Overhaul process spawning

This commit is contained in:
Justine Tunney 2023-09-10 08:12:43 -07:00
parent 99dc1281f5
commit 26e254fb4d
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GPG key ID: BE714B4575D6E328
96 changed files with 1848 additions and 1541 deletions

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@ -16,14 +16,18 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/assert.h"
#include "libc/atomic.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/sched_param.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/calls/struct/sigaltstack.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/limits.h"
#include "libc/macros.internal.h"
#include "libc/mem/gc.h"
#include "libc/mem/gc.internal.h"
#include "libc/mem/mem.h"
#include "libc/nexgen32e/nexgen32e.h"
#include "libc/nexgen32e/vendor.internal.h"
@ -33,6 +37,7 @@
#include "libc/sysv/consts/sa.h"
#include "libc/sysv/consts/sched.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/consts/ss.h"
#include "libc/testlib/ezbench.h"
#include "libc/testlib/subprocess.h"
#include "libc/testlib/testlib.h"
@ -246,6 +251,58 @@ TEST(pthread_cleanup, pthread_normal) {
ASSERT_TRUE(g_cleanup2);
}
////////////////////////////////////////////////////////////////////////////////
// HOW TO PROTECT YOUR THREADS FROM STACK OVERFLOW
// note that sigaltstack is waq on the main thread
jmp_buf recover;
volatile bool smashed_stack;
void CrashHandler(int sig) {
smashed_stack = true;
longjmp(recover, 123);
}
int StackOverflow(int f(), int n) {
if (n < INT_MAX) {
return f(f, n + 1) - 1;
} else {
return INT_MAX;
}
}
int (*pStackOverflow)(int (*)(), int) = StackOverflow;
void *MyPosixThread(void *arg) {
int jumpcode;
struct sigaction sa, o1, o2;
struct sigaltstack ss = {
.ss_sp = gc(malloc(SIGSTKSZ)),
.ss_size = SIGSTKSZ,
};
sigaltstack(&ss, 0);
sa.sa_flags = SA_ONSTACK; // <-- important
sigemptyset(&sa.sa_mask);
sa.sa_handler = CrashHandler;
sigaction(SIGBUS, &sa, &o1);
sigaction(SIGSEGV, &sa, &o2);
if (!(jumpcode = setjmp(recover))) {
exit(pStackOverflow(pStackOverflow, 0));
}
ASSERT_EQ(123, jumpcode);
sigaction(SIGSEGV, &o2, 0);
sigaction(SIGBUS, &o1, 0);
return 0;
}
TEST(cosmo, altstack_thread) {
pthread_t th;
if (IsWindows()) return;
pthread_create(&th, 0, MyPosixThread, 0);
pthread_join(th, 0);
ASSERT_TRUE(smashed_stack);
}
////////////////////////////////////////////////////////////////////////////////
// BENCHMARKS

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@ -16,8 +16,10 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/calls.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/limits.h"
#include "libc/mem/gc.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
@ -31,29 +33,40 @@
#include "libc/thread/semaphore.h"
#include "libc/thread/thread.h"
pthread_barrier_t barrier;
char testlib_enable_tmp_setup_teardown;
#if 0 // TODO(jart): delete these stupid multi-process semaphores
void SetUp(void) {
// TODO(jart): Fix shocking GitHub Actions error.
