From 536349ee7a5e136e49ca5df141d6e4919674f30c Mon Sep 17 00:00:00 2001 From: Marco Casaroli Date: Tue, 28 Jul 2026 00:36:25 +0200 Subject: [PATCH] testing/ostest: split the fork test into task_fork, vfork and fork nuttx implements fork() and vfork() as the same function, and is gaining the three separate primitives its issue #19540 describes: task_fork() (shares memory, private stack copy, both running), vfork() (shares memory, parent suspended) and POSIX fork() (child gets its own copy). This is the apps side of that, and it lands first: it works against nuttx with or without the split, so the tests keep running across the transition rather than silently compiling out. ostest's "vfork" test was never testing vfork(). It has the child write a global and the parent observe the write -- which is the defining property of *sharing*, not of vfork(), whose defining property is that the parent is suspended and whose contract forbids the child to write anything at all. It is renamed to task_fork.c, unchanged, because that is the primitive it has always described. vfork.c is rewritten to test what vfork() promises. The child does only what POSIX permits -- it calls _exit(42), and nothing else, not even exit(), which would run atexit handlers and flush stdio in the parent's address space. The observable is therefore the child's exit status rather than a memory write. Where child status is not retained -- ostest_main() sets SA_NOCLDWAIT for the whole run, deliberately -- waitpid() returning ECHILD is accepted as equally good evidence: it says the child was already gone when the parent asked. fork.c is new and tests POSIX fork(): the child's writes to .data, .bss and the heap are invisible to the parent and vice versa, a pointer to a stack local taken before the fork names the same object in both, and the child does everything a vfork() child may not -- calls malloc() and printf(), and returns from the function that called fork(). All three run at the top of user_main() rather than in the middle. They exercise the lowest-level machinery in the suite -- address environments, stack setup, the architecture's register context -- so a fault in one takes the process down instead of reporting a failure, and finding that out in seconds rather than after everything else has passed is the difference between a usable iteration and a coffee break when a port is being brought up. The other in-tree callers are audited for which primitive they actually meant. nand_sim wants a daemon that outlives its caller and shares its memory, which is task_fork(). bas's SHELL and EDIT statements, python's _posixsubprocess and libwebsockets' feature macros want the fork-then-exec path, which vfork() serves; python's os.fork() and libwebsockets' LWS_HAVE_FORK stay on fork() proper. fdsantest's vfork case follows vfork(). Two third-party suites need their source lists narrowed, because they call fork() from code that is compiled unconditionally: * system/libuv -- test-fork.c and test-pipe-close-stdout-read-stdin.c are filtered out of the test-*.c glob. Every test they define is already excluded from the task list on NuttX by 0001-libuv-port-for-nuttx.patch -- the nine fork_* entries and pipe_close_stdout_read_stdin -- so they were dead code being compiled only because fork() happened to be declared. * testing/ltp -- the open_posix_testsuite is filtered through the existing BLACKWORDS mechanism, which already drops tests for absent features and is already conditioned on configuration symbols. Where fork() is not provided this drops 278 of 1943 test files; the pattern is written to spare vfork() and task_fork(), which remain available. Where fork() is provided -- which today is everywhere -- nothing is dropped. Compatibility: CONFIG_ARCH_HAVE_TASK_FORK and CONFIG_ARCH_HAVE_VFORK do not exist in nuttx yet, so everything here also accepts the CONFIG_ARCH_HAVE_FORK that stands in for them today -- today's