linux(4): Add struct clone_args for future clone3 system call.

In preparation for clone3 system call add struct clone_args and use it in
clone implementation.
Move all of clone related bits to the newly created linux_fork.h header.

Differential revision:	https://reviews.freebsd.org/D31474
MFC after:		2 weeks

(cherry picked from commit 0a4b664ae8582b7596858317b53d84eb4f8bbf9a)

14 files changed, 140 insertions, 55 deletions

diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
index 5de27a7ee7d3..dc6b6140f60c 100644
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -88,6 +88,7 @@ __FBSDID("$FreeBSD$");
 #include <amd64/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
 #include <compat/linux/linux_file.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ipc.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_mmap.h>
diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
index f9ab19a40ef2..b008b4b49c1c 100644
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -77,6 +77,7 @@ __FBSDID("$FreeBSD$");
 #include <amd64/linux/linux.h>
 #include <amd64/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ioctl.h>
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_misc.h>
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index 926c69c9ebac..5801fac7f126 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -76,6 +76,7 @@ __FBSDID("$FreeBSD$");
 #include <amd64/linux32/linux.h>
 #include <amd64/linux32/linux32_proto.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ipc.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_mmap.h>
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index 42b40ee3094a..7905b8587192 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -83,6 +83,7 @@ __FBSDID("$FreeBSD$");
 #include <amd64/linux32/linux.h>
 #include <amd64/linux32/linux32_proto.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ioctl.h>
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_misc.h>
diff --git a/sys/arm64/linux/linux_machdep.c b/sys/arm64/linux/linux_machdep.c
index eff084eb9f96..055e9374424c 100644
--- a/sys/arm64/linux/linux_machdep.c
+++ b/sys/arm64/linux/linux_machdep.c
@@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$");
 #include <arm64/linux/linux_proto.h>
 #include <compat/linux/linux_dtrace.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_mmap.h>
 #include <compat/linux/linux_util.h>
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
index 63438cb62ec4..dfbc12ee4b42 100644
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$");
 #include <arm64/linux/linux_proto.h>
 #include <compat/linux/linux_dtrace.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ioctl.h>
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_misc.h>
diff --git a/sys/compat/linux/linux.h b/sys/compat/linux/linux.h
index 0b405b692796..f73a0484cf55 100644
--- a/sys/compat/linux/linux.h
+++ b/sys/compat/linux/linux.h
@@ -259,4 +259,6 @@ struct l_statx {
 	uint64_t __spare2[13];
 };
 
+#define	lower_32_bits(n)	((uint32_t)((n) & 0xffffffff))
+
 #endif /* _LINUX_MI_H_ */
diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
index fbfe9080cac7..86688d50c8a8 100644
--- a/sys/compat/linux/linux_emul.c
+++ b/sys/compat/linux/linux_emul.c
@@ -139,7 +139,7 @@ linux_set_default_stacksize(struct thread *td, struct proc *p)
 }
 
 void
-linux_proc_init(struct thread *td, struct thread *newtd, int flags)
+linux_proc_init(struct thread *td, struct thread *newtd, bool init_thread)
 {
 	struct linux_emuldata *em;
 	struct linux_pemuldata *pem;
@@ -150,7 +150,7 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 
 		/* non-exec call */
 		em = malloc(sizeof(*em), M_TEMP, M_WAITOK | M_ZERO);
-		if (flags & LINUX_CLONE_THREAD) {
+		if (init_thread) {
 			LINUX_CTR1(proc_init, "thread newtd(%d)",
 			    newtd->td_tid);
 
@@ -312,12 +312,12 @@ linux_on_exec(struct proc *p, struct image_params *imgp)
 		 * before exec.  Update emuldata to reflect
 		 * single-threaded cleaned state after exec.
 		 */
-		linux_proc_init(td, NULL, 0);
+		linux_proc_init(td, NULL, false);
 	} else {
 		/*
 		 * We are switching the process to Linux emulator.
 		 */
-		linux_proc_init(td, td, 0);
+		linux_proc_init(td, td, false);
 
