kernel: replace await with wait2, roughly compatible with POSIX

dash works now :^)))

13 files changed, 91 insertions, 8 deletions

diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index ecbd839..3ef35c0 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -349,7 +349,18 @@ void proc_tryreap(Proc *dead) {
 			if (parent->state != PS_WAITS4CHILDDEATH) {
 				return; /* don't reap yet */
 			}
-			regs_savereturn(&parent->regs, dead->death_msg);
+			if (parent->awaited_death.legacy) {
+				regs_savereturn(&parent->regs, dead->death_msg);
+			} else {
+				regs_savereturn(&parent->regs, proc_ns_id(parent->pns, dead));
+				if (parent->awaited_death.out) {
+					struct sys_wait2 __user *out = parent->awaited_death.out;
+					struct sys_wait2 data;
+					memset(&data, 0, sizeof data);
+					data.status = dead->death_msg;
+					pcpy_to(parent, out, &data, sizeof data);
+				}
+			}
 			proc_setstate(parent, PS_RUNNING);
 		}
 		/* can't be reaped anymore */
diff --git a/src/kernel/proc.h b/src/kernel/proc.h
index f473124..a1820dc 100644
--- a/src/kernel/proc.h
+++ b/src/kernel/proc.h
@@ -45,6 +45,10 @@ struct Proc {
 	union { /* saved value, meaning depends on .state */
 		int death_msg; // PS_DEAD
 		struct {
+			bool legacy; /* false = wait2, true = await */
+			struct sys_wait2 __user *out;
+		} awaited_death;
+		struct {
 			char __user *buf;
 			size_t max_len;
 			struct ufs_request __user *res;
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index 1e75f9d..66f8757 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -25,6 +25,7 @@ _Noreturn void _sys_exit(long ret) {
 long _sys_await(void) {
 	bool has_children = false;
 	proc_setstate(proc_cur, PS_WAITS4CHILDDEATH);
+	proc_cur->awaited_death.legacy = true;
 
 	for (Proc *iter = proc_cur->child;
 			iter; iter = iter->sibling)
@@ -401,6 +402,32 @@ uint32_t _sys_getppid(void) {
 	}
 }
 
+int _sys_wait2(int pid, int flags, struct sys_wait2 __user *out) {
+	if (pid != -1 || flags != 0) {
+		SYSCALL_RETURN(-ENOSYS);
+	}
+
+	bool has_children = false;
+	proc_setstate(proc_cur, PS_WAITS4CHILDDEATH);
+	proc_cur->awaited_death.legacy = false;
+	proc_cur->awaited_death.out = out;
+
+	for (Proc *iter = proc_cur->child; iter; iter = iter->sibling) {
+		if (iter->noreap) continue;
+		has_children = true;
+		if (iter->state == PS_TOREAP) {
+			proc_tryreap(iter);
+			return 0; // dummy
+		}
+	}
+
+	if (!has_children) {
+		proc_setstate(proc_cur, PS_RUNNING);
+		SYSCALL_RETURN(-ECHILD);
+	}
+	return 0; // dummy
+}
+
 long _sys_execbuf(void __user *ubuf, size_t len) {
 	if (len == 0) SYSCALL_RETURN(0);
 	if (len > EXECBUF_MAX_LEN)
@@ -455,6 +482,7 @@ long _syscall(long num, long a, long b, long c, long d, long e) {
 		break; case _SYS_INTR_SET:	_sys_intr_set((userptr_t)a);
 		break; case _SYS_GETPID:	_sys_getpid();
 		break; case _SYS_GETPPID:	_sys_getppid();
+		break; case _SYS_WAIT2:	_sys_wait2(a, b, (userptr_t)c);
 		break; case _SYS_EXECBUF:	_sys_execbuf((userptr_t)a, b);
 		break; case _SYS_DEBUG_KLOG:	_sys_debug_klog((userptr_t)a, b);
 		break;
diff --git a/src/shared/include/camellia/errno.h b/src/shared/include/camellia/errno.h
index b56ba91..e29f3d7 100644
--- a/src/shared/include/camellia/errno.h
+++ b/src/shared/include/camellia/errno.h
@@ -15,6 +15,7 @@
 #define EMFILE 11 /* all file descriptors taken */
 #define ECONNRESET 12
 #define EPIPE 13
+#define ECHILD 14
 
 #define EISDIR 200
 #define ENAMETOOLONG 201
diff --git a/src/shared/include/camellia/syscalls.h b/src/shared/include/camellia/syscalls.h
index 809cad7..9a8fa94 100644
--- a/src/shared/include/camellia/syscalls.h
+++ b/src/shared/include/camellia/syscalls.h
@@ -21,6 +21,7 @@
 #define _SYS_INTR_SET 18
 #define _SYS_GETPID 19
 #define _SYS_GETPPID 20
+#define _SYS_WAIT2 21
 
 #define _SYS_EXECBUF 100
 #define _SYS_DEBUG_KLOG 101
@@ -84,6 +85,9 @@ void _sys_intr_set(void __user *ip);
 uint32_t _sys_getpid(void);
 uint32_t _sys_getppid(void);
 