fork() *is* task_fork(), and today's vfork() is that plus a waitpid(). fork_test() deliberately has no such fallback: the copy semantics it checks are exactly what today's fork() does not provide, so it is gated on ARCH_HAVE_VFORK, whose existence is the evidence that the split has landed. A follow-up removes the fallbacks once it has. Signed-off-by: Marco Casaroli Assisted-by: Claude Opus 5 (1M context) --- interpreters/python/Makefile | 10 +- netutils/libwebsockets/lws_config_private.h | 7 + system/libuv/CMakeLists.txt | 5 + system/libuv/Makefile | 10 +- testing/drivers/nand_sim/Kconfig | 1 + testing/drivers/nand_sim/nand_sim_main.c | 13 +- testing/fs/fdsantest/fdsantest_simple.c | 4 + testing/ltp/CMakeLists.txt | 6 + testing/ltp/Makefile | 7 + testing/ostest/CMakeLists.txt | 17 +- testing/ostest/Makefile | 15 +- testing/ostest/fork.c | 280 ++++++++++++++++++++ testing/ostest/ostest.h | 40 ++- testing/ostest/ostest_main.c | 29 +- testing/ostest/task_fork.c | 98 +++++++ testing/ostest/vfork.c | 71 +++-- 16 files changed, 581 insertions(+), 32 deletions(-) create mode 100644 testing/ostest/fork.c create mode 100644 testing/ostest/task_fork.c diff --git a/interpreters/python/Makefile b/interpreters/python/Makefile index bac4013f886..8f1a510e0ea 100644 --- a/interpreters/python/Makefile +++ b/interpreters/python/Makefile @@ -114,6 +114,11 @@ ifeq ($(CONFIG_ARCH_HAVE_FORK),y) else @echo "export ac_cv_func_fork=\"no\"" >> $@ endif +ifneq ($(CONFIG_ARCH_HAVE_VFORK)$(CONFIG_ARCH_HAVE_FORK),) + @echo "export ac_cv_func_vfork=\"yes\"" >> $@ +else + @echo "export ac_cv_func_vfork=\"no\"" >> $@ +endif ifeq ($(CONFIG_SYSTEM_SYSTEM),y) @echo "export ac_cv_func_system=\"yes\"" >> $@ else @@ -135,7 +140,10 @@ endif $(SETUP_LOCAL): $(Q) ( cp $(SETUP_LOCAL).in $(SETUP_LOCAL)) -ifneq ($(CONFIG_ARCH_HAVE_FORK),y) +# _posixsubprocess is the fork-then-exec path, so vfork() is enough for it; +# os.fork() itself needs a real fork() and is governed by ac_cv_func_fork +# above. +ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_ARCH_HAVE_VFORK),) @echo "_posixsubprocess" >> $@ endif ifneq ($(CONFIG_LIBC_DLFCN),y) diff --git a/netutils/libwebsockets/lws_config_private.h b/netutils/libwebsockets/lws_config_private.h index 8f5170faff9..cacf92f5f79 100644 --- a/netutils/libwebsockets/lws_config_private.h +++ b/netutils/libwebsockets/lws_config_private.h @@ -43,7 +43,10 @@ /* #undef USE_CYASSL */ /* Define to 1 if you have the `fork' function. */ + +#ifdef CONFIG_ARCH_HAVE_FORK #define LWS_HAVE_FORK +#endif #ifndef CONFIG_DISABLE_ENVIRON /* Define to 1 if you have the `getenv' function. */ @@ -111,10 +114,14 @@ /* #undef LWS_HAVE_VFORK_H */ /* Define to 1 if `fork' works. */ +#ifdef CONFIG_ARCH_HAVE_FORK #define LWS_HAVE_WORKING_FORK +#endif /* Define to 1 if `vfork' works. */ +#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK) #define LWS_HAVE_WORKING_VFORK +#endif /* Define to 1 if execvpe() exists */ #define LWS_HAVE_EXECVPE diff --git a/system/libuv/CMakeLists.txt b/system/libuv/CMakeLists.txt index 12cde4fa749..22232faf023 100644 --- a/system/libuv/CMakeLists.txt +++ b/system/libuv/CMakeLists.txt @@ -171,6 +171,11 @@ if(CONFIG_LIBUV) ${LIBUV_TEST_DIR}/run-tests.c ${LIBUV_TEST_DIR}/runner.c ${LIBUV_TEST_DIR}/runner-unix.c ${LIBUV_TEST_DIR}/echo-server.c) file(GLOB TEST_CSRCS ${LIBUV_TEST_DIR}/test-*.c) + + # See system/libuv/Makefile. + + list(REMOVE_ITEM TEST_CSRCS ${LIBUV_TEST_DIR}/test-fork.c + ${LIBUV_TEST_DIR}/test-pipe-close-stdout-read-stdin.c) list(APPEND LIBUV_UTILS_TEST_SRCS ${TEST_CSRCS}) nuttx_add_application( NAME diff --git a/system/libuv/Makefile b/system/libuv/Makefile index dec76cc1aa0..7498919b5ab 100644 --- a/system/libuv/Makefile +++ b/system/libuv/Makefile @@ -144,7 +144,15 @@ CSRCS += runner.c CSRCS += runner-unix.c CSRCS += echo-server.c -CSRCS += $(wildcard libuv/test/test-*.c) +# test-fork.c and test-pipe-close-stdout-read-stdin.c call fork(). Every +# test