Merged the os_kill_process and the driver from_user changes from

the 2.4 pool.
Also merged some other cleanups.

arch/um/drivers/line.c

@@ -8,11 +8,13 @@
 #include "linux/list.h"
 #include "linux/devfs_fs_kernel.h"
 #include "asm/irq.h"
+#include "asm/uaccess.h"
 #include "chan_kern.h"
 #include "irq_user.h"
 #include "line.h"
 #include "kern.h"
 #include "user_util.h"
+#include "kern_util.h"
 #include "os.h"
 
 #define LINE_BUFSIZE 4096
@@ -87,15 +89,26 @@ static int flush_buffer(struct line *line)
 	return(line->head == line->tail);
 }
 
-int line_write(struct line *lines, struct tty_struct *tty, const char *buf, 
-	       int len)
+int line_write(struct line *lines, struct tty_struct *tty, int from_user,
+	       const char *buf, int len)
 {
 	struct line *line;
+	char *new;
 	unsigned long flags;
 	int n, err, i;
 
 	if(tty->stopped) return 0;
 
+	if(from_user){
+		new = kmalloc(len, GFP_KERNEL);
+		if(new == NULL)
+			return(0);
+		n = copy_from_user(new, buf, len);
+		if(n == len)
+			return(-EFAULT);
+		buf = new;
+	}
+
 	i = minor(tty->device) - tty->driver.minor_start;
 	line = &lines[i];
 
@@ -451,7 +464,7 @@ static void winch_cleanup(void)
 	list_for_each(ele, &winch_handlers){
 		winch = list_entry(ele, struct winch, list);
 		close(winch->fd);
-		if(winch->pid != -1) os_kill_process(winch->pid);
+		if(winch->pid != -1) os_kill_process(winch->pid, 0);
 	}
 }
 

arch/um/drivers/port_kern.c

@@ -99,14 +99,13 @@ static int port_accept(struct port_list *port)
 	}
 
 	list_add(&conn->list, &port->pending);
-	ret = 1;
-	goto out;
+	return(1);
 
  out_free:
 	kfree(conn);
  out_close:
 	os_close_file(fd);
-	if(pid != -1) os_kill_process(pid);
+	if(pid != -1) os_kill_process(pid, 0);
  out:
 	return(ret);
 } 
@@ -210,9 +209,9 @@ void port_remove_dev(void *d)
 	struct port_dev *dev = d;
 
   	if(dev->helper_pid != -1)
- 		os_kill_process(dev->helper_pid);
+ 		os_kill_process(dev->helper_pid, 0);
  	if(dev->telnetd_pid != -1)
- 		os_kill_process(dev->telnetd_pid);
+ 		os_kill_process(dev->telnetd_pid, 0);
  	dev->helper_pid = -1;
 }
 
@@ -275,8 +274,8 @@ void port_kern_free(void *d)
 {
 	struct port_dev *dev = d;
 
- 	if(dev->helper_pid != -1) os_kill_process(dev->telnetd_pid);
- 	if(dev->telnetd_pid != -1) os_kill_process(dev->telnetd_pid);
+ 	if(dev->helper_pid != -1) os_kill_process(dev->helper_pid, 0);
+ 	if(dev->telnetd_pid != -1) os_kill_process(dev->telnetd_pid, 0);
 	kfree(dev);
 }
 

arch/um/drivers/ssl.c

@@ -83,12 +83,12 @@ static void ssl_close(struct tty_struct *tty, struct file * filp)
 static int ssl_write(struct tty_struct * tty, int from_user,
 		     const unsigned char *buf, int count)
 {
-	return(line_write(serial_lines, tty, buf, count));
+	return(line_write(serial_lines, tty, from_user, buf, count));
 }
 
 static void ssl_put_char(struct tty_struct *tty, unsigned char ch)
 {
-	line_write(serial_lines, tty, &ch, sizeof(ch));
+	line_write(serial_lines, tty, 0, &ch, sizeof(ch));
 }
 
 static void ssl_flush_chars(struct tty_struct *tty)