+// TODO deprecate await
+int _sys_wait2(int pid, int flags, struct sys_wait2 __user *out);
+
 /* see shared/execbuf.h */
 long _sys_execbuf(void __user *buf, size_t len);
 
diff --git a/src/shared/include/camellia/types.h b/src/shared/include/camellia/types.h
index 3b9cfb4..65200d7 100644
--- a/src/shared/include/camellia/types.h
+++ b/src/shared/include/camellia/types.h
@@ -35,3 +35,7 @@ struct intr_data {
 	void __user *ip;
 	void __user *sp; /* last for pop %rsp */
 };
+
+struct sys_wait2 {
+	long status;
+};
diff --git a/src/user/app/testelf/main.c b/src/user/app/testelf/main.c
index 5608cc7..a2e5932 100644
--- a/src/user/app/testelf/main.c
+++ b/src/user/app/testelf/main.c
@@ -10,7 +10,7 @@ int main(int argc, char **argv) {
 	printf("argc == %u\n", argc);
 	for (int i = 0; i < argc; i++)
 		printf("argv[%u] == %p == \"%s\"\n", i, argv[i], argv[i]);
-	if (strcmp(argv[1], "stackexec") == 0) {
+	if (argv[1] && strcmp(argv[1], "stackexec") == 0) {
 		/* exec something with arguments on the stack */
 		const char s_d[] = "I am a pretty long string on the stack. Oh my. " \
 			"I hope I won't get corrupted.\0";
diff --git a/src/user/app/tests/kernel/miscsyscall.c b/src/user/app/tests/kernel/miscsyscall.c
index c90560e..459da2a 100644
--- a/src/user/app/tests/kernel/miscsyscall.c
+++ b/src/user/app/tests/kernel/miscsyscall.c
@@ -40,6 +40,18 @@ static void test_await2(void) {
 	_sys_filicide();
 }
 
+static void test_wait2_basic(void) {
+	struct sys_wait2 data = {0};
+	int pid;
+	pid = fork();
+	if (pid == 0) {
+		exit(420);
+	}
+	test(_sys_wait2(-1, 0, &data) == pid);
+	test(data.status == 420);
+	test(_sys_wait2(-1, 0, NULL) == -ECHILD);
+}
+
 static void test_pipe(void) {
 	const char *pipe_msgs[2] = {"hello", "world"};
 	hid_t ends[2];
@@ -293,6 +305,7 @@ static void test_badopen(void) {
 void r_k_miscsyscall(void) {
 	run_test(test_await);
 	run_test(test_await2);
+	run_test(test_wait2_basic);
 	run_test(test_pipe);
 	run_test(test_memflag);
 	run_test(test_dup);
diff --git a/src/user/lib/include/__errno.h b/src/user/lib/include/__errno.h
index f72fcf6..0808ac6 100644
--- a/src/user/lib/include/__errno.h
+++ b/src/user/lib/include/__errno.h
@@ -13,6 +13,7 @@ E( 10, "EACCES")
 E( 11, "EMFILE all file descriptors taken")
 E( 12, "ECONNRESET")
 E( 13, "EPIPE")
+E( 14, "ECHILD")
 E(200, "EISDIR")
 E(201, "ENAMETOOLONG")
 E(202, "ENOTDIR")
diff --git a/src/user/lib/include/sys/wait.h b/src/user/lib/include/sys/wait.h
index c71418c..cff407e 100644
--- a/src/user/lib/include/sys/wait.h
+++ b/src/user/lib/include/sys/wait.h
@@ -2,8 +2,8 @@
 #include <sys/types.h>
 
 #define WIFSTOPPED(x) 0
-#define WEXITSTATUS(x) 0
-#define WIFEXITED(x) 0
+#define WEXITSTATUS(x) ((x)&0xFF)
+#define WIFEXITED(x) 1
 #define WSTOPSIG(x) 0
 #define WTERMSIG(x) 0
 
diff --git a/src/user/lib/signal.c b/src/user/lib/signal.c
index d8b673d..41340e7 100644
--- a/src/user/lib/signal.c
+++ b/src/user/lib/signal.c
@@ -76,8 +76,7 @@ int sigfillset(sigset_t *set) {
 }
 
 int sigprocmask(int how, const sigset_t *set, const sigset_t *oldset) {
-	(void)how; (void)set; (void)oldset;
-	__libc_panic("unimplemented");
+	return 0;
 }
 
 int sigsuspend(const sigset_t *mask) {
diff --git a/src/user/lib/syscall.c b/src/user/lib/syscall.c
index 3e8473c..5196683 100644
--- a/src/user/lib/syscall.c
+++ b/src/user/lib/syscall.c
@@ -90,6 +90,10 @@ uint32_t _sys_getppid(void) {
 	return (uint32_t)_syscall(_SYS_GETPPID, 0, 0, 0, 0, 0);
 }
 
+int _sys_wait2(int pid, int flags, struct sys_wait2 __user *out) {
+	return (int)_syscall(_SYS_WAIT2, (long)pid, (long)flags, (long)out, 0, 0);
+}
+
 long _sys_execbuf(void __user *buf, size_t len) {
 	return _syscall(_SYS_EXECBUF, (long)buf, (long)len, 0, 0, 0);
 }
diff --git a/src/user/lib/syswait.c b/src/user/lib/syswait.c
index 6389cb2..ce80c7b 100644
--- a/src/user/lib/syswait.c
+++ b/src/user/lib/syswait.c
@@ -1,8 +1,22 @@
 #include <bits/panic.h>
+#include <camellia.h>
+#include <camellia/syscalls.h>
+#include <errno.h>
 #include <sys/resource.h>
 #include <sys/wait.h>
 
 pid_t wait3(int *wstatus, int opts, struct rusage *rusage) {
-	(void)wstatus; (void)opts; (void)rusage;
-	__libc_panic("unimplemented");
+	struct sys_wait2 res;
+	if (opts || rusage) {
+		__libc_panic("unimplemented");
+	}
+	pid_t ret = _sys_wait2(-1, 0, &res);
+	if (ret < 0) {
+		errno = -ret;
+		return -1;
+	}
+	if (wstatus) {
+		*wstatus = res.status & 0xFF;
+	}
+	return ret;
 }