 		/*
 		 * Create a transient td_emuldata for all suspended
@@ -328,7 +328,7 @@ linux_on_exec(struct proc *p, struct image_params *imgp)
 		FOREACH_THREAD_IN_PROC(td->td_proc, othertd) {
 			if (othertd == td)
 				continue;
-			linux_proc_init(td, othertd, LINUX_CLONE_THREAD);
+			linux_proc_init(td, othertd, true);
 		}
 	}
 #if defined(__amd64__)
diff --git a/sys/compat/linux/linux_emul.h b/sys/compat/linux/linux_emul.h
index ed5332b2c96c..70646cc93847 100644
--- a/sys/compat/linux/linux_emul.h
+++ b/sys/compat/linux/linux_emul.h
@@ -55,12 +55,11 @@ struct linux_emuldata {
 struct linux_emuldata	*em_find(struct thread *);
 
 int	linux_exec_imgact_try(struct image_params *);
-void	linux_proc_init(struct thread *, struct thread *, int);
+void	linux_proc_init(struct thread *, struct thread *, bool);
 void	linux_on_exit(struct proc *);
 void	linux_schedtail(struct thread *);
 void	linux_on_exec(struct proc *, struct image_params *);
 void	linux_thread_dtor(struct thread *);
-void	linux_thread_detach(struct thread *);
 int	linux_common_execve(struct thread *, struct image_args *);
 void 	linux32_prepare_notes(struct thread *, struct note_info_list *, size_t *);
 void 	linux64_prepare_notes(struct thread *, struct note_info_list *, size_t *);
diff --git a/sys/compat/linux/linux_fork.c b/sys/compat/linux/linux_fork.c
index 955e9e512bd1..97f5b7d89de4 100644
--- a/sys/compat/linux/linux_fork.c
+++ b/sys/compat/linux/linux_fork.c
@@ -60,7 +60,9 @@ __FBSDID("$FreeBSD$");
 #include <machine/../linux/linux.h>
 #include <machine/../linux/linux_proto.h>
 #endif
+#include <compat/linux/linux.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_futex.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_util.h>
@@ -82,7 +84,7 @@ linux_fork(struct thread *td, struct linux_fork_args *args)
 
 	td2 = FIRST_THREAD_IN_PROC(p2);
 
-	linux_proc_init(td, td2, 0);
+	linux_proc_init(td, td2, false);
 
 	td->td_retval[0] = p2->p_pid;
 
@@ -112,7 +114,7 @@ linux_vfork(struct thread *td, struct linux_vfork_args *args)
 
 	td2 = FIRST_THREAD_IN_PROC(p2);
 
-	linux_proc_init(td, td2, 0);
+	linux_proc_init(td, td2, false);
 
 	td->td_retval[0] = p2->p_pid;
 
@@ -128,7 +130,7 @@ linux_vfork(struct thread *td, struct linux_vfork_args *args)
 #endif
 
 static int
-linux_clone_proc(struct thread *td, struct linux_clone_args *args)
+linux_clone_proc(struct thread *td, struct l_clone_args *args)
 {
 	struct fork_req fr;
 	int error, ff = RFPROC | RFSTOPPED, f2;
@@ -138,11 +140,12 @@ linux_clone_proc(struct thread *td, struct linux_clone_args *args)
 	struct linux_emuldata *em;
 
 	f2 = 0;
-	exit_signal = args->flags & 0x000000ff;
-	if (LINUX_SIG_VALID(exit_signal)) {
-		exit_signal = linux_to_bsd_signal(exit_signal);
-	} else if (exit_signal != 0)
+	if (LINUX_SIG_VALID(args->exit_signal)) {
+		exit_signal = linux_to_bsd_signal(args->exit_signal);
+	} else if (args->exit_signal != 0)
 		return (EINVAL);
+	else
+		exit_signal = 0;
 