arch/um/drivers/stdio_console.c

@@ -120,7 +120,7 @@ static void con_close(struct tty_struct *tty, struct file *filp)
 static int con_write(struct tty_struct *tty, int from_user, 
 		     const unsigned char *buf, int count)
 {
-	return(line_write(vts, tty, buf, count));
+	 return(line_write(vts, tty, from_user, buf, count));
 }
 
 static void set_termios(struct tty_struct *tty, struct termios * old)

arch/um/include/line.h

@@ -70,8 +70,9 @@ extern void line_write_interrupt(int irq, void *data, struct pt_regs *unused);
 extern void line_close(struct line *lines, struct tty_struct *tty);
 extern int line_open(struct line *lines, struct tty_struct *tty, 
 		     struct chan_opts *opts);
-extern void line_setup(struct line *lines, int num, char *init);
-extern int line_write(struct line *line, struct tty_struct *tty, 
+extern int line_setup(struct line *lines, int num, char *init, 
+		      int all_allowed);
+extern int line_write(struct line *line, struct tty_struct *tty, int from_user,
 		      const char *buf, int len);
 extern int line_write_room(struct tty_struct *tty);
 extern char *add_xterm_umid(char *base);

arch/um/include/os.h

@@ -103,10 +103,16 @@ extern int os_write_file(int fd, char *buf, int count);
 extern unsigned long os_process_pc(int pid);
 extern int os_process_parent(int pid);
 extern void os_stop_process(int pid);
-extern void os_kill_process(int pid);
+extern void os_kill_process(int pid, int reap_child);
 extern void os_usr1_process(int pid);
 extern int os_getpid(void);
 
+extern int os_map_memory(void *virt, int fd, unsigned long off, 
+			 unsigned long len, int r, int w, int x);
+extern int os_protect_memory(void *addr, unsigned long len, 
+			     int r, int w, int x);
+extern int os_unmap_memory(void *addr, int len);
+
 #endif
 
 /*

arch/um/kernel/helper.c

@@ -43,9 +43,12 @@ static int helper_child(void *arg)
 	execvp(argv[0], argv);
 	printk("execvp of '%s' failed - errno = %d\n", argv[0], errno);
 	write(data->fd, &errno, sizeof(errno));
-	_exit(1);
+	os_kill_process(os_getpid(), 0);
+	return(0);
 }
 
+/* XXX The alloc_stack here breaks if this is called in the tracing thread */
+
 int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
 	       unsigned long *stack_out)
 {

arch/um/kernel/process.c

@@ -164,19 +164,18 @@ static int ptrace_child(void *arg)
 
 	if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
 		perror("ptrace");
-		_exit(1);
+		os_kill_process(pid, 0);
 	}
 	os_stop_process(pid);
 	_exit(os_getpid() == pid);
 }
 
-void __init check_ptrace(void)
+static int start_ptraced_child(void **stack_out)
 {
 	void *stack;
 	unsigned long sp;
-	int status, pid, n, syscall;
-
-	printk("Checking that ptrace can change system call numbers...");
+	int pid, n, status;
+	
 	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if(stack == MAP_FAILED)
@@ -191,6 +190,33 @@ void __init check_ptrace(void)
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
 		panic("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
+
+	*stack_out = stack;
+	return(pid);
+}
+
+static void stop_ptraced_child(int pid, void *stack, int exitcode)
+{
+	int status, n;
+
+	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
+		panic("check_ptrace : ptrace failed, errno = %d", errno);
+	n = waitpid(pid, &status, 0);
+	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode))
+		panic("check_ptrace : child exited with status 0x%x", status);
+
+	if(munmap(stack, PAGE_SIZE) < 0)
+		panic("check_ptrace : munmap failed, errno = %d", errno);
+}
+
+void __init check_ptrace(void)
+{
+	void *stack;
+	int pid, syscall, n, status;
+
+	printk("Checking that ptrace can change system call numbers...");
+	pid = start_ptraced_child(&stack);
+
 	while(1){
 		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
 			panic("check_ptrace : ptrace failed, errno = %d", 
@@ -213,23 +239,19 @@ void __init check_ptrace(void)
 			break;
 		}
 	}
-	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		panic("check_ptrace : ptrace failed, errno = %d", errno);
-	n = waitpid(pid, &status, 0);
-	if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
-		panic("check_ptrace : child exited with status 0x%x", status);
-
-	if(munmap(stack, PAGE_SIZE) < 0)
-		panic("check_ptrace : munmap failed, errno = %d", errno);
+ 	stop_ptraced_child(pid, stack, 0);
 	printk("OK\n");
 }
 