they define is already excluded from the task list on NuttX by +# 0001-libuv-port-for-nuttx.patch, so they are dead code here. + +LIBUV_TEST_CSRCS = $(wildcard libuv/test/test-*.c) +LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-fork.c,$(LIBUV_TEST_CSRCS)) +LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-pipe-close-stdout-read-stdin.c,$(LIBUV_TEST_CSRCS)) + +CSRCS += $(LIBUV_TEST_CSRCS) endif ifneq ($(CONFIG_LIBUV_UTILS_BENCHMARK),) diff --git a/testing/drivers/nand_sim/Kconfig b/testing/drivers/nand_sim/Kconfig index e76cdc3f5a4..d6240d740ee 100644 --- a/testing/drivers/nand_sim/Kconfig +++ b/testing/drivers/nand_sim/Kconfig @@ -6,6 +6,7 @@ config TESTING_NAND_SIM boolean "NAND Flash Simulator" depends on MTD_NAND_RAM && ENABLE_ALL_SIGNALS + depends on ARCH_HAVE_TASK_FORK || ARCH_HAVE_FORK default n ---help--- Enable the NAND Flash Simulator device. diff --git a/testing/drivers/nand_sim/nand_sim_main.c b/testing/drivers/nand_sim/nand_sim_main.c index 70ea24227ff..151589b3f0a 100644 --- a/testing/drivers/nand_sim/nand_sim_main.c +++ b/testing/drivers/nand_sim/nand_sim_main.c @@ -25,7 +25,9 @@ ****************************************************************************/ #include +#include #include +#include #include #include @@ -140,9 +142,16 @@ int main(int argc, FAR char *argv[]) int ret; pid_t pid; - /* Daemon */ + /* task_fork() rather than fork(): this wants a clone that outlives the + * caller and shares its memory. The fallback below covers a nuttx that + * does not have task_fork() yet. + */ - pid = fork(); +#ifndef CONFIG_ARCH_HAVE_TASK_FORK +# define task_fork() fork() +#endif + + pid = task_fork(); if (pid > 0) { diff --git a/testing/fs/fdsantest/fdsantest_simple.c b/testing/fs/fdsantest/fdsantest_simple.c index 128e2878bff..e5dc468178a 100644 --- a/testing/fs/fdsantest/fdsantest_simple.c +++ b/testing/fs/fdsantest/fdsantest_simple.c @@ -96,6 +96,7 @@ static void test_case_overflow(void **state) assert_int_equal(open_count, close_count); } +#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK) static void test_case_vfork(void **state) { int fd = open("/dev/null", O_RDONLY); @@ -112,6 +113,7 @@ static void test_case_vfork(void **state) android_fdsan_close_with_tag(fd, 0xbadc0de); } +#endif /**************************************************************************** * Public Functions @@ -129,7 +131,9 @@ int main(int argc, FAR char *argv[]) cmocka_unit_test(test_case_unowned_tagged_close), cmocka_unit_test(test_case_owned_tagged_close), cmocka_unit_test(test_case_overflow), +#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK) cmocka_unit_test(test_case_vfork), +#endif }; return cmocka_run_group_tests(tests, NULL, NULL); diff --git a/testing/ltp/CMakeLists.txt b/testing/ltp/CMakeLists.txt index 2e458d5e4d2..dde159976fc 100644 --- a/testing/ltp/CMakeLists.txt +++ b/testing/ltp/CMakeLists.txt @@ -86,6 +86,12 @@ if(CONFIG_TESTING_LTP) list(APPEND BLACKWORDS "pthread_spin_init" "pthread_spin_destroy" "pthread_spin_trylock") endif() + + # See testing/ltp/Makefile. + + if(NOT CONFIG_ARCH_HAVE_FORK AND NOT CONFIG_FORK_IS_TASK_FORK) + list(APPEND BLACKWORDS "[^v_]fork(") + endif() list( APPEND BLACKWORDS diff --git a/testing/ltp/Makefile b/testing/ltp/Makefile index 39a7d931b94..50a631d39b0 100644 --- a/testing/ltp/Makefile +++ b/testing/ltp/Makefile @@ -44,6 +44,13 @@ BLACKWORDS += "pthread_spin_destroy" BLACKWORDS += "pthread_spin_trylock" endif +# Where NuttX does not declare fork(), a test that calls it cannot be built. +# The pattern spares vfork() and task_fork(), which remain available. + +ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_FORK_IS_TASK_FORK),) +BLACKWORDS += "[^v_]fork(" +endif + BLACKWORDS += "CHILD_MAX" BLACKWORDS += "setpgid(" BLACKWORDS += "PTHREAD_SCOPE_PROCESS" diff --git a/testing/ostest/CMakeLists.txt b/testing/ostest/CMakeLists.txt index 74103db4118..2ab55d88444 100644 --- a/testing/ostest/CMakeLists.txt +++ b/testing/ostest/CMakeLists.txt @@ -143,10 +143,19 @@ if(CONFIG_TESTING_OSTEST) endif() endif() - if(CONFIG_ARCH_HAVE_FORK) - if(CONFIG_SCHED_WAITPID) - list(APPEND SRCS vfork.c) - endif() + # See testing/ostest/Makefile for why each test also accepts the symbol that + # stands in for it on a nuttx without the fork()/vfork() split. + + if(CONFIG_ARCH_HAVE_TASK_FORK OR CONFIG_ARCH_HAVE_FORK) + list(APPEND SRCS task_fork.c) + endif() + + if(CONFIG_ARCH_HAVE_VFORK OR (CONFIG_ARCH_HAVE_FORK AND CONFIG_SCHED_WAITPID)) + list(APPEND SRCS vfork.c) + endif() + + if(CONFIG_ARCH_HAVE_FORK AND CONFIG_ARCH_HAVE_VFORK) + list(APPEND SRCS fork.c) endif() if(CONFIG_ARCH_SETJMP_H) diff --git a/testing/ostest/Makefile b/testing/ostest/Makefile index f443ecb0b39..d5d8df42aae 100644 --- a/testing/ostest/Makefile +++ b/testing/ostest/Makefile @@ -144,10 +144,21 @@ CSRCS += sigev_thread.c endif endif -ifeq ($(CONFIG_ARCH_HAVE_FORK),y) -ifeq ($(CONFIG_SCHED_WAITPID),y) +# Each test is built where the primitive it tests exists. See ostest.h for +# why each also accepts ARCH_HAVE_FORK, and why fork.c does not. + +ifneq ($(CONFIG_ARCH_HAVE_TASK_FORK)$(CONFIG_ARCH_HAVE_FORK),) +CSRCS += task_fork.c +endif + +ifeq ($(CONFIG_ARCH_HAVE_VFORK),y) +CSRCS += vfork.c +else ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_SCHED_WAITPID),yy) CSRCS += vfork.c endif + +ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_ARCH_HAVE_VFORK),yy) +CSRCS += fork.c endif ifeq ($(CONFIG_ARCH_SETJMP_H),y) diff --git a/testing/ostest/fork.c b/testing/ostest/fork.c new file mode 100644 index 00000000000..e6a3a0945f7 --- /dev/null +++ b/testing/ostest/fork.c @@ -0,0 +1,280 @@ +/**************************************************************************** + * apps/testing/ostest/fork.c + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ostest.h" + +#ifdef OSTEST_HAVE_FORK + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define FORK_HEAPSIZE 256 +#define FORK_PARENTMARK 0x5a +#define FORK_CHILDMARK 0xa5 + +/* Distinct values written through a pointer to a stack local, to check that + * the child's stack is at the same virtual address as the parent's. + */ + +#define FORK_STACKPARENT 0x1234 +#define FORK_STACKCHILD 0x5678 + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/* .data and .bss, which a fork() child must get its own copy of */ + +static volatile int g_forkdata = 1; +static volatile int g_forkbss; +static FAR unsigned char *g_forkheap; + +/* Pointer to a local in fork_test()'s frame, taken before fork(). In .data + * rather than on the stack: the compiler could rematerialise a local + * pointer from the current stack pointer, which would test nothing. + */ + +static FAR volatile int *g_forkstackptr; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: fork_child + * + * Description: + * Everything here is forbidden to a vfork() child and permitted to a + * fork() child. Returns the child's exit status. + * + ****************************************************************************/ + +static int fork_child(void) +{ + FAR char *scratch; + + /* The parent must see none of this. */ + + g_forkdata = 2; + g_forkbss = 2; + memset(g_forkheap, FORK_CHILDMARK, FORK_HEAPSIZE); + + /* A vfork() child may not call these; a fork() child may. */ + + scratch = malloc(64); + if (scratch == NULL) + { + printf("fork_test: ERROR Child could not malloc()\n"); + return 1; + } + + strlcpy(scratch, "child", 64); + printf("fork_test: Child running independently (%s)\n", scratch); + free(scratch); + + /* Give the parent time to make its own writes, so that if the two shared + * memory we would see the parent's values below rather than our own. + */ + + usleep(200 * 1000); + + if (g_forkdata != 2 || g_forkbss != 2) + { + printf("fork_test: ERROR Child saw the parent's writes: " + "data=%d bss=%d\n", g_forkdata, g_forkbss); + return 1; + } + + if (g_forkheap[0] != FORK_CHILDMARK || + g_forkheap[FORK_HEAPSIZE - 1] != FORK_CHILDMARK) + { + printf("fork_test: ERROR Child saw the parent's heap writes\n"); + return 1; + } + + return 0; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: fork_test + * + * Description: + * Verify the defining property of POSIX fork(): the child gets its own + * copy of the parent's memory, in both directions. That is the exact + * opposite of what task_fork_test() checks. Also verifies that none of + * vfork()'s restrictions apply. + * + ****************************************************************************/ + +int fork_test(void) +{ + pid_t pid; + int status = 0; + int ret = 0; + + /* volatile so it is really in memory and the compare is not folded. */ + + volatile int stackvar = FORK_STACKPARENT; + + printf("fork_test: Started\n"); + + /* Publish its address before forking. See g_forkstackptr. */ + + g_forkstackptr = &stackvar; + + g_forkdata = 1; + g_forkbss = 1; + + g_forkheap = malloc(FORK_HEAPSIZE); + if (g_forkheap == NULL) + { + printf("fork_test: ERROR Failed to allocate the heap probe\n"); + ASSERT(false); + return -1; + } + + memset(g_forkheap, FORK_PARENTMARK, FORK_HEAPSIZE); + + pid = fork(); + if (pid == 0) + { + /* The child's stack is at the parent's virtual addresses, so this + * pointer names the child's own live local. A relocated stack would + * write into the copy of the parent's instead. + */ + + *g_forkstackptr = FORK_STACKCHILD; + if (stackvar != FORK_STACKCHILD) + { + printf("fork_test: ERROR Child stack was relocated: wrote %d " + "through %p, local at %p reads %d\n", + FORK_STACKCHILD, g_forkstackptr, &stackvar, stackvar); + _exit(1); + } + + /* Returns from fork_child() and from this branch -- both illegal + * for a vfork() child. + */ + + _exit(fork_child()); + } + else if (pid < 0) + { + printf("fork_test: ERROR fork() failed: %d\n", errno); + free(g_forkheap); + ASSERT(false); + return -1; + } + + /* Parent runs concurrently: write now, check isolation afterwards. */ + + g_forkdata = 3; + g_forkbss = 3; + memset(g_forkheap, FORK_PARENTMARK, FORK_HEAPSIZE); + +#ifdef CONFIG_SCHED_WAITPID + /* Wait for the child to be done before comparing memory. waitpid() blocks + * on a child that is still alive whether or not its exit status will be + * retained, so this synchronises either way; ECHILD simply means the child + * had already finished, which is just as good. It is not a failure: + * ostest_main() sets SA_NOCLDWAIT on SIGCHLD for the whole run, so an + * exited child's status is not kept even where CONFIG_SCHED_CHILD_STATUS + * is enabled. + */ + + if (waitpid(pid, &status, 0) != pid && errno != ECHILD) + { + printf("fork_test: ERROR waitpid() failed: %d\n", errno); + free(g_forkheap); + ASSERT(false); + return -1; + } +#else + sleep(1); +#endif + + if (g_forkdata != 3 || g_forkbss != 3) + { + printf("fork_test: ERROR Parent saw the child's writes: " + "data=%d bss=%d (expected 3, 3)\n", g_forkdata, g_forkbss); + ret = -1; + } + + if (g_forkheap[0] != FORK_PARENTMARK || + g_forkheap[FORK_HEAPSIZE - 1] != FORK_PARENTMARK) + { + printf("fork_test: ERROR Parent saw the child's heap writes\n"); + ret = -1; + } + + /* The child wrote to the same stack address; the parent must not see it */ + + if (stackvar != FORK_STACKPARENT) + { + printf("fork_test: ERROR Parent saw the child's stack write: " + "%d (expected %d)\n", stackvar, FORK_STACKPARENT); + ret = -1; + } + +#ifdef CONFIG_SCHED_WAITPID + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) + { + printf("fork_test: ERROR Child reported failure, status 0x%04x\n", + status); + ret = -1; + } +#endif + + free(g_forkheap); + g_forkheap = NULL; + + if (ret < 0) + { + ASSERT(false); + return ret; + } + + printf("fork_test: Parent and child had independent memory\n"); + return 0; +} + +#endif /* OSTEST_HAVE_FORK */ diff --git a/testing/ostest/ostest.h b/testing/ostest/ostest.h index 5e01626c0e2..6ee7e9f7641 100644 --- a/testing/ostest/ostest.h +++ b/testing/ostest/ostest.h @@ -282,12 +282,50 @@ void priority_inheritance(void); void sched_lock_test(void); +/* The fork family **********************************************************/ + +/* Until nuttx has the three separate primitives, ARCH_HAVE_FORK stands in + * for the first two: today's fork() is task_fork(), and today's vfork() is + * that plus a waitpid(). fork_test() is deliberately not mapped -- the copy + * semantics it checks are what does not exist yet, and ARCH_HAVE_VFORK is + * the evidence that they do. These blocks come out with the split. + */ + +#if defined(CONFIG_ARCH_HAVE_TASK_FORK) || defined(CONFIG_ARCH_HAVE_FORK) +# define OSTEST_HAVE_TASK_FORK 1 +#endif + +#if defined(CONFIG_ARCH_HAVE_VFORK) || \ + (defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID)) +# define OSTEST_HAVE_VFORK 1 +#endif + +#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_ARCH_HAVE_VFORK) +# define OSTEST_HAVE_FORK 1 +#endif + +#if defined(OSTEST_HAVE_TASK_FORK) && !defined(CONFIG_ARCH_HAVE_TASK_FORK) +# define task_fork() fork() +#endif + +/* task_fork.c **************************************************************/ + +#ifdef OSTEST_HAVE_TASK_FORK +int task_fork_test(void); +#endif + /* vfork.c ******************************************************************/ -#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID) +#ifdef OSTEST_HAVE_VFORK int vfork_test(void); #endif +/* fork.c *******************************************************************/ + +#ifdef OSTEST_HAVE_FORK +int fork_test(void); +#endif + /* setjmp.c *****************************************************************/ void setjmp_test(void); diff --git a/testing/ostest/ostest_main.c b/testing/ostest/ostest_main.c index 92224701f9b..e717b291d7e 100644 --- a/testing/ostest/ostest_main.c +++ b/testing/ostest/ostest_main.c @@ -224,6 +224,29 @@ static int user_main(int argc, char *argv[]) g_mmbefore = mallinfo(); g_mmprevious = g_mmbefore; + /* Run the three fork primitives first. They exercise the lowest-level + * machinery in the suite, so a fault takes the process down rather than + * reporting a failure -- better to learn that in seconds. + */ + +#ifdef OSTEST_HAVE_TASK_FORK + printf("\nuser_main: task_fork() test\n"); + task_fork_test(); + check_test_memory_usage(); +#endif + +#ifdef OSTEST_HAVE_VFORK + printf("\nuser_main: vfork() test\n"); + vfork_test(); + check_test_memory_usage(); +#endif + +#ifdef OSTEST_HAVE_FORK + printf("\nuser_main: fork() test\n"); + fork_test(); + check_test_memory_usage(); +#endif + printf("\nuser_main: Begin argument test\n"); printf("user_main: Started with argc=%d\n", argc); @@ -637,12 +660,6 @@ static int user_main(int argc, char *argv[]) check_test_memory_usage(); #endif -#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID) && \ - !defined(CONFIG_ARCH_SIM) - printf("\nuser_main: vfork() test\n"); - vfork_test(); -#endif - #if defined(CONFIG_SMP) && defined(CONFIG_BUILD_FLAT) printf("\nuser_main: smp call test\n"); smp_call_test(); diff --git a/testing/ostest/task_fork.c b/testing/ostest/task_fork.c new file mode 100644 index 00000000000..2bd00ee7698 --- /dev/null +++ b/testing/ostest/task_fork.c @@ -0,0 +1,98 @@ +/**************************************************************************** + * apps/testing/ostest/task_fork.c + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include + +#include +#include +#include +#include +#include +#include +#include + +#include "ostest.h" + +#ifdef OSTEST_HAVE_TASK_FORK + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +static volatile bool g_taskforkchild; + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: task_fork_test + * + * Description: + * Verify the defining property of task_fork(): the child shares the + * parent's memory, so the parent observes the child's write. This is the + * test that used to be called the "vfork" test. A real fork() child's + * write would be invisible here; see