 	if (args->flags & LINUX_CLONE_VM)
 		ff |= RFMEM;
@@ -158,7 +161,7 @@ linux_clone_proc(struct thread *td, struct linux_clone_args *args)
 	}
 
 	if (args->flags & LINUX_CLONE_PARENT_SETTID)
-		if (args->parent_tidptr == NULL)
+		if (args->parent_tid == NULL)
 			return (EINVAL);
 
 	if (args->flags & LINUX_CLONE_VFORK)
@@ -175,23 +178,23 @@ linux_clone_proc(struct thread *td, struct linux_clone_args *args)
 	td2 = FIRST_THREAD_IN_PROC(p2);
 
 	/* create the emuldata */
-	linux_proc_init(td, td2, args->flags);
+	linux_proc_init(td, td2, false);
 
 	em = em_find(td2);
 	KASSERT(em != NULL, ("clone_proc: emuldata not found.\n"));
 
 	if (args->flags & LINUX_CLONE_CHILD_SETTID)
-		em->child_set_tid = args->child_tidptr;
+		em->child_set_tid = args->child_tid;
 	else
 		em->child_set_tid = NULL;
 
 	if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
-		em->child_clear_tid = args->child_tidptr;
+		em->child_clear_tid = args->child_tid;
 	else
 		em->child_clear_tid = NULL;
 
 	if (args->flags & LINUX_CLONE_PARENT_SETTID) {
-		error = copyout(&p2->p_pid, args->parent_tidptr,
+		error = copyout(&p2->p_pid, args->parent_tid,
 		    sizeof(p2->p_pid));
 		if (error)
 			linux_msg(td, "copyout p_pid failed!");
@@ -235,7 +238,7 @@ linux_clone_proc(struct thread *td, struct linux_clone_args *args)
 }
 
 static int
-linux_clone_thread(struct thread *td, struct linux_clone_args *args)
+linux_clone_thread(struct thread *td, struct l_clone_args *args)
 {
 	struct linux_emuldata *em;
 	struct thread *newtd;
@@ -244,12 +247,12 @@ linux_clone_thread(struct thread *td, struct linux_clone_args *args)
 
 	LINUX_CTR4(clone_thread, "thread(%d) flags %x ptid %p ctid %p",
 	    td->td_tid, (unsigned)args->flags,
-	    args->parent_tidptr, args->child_tidptr);
+	    args->parent_tid, args->child_tid);
 
 	if ((args->flags & LINUX_CLONE_PARENT) != 0)
 		return (EINVAL);
 	if (args->flags & LINUX_CLONE_PARENT_SETTID)
-		if (args->parent_tidptr == NULL)
+		if (args->parent_tid == NULL)
 			return (EINVAL);
 
 	/* Threads should be created with own stack */
@@ -284,7 +287,7 @@ linux_clone_thread(struct thread *td, struct linux_clone_args *args)
 	thread_cow_get(newtd, td);
 
 	/* create the emuldata */
-	linux_proc_init(td, newtd, args->flags);
+	linux_proc_init(td, newtd, true);
 
 	em = em_find(newtd);
 	KASSERT(em != NULL, ("clone_thread: emuldata not found.\n"));
@@ -293,12 +296,12 @@ linux_clone_thread(struct thread *td, struct linux_clone_args *args)
 		linux_set_cloned_tls(newtd, PTRIN(args->tls));
 
 	if (args->flags & LINUX_CLONE_CHILD_SETTID)
-		em->child_set_tid = args->child_tidptr;
+		em->child_set_tid = args->child_tid;
 	else
 		em->child_set_tid = NULL;
 
 	if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
-		em->child_clear_tid = args->child_tidptr;
+		em->child_clear_tid = args->child_tid;
 	else
 		em->child_clear_tid = NULL;
 