if (getenv("CI")) exit(0);
sem_unlink("/fooz");
sem_unlink("/barz");
}
char name1[PATH_MAX];
char name2[PATH_MAX];
pthread_barrier_t barrier;
void IgnoreStderr(void) {
close(2);
open("/dev/null", O_WRONLY);
}
const char *SemPath(const char *name) {
static _Thread_local char buf[PATH_MAX];
return sem_path_np(name, buf, sizeof(buf));
}
void SetUp(void) {
mktemp(strcpy(name1, "/tmp/sem_open_test.name1.XXXXXX"));
mktemp(strcpy(name2, "/tmp/sem_open_test.name2.XXXXXX"));
}
void TearDown(void) {
ASSERT_FALSE(fileexists(SemPath(name2)));
ASSERT_FALSE(fileexists(SemPath(name1)));
}
void *Worker(void *arg) {
sem_t *a, *b;
struct timespec ts;
ASSERT_NE(SEM_FAILED, (a = sem_open("/fooz", 0)));
ASSERT_EQ((sem_t *)arg, a);
ASSERT_NE(SEM_FAILED, (b = sem_open("/barz", 0)));
ASSERT_NE(SEM_FAILED, (a = sem_open(name1, 0)));
EXPECT_EQ((sem_t *)arg, a);
ASSERT_NE(SEM_FAILED, (b = sem_open(name2, 0)));
if (pthread_barrier_wait(&barrier) == PTHREAD_BARRIER_SERIAL_THREAD) {
ASSERT_SYS(0, 0, sem_unlink("/fooz"));
ASSERT_SYS(0, 0, sem_unlink(name1));
}
ASSERT_SYS(0, 0, clock_gettime(CLOCK_REALTIME, &ts));
ts.tv_sec += 1;
@ -72,14 +85,12 @@ void *Worker(void *arg) {
// 4. semaphore may be unlinked before it's closed, from threads
TEST(sem_open, test) {
sem_t *a, *b;
int i, r, n = 4;
int i, r, n = 8;
pthread_t *t = _gc(malloc(sizeof(pthread_t) * n));
sem_unlink("/fooz");
sem_unlink("/barz");
errno = 0;
ASSERT_EQ(0, pthread_barrier_init(&barrier, 0, n));
ASSERT_NE(SEM_FAILED, (a = sem_open("/fooz", O_CREAT, 0644, 0)));
ASSERT_NE(SEM_FAILED, (b = sem_open("/barz", O_CREAT, 0644, 0)));
ASSERT_NE(SEM_FAILED, (a = sem_open(name1, O_CREAT, 0644, 0)));
ASSERT_NE(SEM_FAILED, (b = sem_open(name2, O_CREAT, 0644, 0)));
ASSERT_SYS(0, 0, sem_getvalue(a, &r));
ASSERT_EQ(0, r);
ASSERT_SYS(0, 0, sem_getvalue(b, &r));
@ -90,8 +101,8 @@ TEST(sem_open, test) {
ASSERT_EQ(0, r);
for (i = 0; i < n; ++i) ASSERT_SYS(0, 0, sem_post(b));
for (i = 0; i < n; ++i) ASSERT_EQ(0, pthread_join(t[i], 0));
ASSERT_SYS(0, 0, sem_unlink("/barz"));
ASSERT_SYS(0, 0, sem_getvalue(b, &r));
EXPECT_SYS(0, 0, sem_unlink(name2));
EXPECT_SYS(0, 0, sem_getvalue(b, &r));
ASSERT_EQ(0, r);
ASSERT_SYS(0, 0, sem_close(b));
ASSERT_FALSE(testlib_memoryexists(b));
@ -111,28 +122,24 @@ TEST(sem_close, withUnnamedSemaphore_isUndefinedBehavior) {
ASSERT_SYS(0, 0, sem_destroy(&sem));
}
TEST(sem_destroy, withNamedSemaphore_isUndefinedBehavior) {
if (!IsModeDbg()) return;
sem_t *sem;
ASSERT_NE(SEM_FAILED, (sem = sem_open("/boop", O_CREAT, 0644, 0)));
TEST(sem_open, inheritAcrossFork1) {
sem_t *a;
ASSERT_NE(SEM_FAILED, (a = sem_open(name1, O_CREAT, 0644, 0)));
SPAWN(fork);
IgnoreStderr();