fork_test(). + * + ****************************************************************************/ + +int task_fork_test(void) +{ + pid_t pid; + + printf("task_fork_test: Started\n"); + + g_taskforkchild = false; + pid = task_fork(); + if (pid == 0) + { + /* Shared memory, so the parent sees this. Runs concurrently. */ + + g_taskforkchild = true; + exit(0); + } + else if (pid < 0) + { + printf("task_fork_test: ERROR task_fork() failed: %d\n", errno); + ASSERT(false); + return -1; + } + + sleep(1); + + if (!g_taskforkchild) + { + printf("task_fork_test: ERROR Child %d did not run, or its write to " + "shared memory was not visible\n", pid); + ASSERT(false); + return -1; + } + + printf("task_fork_test: Child %d ran successfully\n", pid); + return 0; +} + +#endif /* OSTEST_HAVE_TASK_FORK */ diff --git a/testing/ostest/vfork.c b/testing/ostest/vfork.c index bd6cfabadb9..d5cdb169a89 100644 --- a/testing/ostest/vfork.c +++ b/testing/ostest/vfork.c @@ -31,36 +31,51 @@ #include #include #include +#include #include #include "ostest.h" -#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID) +#ifdef OSTEST_HAVE_VFORK /**************************************************************************** * Private Data ****************************************************************************/ -static volatile bool g_vforkchild; +/* Set and cleared by the parent only: a vfork() child may not write it. */ + +static volatile bool g_vforkrunning; /**************************************************************************** * Public Functions ****************************************************************************/ +/**************************************************************************** + * Name: vfork_test + * + * Description: + * Verify the defining property of vfork(): the parent is suspended until + * the child _exit()s or exec()s. The child does only what POSIX + * permits -- _exit(), not exit(), which would flush stdio in the parent's + * address space. Since the child may not write memory, the observable is + * its exit status: an unsuspended parent would reach waitpid() first. + * + ****************************************************************************/ + int vfork_test(void) { pid_t pid; - g_vforkchild = false; + printf("vfork_test: Started\n"); + + g_vforkrunning = true; + pid = vfork(); if (pid == 0) { - /* There is not very much that the child is permitted to do. Perhaps - * it can just set g_vforkchild. - */ + /* The only thing a vfork() child may do is leave. */ - g_vforkchild = true; - exit(0); + _exit(42); } else if (pid < 0) { @@ -68,22 +83,48 @@ int vfork_test(void) ASSERT(false); return -1; } - else + + /* Reached only once the child has exited or exec'ed. */ + + g_vforkrunning = false; + +#ifdef CONFIG_SCHED_WAITPID { - sleep(1); - if (g_vforkchild) + int status = 0; + pid_t ret; + + ret = waitpid(pid, &status, 0); + + /* Two answers are correct, and which one comes back is a property of + * the configuration: a retained status must be exit(42), and ECHILD + * is equally good evidence -- it says the child was already gone when + * we asked. ostest_main() sets SA_NOCLDWAIT for the whole run, so + * testing CONFIG_SCHED_CHILD_STATUS alone is not enough. + */ + + if (ret == pid) { - printf("vfork_test: Child %d ran successfully\n", pid); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 42) + { + printf("vfork_test: ERROR Child %d status 0x%04x, expected " + "exit(42)\n", pid, status); + ASSERT(false); + return -1; + } } - else + else if (ret >= 0 || errno != ECHILD) { - printf("vfork_test: ERROR Child %d did not run\n", pid); + printf("vfork_test: ERROR waitpid() returned %d (%d), expected " + "the child's status or ECHILD\n", ret, errno); ASSERT(false); return -1; } } +#endif + printf("vfork_test: Child %d ran and exited before the parent resumed\n", + pid); return 0; } -#endif /* CONFIG_ARCH_HAVE_FORK && CONFIG_SCHED_WAITPID */ +#endif /* OSTEST_HAVE_VFORK */