@@ -328,7 +331,7 @@ linux_clone_thread(struct thread *td, struct linux_clone_args *args)
 	    td->td_tid, newtd->td_tid);
 
 	if (args->flags & LINUX_CLONE_PARENT_SETTID) {
-		error = copyout(&newtd->td_tid, args->parent_tidptr,
+		error = copyout(&newtd->td_tid, args->parent_tid,
 		    sizeof(newtd->td_tid));
 		if (error)
 			linux_msg(td, "clone_thread: copyout td_tid failed!");
@@ -359,11 +362,19 @@ fail:
 int
 linux_clone(struct thread *td, struct linux_clone_args *args)
 {
+	struct l_clone_args ca = {
+		.flags = (lower_32_bits(args->flags) & ~LINUX_CSIGNAL),
+		.child_tid = args->child_tidptr,
+		.parent_tid = args->parent_tidptr,
+		.exit_signal = (lower_32_bits(args->flags) & LINUX_CSIGNAL),
+		.stack = args->stack,
+		.tls = args->tls,
+	};
 
 	if (args->flags & LINUX_CLONE_THREAD)
-		return (linux_clone_thread(td, args));
+		return (linux_clone_thread(td, &ca));
 	else
-		return (linux_clone_proc(td, args));
+		return (linux_clone_proc(td, &ca));
 }
 
 int
diff --git a/sys/compat/linux/linux_fork.h b/sys/compat/linux/linux_fork.h
new file mode 100644
index 000000000000..04dfb8ac8a70
--- /dev/null
+++ b/sys/compat/linux/linux_fork.h
@@ -0,0 +1,92 @@
+/*-
+ * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LINUX_FORK_H_
+#define _LINUX_FORK_H_
+
+#define	LINUX_CLONE_VM			0x00000100
+#define	LINUX_CLONE_FS			0x00000200
+#define	LINUX_CLONE_FILES		0x00000400
+#define	LINUX_CLONE_SIGHAND		0x00000800
+#define	LINUX_CLONE_PID			0x00001000	/* No longer exist in Linux */
+#define	LINUX_CLONE_PTRACE		0x00002000
+#define	LINUX_CLONE_VFORK		0x00004000
+#define	LINUX_CLONE_PARENT		0x00008000
+#define	LINUX_CLONE_THREAD		0x00010000
+#define	LINUX_CLONE_NEWNS		0x00020000	/* New mount NS */
+#define	LINUX_CLONE_SYSVSEM		0x00040000
+#define	LINUX_CLONE_SETTLS		0x00080000
+#define	LINUX_CLONE_PARENT_SETTID	0x00100000
+#define	LINUX_CLONE_CHILD_CLEARTID	0x00200000
+#define	LINUX_CLONE_DETACHED		0x00400000	/* Unused */
+#define	LINUX_CLONE_UNTRACED		0x00800000
+#define	LINUX_CLONE_CHILD_SETTID	0x01000000
+#define	LINUX_CLONE_NEWCGROUP		0x02000000	/* New cgroup NS */
+#define	LINUX_CLONE_NEWUTS		0x04000000
+#define	LINUX_CLONE_NEWIPC		0x08000000
+#define	LINUX_CLONE_NEWUSER		0x10000000
+#define	LINUX_CLONE_NEWPID		0x20000000
+#define	LINUX_CLONE_NEWNET		0x40000000
+#define	LINUX_CLONE_IO			0x80000000
+
+#define	LINUX_CSIGNAL			0x000000ff
+
+/*
+ * User-space clone3 args layout.
+ */
+struct l_user_clone_args {
+	uint64_t flags;
+	uint64_t pidfd;
+	uint64_t child_tid;
+	uint64_t parent_tid;
+	uint64_t exit_signal;
+	uint64_t stack;
+	uint64_t stack_size;
+	uint64_t tls;
+	uint64_t set_tid;
+	uint64_t set_tid_size;
+	uint64_t cgroup;
+};
+
+/*
+ * Kernel clone3 args layout.
+ */
+struct l_clone_args {
+	uint64_t flags;
+	l_int *child_tid;
+	l_int *parent_tid;
+	l_int exit_signal;
+	l_ulong stack;
+	l_ulong stack_size;
+	l_ulong tls;
+};
+
+int linux_set_upcall(struct thread *, register_t);
+int linux_set_cloned_tls(struct thread *, void *);
+void linux_thread_detach(struct thread *);
+
+#endif /* _LINUX_FORK_H_ */
diff --git a/sys/compat/linux/linux_misc.h b/sys/compat/linux/linux_misc.h
index dc17ed430014..80f6b8a58e81 100644
--- a/sys/compat/linux/linux_misc.h
+++ b/sys/compat/linux/linux_misc.h
@@ -98,31 +98,6 @@
 #define	__LINUX_NPXCW__		0x37f
 #endif
 