 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
 {
 	jmp_buf buf;
+ 	int n;
 
 	*jmp_ptr = &buf;
-	if(setjmp(buf)) return(1);
+ 	n = setjmp(buf);
+ 	if(n != 0)
+ 		return(n);
 	(*fn)(arg);
 	return(0);
 }
@@ -244,6 +266,65 @@ void forward_pending_sigio(int target)
 		kill(target, SIGIO);
 }
 
+#ifdef CONFIG_MODE_SKAS
+static void init_registers(int pid)
+{
+	int err;
+
+	if(ptrace(PTRACE_GETREGS, pid, 0, exec_regs) < 0)
+		panic("check_ptrace : PTRACE_GETREGS failed, errno = %d", 
+		      errno);
+
+	err = ptrace(PTRACE_GETFPXREGS, pid, 0, exec_fpx_regs);
+	if(!err)
+		return;
+
+	have_fpx_regs = 0;
+	if(errno != EIO)
+		panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d", 
+		      errno);
+
+	err = ptrace(PTRACE_GETFPREGS, pid, 0, exec_fp_regs);
+	if(err)
+		panic("check_ptrace : PTRACE_GETFPREGS failed, errno = %d", 
+		      errno);
+}
+#endif	
+
+int can_do_skas(void)
+{
+	struct ptrace_faultinfo fi;
+	void *stack;
+	int pid, n, ret = 1;
+
+	printk("Checking for the skas3 patch in the host...");
+	pid = start_ptraced_child(&stack);
+
+	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
+	if(n < 0){
+		if(errno == EIO)
+			printk("not found\n");
+		else printk("No (unexpected errno - %d)\n", errno);
+		ret = 0;
+	}
+	else printk("found\n");
+
+	init_registers(pid);
+	stop_ptraced_child(pid, stack, 1);
+
+	printk("Checking for /proc/mm...");
+	if(access("/proc/mm", W_OK)){
+		printk("not found\n");
+		ret = 0;
+	}
+	else printk("found\n");
+
+	return(ret);
+#else
+	return(0);
+#endif	
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically

arch/um/kernel/signal_user.c

@@ -21,13 +21,12 @@
 
 void set_sigstack(void *sig_stack, int size)
 {
-	stack_t stack;
+	stack_t stack = ((stack_t) { .ss_flags	= 0,
+				     .ss_sp	= (__ptr_t) sig_stack,
+				     .ss_size 	= size - sizeof(void *) });
 
-	stack.ss_sp = (__ptr_t) sig_stack;
-	stack.ss_flags = 0;
-	stack.ss_size = size - sizeof(void *);
 	if(sigaltstack(&stack, NULL) != 0)
-		panic("sigaltstack failed");
+		panic("enabling signal stack failed, errno = %d\n", errno);
 }
 
 void set_handler(int sig, void (*handler)(int), int flags, ...)
@@ -103,6 +102,15 @@ int get_signals(void)
 	return(enable_mask(&mask));
 }
 
+int get_signals(void)
+{
+	sigset_t mask;
+	
+	if(sigprocmask(SIG_SETMASK, NULL, &mask) < 0)
+		panic("Failed to get signal mask");
+	return(enable_mask(&mask));
+}
+
 int set_signals(int enable)
 {
 	sigset_t mask;

arch/um/os-Linux/process.c

@@ -75,9 +75,12 @@ void os_stop_process(int pid)
 	kill(pid, SIGSTOP);
 }
 
-void os_kill_process(int pid)
+void os_kill_process(int pid, int reap_child)
 {
 	kill(pid, SIGKILL);
+	if(reap_child)
+		waitpid(pid, NULL, 0);
+		
 }
 
 void os_usr1_process(int pid)