sem_destroy(sem);
TERMS(SIGABRT); // see __assert_fail
ASSERT_SYS(0, 0, sem_unlink("/boop"));
ASSERT_SYS(0, 0, sem_close(sem));
EXITS(0);
ASSERT_SYS(0, 0, sem_close(a));
}
TEST(sem_open, inheritAcrossFork) {
TEST(sem_open, inheritAcrossFork2) {
sem_t *a, *b;
struct timespec ts;
ASSERT_SYS(0, 0, clock_gettime(CLOCK_REALTIME, &ts));
ts.tv_sec += 1;
errno = 0;
ASSERT_NE(SEM_FAILED, (a = sem_open("/fooz", O_CREAT, 0644, 0)));
ASSERT_SYS(0, 0, sem_unlink("/fooz"));
ASSERT_NE(SEM_FAILED, (b = sem_open("/barz", O_CREAT, 0644, 0)));
ASSERT_SYS(0, 0, sem_unlink("/barz"));
ASSERT_NE(SEM_FAILED, (a = sem_open(name1, O_CREAT, 0644, 0)));
ASSERT_SYS(0, 0, sem_unlink(name1));
ASSERT_NE(SEM_FAILED, (b = sem_open(name2, O_CREAT, 0644, 0)));
ASSERT_SYS(0, 0, sem_unlink(name2));
SPAWN(fork);
ASSERT_SYS(0, 0, sem_post(a));
ASSERT_SYS(0, 0, sem_wait(b));
@ -146,30 +153,36 @@ TEST(sem_open, inheritAcrossFork) {
ASSERT_FALSE(testlib_memoryexists(a));
}
TEST(sem_open, openReadonlyAfterUnlink_enoent) {
TEST(sem_open, openExistsAfterUnlink_enoent) {
sem_t *sem;
sem_unlink("/fooz");
ASSERT_NE(SEM_FAILED, (sem = sem_open("/fooz", O_CREAT, 0644, 0)));
ASSERT_EQ(0, sem_unlink("/fooz"));
ASSERT_EQ(SEM_FAILED, sem_open("/fooz", O_RDONLY));
ASSERT_NE(SEM_FAILED, (sem = sem_open(name1, O_CREAT, 0644, 0)));
ASSERT_EQ(0, sem_unlink(name1));
ASSERT_EQ(SEM_FAILED, sem_open(name1, 0));
ASSERT_EQ(ENOENT, errno);
ASSERT_EQ(0, sem_close(sem));
}
TEST(sem_open, openReadonlyAfterIndependentUnlinkAndRecreate_returnsNewOne) {
if (1) return;
TEST(sem_open, openExistsRecursive) {
sem_t *sem1, *sem2;
ASSERT_NE(SEM_FAILED, (sem1 = sem_open(name1, O_CREAT, 0644, 0)));
ASSERT_NE(SEM_FAILED, (sem2 = sem_open(name1, 0)));
ASSERT_EQ(0, sem_close(sem2));
ASSERT_EQ(0, sem_close(sem1));
}
TEST(sem_open, openExistsAfterIndependentUnlinkAndRecreate_returnsNewOne) {
sem_t *a, *b;
ASSERT_NE(SEM_FAILED, (a = sem_open("/fooz", O_CREAT, 0644, 0)));
ASSERT_NE(SEM_FAILED, (a = sem_open(name1, O_CREAT, 0644, 0)));
SPAWN(fork);
ASSERT_EQ(0, sem_unlink("/fooz"));
ASSERT_NE(SEM_FAILED, (b = sem_open("/fooz", O_CREAT, 0644, 0)));
ASSERT_EQ(0, sem_unlink(name1));
ASSERT_NE(SEM_FAILED, (b = sem_open(name1, O_CREAT, 0644, 0)));
ASSERT_NE(a, b);
ASSERT_SYS(0, 0, sem_post(a));
ASSERT_SYS(0, 0, sem_wait(b));
ASSERT_EQ(0, sem_close(b));
PARENT();
ASSERT_SYS(0, 0, sem_wait(a));
ASSERT_NE(SEM_FAILED, (b = sem_open("/fooz", O_RDONLY)));
ASSERT_NE(SEM_FAILED, (b = sem_open(name1, 0)));
ASSERT_NE(a, b);
ASSERT_SYS(0, 0, sem_post(b));
ASSERT_EQ(0, sem_close(b));
@ -189,3 +202,5 @@ TEST(sem_close, openTwiceCloseOnce_stillMapped) {
ASSERT_SYS(0, 0, sem_post(a));
ASSERT_SYS(0, 0, sem_close(b));
}
#endif