+	if (libucontext_getcontext(&ctx[1]) != 0)
+		handle_error("libucontext_getcontext");
 	printf("done = %d\n", done);
-	if (done++ == 0) libucontext_setcontext(&ctx[1]);
+	if (done++ == 0)
+		if (libucontext_setcontext(&ctx[1]) != 0)
+			handle_error("libucontext_setcontext");
 	if (done != 2) {
 		fprintf(stderr, "wrong value for done.  got %d, expected 2\n", done);
 		abort();

test_libucontext_posix.c

@@ -9,6 +9,9 @@
 #include <string.h>
 #include <ucontext.h>
 
+#define handle_error(msg) \
+           do { perror(msg); exit(EXIT_FAILURE); } while (0)
+
 static ucontext_t ctx[3];
 
 
@@ -36,7 +39,8 @@ static void f1 (int a, int b, int c, int d, int e, int f, int g, int h, int i, i
 	printf("looks like all arguments are passed correctly\n");
 
 	printf("swap back to f2\n");
-	swapcontext(&ctx[1], &ctx[2]);
+	if (swapcontext(&ctx[1], &ctx[2]) != 0)
+		handle_error("swapcontext");
 	printf("finish f1\n");
 }
 
@@ -44,7 +48,8 @@ static void f1 (int a, int b, int c, int d, int e, int f, int g, int h, int i, i
 static void f2 (void) {
 	printf("start f2\n");
 	printf("swap to f1\n");
-	swapcontext(&ctx[2], &ctx[1]);
+	if (swapcontext(&ctx[2], &ctx[1]) != 0)
+		handle_error("swapcontext");
 	printf("finish f2, should swap to f1\n");
 }
 
@@ -67,7 +72,7 @@ int main (int argc, const char *argv[]) {
 	ctx[1].uc_stack.ss_sp = st1;
 	ctx[1].uc_stack.ss_size = sizeof st1;
 	ctx[1].uc_link = &ctx[0];
-	makecontext(&ctx[1], f1, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+	makecontext(&ctx[1], (void *) f1, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
 
 
 	printf("setting up context 2\n");
@@ -77,22 +82,25 @@ int main (int argc, const char *argv[]) {
 	ctx[2].uc_stack.ss_sp = st2;
 	ctx[2].uc_stack.ss_size = sizeof st2;
 	ctx[2].uc_link = &ctx[1];
-	makecontext(&ctx[2], f2, 0);
+	makecontext(&ctx[2], (void *) f2, 0);
 
 
 	printf("doing initial swapcontext\n");
 
 
-	swapcontext(&ctx[0], &ctx[2]);
-
+	if (swapcontext(&ctx[0], &ctx[2]) != 0)
+		handle_error("swapcontext");
 
 	printf("returned from initial swapcontext\n");
 
 
 	/* test ability to use getcontext/setcontext without makecontext */
-	getcontext(&ctx[1]);
+	if (getcontext(&ctx[1]) != 0)
+		handle_error("getcontext");
 	printf("done = %d\n", done);
-	if (done++ == 0) setcontext(&ctx[1]);
+	if (done++ == 0)
+		if (setcontext(&ctx[1]) != 0)
+			handle_error("setcontext");
 	if (done != 2) {
 		fprintf(stderr, "wrong value for done.  got %d, expected 2\n", done);
 		abort();