-#define	LINUX_CLONE_VM			0x00000100
-#define	LINUX_CLONE_FS			0x00000200
-#define	LINUX_CLONE_FILES		0x00000400
-#define	LINUX_CLONE_SIGHAND		0x00000800
-#define	LINUX_CLONE_PID			0x00001000	/* No longer exist in Linux */
-#define	LINUX_CLONE_PTRACE		0x00002000
-#define	LINUX_CLONE_VFORK		0x00004000
-#define	LINUX_CLONE_PARENT		0x00008000
-#define	LINUX_CLONE_THREAD		0x00010000
-#define	LINUX_CLONE_NEWNS		0x00020000	/* New mount NS */
-#define	LINUX_CLONE_SYSVSEM		0x00040000
-#define	LINUX_CLONE_SETTLS		0x00080000
-#define	LINUX_CLONE_PARENT_SETTID	0x00100000
-#define	LINUX_CLONE_CHILD_CLEARTID	0x00200000
-#define	LINUX_CLONE_DETACHED		0x00400000	/* Unused */
-#define	LINUX_CLONE_UNTRACED		0x00800000
-#define	LINUX_CLONE_CHILD_SETTID	0x01000000
-#define	LINUX_CLONE_NEWCGROUP		0x02000000	/* New cgroup NS */
-#define	LINUX_CLONE_NEWUTS		0x04000000
-#define	LINUX_CLONE_NEWIPC		0x08000000
-#define	LINUX_CLONE_NEWUSER		0x10000000
-#define	LINUX_CLONE_NEWPID		0x20000000
-#define	LINUX_CLONE_NEWNET		0x40000000
-#define	LINUX_CLONE_IO			0x80000000
-
 /* Scheduling policies */
 #define	LINUX_SCHED_OTHER	0
 #define	LINUX_SCHED_FIFO	1
@@ -180,8 +155,6 @@ extern int stclohz;
 int linux_ptrace_status(struct thread *td, int pid, int status);
 #endif
 void linux_to_bsd_waitopts(int options, int *bsdopts);
-int linux_set_upcall(struct thread *td, register_t stack);
-int linux_set_cloned_tls(struct thread *td, void *desc);
 struct thread	*linux_tdfind(struct thread *, lwpid_t, pid_t);
 
 #endif	/* _LINUX_MISC_H_ */
diff --git a/sys/i386/linux/linux_machdep.c b/sys/i386/linux/linux_machdep.c
index 1a51b7954063..c81bf1b4e2e5 100644
--- a/sys/i386/linux/linux_machdep.c
+++ b/sys/i386/linux/linux_machdep.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include <i386/linux/linux.h>
 #include <i386/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ipc.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_mmap.h>
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index 6805a29204c5..8968a491ce95 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include <i386/linux/linux.h>
 #include <i386/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_fork.h>
 #include <compat/linux/linux_ioctl.h>
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_misc.h>